potential opportunities in cereals production - merid.org/media/files/projects/ccfs/cereals...

Opportunity Mitigation Potential Adaptation Potential Co‐benefits Challenges Examples of Food System Implications

Qualitative description plus quantitative if available (range of possible emission reductions?)

Qualitative description plus quantitative if available

Potential feedbacks and interactions

Manure application: Injection

Minimal for CH4, N2O, high for NH3 (Montes 2013). Variable and contradictory results‐ but Eagle et al. 2012 estimate 0.25 t CO2 e ha/yr potential).

If manure is better incorporated into soil, could increase SOC and water holding capacity for potential drought conditions

Could increase plant nutrient uptake, can reduce odors, may reduce runoff

Expensive, requires new equipment

Shift towards manure injection would require equipment investments with positive benefits for agriculture industries. Costs are prohibitive for many small and medium farms, but potential co‐benefits could warrant public investment.

Manure application: Timing

High potential for N2O and NH3 (Montes et al. 2013). Potential of 0.18 t CO2e ha/yr in US (Eagle et al. 2012).

NA Maximizes when plants will uptake, can reduce N leaching and water quality issues

Requires greater farmer involvement; Education and training

May potentially involve increased farmer training through industry professionals or extension around timing for a given crop and system. May result in yield benefits for farmers and public benefits through water quality.

Winter cover crops

Has the highest potential in warmer winter regions. Could reduce N2O emissions and increase productivity. Potential of 1.92 t CO2 eq ha/yr. (Eagle et al. 2012)

Can provide nutrient benefits and increase water holding capacity

Cover cropping can reduce soil erosion, improve soil quality and fertility, improve water, weed, disease, and pest management, and enhance plant and wildlife diversity on the farm (Lu et al., 2000; Haramoto and Gallandt, 2004).

May increase NH3 (Montes 2013). Requires increased farmer time, costs and planning.

Cover crop additions would be an increased cost for farmers for inputs and labor, but feedback to provide public and on‐farm benefits that may require a time lag to see. Total GHG emissions should be further monitored.

Opportunity Table: Cereals (Intensive; USA)

Potential Opportunities in Cereals Production Major transformations are required to create sustainable food systems, but near‐term immediate actions can support longer‐term, more fundamental transition to sustainability. For incremental steps to contribute to long‐term changes, stakeholders should define sustainability, measure unsustainability, and understand what interests, ideas and institutions contributed to the current structures, ideas, institutions, policies, and practices. Such understanding will enable stakeholders to choose near‐term actions that can lead towards sustainability.

The tables, below, are intended to provide a starting point for stakeholders who are working to build sustainable food systems and are considering a range of near‐term interventions. Much additional experience and knowledge by farmers, peasants, indigenous groups and other practitioners should be consulted for a full understanding of these and additional potential interventions.

The following tables summarize mitigation opportunities, adaptation potential, and food system implications in cereals production systems in four regions: Central and Latin South America, Africa, North America, and South Asia. Although the opportunity tables focus on mitigation opportunities, the tables identify adaptation potential of most opportunities.






Nitrification inhibitors

High potential‐ Nitrification inhibitors (NIs), double inhibitors (DIs: urease plus nitrification inhibitors) consistently reduced N2O emissions compared with conventional N fertilizers across soil and management conditions (grand mean decreases of 38, 30, respectively) (Thapa et al. 2016). a meta‐analysis conducted by Gilsanz et al. (2016) found that the nitrification inhibitors DCD and DMPP were effective in reducing emissions; however, the magnitude of the effect differed across fertilizer formulations and soil types. Di and Cameron (2016) found an average reduction of 57% of N2O, ranging from 28 to 86%.

Potential yield benefits Yield benefits but variable Variable‐ may have food safety implications (currently outlawed in New Zealand) Expensive. Lack of long‐term ecological studies.

Nitrification inhibitors have been banned in some countries for their potential public health implications as they've been found in milk. Thus, consumer acceptance is important to assess. The cost of such mitigation options is unlikely to work well for extensive systems, but is more feasible in intensive systems. Potential productivity gains would help offset costs, but gains are not universal.

Urease inhibitors

Urease inhibitors reduced N2O emissions compared with conventional N fertilizers in coarse‐textured soils and irrigated systems. (Thapa et al. 2016)

NA Little long term research regarding ecological impact

Variable based on soil type and geography. Expensive

Similar to nitrification inhibitors, there is potential for emission reductions, but they are not universal and long‐term ecological feedbacks are unknown. Coupled with current costs, additional research is required.

Slow release/enhanced efficiency fertilizers

Controlled‐release N fertilizers (CRFs) in one review reduced N2O emissions by 19% on average (Thapa et al. 2016). Recent work in rice demonstrates half the use of nitrogen with 10% yield gain (Kottegoda et al. 2017)

Potential yield gain Water quality benefits if nutrient runoff is minimized (Liu 2012; Li et al. 2017)

Costly without a yield gain; variable by geography

Added costs of these fertilizers may prevent uptake without yield benefits, though yield benefits are likely in many places. Further research on specific technologies and yield gains is needed.

Conservation or no tillage

Variable results‐ reduced tractor time will decrease CO2 emissions; however many studies find that no‐till in wet conditions increases N2O emissions. The debate over no‐till and its ability to store carbon is also strong‐ many original early studies found studies weren't taking soil cores that were deep enough. "The most consistent trend in the literature suggests that overall, zero tillage reduces GHG emissions in the long term (c. 20 years), but crucially some uncertainty still exists as to when the positive effects are first recorded and how long these effects can be observed. (Mangalassery 2015)

If there are soil organic carbon gains, this can have positive benefits on soil structure and quality for future adaptation benefits

Reduced CO2 emissions, tractor time for farmers

Not a one size fits all solution‐ Highly variable by temperature, soil, etc.

No‐till agriculture can improve farmer profits by reducing fuel and labor costs. However, it may not consistently provide GHG benefits. No‐till is also commonly associated with GMO crops, particularly herbicide tolerant ones, which are associated with increased herbicide use (Perry et al. 2016), which could influence public health and have consumer acceptance challenges.

Integrated Nutrient Management

Involves optimizing fertilizer application rates and timing, utilizing multiple sources of fertilization. Prioritizes organic fertilizers (Wu and Ma 2015). See Chen et al. 2014 for additional details‐ much of this work is happening in China

Can significantly increase yield without increasing fertilizers. May provide soil health benefits. Increases water holding capacity potentially (Wu and Ma 2015).

Water quality, increased yields, reduced environmental pollutants

Requires greater farmer involvement, testing, etc.

Currently much focus of this work is in China, so greater research elsewhere is needed. Though this dual approach could provide high benefits, it would also influence agricultural input industries and require farmer training and Extension as well as potentially costly tests. Adaptation and environmental and public health impacts could be high.

Eliminate summer fallow

Could be implemented on 20Mha in US‐ would have small potential GHG reductions (0.44 ha/yr of CO2 eq (Eagle et al. 2012)

N/A Additional food production Typically employed because of drought and lack of water

May not be feasible if summer fallow is the result of drought or lack of water‐ maybe potentially increase GHGs if done with intensive cropping and/or significant inputs. However, could provide additional food production and maximize land potential, which would reduce the need for agricultural land expansion and LUC.






Diversify crop rotations

Can potentially increase carbon sequestration, but benefits are small and not significant for corn‐soy. Small potential reduction of 0.1 t co2e ha/yr. (Eagle et al. 2012)

Diversification Soil organic carbon, soil health Small potential mitigation Comparatively small potential GHG reductions, but many other potential co‐benefits. Likely greatest impact would be coupled with nutrient management and other agroecological practices. Would involve greater farmer planning, time and potential training.

Include perennials in crop rotations

Including a perennial crop like alfalfa or grass hay into an annual crop rotation can potentially increase SOC, but hard to separate the effect from tillage differences. With reduced N fertilizer needs, a net GHG mitigation or 0.7 t CO2 e ha/yr is possible. (Eagle et al. 2012)

Increase SOC, water/drought benefits System diversification Could reduce yield. May reduce farmer costs from inputs.

Perennial rotations could reduce farmer time and costs associated with additional inputs while providing potential ecosystem services. Some perennial crops may be water intensive (like alfalfa), and could reduce farmer incomes if harvest times are longer.

Replacing annuals with perennial crops

Can reduce tilling and fertilizer needs. Potential for 1.46 GHG t CO2 e ha/yr possible. (Eagle et al. 2012)

SOC Soil health Food production implications‐ food security impacts?

While perennial crops can provide many ecosystem services, replacement should consider food security implications of perennial systems, since much food is provided through annual systems. Additional research on perennial crops should be conducted to explore future potential.

Switch to organic fertilizers

Has the potential to increase SOC. Studies in the US are variable, ranging from a potential t CO2 eq. ha/yr of 0.7 to 3.50 depending on crop, manure, soil, etc. (Eagle et al. 2012)

SOC Soil health Availability, unless cropping is situated close to sources of organic fertilizers, it is costly to transport long distances

Organic fertilizers would offset GHGs associated with synthetic N fertilizer production, reducing pre‐production emissions. However, such shifts may involve a fundamental transition to more farm or regionally integrated crop and livestock systems, since transporting organic fertilizers long distances is costly (they are heavy). Decoupled crop and livestock systems would prevent scalable implementation of this practice.

Reduce N fertilizer rate

Overall, in the US and other intensive input systems, N fertilizer is overapplied. In tandem with INM, reducing fertilizer rate is a potential GHG strategy in the US with reductions of 0.33 t CO2 eq. ha/yr. Note that the US currently has protocols that would incentivize farmers to reduce N fertilizer rate

NA Improved water quality, reduced costs for farmers

May require farmer training and extension to assess when and how to reduce inputs. Precision agriculture offers opportunity to assist farmers.

Reductions in N fertilizer rates is possible for many farms overapplying without a yield loss. This would save farmers money, and improve water quality. Precision agriculture technologies offer great potential for implementing this strategy, though typically only large farms have this capacity. Agricultural industry may benefit from spread of precision agriculture technologies.

Switch from anhydrous ammonia to urea

N2O emissions decrease of 0.6 t CO2e ha/yr. on average (Eagle et al. 2012)

NA Input switches‐ may require agricultural input dealer consultation. Potential increased costs for farmers.

On a pound per nitrogen basis, anhydrous ammonia is cheaper than urea, so this would potentially require an increased cost to farmers. Such costs could be offset if coupled with potential N reductions achievable through precision agriculture.

Organic production

Organic production may use less energy (Smith et al. 2015), but could produce lower yields (Reganold and Wachter 2016). However, organic production used with other agroecological practices such as multi‐cropping and crop rotations can reduce yield gaps (Ponisio et al. 2014) and provide mitigation and adaptation benefits

Can increase SOC, and when coupled with other practices spread future risk

Can provide greater ecosystem services, social benefits and farmer profitability (Reganold and Wachter 2016).

May result in yield reductions, but can be overcome. Certification can be costly for farmers, which is often necessary for a price premium.

Shift towards organic production would shift production from input driven to practice and labor driven, which would potentially increase agricultural jobs and require farmer training. If organic production results in price premiums, this could increase food costs for consumers, though in high‐income countries organic product demand is growing.

Opportunity Mitigation Potential Adaptation Potential Co‐benefits ChallengesExamples of Food System

Implications

Qualitative description plus quantitative if available (range of possible emission reductions?) Qualitative description plus quantitative if availablePotential feedbacks and

interactions

R&D seeds & other inputs

While there are a large varieties of seeds in India, it is unknown whether the effort around development of new seeds and other inputs takes into the account the climate mitigation impacts of the new varieties. Based on personal interviews and conversations there is strong focus on integrating climate impacts & developing climate friendly varieties of crops, especially field crops. Several varieties have already been developed and are under field testing. Water being the most critical input for managing crop productivity and in the changed climate, drought being the most important factor affecting crop productivity, the majority of the varieties being developed are focused on this relationship with water. A few short‐duration varieties of wheat capable of withstanding drought at the grain filling stage are already in the field. Agencies are trying to reach the farmers with the seeds of such varieties. ICAR has a strong integrated program entitled NICRA already in operation. The field level impacts on mitigation need to be better understood

Medium‐high

R&D technology / mechanization

There is a growing effort to develop appropriate technologies for the small holder farmers ‐ from smaller seed drills, levelers, weeders, low cost drip systems, etc. With the drop in availability of labor for the farms and the expected broader deployment of credit access for the farmers, this segment is expected to grow rapidly. In the long run, deployment of these technologies at scale can lead to significant emission reductions through gained efficiency and productivity.

Medium‐high by reducing economic risk exposure Economic growth

Fertilizer manufacturing

Of the approximtely 130 MtCO2e of annual emission from fertlizers, approximately 50% can be attributed to production. There is scope for reductions in emissions by as much as 20‐30% (determine exact source). Ensuring NUE reduced future demand and manufacture processes that use natural gas are the main contributors for mitigation

Reduce on farm energy use for water

Low‐medium mitigation potential, ‐ eg through use of solar pumps

For farmers some option for navigating low rainfall years; although long term efficacy of such an approach is not well understood. With water tables dropping rapidly in many parts of the country, over long term this approach could exacerbate the problem.

Manage the timing of N input and organic input

Medium mitigation potential. Focus on NUE; use of neem coated urea for slower release of N; application of organic N to improve soil carbon

Improve water retention capacity of soils through increased humus content of soil

Reduced N run off in landscape, economic benefits

Create ecosystem to increase availability of seed drills, and laser levelers, harvesters, etc

Cereals in India are grown in both irrigated and upland systems. The country seeks to decrease the yield gap between the two ‐ while also improving productivity in both systems. Improved productivity through sustainable intensification offers significant mitigation potential. Mechanization can help increase prodcutivity and in the process, if managed well, can also help reduce yield scaled emissions.

Reduced risk for farmers, improved soil health

Increase avalability of technology and training to manage post harvest losses at producer level

High mitigation potential because producer level post harvest losses during harvesting, collection, threshing, etc at ~4%.

Improved incomes

Re‐incorporating residue into soil; or using biomass/straw for regenrating energy

Wheat contributes to 25‐30% of total (~100 Mt) residue burned in India. Of the other key cereals, millet and maize are low residue crops.

Medium‐high (reduces soil nutrient loss)Health/lower pollution / reduced black carbon

Opportunity Table: Cereals (India)

Opportunity Mitigation Potential Adaptation Potential Co‐benefits ChallengesExamples of Food System

Implications

Opportunity Table: Cereals (India)

Water constraints (likely in the short term) and demand changes (in the long term) will cause this shift. Important to catch it early and actively help manage the shift OR identify incentives that can catalyze this shift

Moderate to high depending on shift. If the producer is shifting cultivation due to water constraints, then early indications are to try and promote tree cultivatiuon (agro‐forestry), intercropping, multicropping etc as a way to manage risk explosure to the vagaries of rainfall. embedded within these are many options for mitigation but the quantum of mitigation potential is not well understood.

Moderate to high ‐ opens pathway to reduce water stress

Education and socialization of the concept of nutritional and environmental value of food

Low‐moderate on level of shift. Cereals in India constitute ~13% of the diet and have a low emission footprint (~3%) Biggest gains to be had are from promoting NUE and on farm energy consumption

Moderate to high ‐ opens pathway to reduce water stress; perhaps also improves food security over the long term

Health and nutrition

Opportunity Mitigation Potential Adaptation Potential Co‐benefits Examples of Food Systems Implications



Cultivar development

In the realm of cultivar development, this would include developing varieties that withstand higher temperatures. But it would also include varieties that are resilient to drought, pests, weeds, salinity, flooding, etcThe best new varieties would be ones resilient to more than one threat considering it takes many years to develop and test new cultivars. A recent study on the economic impact of climate change on cereal crop production in Northern Ghana (Bawayelaazaa et. al. 2016) indicated that early season precipitation was beneficial for sorghum, but harmful for maize. However, mid‐season precipitation tended to promote maize production. More is being done on Drought Tolerant Maize by IITA.

On‐farm surveys have shown farmers transition more to dominant traditional crops, like millet and sorghum, that suit the environment at the expense of maize and rice as they are heat and drought tolerant (Traore et al., 2011). Drought Tolerant Maize has also been released by IITA and CIMMYT (CCAFS). Other endemic crop varieties that are increasingly being grown by farmers due to climate change are groundnut and Yam. Parkes etal.(2015) investigated the benefits of breeding cultivars of ground nuts with heat and water stress resistance as well as the potential of marine cloud brightening to reduce the rate of crop failures in West Africa using the GLAM model. The authors foundthat climate change will increase mean yields of groundnut and reduce the risk of crop failure in West Africa. Yam is the second most important crop in Africa in terms of production after cassava. Srivastava et al. (2015) simulated the advantages of specific adaptation strategies using the EPIC model. They found that changing solely sowing datemay be less effective in reducing adverse climatic effects than adopting late maturing cultivars. Cassava: Using the EcoCrop model to investigate the response of important staple food crops for Africa including maize, millets, sorghum, banana, and beans to climate projections by 2030, Jarvis et al. (2012) found that cassava reacted very well to the predicted future climate conditions compared to other crops.

In sub‐Saharan Africa, the Drought Tolerant Maize for Africa initiative has released 160 drought‐tolerant maize varieties between 2007 and 2013 (CCAFS 2016). These generate yields 25‐30% superior to those of currently available commercial maize varieties under both stress and optimal growing conditions (CCAFS 2016).

In West Africa, there is now a trade‐off between Maize, Rice and other indigenous crops such as Sorghum and millet. While maize and Rice contribute to climate change markedly. However cassava, yam, and pearl millet show, on average, either little loss or even gains in the area suitable for production due to climate change. Breeding and selecting cultivars that are drought tolerant and contribute less to climate change seems to be offering solutions to food security in West Africa. Western Africa appears to be a highly vulnerable region, with significant (>10 %) reductions in suitable area for maize.

Seasonal weather and climate forecasting

With climate information services, farmers will be able to plan their planting and make projections about rainfall distribution patterns and temperature variations. Local ICT companies and meteorological institutions must be supported in providing the most accurate and reliable information to farmers.

Recently, a sound approach was successfully implemented (CCAFS 2016) to designing tailored climate information services and (FAO 2015)) to communicate them appropriately to farmers for their farm management decision making vis‐àvis climate variability in Senegal (CCAFS 2015). A collaboration between scientists and the national meteorological agencies of Senegal, Ghana and IT‐based service providers allowed for development of more accurate and specific seasonal rainfall forecasts and to raise capacity of partners to do longer‐term analysis and provide more targeted information for farmers.

A cost– benefit analysis in Burkina Faso by Ouedraogo et al (2015) showed that farmers exposed to climate information have used less local seed and more improved seed for cowpea and sesame production. They also used less organic manure and more fertilizers for sesame production. Cowpea producers exposed to climate information obtained higher yields while covering lower inputs costs and their gross margins were therefore higher compared to non‐exposed farmers.

Choosing the right varieties to grow based on weather and seasonality information acts as safety nets to farmers against total loss of their produce, thereby enhancing food security. Besides weather can be a contributor to total loss of crop harvests. For maize and beans, two key staple crops in Africa, areas of suitability could decline by 20‐40 % relative to the period 1970‐2000 due to increases in temperatures. Conversely, across most of West Africa, sorghum, cassava, yam, and pearl millet show, on average, either little loss or even gains in the area suitable for production. This explains why people of this region are turning to growing these crops.

Opportunity Table: Cereals (Extensive; West Africa)Country Examples: Burkina Faso, Mali, Niger, Senegal, Ghana, Nigeria (Sudan Savannah/Sahel Agro‐ecology)





Soil carbon sequestration

Soil organic matter has been known for years to be beneficial to cultivation, due to its abilities to improve soil structure and enhance water and nutrient retention. The challenge is to leave enough (or place enough) vegetation for the SOM to increase. Agroforestry is one option, but other possibilities include no‐till agriculture, off‐season cover crops, use of animal manure and biochar (a by‐product of the pyrolysis of biomass under limited oxygen conditions) (Partey et. al. 2016). Although soil carbon sequestration has direct benefits to the farmer and mitigates climate change, increasing SOM may increase the emission of some greenhouse gases. Not all the science on this latter point is settled. However, it is reported that nitrous oxide, a greenhouse gas approximately 300 times more powerful than carbon dioxide, can be emitted during nitrification and denitrification from organic matter (Corsiet. al. (2012; Duxbury, 2016).

Adaptation potential is very high due to emergence of markets for climate change mitigation using soil carbon sequestration (Lipper et al. 2010). Agroforestry and conservation agriculture are some of the adaptation technologies that are being used to sequestre carbon in West Africa countries. Specifically, in Burkina Faso, Mali, Niger, Senegal, Ghana and Nigeria, where no till and agroforestry are encouraged (Zougmoré et al. 2016). Some of the conservation technologies that are being adapted in these countries, crop residue retention, cover cropping, minimum tillage, crop rotations, water harvesting and nutrient management. Conservation agriculture has the potential to sequester soil carbon, especially when it leads to increased crop biomass production via double cropping (two crops per year), thereby contributing to climate change mitigation (Corbeels et al. 2006).

In addition to mitigating carbon emissions, increasing soil carbon can have profound effects on soil quality and agroecosystem productivity. Soil carbon plays important roles in maintaining soil structure (Bronick and Lal, 2005), improving soil water retention (Rawls et al., 2003), fostering healthy soil microbial communities (Wilson et al., 2009), and providing fertility for crops (Schmidt et al., 2011). These improvements are well documented and have generated a consensus that improvements to soil carbon are key to improving agricultural systems as a whole. While uncertainties may remain about the potential of agricultural soils to act as a carbon sink, the vast number of co‐benefits should remain an incentive to modify agricultural practices to increase soil carbon in their own right.

Improved soil fertility due to increased organic matter. Improved crop yields hence food security. Provision of fodder to livestock if fodder trees are used. Extra income to farmers through carbon credits.

Water management

Along with cultivar development, supporting farming techniques should be developed. These might include irrigation and water harvesting. Theremay be benefits from shifting the focus from large‐scale public irrigation to small‐scale private irrigation, which may include more efficient management and distribution of water, related to the user actually bearing the costs of the water use, bypassing issues related to equitability and funding in large‐scale schemes. Furthermore, one of the critical issues surrounding climate change is the variability in weather, with floods and droughts both becoming more frequent. Water conservation and supplementation are both important to develop when feasible, especially in marginal areas. Research for development work to build climate‐smart farming systems through integrated water storage and crop livestock interventions has been conducted in Burkina Faso, Mali, and Ghana (Amole and Ayatunde, 2016).

Through this project, synergies that exist between water retention interventions (such azaï, contour ridges, dugouts, small reservoirs) and crop‐livestock interventions (such as trees and legumes, fodder production, crop residue management) have been identified to improve water availability for crops, livestock and humans throughout every year (Amole and Ayatunde (2016). Development of small reservoirs in Ghana and Burkina Faso (Van de Giesen et al. 2002). Small reservoirs supply rural populations locally with water for irrigation, cattle, household, fisheries, and recreation. By 2005 these small water reservoirs were about 2000 in Burkina Faso (Liebe et al. 2005). Many have been constructed in the volta basin of Ghana (Faulkner et al. 2008). An alternative to the construction of small reservoirs is the use of groundwater in shallow alluvial aquifers. In northern Ghana, specifically the Upper East Region, shallow groundwater irrigation has expanded spontaneously over, roughly, the past five years.

Water management benefits both crops and livestock. In some cases there is large pond fish farming being practiced alongside crop production. This improves household food security and income.

Small reservoirs supply rural populations locally with water for irrigation during dry season, cattle, household use, and fish farming. All these supplement the food that is required during the dry season (van de Giesen et al 2008).





Agroforestry

Cultivated lands have the potential to contribute significantly to climate change mitigation by improved cropping practices and greater numbers of trees on farms. The global estimated potential of all greenhouse gas (GHG) sequestration in agriculture ranges from 1500 to 4300 Mt CO2e yr 1, with about 70% from developing countries; 90% of this potential liesin soil carbon restoration and avoided net soil carbon emission (Rust and Rust 2013). Tree densities in farming landscapes range from low cover of about 5% in the Sahel to more than 45% in humid tropical zones where cocoa, coffee and palm oil agroforestry systems prevail (Rhodes et al. 2014).

Adaptation potential is very high. A synthesis report by Nyasimi et al. (2014) and Reij et al. (2009) showed that farmers have grown 200 million new trees on cultivated fields in West Africa. Agroforestry practices can provide pathways to ecological intensification and contribute significantly to reduce the yield gap. Recent studies in Niger shows that thousands of farmers now have surplus grain to sell even in drought years and similar trends are noted in Mali and Senegal in the Faidherbia parklands. Fortunately, agroforestry farms and landscapes are a major part of Africa’s rural landscapes and provide income and environmental outcomes, and a range of other ecological services. In the Sahel, woodfuel accounts for more than 80% of the region’s energy supply, most of these energy needs are satisfied by encroaching on the rapidly shrinking forest cover. The adoption of agroforestry can reduce the human impact on forest cover and spare more lands to sustain healthy ecosystems and biodiversity. Expansion of crop lands at the expense of trees – have many negative impacts for local livelihoods.

Agroforestry has potential to improve soil fertility through nitrogen fixing trees. The trees contribute to climate change adaption by reducing wind speed and decreasing damage tocrops from windblown sand. Taking into account all factors, including enhanced soil fertility and increased food, wood and fodder supply, FNMR can bring an estimated benefit ofUSD 56 ha−1 year−1(Cooper et al. 2013; Dinesh et al. 2015).

The natural regeneration and the improvements that it brings in soil fertility, fodder, food and fuelwood, have been valued at US$56 ha−1 year−1 or a total annual value of US$280 million. The integration of trees and shrubs with crops and livestock systems – has strong potential in addressing problems of food insecurity in developing countries. Done well, it allows producers to make the best use of their land, can boost field crop yields, diversify income, and increase resilience to climate change. For example, one of the major potential benefits of on‐farm trees is their ability to replenish nutrient‐depleted soi). Social implications such as the substantial income, mostly for women for Shea butter fruits inBurkina Faso, fruits from Cordyla pinnata in Senegal, Detarium senegalense in Mali, Parkia biglobosa or Nere in all Sahelian countries, Adansonia digitata a or Baboab fruits, Tamarindus are also having a higher market value…can improve poverty alleviation in rural areas. Perennial evergreen agriculture is in that context very promising for the future food security and the build‐up of social capital (Mbow 2013).





Fertilizer use efficiency

In addition to the use of inappropriate types of fertilizer depending on the soil type and native soil fertility, too much fertilizer, or fertilizer applied at less than optimal levels and times can be wasted, going beyond the reach of the crop. Not only is this economically inefficient, but the fertilizer can be converted to nitrous oxide and emitted to the atmosphere. However, the right type of fertilizer applied at proper times and amounts can be used efficiently by the crops while minimizing emissions. This may involve promoting integrated soil fertility management that seeks, among other things, to enhance the soil organic matter content of the soils, which improves nutrient retention (Zougmoré et al. 2014).

Adaptation potential is high since several organizations are now testing and mapping soil nutrient content in Africa and providing agribusinesses and fertilizer manufacturers with solid data on which to base fertilizer recommendations. Along with improving policy environments and better fertilizer blends (that include secondary and micronutrients), agricultural productivity in Africa is growing and primed for greater success.

In addition to sequestering carbon, appropriately applied fertilizers may prevent deforestation and conversion of other lands into agricultural land. Currently, land conversion is the annual source of 12 percent of all greenhouse gases (IFDC 2016). But by allowing for the production of more food from less land, fertilizers have averted the conversion of about 1 billion hectares of virgin land into agricultural land since 1960.

Fertilizer use in West Africa is far below the world average, leaving farmers without an important input that can significantly improve yields. In West Africa, farmers are employing integrated soil fertility management by applying crop resides, compost, mulch, livestock manure, leaves, and fertilizer. These practices help farmers meet the nutrient needs of the crop while restoring soil organic matter and overall soil fertility, which contributes to sustainable intensification of crop production. Integrated soil fertility management across more than 200,000 hectares resulted in crop yield increases of 33‐58 percent over a four‐year period. Farmers also saw revenue increases of 179% from maize and 50% from cassava and cowpea. Farmers in Burkina Faso and Niger are using water‐harvesting techniques such as building stone lines and improved planting pits (locally known as zai). These practices help to trap rainfall on crop fields, increasing average cereal yields from 400 to 900 kilograms per hectare (kg/ha) or more. Applying small quantities of fertilizer directly to seeded crops or young shoots early in the rainy season can complement these low‐tech land and water management techniques. Combining this “micro‐dosing” with practices like water‐harvesting has increased millet and sorghum yields from fewer than 500 kg/ha to 1,000 or 1,500 kg/ha (Winterbottom and Reij 2013).

Conservation Agriculture

Conservation agriculture is as an approach to farming that seeks to increase food security, alleviate poverty, conserve biodiversity, and safeguard ecosystem services. Conservation agriculture practices can also contribute to making agricultural systems more resilient to climate change. In many cases, conservation agriculture has been proven to reduce farming systems’ greenhouse gas emissions andenhance their role as carbon sinks (USAID 2012).

Adaptation potential is very high. Climate variability and change are increasingly posing a threat to Western Africa’s socio‐economic development and environment. The beneficial effects of mulching with crop residues on the soil water balance (through reduced water runoff and soil evaporation) may enhance adaptation to future climate change, when rainfall is projected to decrease and become more unreliable (Scopel et al2004; Thierfelder and Wall 2010).

Conservation agriculture – or zero tillage ‐ also helps to maintain and improve the environment. Tractor use is substantially reduced when cultivation is eliminated, thus reducing emissions of greenhouse gases and other pollutants. Moreover, under zero tillage, soil moisture conservation and wind and water erosion are reduced because the soil surface is not plowed and residues, crowns, and roots from previous crops and pastures protect the soil. There are even cost benefits: zero tillage reduces the need for tractors and thereby lowers fuel and labor costs.

Conservation agriculture is among a group of practices that provide a “triple win” of increased agricultural productivity, enhanced resilience to climate change, and sequestration of carbon (Mango et.al. 2017)





Rice water management

With optimal management of water in a rice system, such as alternate wet and dry (AWD), methane emissions can be reduced without adversely impacting yield and potentially increasing yields. It may also prove to be a more efficient use of water in many locales.

The danger of such a system is that if done incorrectly, the nitrous oxide emissions will increase so much that they will negate any gains in methane emission reductions (Amoleand Ayantunde 2016)

It may also prove to be a more efficient use of water in many locales. Wetlands are high in plant and animal species diversity, particularly bird and fish populations, and can be found in river basins, lakes, and coastal areas in Western Africa. They provide resources such as fisheries, shellfish, fuelwood, medicine, and agricultural products, as well as protect human settlements, infrastructure, and various other coastal activities from the impacts of heavy rainfall, storms, and sea level rise. Wetlands are also pertinent to tourism in countries such as Senegal, the Gambia, and Ghana.

Research from West Africa show that irrigated rice is of higherquality than upland rice. Water from irrigated rice can be used for other crop production such as vegetables and fish farming. Thus rice water management creates a win‐win scenario as far as food systems is concerned. Its contribution to GHG emmissions is equally very low as climate compared to upland rice.

Appropriate institutional support:

Regional actors and networks that focus on and fund environmental and climate‐change related initiatives in the region include the African Union, African Development Bank (AfDB), Environmental Development Action in the Third World, Organization for the Development of the Senegal River Basin, Niger Basin Authority (NBA), and the Global Water Partnership West Africa. Many initiatives in the region have also been led and/or financed by international agencies, institutions, and NGOs working with regional climate change adaptation in Western African partners.

Adaptation potential is quite high. Here are some of the selected initiatives. (1) Strengthening the Capacities of Permanent Interstate Committee for Drought Control in the Sahel Member States to Adapt to Climate Change (Burkina Faso, Chad, the Gambia, Guinea Bissau, Mali, Mauritania, Niger, Senegal) (2) Adaptation to Climate and Coastal Change in West Africa – Responding to shoreline change and its human dimensions in West Africa through integrated coastal area management (Senegal, Guinea Bissau, Gambia, and Mauritania) (3), Seasonal Rain and Flow Regimes Forecast Project in West Africa (4) Africa Water Vision for 2025 – Effective management of droughts, floods, and desertification in half of African countries by 2015 and in all countries by 2025

Improved food security, cleaner environment, improved crop and livestock production, and better human health

These regional actors and networks give hope for large‐scale Climate Smart Agriculture adoption for improved resilience to climate change and food security in West Africa. Climate Smart Agriculture is already endorsed for inclusion in the NEPAD program on agriculture and climate change by the African Union, while in the framework of the formulation of the Economic Community of West African States 10 year Policy (ECOWAP + 10), the new common agricultural policy for the region, ECOWAS seeks for a focus on the mainstreaming of climate change and CSA into local plans andpolicies of member countries (Zougmoré et al. 2016).

Conducive policy

Governments in West Africa have enacted policies that promote climate smart agriculture. The aim of these policies is to mitigate GHG emissions.

There is high adaptation potential given that there is government support More food security, environmental management.

With financial support from the United Nations the Economic Community of West African States (ECOWAS) are formulating regional policies that will alleviate the negative impacts of climate change on food security, and promote sustainable development in the region. These policies will support the effort of ECOWAS to mainstream climate change information into agricultural policies that will in the end increase food security.

Opportunity Table: Cereals East and Southern Africa

Opportunity and Countries Affected Adaptation Strategies Co‐benefits and Food Systems Adaptation Challenges and Climate Change Impacts Examples of Food System Implications

Qualitative description plus quantitative if available Potential feedbacks and interactions

Maize, the most widely cultivated staple crop in Sub‐Saharan Africa (SSA), is primarily grown by smallholders and 77% of the total production in SSA (excluding South Africa) is consumed as food (Smale et al. 2011 ). Countries highlighted in this report are, Ethiopia, Kenya, Uganda, Tanzania, Rwanda, Burundi, Zambia, Mozambique and Zimbabwe.

Scientists are already developing Drought Tolerant Maize for Africa (CIMMYT, IITA in collaboration with National Research Organizations. Conservation agriculture is being promoted alongside organic farming to sequester carbon and minimize fertilizer use. New maize varieties with improved drought and heat tolerance will play an important role in adapting maize systems to climate change in SSA, however maize yields in this region are currently amongst the lowest in the world. Agroforestry practices are being promoted by World Agroforestry Centre. Water harvesting techniques, and small irrigation are on the rise in the region. Conservation agriculture practices increase stored soil water by improved water infiltration, reduce evapotranspiration and reduce water runoff (Verhulst et al. 2010; Thierfelder and Wall 2012).

Farmers are now transitioning to growing more of drought tolerant land races than hybrid maize. Though low yielding, they are more adapted to the environment than high yielding hybrid maize. CIMMYT and IITA have also come up with Drought Tolerant Maize that they are promoting alongside conservation agriculture practices. NGOs are encouraging farmers to practice ecological agriculture and practice more of organic farming to reduce the use of synthetic fertlizers. Farmers are now transitioning the consumption of maize only and are reverting to consuming more of root, tuber and bananas. This is predominant in the East Africa region towards the Congo Basin.

Overall, maize production will decrease under future climate scenarios, though the degree of impact differs among simulations. Using the CERES‐ Maize model, Jones and Thornton ( 2003 ) predicted a 3–19% reduction in maize yield in the FtF countries by 2055 compared to 2000, where Ethiopia and Mozambique were projected to experience the least and greatest decrease in maize yield, respectively. Furthermore, the authors projected spatial heterogeneity for maize production with larger areas experiencing reduced yield as compared to the areas with yield gains in East Africa. Despite large variations in projected impact on maize yield, there is a general consensus that climate change will adversely affect maize yield in East Africa. Multiple studies indicated that East Africa could lose as much as 40% of its maize production by the end of the 21st century.

Maize is the most important source of dietary protein and the second most important source of calories in eastern and southern Africa (Broughton et al. 2003 ). However with projected decrease in maize yields due to climate change it means many regions in East and Southern Africa will suffer from hunger.

Opportunity Table: Impacts of Climate Change on East and Southern African Crops, their Consumption, and Adaptation Strategies

Cultivation of cereal crops is the main source of GHG emissions in South Africa with 68% of the total emissions from field crops. Totals of 61%, 14% and 25% of emissions from production of cereal crops are from synthetic fertilizer, crop residues and lime, respectively. Production of cereal crops accounts for 73% of national total GHG emissions from application of synthetic fertiliser, 72% of emissions from crop residues and 57% of CO2 from lime. Maize (82%) and wheat (14%) are the main sources of total cereal crop GHG emissions (Tongwane et al.2016). Application of synthetic fertilizer during maize production results in 85% of emissions from cereal crops (Tongwane et al.2016). A total of 84% of emissions are from crop residues left in the field after harvest.

Cultivation of maize (Tongwane et al.2016) and production of this commodity accounts for three quarters of emissions from the addition of lime to the soil (Tongwane et al.2016). Production of wheat contributes totals of 11%, 15% and 17% of cereals’ emissions from synthetic fertilizer, cropresidues and lime,respectively (Tongwane et al.2016). Productions of sorghum account for less than 5% of total emissions from application of manure during cultivation of cereal crops.

Production of legumes and oilseeds contributed 11% of total national GHG emissions from field crops in South Africa. Unlike with other crop groups, application of lime is the main source of emissions with 60% of the emissions from legumes and oilseeds. Synthetic fertilizer and crop residues account for 34% and 5% of the emissions from this group, respectively. Production of soybeans and groundnuts accounts for the largest sources of emissions from legumes and oilseeds with 47%, 30% and 19%, respectively (Tongwane et al. 2016).

Application of synthetic fertilizer during the management of groundnuts is the largest source of emissions for this agricultural input in this group (Tongwane et al. 2016). Similarly, soybean is the major source of emissions from lime application (Tongwane et al. 2016).

No proper data exists for impacts on cassava and sweet potato production.




Wheat is generally cultivated as a winter rainfed crop in the highlands of Ethiopia, Kenya, Uganda, Rwanda, and Tanzania and as a winter irrigated crop in Zambia, Malawi, and Mozambique (Negassa et al. 2012 ).

For crops, such as wheat that are more impacted by heat stress switching to heat‐ resistant and drought tolerant crops, such as sorghum and millet, may mitigate temperature stress‐ related crop failure. As an adaptive measure to climate change, farmers in Africa have already begun selecting a combination of crops based on the prevailing climate (Kurukulasuriya & Mendelsohn 2006 ).

With persistent and prolonged drought in Africa due to climate change, people are changing their eating behaviour and consuming more of wheat product than maize. In Kenya today a 2 kg packet of maize is costing more than a 2 Kg packet of maize flour. This has forced the Kenyan government to subsidise the packet of maize flour imported from Mexico. Not many people consider wheat as a staple food in Kenya other than in urban areas. However maize being a staple crop and having been hit hard by climate variability and change, its flour has become so scarce. Wheat flour which has been considered a luxury and food only for the rich and the middle class is now more abundant in the super markets than maize flour. Besides wheat flour is far more cheaper.

Wheat is a coolseason crop and increasing temperature shortens its growth period by accelerating phonological development, resulting in reduced yield (You et al. 2005 ; Asseng et al. 2011 ).In SSA, average annual temperature in 1990 was 20.3°Cin wheat harvest areas, which already exceeded the optimum wheat‐growing temperature of 15–20°C (Liu et al. 2008 ). The exact level of the effects of climate change differ by location, but some studies suggest that a 1°C increase in temperature above norm reduces wheat yield by 10% (Brown 2009).

The results presented here indicate that wheat is one of the most sensitive crops to climate change. Projected impacts in East Africa vary widely, but without climatechange adaptation, eastern Africa could lose about twothirds of the wheat productivity by the end of the 21st century.

Rice is a vital crop in East Africa where it is primarily grown by smallholder farmers as a rainfed crop (excluding Kenya, where the majority of rice is irrigated). It is the second most important crop in Tanzania and Malawi and the third most important crop in Kenya and Zambia (EUCORD 2002 ; Saka et al. 2006 ; FoDiS 2010 ). Rice is grown as upland rice, lowland rainfed rice, mangrove swamp rice, floating rice, and irrigated rice (EUCORD 2002 ).

Rice is very much of a cash crop for small‐to medium‐scale farmers in the East and Southern Africa (ESA) region. While rice is more resilient to climate change than wheat and maize, high rates of loss (up to 16%) are expected due to climatic conditions. Africa Rice Centre is developing varieties that can withstand both flooding and also moisure stress ( Somado et al. 2008). A perfect example is Nerica Rice developed by Africa Rice Centre (WARDA).

Consumption of rice is gaining ground in the entire African continent, given the frequent failure of maize due to climate change. Since Uganda launched the Upland Rice Project in 2004, in which Nerica is a major component, the Ugandan National Agricultural Research Organization (NARO) reports an almost nine‐fold increase in the number of rice farmers from 4,000 to over 35,000 in 2007. At the same time, the country has almost halved its rice imports from 60,000 tonnes in 2005 to 35,000 in 2007, saving roughly US$30 million in the process (Somado et al. 2008).

Projections of the impact of climate change on ricein the region vary among studies. Lobell et al. ( 2008 )used 20 GCM models and projected a slight increase(<5%) in rice production in East Africa by 2030 as compared to 1998–2002. Using the Impact model, Ringler et al. ( 2010 ) projected a 0.24% increase in rice yield in eastern Africa and a 2.32% reduction in southern Africa by 2050. Overall, rice appears to be more resilient to climate change than maize or wheat. Nonetheless, climate change is projected to have negative impact on rice yield and eastern Africa could lose as much as 16% of its current rice production by the end of the 21st century.

Given that Maize and wheat are more susceptible to climate change, rice offers a better alternative to most urban dwellers where it is preferred. New Nerica varieties can smother weeds like the African parents, resist drought and pests or can thrive in poor soils. Like its Asian parents Nerica rice has a high yield. The grain head holds 300 to 400 grains compared to the 75 to 100 grains of traditional varieties grown in the region. Its strong stems and heads prevent shattering, and the taller plants make harvesting easier. Nerica Rice is offering an alternative to Wheat and Maize in Africa. Moreover, the most popular Nerica lines take only three months to ripen, as opposed to six months for the parent species, thus allowing African farmers to “double crop” it in a single growing season with nutritionally rich vegetables or high‐value fiber crops. As a further bonus, some of the new lines contain up to 12 percent protein, compared to about 10 percent in the imported rice sold in the local market.




In terms of quantity, sorghum is the second most important crop in Africa after maize and is the most important crop in the semiarid tropics (Obalum et al. 2011 ). Major sorghum‐ growing areas in FtF countries include much of north central, northwestern, western, and eastern mid‐ altitude areas of Ethiopia, Rwanda, northern and eastern Uganda, central Tanzania, and the areas in Kenya and Tanzania east of Lake Victoria (Wortmann et al. 2009 ). The importance of sorghum to Africa lies in its inherent ability to resist drought and withstand periods of high temperatures (Taylor 2003 ). Maiti ( 1996 ) reported the optimum vegetative growth temperature of sorghum is 26–34°C and an optimum reproductive growth temperature is 25–28°C. Currently, most of the sorghum in the region is grown under sub‐ optimum temperatures. About 54% of the sorghum is produced below 24°C (Wortmann et al. 2009 ).

Using heat‐tolerant varieties of sorghum as a new management practice shows the most potential as an adaptation for maintaining crop yield as global warming raises the temperatures in Africa. Sorghum and millet, which have higher tolerance to drought and heat, could replace maize in most places under threat.

Within ESA, the utilization of sorghum as food is dominated by Sudan and Ethiopia, where consumption in 2009‐11 averaged 3 and 2 million t, respectively. Elsewhere in ESA, utilization for food was rivaled by utilization for beer. Opaque beer manufactured by modern breweries (eg, Chibuku shake‐shake) is a popular alcoholic drink. In Uganda and Tanzania, the use of sorghum for ‘food processing’ (mostly opaque beer) equals or exceeds the use of sorghum for food. Generally, sorghum that is not used for food is used to make beer rather than used as feed for livestock or poultry. The only country that seemingly uses sorghum as feed on a significant scale is Sudan, where hybrid sorghum is widely grown with irrigation, maize is not a staple crop and meat is exported to the Middle East (Orr et al. 2016)

Based on Maiti ( 1996 ) and Wortmann et al. ( 2009 ), sorghum production should increase in the region with slight increases in temperature. However, some researchers have projected climate change to negatively impact sorghum yield. In a global simulation of sorghum yield, Lobell and Field ( 2007 ) reported an 8.4% decrease in sorghum yield for 1°C increase in temperature. Similarly, Hatfield et al. ( 2008 ) reported a 7.8% decrease in sorghum yield for 1°C rise in temperature from 18.5°C to 27.5°C. Water deficiency is another constraint in the region that has been cited as the most important sorghum production constraint (Wortmann et al. 2009 ).These findings suggest that sorghum is more resilient to climate change than maize or wheat and will be minimally impacted (<5%) by the middle of this century.

Sorghum has a wide variety of uses. The grain is eaten after boiling the flour to produce foods such as ugali, sadza and uji. In Ethiopia, sorghum flour is used to make injera, a traditional bread made from fermented dough. Sorghum grain is also used for brewing. Varieties of sorghum suitable for brewing have low tannin content since consumers prefer beer with this taste. Although sorghum grain is not usually fed to livestock, sorghum stover is used for fodder as well as fuel and material for building and roofing houses (Orr et al. 2016)

Millet is cultivated mostly in the semiarid tropics and subtropics of Africa; however, it is also cultivated in other drought‐ prone sub‐ humid and medium‐ high altitude areas (Obilana 2003 ). Millet is a hardy crop that requires few inputs, is less susceptible to pests and diseases, and can be grown in the areas that are too hot and dry for sorghum (Cagley et al. 2009 ). Pearl millet and finger millet are the most commonly grown millet varieties, where pearl millet is grown in all sub‐ Saharan countries and finger millet is grown in eastern, southern and central Africa (Obilana 2003 ). Pearl millet is grown as a dry‐ land crop in semiarid regions, while finger millet is generally grown in uplands and sub‐ humid areas (Gari 2002 ).

Millets (pearl, foxtail and finger millet) are an example of indigenous cereals grown in the dry parts of SSA (Chivenge et al 2015). These crops may have been indigenized to the dry areas due to many years of cultivation, as well as natural and farmer selection. However, now the production of millets is limited to certain areas that are not considered as cereals producing areas in SSA (Chivenge at al. 2015). Across much of SSA, cultivation of pearl millet is mainly practised at a subsistence level by smallholder farmers. It is only grown commercially as forage for animal consumptions in some areas (Chivenge at al. 2015). Millets are an annual C4 plant that can grow on a wide variety of soils ranging from clay loams to deep sands but the best soil for cultivation is deep, well‐drained soil. This makes it suitable for cultivation by smallholder farmers in semi‐arid areas where deep sands and sandy loam soils dominate. In addition, millets are easy to cultivate and can be grown in arid and semi‐arid regions where water is a limiting factor for cropgrowth (Chivenge at al. 2015).

In Kenya, Tanzania and Uganda, finger millet is widely recognized by consumers as a nutritious cereal, particularly for infants, the sick and the elderly. This has led to growing demand from urban, middle class consumers. In northern Ethiopia and western Kenya, finger millet remains an important staple cereal, while in southern Africa, farmers in semi‐arid areas plant millet alongside maize to insure against crop loss from drought (Orr et al. 2016). In ESA, while in 2009‐11 1.5 million tons (68%) was used as food, a relatively high share of millets (0.3 million tons, or 20%) was used for food processing. This reflects the traditional use of millet to produce local beer. Within ESA, food processing is concentrated in Tanzania (0.2 million tons in 2009‐11, or 43% of the available supply). In Sudan, the biggest regional producer, no millet was used for alcohol processing since the majority of the population is Muslim. Similarly, in Ethiopia, the second biggest regional producer, only 14% of available supply was used for this type of processing. In ESA as a whole, only 3% of total supply was used as feed in 2009‐11 (Orr et al. 2016).

Climate change is expected to raise the temperature in millet growing areas closer to the optimum temperature, leading to a general increase in millet yield. However, similar to sorghum, millet is not expected to gain much from elevated atmospheric CO2 levels. Overall, millet is more resilient to climate change than maize or wheat but less resilient than sorghum. It is expected that there will be about a 15% yield loss in East Africa by the middle of the century (Knox et al. 2012).

Millets are often referred to as a “high‐energy” cereal as they contain higher oil content than maize grains; their protein and vitamin A content are also higher than maize (Chivenge at al. 2015). The fact that millets contain vitamin A, a major deficiency in staple diets, makes it a suitable crop for combating nutritional challenges in these communities. Compared with other staple grains such as maize, wheat and sorghum, pearl millet is less susceptible to pests and diseases. Millets are used almost exclusively for food and for food processing to make local beer. Although South Asia has seen growing demand for pearl millet as poultry feed, the higher price of millet relative to maize has so far prevented the development of this value chain in ESA (Orr et al. 2016).




In eastern and southern Africa, beans are the second most important source of dietary protein following maize and the third most important source of calories after cassava and maize, with annual consumption exceeding 50 kg per person (Wortmann et al. 1998 ; Broughton et al. 2003 ). Beans are produced in over 20 countries in eastern and southern Africa covering over four million hectares, where Ethiopia, Kenya, Rwanda, Tanzania, and Uganda are among the major producers (Wortmann et al. 1998 ; Asfaw et al. 2009 ). Cultivation areas are concentrated in cooler highlands and warmer mid‐ elevation areas with altitudes greater than 1000 m above sea level. However, due to population pressure, the cropping area is being extended to lower elevations (Katungi et al. 2009 ).

The ability to fix atmospheric nitrogen makes legumes excellent components within the various farming systems because they provide residual nitrogen and reduce the needs for mineral nitrogen fertilizers by associated non‐legumes. Intensification of low‐input agricultural production has led to a rapid increase in soil degradation and nutrient depletion in many parts of sub‐Saharan Africa, constituting serious threats to food production and food security. Nitrogen depletion in maize‐based systems in some farmers’ fields in African savanna is estimated to be 36‐80 kg N ha‐1 per year (Sanginga et al., 2001) and it has been obvious since the mid‐1990s that fertilizer use is necessary if sustainable agricultural production in smallholder farms is to be raised to levels that can sustain the growing population. Assuming that only seeds are harvested, net soil nitrogen accrual from the incorporation of grain legume residue can be as much as 140 kg N ha‐1 depending on the legume variety (Giller, 2001). This N tends to be released quickly when legume residues are incorporated into the soil and can contribute to substantial improvements in yield of subsequent crops.

Thus, legumes represent a major direct source of food for man and livestock and, therefore, make a critical contribution to increased food security of subsistence farmers, reduced cost of food for poor consumers and enhanced rural incomes. The opportunity exists to improve yields of legumes in sub‐Saharan Africa since current yields are only a fraction of their potential (Giller et al. 2013).

As a C3 crop, beans are expected to benefit from elevated atmospheric CO 2 concentration. Ainsworth et al. ( 2002 ) reported a mean increase of 24% in soybean yield with elevated atmospheric CO 2 , which was mainly due to pod number increases. Soybean yield is also affected by precipitation and subsequent moisture availability. In 65% of the bean‐ producing area in the region, the mean rainfall exceeds 400 mm during the three months after sowing, while in other areas yield is severely impacted by moisture deficit (Wortmann et al. 1998). When precipitation falls below 300 mm during the growing season, yield decline in beans is estimated to be 1000 kg/ha (Wortmann et al. 1998 ). Hence, in eastern and southern Africa, rainfall variability and soil moisture content, rather than rising temperature, are the crucial factors in determining the effect of climate change in soybean production.

Grain legumes are a key source of nitrogen‐rich edible seeds, providing a wide variety of high‐protein products and constituting the major source of dietary protein in the diets of the poor in most parts of sub‐Saharan Africa. Largely grown as subsistence food crops, they are predominantly crops grown by women and used within the family, with an annual per capita consumption of about 9 kg and providing 88 kcal/capita/day. Legumes such as groundnut and soybean are also major sources of edible oil and other industrial by‐products. Residues of grain legumes as well as herbaceous and fodder tree legumes provide an excellent source of high quality feed to livestock especially during dry seasons when animal feeds are in short supply.

Cassava is the most important crop in SSA in terms of caloric intake (Rosenthal and Ort 2012 ). In East Africa, cassava is also the most important staple food crop in terms of total production, where production is concentrated in mid‐ altitude areas in the African Great Lakes region and the coastal zones of Tanzania and Kenya (Fermont 2009 ). Cassava is also traditionally cultivated in the northern part of Zambia, while about 70% of farmers in Mozambique cultivate cassava (Nielson 2009 ).

Research has shown that cassava tubers become even more productive in hotter temperatures and outperforms potatoes, maize, beans, bananas, millet and sorghum ‐ some of Africa's main food crops. With cassava being the second most important source of carbohydrates in sub‐Saharan African after maize its importance for food security is upheld by most scientists (Jarvis et al. 2012). Scientists state that East Africa could increase the cassava production up to 10 percent if temperatures rise as predicted. Likewise production is likely to grow in Western Africa with a slightly smaller increase in production in Southern Africa.

“Cassava is a survivor; it’s like the Rambo of the food crops. It can enhance nutrition and reduce climate risk,” (Jarvis et al. 2012). It can be consumed both as tubers and leaves. Tubers can be stored in the ground after harvesting for as long as 4 months. Cassava can be prepared and processed for consumption in many different ways, either by just boiling the tuber or by drying and grounding it into powder which can be used to cook sadza (thick porridge) or make bread and which can also be fried as chips (Jarvis, et al. 2012)

The crop is more resilient to climate change due to its tolerance of high temperatures and intraseasonal drought (Jarvis et al. 2012 ). However, if a prolonged drought period (>2 months) falls during the root thickening initiation state, a root yield reduction of up to 60% may occur (Jarvis et al. 2012 ). Cassava shows better yield gain than grain crops at higher CO2 concentrations, can recover from very long drought periods, and exhibits increases in optimum growth temperature under elevated CO2 levels (Rosenthal and Ort 2012 ). These qualities make cassava a suitable crop in a future that is projected to experience elevated CO2, increased temperature, and variable rainfall patterns. The fi ndings are supported by other researchers who projected minimum impact, if not positive, or at least better performance of cassava than other crops.

Cassava is the second most important source of carbohydrate in sub‐Saharan Africa consumed by over 500 million people every day‐ the highest per capita in the world. It is also used in making industrial products like confectionery and animal feeds.




One of the most widely grown crops in SSA, sweet potato is an important crop in the areas surrounding the Great Lakes in eastern and central Africa, such as Malawi and Mozambique (Shonga et al. 2013 ). Sweet potato is a major staple crop in Uganda, Rwanda, and parts of Tanzania, while it is a secondary food source in Kenya and most of Tanzania and Ethiopia (Smit 1997). Mainly cultivated by smallholders, sweet potato is the third most important source of carbohydrates in Uganda, while the country is the third largest producer of sweet potato in the world (Muyinza et al. 2012 ). Although the crop grows from semiarid lowlands to high‐ altitude zones, cultivation of sweet potato is most intense in altitudes of 800–1900 m (Smit 1997 ). Sweet potato is a tropical or a subtropical plant, which has an optimum‐ growing temperature of 20–25°C, but can be grown in temperatures ranging from 15°C to 33°C (Ramirez 1992).

The studies on the impact of climate change on sweet potato in East Africa are not adequate to draw conclusions on the potential yield impact. However, susceptibility of sweet potato to high temperatures at night and climate induced water stress suggest that the crop might be negatively impacted in the future.

Sweet potato remains an important root crop of the tropics owing to its versatility (Mukhopadhyay et al. 1990). This is with regards to its suitability to low input systems, drought tolerance and large environmental plasticity which allow it to be planted and harvested at any time of the year, especially in frost free areas Motsa (2015). Within the communities that consume it, both the leaves and root are utilised for human and animal consumption with limited industrial use (Mukhopadhyay et al. 1990; 2011). Its versatility makes it an ideal food security crop (Low, 2007) capable of contributing to the food and nutritional security of smallholder farmers residing on marginal production lands (Yngve, 2009).

Studies conducted by Low et al. (2007) in sub‐Saharan Africa established that incorporation of orange‐fleshed sweet potato varieties in diets of children led to an improved vitamin A status. Amagloh et al. (2012) concurred that due to their relatively high levels of vitamin A, orange‐fleshed sweet potato varieties could be used as a complementary food for feeding infants. Several studies by Kulembeka et al. (2005), Laurie and Magoro (2008) as well as Laurie and van Heerden (2012) reported good acceptability of orange‐fleshed sweet potato varieties including the leaves. However, more work still needs to be done to improve on acceptance and utilization.

Perhaps the biggest contribution of sweet potatoes lies in the potential of the orange‐fleshed sweet potato varieties, which are reported to contain significant concentrations of β‐carotene, a precursor for vitamin A. As such, orange‐fleshed sweet potato varieties are seen to offer potential to contribute significantly towards Vitamin A deficiency; the nutritional dimension of food security (Chivenge et al. 2015).

Opportunity Table: Cereals (Intensive; Central and South America)


Qualitative description plus quantitative if available (range of possible emission reductions?)Qualitative description plus quantitative if available


Organic inputs (Use of non‐chemical agricultural products i.e, fertilizers, herbicides and plaguicides) ‐ Agrochemical use

Globally. Song et al. (2013) indicated that the phytolith sink annually sequesters 26.35610.22 Tg of carbon dioxide (CO2) and may contribute 40% of the global net cropland soil C sink for 1961–2010. Rice (25%), wheat (19%) and maize (23%) are the dominant contributing crop species to this phytolith C sink. Continentally, the main contributors are Asia (49%), North America (17%) and Europe (16%). The sink has tripled since 1961, mainly due to fertilizer application and irrigation. Cropland phytolith C sinks may be further enhanced by adopting cropland management practices such as optimization of cropping system and fertilization. Silicon fertilizer application, rock powder amendment and organic mulching will increase soil bioavailable silicon input, plant silicon uptake and phytolith content for cereals and sugarcane (Song et al. 2013). Brazil. Soares et al. (2015) evaluated the use of nitrification inhibitors (NIs) dicyandiamide (DCD) and 3,4 dimethylpyrazole phosphate (DMPP) and a controlled‐release fertilizer (CRF) to reduce N2O emissions from urea, applied at a rate of 120 kg ha‐1 of N in sugarcane, the treatments were (i) no N (control), (ii) urea, (iii) urea+DCD, (iv) urea+DMPP, and (v) CRF. The results showed that the cumulative N2 O N emissions in the first ratoon cycle were 1098 g ha‐1 in the control treatment and 1924 g ha‐1 with urea (0.7% of the total N applied). Addition of NIs to urea reduced N2 O emissions by more than 90%, which did not differ from those of the plots without N. The CRF treatment showed N2 O emissions no different from those of urea. Chile. Huerta et al. (2012) studied the conventional and organic methods in the Chilean wheat. They found that the use of compost as a strategy fixed important amounts of biogenic carbon, generating environmental benefits in the impact category of climate change –4.39 kg CO2 eq/ton of grain. Honduras. Farmers from central Honduras have intercropped runner beans with their maize for 20 years without using chemical fertilizer and without seeing any decrease in their soil’s productivity (FAO 2016d).

Fertilization schemes potentially maintain or increase crop productivity and reduce the biophysical impacts of extreme weather events in face of climate change. Alternative fertilization measures could include silicon fertilizer application, rock powder amendment, organic mulching and traditional (no conventional) fertilization.

Restoring and maintaining soil structure, biodiversity, and fertility. Reduce soil erosion, leaching or gaseous emissions, degradation and loss of productivity. Potential reduction in the cost of production. Avoid contamination of soil and water courses. Reduce crop, insect, and bacterial resistence to chemical pathogen controls (Tilman et al. 2002).

Green manures and cover crops are often considered as expensive, inefficient production elements (as nitrogen sources), disregarding the various environmental services they perform (Ceballos et al. 2012). Effort should be made to search for indigenous plants as a source of pesticides compounds and to bioprospect the pesticidal properties of these plant products (Sharma and Bhandari 2014). A major global evaluation of current cereal production systems should be undertaken, with a view toward using scientific and technological advances to increase input efficiencies.

Potential improvement of food diversity, availability, access, and utilization. Reduction of health problem as a result of wrong handle of agrochemicals. Reduction of production cost for the utilization of organic fertilization. Improve the quality of soils, clean water and protect the groundwater sources. Reduction in the contamination and improvements in the quality of animal and human food and populations.

Conservation Agriculture ‐ CA (use of cover crops, multispecies crops, improved crop or fallow rotations, crop varieties and legumes in crop rotations) ‐ Agronomy practices

Globally. Improved agronomic practices that increase yields and generate higher inputs of residue C can lead to increased soil C storage (Follett 2001). Branca et al . (2011) estimated all GHGs (change in soil C stock + emissions) in dry and humid areas around the world for agronomy practices finding that mitigation potential was 0.39 for dry and 0.98 for humid (tCO2e/ha/year). Jensen et al. (2011) estimated that between 350 and 500 Tg CO2 could be emitted globally as a result of the 33 to 46 Tg N that is biologically fixed by agricultural legumes each year. Averages across 71 site‐

years of data, soils under legumes emitted a total of 1.29 kg N2O–N ha−1 during a growing season. Legume crops and legume‐based pastures use 35%

to 60% less fossil energy than N‐fertilized cereals or grasslands, and the inclusion of legumes in cropping sequences reduced the average annual energy usage over a rotation by 12% to 34%. Mexico. Legumes in rotation with maize contribute organic matter and nitrogen that help boost maize yields by 25% (FAO 2016d). Honduras. The introduction of mulching and other soil conservation techniques like the Quesungual doubled maize yields in shifting agriculture systems, reduced soil erosion and increased the quality and availability of water for downstream users (FAO 2016d). Argentina. Dyer et al. (2012) developed an experiment to quantify the short‐term GHG emission rates from maize‐soybean (Glycine max [L.] Merr.) intercrops and maize and soybean sole crops in La Pampa. Soil CO2 emission rates were significantly greater in the maize sole crop than in intercrops (maize‐soybean), but did not differ significantly for N2O emissions. Over two field seasons, both trace gases showed a general trend of greater emission rates in the maize sole crop followed by the soybean sole crop, and were lowest in the intercrops. Brazil, Argentina. The measurements of N2O emissions for soybean–wheat, soybean–vetch and maize–wheat sequences over two consecutive years in Brazil ,showed that the N2O emissions from a soybean–vetch (Vicia spp. ) sequence were similar to N2O. In Argentina, the peak in N2O emissions from the soybean plots also corresponded with a spike in N2O fluxes from the unplanted soil control plots implying that background soil factors were largely responsible for the generation of N2O, not the presence of the legume (Jensen et a l. 2011).

Potentially maintain or incresing crop productivity and reduce the biophysical impacts of extreme weather events in face of climate change (Vignola et al 2015, 2017). The use of legumes in crops promotes soil improvement, through the incorporation of organic matter into soil, which can affect soil characteristics and especially its biological properties, promoting beneficial organisms at the expense of plant parasitics and plagues (Widmer et al 2002).

Potential of improving biodiversity and ecosystem services from cereal crop locations and landscapes. Reduction of soil and water contamination and nutrient depletion. Increasing water holding capacity (Mueller et a l 2012)

A lagging of pulse productivity in developing countries, which can be explained by a low‐input system based on very limited or no use of fertilizer either chemical or organic inputs, and because it is characterized by small‐scale subsistence production systems in most developing countries (Akibode and Maredia 2011). Reduction in pulse production as a result of increased competition for farm land use from other crops (Akibode and Maredia 2011). Fully understand the interactions among nutrient and water availability (Mueller et al 2012).

Source of food and water which guarantees a reliable access to adequate food at all times. Potential increase in food security for cereals, as the average marginal yield increase with respect to conventional in 116 for dry and 122 for humid areas (Branca et al. 2011).



Agroforestry Systems ‐AFS (Integrated crops, cultivation along contour lines, planting trees in isolation or in lines, live barries/fences, crops on tree lands, tree natural regeneration and biological plagues management) ‐ Agronomy practices

Globally. Agro‐forestry systems can increase C storage in the vegetation and in the soil and may also reduce soil C losses stemming from erosion (Branca et al. 2011). Cerri et al. (2010) estimated that the conversion of 12 million ha into the NT system until 2020 (Committed mitigation scenario) may represent a removal of 138.5 Mt CO2–eq. from the atmosphere. Nair et al. (2009) estimates of Carbon Sequestration Potential in agroforestry systems are highly variable, ranging from 0.29 to 15.21 Mg ha–1 y–1. Watson et al. (2000) estimated that in the world all agroforestry systems are using 400 (million ha) with a Potential for C sequestration of 0.026 (Pg C y–1; sum of above‐ and belowground storage) (Remarks: estimate for 2010; C gain of 0.72 Mg C ha–1 y–1) (Nair et al. 2009).The average carbon storage by agroforestry practices has been estimated as 9, 21, 50, and 63 Mg C ha−1 in semiarid, subhumid, humid, and temperate regions. For smallholder agroforestry systems in the tropics, potential C sequestration rates range from 1.5 to 3.5 Mg C ha−1 yr−1 (Montagnini and Nair 2004). Central America. Farmers have developed a ‘slash‐and‐mulch’ production system that preserves trees and shrubs, conserves soil and water, doubles yields of maize and beans, and even resists hurricanes. Honduras. Pauli et al. (2005) researched the effects of four common land use types (secondary forest, recently cleared agroforestry fields, mature agroforestry fields, and silvopastoral fields) in the Quesungual area on soil macrofauna. They found that all land uses surveyed contained substantial soil macrofauna communities, which may be the result of incorporation of diverse organic matter inputs in the form of mulch pruned from trees, diverse vegetation, and a continuous litter cover. Costa Rica . Nair et al. (2009) illustrated the example of the agroforestry system of alley cropping system: Erythrina poeppigiana + maize and bean (Phaseolus vulgaris ), which with 19 years, 0‐40 soil depth (cm), has 1.62 of Soil C (Mg ha–1). Brazil. Brazilian farmers have integrated Brachiaria in a direct‐seeded maize system that is replacing soybean monocropping. United States. Martellotto (2010) time. evaluated the changes in SOC for two long‐term experiments; one an irrigated site at Mead, NE (1997) with continuous corn (CC) (Zea mays L.) and corn‐soybean [Glycine max (L.) Merr.] (CS) rotation) and 3 nitrogen (N) application rates (0, 100 and 300 kg ha‐1); and the other a rainfed site at Concord, NE, (1985) with three tillage treatments (no‐till, NT, disk, DK, and moldboard plow, MP), two crop sequences (CC and CS) and three N application rates (0, 80 and 160 kg ha‐1). The author found that Nitrogen fertilizer application resulted in a 3% increase in SOC, but required 24 years to generate detectable differences in the surface 400 kg of soil m‐2. Over the last 12 years, MP lost 1.52 ±0.4 kg of C m‐2 while NT lost 0.73 ±0.4 and DK lost 0.76 ±0.4 kg of C m‐2 in the 1200 kg of soil m‐2 profile.

Potential maintenance or increase in crop productivity and reduce the biophysical impacts of extreme weather events in face of climate change (Vignola et al 2015, 2017). Incorporating trees on farms through agroforestry systems has emerged as having the potential to enhance the resilience of smallholders to current and future climate risks including future climate change (Lasco et al 2014). Agroforestry systems include native, multipurpose and resistant varieties of trees which can reduce the incidents of pests and diseases (Lasco et al 2014). Trees can reduce the microclimatic stress exorted by high temperatures (Vignola et al 2015)

Improving biodiversity and ecosystem services from crop lands that are beneficial to both humans and animals poppulations. Promote a better land‐use system and multifunctional landscapes: increasing productivity, improving rural livelihood, increasing carbon sequestration in biomass and in the soils, reducing soil erosion and increasing soil organic matter and nutrient availability, reducing plagues and pests, etc (Cerri et al. 2010).

Reduced adoption potential, reduced number of multifunctional tree species studied so far and in a reduced number of ecosystems (Esquivel et al 2008). The methodologies and approaches used for C‐sequestration potential of land‐use systems are unfortunately not rigorous (Nair et al. 2009). Aboveground biomass is typically estimated using allometric equations developed for trees in the natural forests. But, they generally lack accuracy either because of their very location‐specific or much “generalized” nature (Kumar et al., 1998a). A major difficulty in estimating the area under agroforestry is lack of proper procedures for delineating the area influenced by trees in a mixed stand of trees and crops. In simultaneous systems, the entire area occupied by multistrata systems such as homegardens, shaded perennial systems and intensive tree‐intercropping situations can be listed also as agroforestry (Nair et al. 2009).

Increase the sources of food and water which guarantees a reliable access to adequate food year round. Prevent soil erosion and lost nutrient to bring better levels of productivity. Integrating pulses in crops can contribute to improving the nutritional balance of food intake to poor people that have a mono‐diets which is associated with poor nutritional outcomes (FAO 2016e).

Nutrient use efficiency ‐ NUE (Nitrogen and organic inputs use efficiency including N fertilizers, compost, manure, etc) ‐ Fertilization management

Globally. A metanalysis of 78 published studies (233 site‐years) with three N‐input levels, found that the N2O response to N inputs grew significantly faster than linear for synthetic fertilizers and for most crop types (Shcherbak et al. 2014). N‐fixing crops had a higher rate of change in Emissions Factor (ΔEF) than others. A higher ΔEF was also evident in soils with carbon >1.5% and soils with pH <7, and where fertilizer was applied only once annually. These results suggest a general trend of exponentially increasing N2O emissions as N inputs increase to exceed crop needs. Brazil. Pires et al. (2015) found that the emissions derived from N fertilization in cereal production represent 27% of the total synthetic fertilization emission contribution from the Brazilian agricultural sector in 2010. Based on current fertilizer use and production rates, a 2.39% hypothetical increase in N use efficiency (NUE) would lead to 50531 ton savings in N fertilizer, which accounts for $ 21 million savings in N fertilizer expenditure. Bernoux et al. (2003) presented a first estimation of net CO2 fluxes from liming of agricultural soils in Brazil for the period of 1990‐2000, whit annual CO2 emissions variying from 4.9 to 9.4 Tg CO2 yr‐1 and a mean CO2 emission of about 7.2 Tg CO2 yr‐1. The south, southeast, and center regions accounted for at least 92% of total emission (Cerri et al. 2010). Pires et al. (2015) analized the evolution and consumption of nitrogen N fertilizers in the Brazilian production of the seven major cereal crops (rice; wheat; corn; oats–Avena sativa L.; rye–Secale cereale L.; barley–Hordeum vulgare L.; and sorghum–Sorghum bicolor (L.) Moench) and correlation of NUE with economic and environmental losses as N2O emissions. Their results showed that the increased consumption of N fertilizers is associated with a large decrease in NUE in recent years.

Using organic fertilizers, green manure, legumes such as cover crops, manuring, and balanced fertilizer application can help maintain and restore soil health and fertility (Tilman et al 2002), potentialy increasing crop yields and vigor which helps to increase tolerance to climate issues (Vignola et al 2015).

Avoid soil erosion, improve organic matter.Save the quality of source of fresh water.Integrated soil fertility management, combined with rainwater harvesting, and soil and water conservation on slopes, could improve rainfed yields (FAO 2011).

Nutrient management approach is sensitive to changes in climatic conditions and could produce negative effects if soil and crop nutrients are not monitored systematically and changes to fertilizer practices made accordingly. Access to mineral fertilizer may be limited in rural or underdeveloped areas due to high import prices and high transport costs, meanwhile the access to organic fertilization sources implies additional manual labor sometimes limited for small farmers. A lack of adequate infrastructure for distribution and conservation can also present a barrier for access and use of more sustainable fertilization sources. Further research is needed to study the effects of this in natural resources according to regional and local levels (Mulvaney et al. 2009).

Improve human and animal health. Protect the source of clean water. Reduce spending in fertilization that results in a cost save for farmers.



Tillage/residue management (Incorporation of crop residues and reduce minimun/zero tillage) ‐ Agronomy practices

Globally. West and Post (2002) found that an enhancement in rotation complexity, can sequester an average 20± 12 g C m‐2 yr‐1, excluding a change from continuous corn (Zea may s L.) to corn‐soybean (Glycine max L.)which may not result in a significant accumulation of soil organic carbon (SOC) (Cerri et al. 2010). Corn–soybean rotations, with a change from CT (under tillage) to NT (no tillage), resulted in the highest C sequestration (90 ±59 g C m ‐2 yr‐ 1 ) of all monoculture and rotation cropping systems (West and Post 2002). Brazil. The conversion from FT (full tillage) to NT systems represents in Brazil a net CO2 uptake rate of 1.91 Mg CO2–eq ha–1 yr–1 (Cerri et al. 2010). The GHG emissions (expressed as CO2–eq.) from agricultural operations (machinery) in NT areas are only 34% of the emissions in FT systems. Moreover, the SOC is a sink of atmospheric CO2, at a rate of 1.98 Mg CO2–eq ha–1 yr–1. In Brazil the rate of C accumulation has been estimated in the two main regions under no‐tillage systems (south and centre‐west regions). In the southern region Sá (2001) and Sá et al. (2001) estimated sequestration rates of 0.8 t C ha‐1 yr‐1 in the 0‐20 cm layer and 1.0 t C ha‐1 yr‐1 in the 0‐40 cm soil depth (Cerri et al. sf). Bernoux et al. (2006) reported that most studies of Brazilian soils report rates of carbon storage in the top 40cm of the soil of 0.4 to 1.7 t C ha‐1 per year, with the highest rates in the Cerrado region. In the Cerrado and pasture Brazil Corbeels et al. (2016) studied the response of soil C stocks to the NT cropping systems in maize and soybean and the duration of soil C sequestration under continuous NT systems. The authors found that the average annual rates of soil C sequestration estimated using the chronosequence approach were respectively 1.61 and 1.48 Mg C ha−1 yr−1 for the 2003 and 2011 sampling. The diachronic sampling revealed that the younger NT fields tended to show higher increases in soil C stocks than the older fields. Converting an extra 8 million ha of cropland from CT to NT represents an estimated soil C storage of about 8 Tg C yr−1 during 10 to 15 years. Considering the 2010‐2020 period, the conserva on management of sugarcane residues has the potential to sequester 404 Mt CO2‐eq under the Nacional Energy Program (NEP) scenario, and 619 Mt CO2‐eq under the NPCC scenario in the form of soil carbon in the first 30 cm. Zanatta et al. (2010) measured the cover crops management (oat ‐ O and vetch ‐ V) under tillage (CT) and no tillage (NT) in a silt loam Acrisol in South Brazil. The authors found that the N2O emissions increased in the presence of crops residues and were further increased in NT V/M in 2007 (193±84 µg N/m2 /ha) and in CT V/M in 2008 (431±138 µg N/m2 /ha) and they are related to high water content and available soil nitrogen. Smallest fluxes of N2O were measured from the NT O/M treatments, which 288±61 µg N/m2 /ha in 2007 and 274±19 µg N/m2 /ha in 2008. In Paraná, Brazil. M. Sá et al. (2001) analized the chronosequence of six treatments: (i) native field (NF); (ii) 1‐yr plow conversion of native field to cropland (PNF‐1); (iii) no‐tillage for 10 yr (NT‐10); (iv) no‐tillage for 20 yr (NT‐20); (v) no‐tillage for 22 yr (NT‐22); and (vi) conventional tillage for 22 yr (CT‐22). The authors found that the C sequestration rate for no‐tillage was 80.6 g C m−2 yr−1 for the 0‐ to 20‐cm depth and 99.4 g C m−2 yr−1 for the 0‐ to 40‐cm depth. The no‐ llage C sequestra on poten al for South Brazil was es mated as 9.37 Tg C yr−1 (M. Sá et al. 2001). Argentina. Alvarez et al. (2012). N2O emission measurements ranged between 1.09 and 2.41 kg N2O–N ha‐1 year‐1. Overall annual emissions were higher in Reduced tillage (RT) than in NT, the highest corresponding to sy–mz (A). This shows the effect of nitrogen fertilization during the corn growing season, the only N‐fertilized treatment. The lowest annual N2O–N emissions corresponded to sy–mz NT (B), which had values similar to those of the control treatment.

Potentially maintenance or incresing crop productivity and reduce the biophysical impacts of extreme weather events in face of climate change (Vignola et al 2015, 2017) through the increase, maintain and restore of soil fertility, the reduction of soil erosion and microclimatic stresses due to temperatures variability (Tilman et al. 2002; Mueller et al. 2012).

Reduced/zero tillage (often in combination with mulching) will in fact increase water availability to plants improving the capacity of the soil surface to intercept rainfall (by affecting the hydraulic conductivity of the topsoil, soil roughness (Branca et al. 2011). No‐till and reduce tillage systems prevent soil erosion (Cassman 1999). Promotes watter conservation and avoid the damage to micro and macro fauna. Cost and labor savings (Corbeels et al. 2016).

Management alternatives to replace machinary often used to till the land. The inequitable land distribution or lack of access of land for small scale farmers prevents them for adopting new and sustainable agriculture systems. Applied research to adapt conservation tillage technologies for use in unfavorable rain‐fed systems in developing countries. No economic instruments to promote NT as a mitigation strategy (Corbeels et al 2016).

Potential for increase the productivity, thus has a potential increase of the access of food and water, having a large positive impact on local food security and increased standards of living of rural areas (Cassman 1999).

Water use efficiency (efficient water supplies for farm irrigation systems i.e., regular drainage in rice water management) ‐ Water management

Brazil. Sass et al. (1992) and Yagi et al. (1996) reported that regular drainage may represent the most efficient method to minimize emissions in Brazil. The authors found that a single drainage during the rice growth phase reduced methane emissions by 50% (Cerri et al. 2010). Considering that the area under irrigated rice will remain constant until 2020 and that permanently flooded areas would revert to periodically drained systems (Sass et al, 1992; Yagi et al., 1996), emissions could be reduced from the 5.4 Mt CO2‐eq (BAU scenario) reported by Cerri et al. (2009) to 2.9 Mt CO2‐eq annually, totaling the emission reduction of 25 Mt CO2‐eq for the 2010‐2020 period (Cerri et al. 2010). The emissions accounted for 1.2% of the total emissions (467 Mt CO2‐eq) from Agriculture sector in 2005 (Cerri et al ., 2009). Colombia. Andrade et al. (2014) found a total emission of 998.1 ± 365.3 kg CO2e/ha/cycle (163.3 ± 55.8 kg CO2e/t) in the rice production in Campoalegre, Huila, having nitrogen fertilization being the greatest contribution (65%).

Relevant to maintain water availavility to reeduce the impacts of water scarcity and variability (Vignola et al 2017). Access to agricultural water through small‐scale water storage projects, recycling and re‐use of water, and irrigation programs for small scale farmers, reduces the incidence and severity of poverty and enables households to improve and stabilize crop productivity, grow high‐value crops, generate high incomes and employment, and earn a higher implicit wage rate (FAO 2011).

Reduce the ecological footprint of production, distribution, and consumption practices, thereby minimizing GHG emissions, soil and water pollution (Altieri et al. 2012). According to FAO (2011) the irrigation systems and infrastructure can provide further services, such as provision of potable water supply (formal and informal).

Global warming is expected to increase the frequency and intensity of droughts and flooding in subtropical areas (FAO 2011). The high cost of irrigation systems. Inequitable land distribution: irrigation’s impact on poverty is highest where landholdings (and thus water) are equitably distributed (World Bank, 2008 in FAO 2011). Reduce investment in such water‐efficient technologies, facilitated when water is valued, and priced appropriately (Tilman et al 2002).

Save natural resources such as water for avoiding its contamination and sustainable use (Tilman et al 2001). Improve food and water security and therefore potential for enhance human health. It has to consider the access of economic resources for investment of farmers (Mueller et al 2012).



Control of soil erosion (i.e., methods to prepare land, compost use, etc.) ‐ Soil management

Globally. The soil C pool comprises soil organic C (SOC) estimated at 1550 Pg (petagram)= 1015 g = 1 billion ton) and soil inorganic C approx. 750 Pg both to 1 m depth (Batjes, 1996). This total soil C pool of 2,300 Pg is three times the atmospheric pool of 770 Pg and 3.8 times the vegetation pool of 610 Pg; a reduction in soil C pool by 1 Pg is equivalent to an atmospheric enrichment of CO2 by 0.47 ppmv (Lal, 2001 in Nair et al. 2009). Chile. Huerta et al. (2012) evaluated conventional and organic methods using life cycle assesement (LCA) in the Chilean wheat the results identified soil management as the stage of conventional production that generates the greatest environmental impact; the most affected impact categories were acidification, with 15.28 kg SO2 equivalent per ton of grain produced, and eutrophication, with 4.83 kg PO4 eq/ton of grain. The category most affected by organic production was soil management, mainly due to the Diesel fuel used in agricultural machinery. In this production method, the category of abiotic resource depletion had the greatest impact, with 0.89 kg Sb eq/ton of grain. The use of compost as a strategy fixed important amounts of biogenic carbon, generating environmental benefits in the impact category of climate change –4.39 kg CO2 eq/ton of grain.

Maintains or improves crop productivity and reduces the biophysical impacts of extreme weather events (Vignola et al 2015) avoiding the losses of nutrients and increasing nutrient use eficience that otherwise would enter surface or ground waters (Tilman et al 2002).

Improve organic matter, quality of soils, productivity and quality of fresh water. Reduce the effects of land degradation on productivity which can sometimes be compensated for by increased fertilization, irrigation, and disease control, which increase production costs (Tilman et al 2002).

Formal and informal land tenure systems in Latin America. Modern laws have rarely defined or protected communal rights which traditional knowledge for soil managements to control erosion. In some situations, this has led to progressive dispossession and inequity in land distribution resulting in unappropriate soil management practices (FAO 2011). Erosion can be severe on steep slopes where windbreaks have been cleared, vegetative cover is absent during the rainy season, and where heavy machinery is involved in land preparation (Tilman et al 2002).

Increase in food availability through the rise of crop productivity due to avoiding soil degradation, promoting C sequestration and improving the quality of products due to a higher organic matter of soil (Lasco et al 2014). Help to maintain and restore clean water for animal and human consumption.

Land use change ‐ LUC (i.e. set aside, change crops and land use, relocation of crops, reforestation, etc.) ‐ Land use management

Globally. Ruddiman (2003) estimated that the emission from land‐use conversion during the postindustrial era (i.e. 200 years), using 0.8 Gt C yr–1 (or2.93 Pg CO2 yr–1), at 160 Gt C (or 587 Pg CO2). Using an average soil C sink rate of –2.93 Pg CO2 yr–1 during 1961–2015, the total soil C sink is about –161.2 Pg CO2. Lal (2004a and 2004b in Song et al. 2013) estimated a high and attainable soil C sequestration potential of 0.55 Gt C yr–1 (or 2.02 Pg CO2 yr–1) for global croplands assuming judicious land use and recommended management practices (RMPs) were taken up world‐wide. Taking an average soil C sink rate of 2.02 Pg CO2 yr–1 during 2016–2100, the total soil C sink is about 171.7 Pg CO2. Nair et al. (2009) assessment of LULUCF mitigation options suggests that the global potential for biologically feasible afforestation and reforestation activities between 1995 and 2050 could average 1.1 to 1.6 Pg C y–1, 70% of which would be in the tropics (IPCC, 2000). The direct effects of land use and land‐use change (including forest loss) have led to a net emission of 1.7 Gt C yr−1 in the 1980s and 1.6 Gt C yr−1 in the 1990s (Watson et al. 2000; Bellamy et al. 2005 in Nair 2009). Latin America. According to Niles et al. (2002) the average carbon mitigation via forest restoration for the years 2003–2012 was 177.9 (MtC). The estimation of carbon mitigation for avoided deforestarion was 1 097.3 (MtC). The potential of carbon stored in the diverse LU however will depend on species composition and forest characteristics (Esquivel et al 2018. in prep.).

Forests provide local ecosystem services that reduce societies‘ vulnerability to climate change (Locatelli et al 2011). Reforestation can protect productivity of agricultural lands by mitigating dry land salinity, favouring water availability and reducing soil erosion when sited strategically within the catchment or landscapes to reduce salt export and manage deep drainage (Cowie et al 2007) and the biodiversity in conservation areas if they reduce pressures on natural forests by serving as sources for forest products (Locatelli et al 2011). Including native and multiservice trees would promote several ecosystem services like nutrient cycling, pollinization, pest control, etc. to maintain agricultural productivity in multifunctional landscapes (Esquivel et al 2018. in prep.). Restoring degraded lands and native forests through assisted and natural regeneration, establishing plantations on non‐forested lands; and managing forests sustainably can provide additional sources for local biomass energy (Niles et al. 2002).

Farmers would be compensated for the C they sequester, based on the quantity of C sequestered and the market price of C and would benefit from any gains in productivity associated with the adoption of C sequestering practices (Nair et al. 2009). These projects can theoretically contribute to income generation, poverty reduction, biodiversity conservation, and environmental preservation (Nair et al. 2009). The net mitigation benefit of afforestation or reforestation projects can be increased through utilization of forest biomass for bioenergy, thereby providing ongoing mitigation through avoidance of fossil fuel emissions (Cowie et al 2007).

The impact of afforestation/reforestation on net GHG emissions, biodiversity, and desertification is dependent on the features of the forest system established and the land use that it replaces (Cowie et al 2007). Design of planting schemes to make trade‐offs between generating ecological services (e.g., C sequestration) and goods (e.g., timber) is indeed a major silvicultural challenge (Nair et al. 2009). Potential trade‐offs can be observed between global ecosystem services, such as the carbon sequestration relevant for mitigation, and the local ecosystem services that are relevant for adaptation. Few climate change or forest policies have addressed these linkages in the forestry sector (Locatelli et al 2011).

The recent sharp increases in fuel prices and concerns over energy security are added incentives for expansion of non‐food crops at expenses of food security (Cowie et al 2007). Greater availability of wild food and water, avoid loss of habitat of flora and fauna, and increase of ecosystem services like pollinization for dependent food crops. Prevents flooding and represents an advantage when there are long periods of drought regulating microclimatic conditions inside agricultural landscapes.



Production of Clean Energy (i.e., use of energy crops and crop residues to produce Bioenergy, Biofuels or Biogas) ‐ Waste management

Globally. Lal (2005) the amount of crop residue produced in the world is estimated at 2802×106 Mg/year for cereal crops, 3107×106 Mg/year for 17 cereals and legumes, and 3758×106 Mg/year for 27 food crops. The fuel value of the total annual residue produced is estimated at 1.5×1015 kcal, about 1 billion barrels (bbl) of diesel equivalent, or about 8 quads for the US; and 11.3×1015 kcal, about 7.5 billion bbl of diesel or 60 quads for the world. Brazil. Macedo et al. (2007) analyzed the energy balance and GHG emissions in the production and use of fuel ethanol from cane. The authors found that for anhydrous ethanol production the total GHG emission was 436 kgCO2 eqm 3 ethanol for 2005/2006, decreasing to 345 kgCO2 eqm 3 in the 2020 scenario. Avoided emissions depend on the final use: for E100 use in Brazil they were (in 2005/2006) 2181 kgCO2 eqm 3 ethanol, and for E25 they were 2323 kgCO2 eqm 3 ethanol (anhydrous). Both values would increase about 26% for the conditions assumed for 2020 mostly due to the large increase in sales of electricity surpluses. Argentina, Brazil, Chile, Colombia, Costa Rica, Ecuador, Mexico, Paraguay, Peru, and Uruguay are using or producing biodiesel, ethanol, or biogas and most of these countries are using bienergy in their energy matrix (FAO 2013c). Mexico. The biomass power has an installed capacity of 548MW in operation, 40MW are from biogas and the rest from sugarcane bagasse biomass. A potential production of bioenergy is estimated between 2635 and 3771PJ/year. The 77.9% would come from solid biomass such as Eucalyptus plantations, agroindustrial waste and crop residues, 20.1% from liquid bioenergetics (from sugarcane, Jatropha curcas and palm oil) and 2% from biogas (from municipal solid waste and cattle manure) (Alemán‐Nava et al. 2014).

An additional source of energy available from agricultural lands to reduce the dependence on fossil fuels in the food supply chain. However the variable near and long term impacts dependent on bioenergy crop species, crop management, soil conditions, and global region.

The use of legume biomass for bioenergy, materials, and chemicals represents a significant trade‐off since the contribution of legume residues to soil organic fertility and C sequestration would be significantly reduced (Jensen et al. 2011).

The externalities of producing biofuels from cereals are mainly to compensate the use of fossil fuel. Reduced SOC due to increased biomass removal and soil disturbance, especially for annual crops, increased fertilizer requirements to replace additional nutrients removed. The degradation of soil, air, and water resources by chemical based cereal production will likely intensify if crop residues are used as a bioenergy feedstock, a practice increasingly advocated for short‐term economic gain by the public and private sectors (Mulvaney et al 2009).

More research is needed to know the effects in natural resources (i.e., land change use for produce cereals for biofuel as in the case of Brazil, Argentina, Colombia, and Mexico). Potential of air and water pollution from the productions of bioenergy. Although, it could benefit people for provinding an alternative source of no fossil derived energy for the food consumption.

Reduce post‐harvest losses (i.e., storage and conservation, transport, procesing, and packaging, households) ‐ Waste management

Globally. About 3.3 Gtonnes of CO2 equivalent emissions have estimated due to food that was produced but not eaten, without even considering the land use change (FAO). The blue water footprints (water use during life cycle of food) for the wasted food globally was estimated to be about 250 km3 [14,17] (Kumar and Kalita 2016). Peru . Postharvest losses of wheat and maize for Peru in 2012 were 15‐25%. Guatemala. St orage losses were estimated between 40% and 45% due to a lack in storage structures along with the region’s high humidity. Ecuador. In 2012 the postharvest losses of maize for Ecuador was 15‐30%, mainly due to insect infestation during storage. Panama. Major losses at the small‐scale level farm due to a lack of adequate technology in Panama reach 20% (Kumar and Kalita 2017).

Reduce the vulverability of cereal productivity and increase food security provision and quality through the prevention of biodeterioration of cereals or Good Agricultural Practices, which should be used to facilitate stored commodities to be effectively conserved with the minimum loss in quality. Practices like the accurate and regular moisture measurements, efficient and prompt drying of wet cereals, storage in hygenic environment and proper monitoring in storage, and the use of natural insecticides and hermetic storages (Sharma and Bhandari 2014) can improve efficiently the storage and transportation of cereals from farms to market, reducing the use of limited natural resources like water and energy, reducing the contamination of food and environment.

Social and environmental benefits provided by food loss reductions. Saving the cereal crop lost during postharvest operations can help in meeting the food demand and reduce the load on the economy (Kumar and Kalita 2017).

Lack of mechanization, bad weather conditions, lack of capital, information and resources, inadequate storage facilities, poor handling facilities and inadequate market structure and policies (Kumar and Kalita 2017). Synthetic insecticides are used in several countries and play an important role in controlling the pests and reducing losses during storage of grains (Kumar and Kalita 2017). Innovation and adaptation of technical solutions to local conditions are essential for success. Cold chain management in perishable foods supply chains offers a very good example of potential solutions and what is needed to implement them in locally adapted ways (HLPE, 2014). The investment in equipment, infrastructure, and education is necessary to avoing loss of production and waste.

Increase food security and quality. Greater available food will be provided for people if loss and waste is avoided. Potential of improving the quality of food and water for human and animal populations, and the quality of environment for other food production.

Appendix: Methodology

Authors used a systematic approach to review the peer reviewed literature for mitigation opportunities along food systems. The approach followed five main phases and nine methodological steps.

Phase 1. Definition of variables and criteria

1. Identification of important food production systems globally. Cereals, horticulture and livestock were identified as important food systems according to previous reports data which highlighted it relevance for food security and as focus of GHG emissions worldwide (Burney et al. 2010; FAO 2016 a,b; Gerber et al. 2013; Herrero et al. 2013 and 2016; IPCC 2007; Jensen et al. 2012; Leff et al. 2004; Smith et al. 2007 and Weinberger & Lumpkin 2007). Fisheries and aquaculture are important production systems, but are not included in this report.

2. Identification of major food production systems across global regions. Authors made a first attempt to identify food systems categories across four selected regions: Central and South America (CSA), North America (NA), South Asia (SA) and Africa (A) based on existing food production systems reports for Cereals, Horticulture (Dixon et al. 2001) and Livestock (Steinfeld and Mäki‐Hokkonen 1995). Major food production systems were defined in terms of coverage (percentage of population, food exports and imports, percent of employment in agriculture), use of resources (area harvested) and GHG emissions from Agriculture, Forestry and other Land of Use (AFOLU) for each of the four selected regions.

Phase 2. Search of technical and scientific information

3. Literature review of mitigation opportunities. A list of potential mitigation opportunities along the three food production systems and four selected regions was developed based on recent scientific and technical literature available until April 2017. Searches were conducted using key words regarding quantification of emissions from food systems worldwide (i.e. mitigation, GHG emissions, livestock, cereals, horticulture, CO2 quantification, Carbon foot prints, Life cycle assessment, etc.) in common scientific and technical database networks (i.e. Google Scholar, Cab Direct, Springer, Elsevier, FAOSTAT, World Bank, International Labor Organization, etc.). Peer‐reviewed journals papers, national and international technical reports, books, and research dissertations were included and are listed in the reference section for consultation.

4. Identification of opportunities with mitigation potential. Across the literature review, opportunities were identified with any quantitative or at least qualitative attempt to measure mitigation potential over the emissions of one or several greenhouse gases (Carbon dioxide (CO2), Methane (CH4) and Nitrous oxide (N2O)).

5. Identification of co‐variables associated to mitigation potential interventions. In addition to the mitigation potential, the co‐benefits, challenges and adaptation potential related with the implementation of the described opportunities, were reported when any qualitative description provide by the cited literature or in consultation with external experts.

Phase 3. Classification of the opportunities along the food systems

6. Identification of mitigation potential opportunities along food systems components and stages. The interventions with mitigation potential were addressed along the five different stages identified for the food systems: Pre‐production, Production, Post‐production, Consumption, and Waste. The interventions were also organized according to the particular stages (i.e. agronomy practices, grazing management, manure management, waste management, etc.) where interventions are expected to take place inside each food system component (i.e. inside Production stages).

7. Identification of mitigation potential opportunities across global regions. Interventions with quantified mitigation potential were also classified into the four previously selected global regions according the countries where measurements takes place. Data from Argentina, Belize, Bolivia, Brazil, Chile, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Guyana, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Suriname, Uruguay and Venezuela, were available for Central and South America (CSA); data from India was available for South Asia (SA); data from USA and New Zealand were grouped as North America (NA); and data from Burkina Faso, Mali, Niger, Senegal, Ghana, Nigeria, Kenya, South Africa, Tanzania, and Uganda was available for Africa (A).

Phase 4. Identification of main patterns for intervention with Mitigation Potential

8. Analyses of the distribution of the number of interventions across food systems components. The resulting literature included over 160 potential interventions for mitigation along the three food systems and the four global regions. The number of interventions with any mitigation data were described in terms of the amount of research, expert confidence, cost estimate, implementation time, and scale and action category were summarized based on the specific information by region in consultation with other experts.

Phase 5. Input from Global Scientific and Technical Stakeholders

9. Presentation of the opportunities for mitigation along food systems in an international dialogue. The mitigation opportunities were presented during the 2nd International Dialogue: The Future of Food in a Climate Changing World a Climate Changing World organized by The Global Alliance for the Future of Food on 2‐3 May 2017.

Suggested Citation: Niles, M.T., Esquivel, M.J., Ahuja, R., Mango, N., Duncan, M., Heller, M., Tirado, C., 2017. Mitigation opportunities and their adaptation potential inside cereal and food system activities. Climate change and food systems: assessing impacts and opportunities. Meridian Institute. Washington, D.C.

potential opportunities in cereals production - merid.org/media/files/projects/ccfs/cereals...

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