Climate change impacts on soil health and their mitigation and adaptation strategies

Rajendra Prasad MeenaRoll no. 10592 (PhD 2nd Yr)

Division of agronomyICAR-Indian Agricultural Research Institute, New Delhi

Contents

Climate change

Soil health

Impacts of climate change on soil health

Mitigation and adaptation strategies

Research finding

Conclusions

2

According to IPCC (2007) “Climate change refers to a statistically significant variation in either the mean state of the climate or in its Variables, persisting for an extended period (typically decades or longer)”

2. SURFACE TEMPERATURE RUNNING THE HORSE RACE

3. CHANGING RAINFALL PATTERN

4. DECLINING OZONE LEVEL

SOIL HEALTH

Climate change……………?

Production

Soil Irrigation

Pests

Livestock

Fishery

Economic

14

Reduction in soil organic matter due to increase in temperature.

Increase atm. CO2 con. leads to wider C:N ratio in crop residues. This may be reduce the rate of decomposition and nutrient availability.

Increase soil temperature increase N mineralization but its availability decrease due to gaseous losses through volatilization and nitrification.

Rising of sea level may lead to salt ingression in coastal lands turning them less suitable for crop production.

Impact of Climate Change on Agriculture

5

Capacity of a specific kind of soil to function, within natural or managed ecosystem boundaries, to sustain plant and animal productivity, maintain or enhance water and air quality, and support human health and habitation.

Soil health…?

Soil Health Indicators

Physical Chemical Biological

Static or Inherent soil properties Mineral composition Soil texture Soil depth

Dynamic soil properties SOM Microbial biomass and diversity Soil respiration C and N mineralization

6

cont.…

SOC

Source of nutrient

Energy source

Microbial activity

Biodegradation

Ecosystem resilience

Water retention

Soil colour

Exchange capacity

Buffering capacity

Aggregate stability

Soil Health

Soil Organic Carbon: A Key Indicator Of Soil Health

Hence, appropriate SOM management is essential for maintaining or improving soil health in the context of

climate change

Lal., 2013

Impacts of climate change on soil health

CLIMATE CHANGE

Temperature Precipitation CO2 conc.. Atm. N deposition

UV – B radiation

Soil health

Qualitative Change

Quantitative Change

Quantitative change :

1. Stock2. Concentration

Qualitative change : 3. C/N ratio4. Functional group5. Acidity

8

Soil health indicators and process relevance to climate change

Soil organic matter fractionsMineralizable C and NTotal C and NSoil respiration, soil microbial

biomassMicrobial diversityPorosityAvailable water

Soil structure pH EC Available N,P and K

9Davidson and Janssens, 2006

Soil organic carbon Rate of soil organic carbon decomposition double with

every 10oC temperature.

SOC Pools Labial pool[particulate organic matter (POM), light

fraction organic matter] Slow pool (SOM within aggregates, humus) Recalcitrant pool (organic-mineral complexes, charcoal C,

phytolith C)

SOM dynamics under climate change…

10

Enzymatic depolymerisation

increase with warming

Increased temperature can lead to greater

enzyme production..

At warmer temperature

greater microbial

respiration and decrease

CUE.

Plant inputs

Available SOM

Depolymerisation

Assimilable SOM

Microbial death

Assimilation

Microbial biomass

CO2

Respiration

Soil Organic matterEnzyme production

Red arrows indicate that decomposition rates accelerate with increasing temperature and blue indicate that rates slow with warming temperatures. Richard et al ., 2004

11

Organic C pools and temperature-sensitive ecosystems

Organic Cstock (Gt C)

Turnovertime (years

Potential loss by2100 (Gt C)

References 

Upland soil (litter layer) 200 6 30 Jones et al. ( 2005)

Upland soil (1 m depth)        

Labile pool 20 6 3 Jones et al. ( 2005)

Slow pool 700 18 40 Jones et al. ( 2005)

Recalcitrant pool 100 1,000 0.1 Jones et al. ( 2005)

Permafrost (3 m depth) 400 4 100 Gruber et al. ( 2004)

Potential changes in organic C stocks in major pools in a simulated upland soil and a permafrost soil in response to global warming by 2100, and not accounting for the interactive effects of elevated [CO2], atmospheric N deposition and changes in precipitation .

modified from Davidson and Janssens 2006

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Increase in CO2 concentration by 40% since the industrial revolution (280 ppm in 1750 to 395.94 ppm in September 14, 2015)

Under elevated CO2 concentrations C3 plants respond with increased rates of photosynthesis, increased productivity and increased biomass (Ainsworth and Long 2005), especially under N inputs) and increased water availability (Housman et al., 2006).

Effect of elevated CO2 on SOC and SOC pools

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Time period  

B2 

A2 

 

 

CO2 (ppm)

Temperature rise (ı)

Rainfall rise (%)  

CO2 (ppm)

Temperature rise (ı)

Rainfall rise (%)  

               

Base line (1961–1990) 376 – – 376 – –  

2011–2040 429 0.9 3.7   440 1.4 3.3  2041–2070 492 1.5 7.0   559 2.6 7.0  2071–2100 561 2.0 10.2   721 3.9 12.9  

                  The climate change scenarios in the next decades in China (compared with the current climate).

SOC Change at 0–30 cm depth compared with 1980s under B2 scenario in the future in China.

Region Original SOC (t C/ha)

 Percentage change of SOC

 Net change of SOC stoc (t C/ha)   

    2020 2050 2080 2020 2050 2080  

                 

North China 36.5 −7.0 −13.8 −17.7 −2.6 −5.0 −6.5  

Northwest China 65.1 −5.4 −11.1 −14.0 −3.5 −7.2 −9.1  

Southwest China 69.5 −3.3 −8.5 −12.0 −1.8 −4.7 −6.7  

South China 55.9 −0.7 −6.1 −8.8 −0.5 −4.2 −6.1  

Average 64.7 −4.9 −10.3 −13.3 −2.7 −6.0 −7.8  

Wan et al., 2011

Climate change and change in SOC stocks

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Climate change and N dynamics….

BNF by legumes Atm. N deposition Fertilization Mineralization and immobilization Nitrification Fixation and release of NH4

+

Surface run-off Denitrification NH4 Volatilization Leaching

Input process

Transformation process

Loss process

Cont.….

15

50 40

30

20

10

0

Low N High N −10

Atmospheric N deposition

SOC

change (g C

m-2 yr-1)

Atmospheric N deposition

Effect of elevated CO2 on changes in soil C stocks under low N (<30 kg N ha-1 year-1) and high N (>30 kg N ha-1 year-1) supply

Hungate et al. ( 2009)

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Salinity alkalinity due to high evaporation demand.

Compaction and crusting due to rain drop impacts.

Increase BD due lack of OM.

Climate change and soil physical condition

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MITIGATION AND ADAPTATION STRATEGIES

So what`s the way out…….Decision tree for cropland GHG mitigating practices

CLIMATE SMART SOIL

Paustian et al., 2016

Potential of climate smart soil in reserving SOC

Paustian et al., 2016

Technological options towards climate smart soil

Paustian et al., 2016

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Option toward…

Conservation tillage Agroforestry and organic farming system Bulky organic manure and green manure Bio char application Legume in cropping system Integrated nutrient and water management Crop diversification and intensification

02468

101214161820

CT NT

SOC

(g

C k

g-1)

SWS WS CW

00.20.40.60.8

11.21.41.61.8

CT NT

SON

(g N

kg-1)

SWS WS CW

Wright and Hons, 2005

Soil organic C and N in NT vs. CT under different cropping systems

SWS= Sorghum-wheat-soybean, WS= Wheat- soybean,

CW= continuous wheat

More carbon convert in microbial biomass

Less runoff losses

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SOC and soil SON concentrations of corn and cotton cropping sequences for various tillage regimes and soil depth intervals.

Wright et al., 2005

Depth(cm) Disk-tillage No-tillage MB-plough till

0-5 13.1a 12.9a 10.5b

0-10 23.8a 24.4a 20.8b

0-20 43.8a 45.3a 39.3b

0-30 57.2a 59.8a 56.3a

0-40 65.6a 68.1a 64.4a

0-50 72.0a 74.8a 70.5a

0-70 81.4a 85.6a 81.0a

0-90 89.3a 93.5a 89.8a

Effect of tillage practices on SOC storage(Mg C/ha) of silt loam soil at Illinois

Yang et al., 1999 24

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Agroforestry system way for C-Sq

Effects of vegetative barriers on runoff, soil and N loss

Land use system Soil loss(t/ha)

Runoff % Nutrient loss(N%)

Eucalyptus – Bhabar grass 0.07 0.05 0.46

A. Catechu – forage grass 0.24 2.00 6.97

Sesame – rape seed 2.69 20.50 42.50

Poplar – Leucaena 1.54 4.80 5.90

Cultivated fallow 5.65 23.0 51.30

(Grewal, 1993) 26

Land use systems SoilpH

Organiccarbon (%)

Availablenitrogen (kg/ha)

Crop based system

-0.45 +0.7 +10

Eucalyptus based -0.67 +0.12 +21

Acacia based -0.63 +0.20 +31

Populus based -0.80 +0.17 +25

(Singh, 2011) 27

Influence of different tree-crop (berseem, rice and mustard) combinations on soil properties

Land use Dehydrogenase(μg/g)

Phosphatase(μg/g)

Cmic

(μg/g)

Sole cropping 12.3 10.0 186

Prosopis cineraria + crop 22.9 26.4 320

Dalbergia sissoo + crop 19.9 21.3 283

Acacia nilotica + crop 19.6 19.4 262

( Yadav et al., 2011)28

Soil biological properties under different agroforestry system

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Split application SRNF Urease inhibitors SSNIM 4Rs INM Nitrification inhibitors

Mitigation of N2O emission

Synchronize

Soil N Supply

Plant N Demand

•Fertilizer

•Manure •Residue

NH4+ Nitrosomonas NO-

2 Nitrobacter NO-

3

30Malla et al., 2003

Emission of N2O–N from fertilized soil with nitrificationinhibitors in rice and wheat

31

Mitigation of CH4 emission

Alternate wetting and drying soil (AWD) Growing DSR, ARS and SRI Improving organic matter management ( low C:N ratio) Develop new plant type through crop breeding

Deep rooted, low water req. variety More effective tillers and high root oxidative activit

Increase crop yield instead of area expansion Use SO3

- containing fertilizers eg- application of 6-7 t/ha of gypsum reduce 50-70% emission

32

Ca MC1b MC2c

Total CH4 flux ( g CH4 m-2) 31.47 10.09 11.93

Reduction in methane emission (%) - 64.15 60.07

Comparison of methane emission reduction between modified cultivation systems and conventional method.

aC: Conventional methodbMC1: Original system of rice intensificationcMC2: Modified system of rice intensification

33

SOC

Lal et al., 2013

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From the forgoing it is clear that climate change could impact

SOM and a number of processes that are strong determinant of

soil health.

To mitigate climate change effect, it is imperative that soil

health is maintained so that it can sustain physical, chemical

and biological function and provide ecosystem resilience.

Establishing climate smart soil management for cost

effective, sustainable climate change mitigation and adaptation.

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THANK YOU