The importance of soils for food security

Professor R Jane Rickson Cranfield Soil and AgriFood Institute

April 22nd 2015

Outline of the presentation

1. The global challenges ahead

2. The importance of soils

3. Threats to soils

4. Soil management for healthy soils and food security

5. Evidence needed to inform policy

6. Take home messages

1. The global challenge ahead

UK Government Chief Scientific Officer’s Foresight Report (2011) ‘The Future of Food and Farming: Challenges and choices for global sustainability’ Population growth: 8 billion by 2030; probably >9 billion by 2050.

Global food production must increase by 3% annually to 2030 (Watts, C. Agriculture in High Growth Markets, Economist Intelligence Unit., London)

94% of all food originates from terrestrial environments (FAOSTAT, 2011)

The Foresight Report, Chief Scientific Officer, UK Government

1. The global challenge ahead

How to achieve this, given:

• Finite amount of land

Whole apple

% Planet earth

3/4 74% Water 1/4 26% Land 1/8 13% Uninhabitable to

humans 1/8 13% Habitable

3/32 10% Only suitable for non arable land

1/32 3% Suitable for arable < 1/32 peel Topsoil

74%

13%

9%

3%

-

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

1961 1965 1969 1973 1977 1981 1985 1989 1993 1997 2001 2005 2009 2013

Area of agricultural land ('000 hectares) (FAOSTAT)

Agricultural area

Arable land andPermanent cropsArable land

Permanent crops

1. The global challenge ahead

How to achieve this, given:

• Finite amount of land

• Competition with other land uses

– biofuels, urban development, infrastructure

Area (000 ha) under maize (forage, biogas and grain) in the UK (Source: Maize Growers Association, pers. comm.)

Photos courtesy of Nicola Geeson

1. The global challenge ahead

How to achieve this, given:

• Finite amount of land

• Competition with other land uses

– biofuels, urban development, infrastructure

• ‘Yield plateau’ – poor yield response to higher fertiliser use

UK national average wheat yields 1980-2011. Knight et al., 2012.

1. The global challenge ahead

How to achieve this, given:

• Finite amount of land

• Competition with other land uses

– biofuels, urban development, infrastructure

• ‘Yield plateau’ – poor yield response to higher fertiliser use

• Climate change and weather variability (and impacts on water [drought or drainage], crop production and land degradation)

SO MAYBE THE ANSWER IS IN THE SOIL???

2. The importance of soil for food security

• Healthy soils are able to "sustain plant and animal productivity”...and much, much more……

• Direct links with sustainability (economic, environmental and social pillars) • Human health and wellbeing (Millennium Ecosystem Assessment) • Individuals’ and national economic status

Ecosystem goods and services delivered by soil Examples

Provisioning of material goods and services

Agricultural production (food, fibre, fodder, fuel) Water storage and supplies Land for development (residential, industry, infrastructure)

Regulation of ecosystem processes

Flood control (water storage) Carbon storage (CO2 emissions: mitigate climate change)

Cultural, non-material services Landscape aesthetic Recreation / amenity, protection of heritage

Supporting services Habitats, biodiversity Soil formation

“The thin layer of soil covering the

earth's surface represents the difference between survival and

extinction for most terrestrial life.”

Doran and Parkin, 1994.

2. The importance of soil for food security

What makes a healthy soil? “Maintenance of the quality (physical, biological and chemical) and quantity of soil relative to the requirements of … food, fuel and material production, carbon sequestration and water regulation, so that the provision of soil ecosystem services is sustainable”

InnovateUK Knowledge Transfer Network (Environmental Sustainability) website: https://connect.innovateuk.org/web/in-situ-land-remediation/at-a-glance-soil-health

Soil quality and soil health are related to soil properties:

• Physical • Biological • Chemical

…and interactions between them: soil as a complex ‘system’ These properties can be improved…or degraded

WATER/AIR

ORGANIC MATTER

NUTRIENTS STRUCTURE

BIOTA

Soil Health: “The pivotal 5” (after Professor Karl Ritz, pers.comm)

3. Threats to soils and food security

• Soil degradation processes as identified in the EU Thematic Strategy for Soil Protection (2006)

• Estimated 12 million hectares of agricultural land are lost to soil degradation every year.

3. Threats to soils: consequences

• Irreversible loss of a natural resource (business asset?) e.g. loss of soil depth due to erosion

• Yield decline (quantity, quality and reliability; e.g. 20 million tonnes of grain per annum; UNCCD, 2011)

• Costs (e.g. re-sowing, nutrient replacement)

• True impacts on food production masked by unsustainable inputs – Irrigation – Chemical fertilisers

Degradation process

Annual agricultural production costs (£ million per annum)

Erosion £30 - 50

Compaction £180 - 220

Loss of organic matter £2

Diffuse contamination ?

Loss of soil biota ?

Soil sealing ?

TOTAL £212 - 270 From: Graves et al. (2011) The Total Costs of Soils Degradation in England and Wales. Final project (SP1606) report to UK Govt. Dept. Environment, Farming and Rural Affairs (Defra).

4. Possible solutions: Soil management practices for healthy soils and food security

1. Soil cultivation and tillage

2. Crop agronomy

3. Soil (organic) amendments

+ 14 minutes rainfall

4. Possible solutions: Soil management practices for healthy soils and food security

1. Soil cultivation and tillage

Conventional v conservation practices (reduced tillage, minimum till, strip tillage, zero till – maintain good seed bed, organic matter, soil structure, soil biology)

+ 14 minutes rainfall

Courtesy of Professor Karl Ritz

Case study: Conservation tillage and food production (Hollands and Dummett, 2015)

Tillage treatments: A Subsoiler B Strip till system (StripCat)

02000400060008000

1000012000140001600018000

Strip-till, sprayedN, with a

companion crop

Strip-till, sprayedN, without a

companion crop

Subsoiler,sprayed N,without a

companion crop

Subsoiler,sprayed N, with acompanion crop

Strip-till, banddrilled N and P,

without acompanion crop

Mea

n N

umbe

r of P

ods (

per m

²)

Mean Number of Pods per m²

Treatments Independent

Variables Subsoiler

Stripcat Tillage

Sprayed

Band Drilled

Fertiliser

Companion Crop

No Companion Crop

Companion Cropping

Dependent Variables

Pods

Leaves

Dry Biomass

Branches

4. Possible solutions: Soil management practices for healthy soils and food security

2. Use of crop agronomy for better soil management – Rotations – Cover and companion cropping – Break crops (deep rooting species) – Nutrient replenishment (e.g. N fixing legumes) – Grass waterways (erosion and runoff control)

N.B. Eligible for Basic Farm Payment under CAP reform and ‘greening’ rules

Crop Root Type

Root traits expected to improve soil structure

Wheat D Fibrous vigorous deep roots

Rye D Deep fibrous roots

Oats D Aggressive deep roots

Italian ryegrass

F Fibrous root system

Lucerne E Deep and aggressive rooting

Phacelia F Prolific root system but more confined to surface

Fodder radish

T Tap root, long and extensive root hairs on laterals

Chicory T Tap root

Sweet clover

E Vigorous and extensive multi-order lateral branching,

Field bean E Large, strong roots

Lupin E Tap root

(Ritz, 2014)

4. Possible solutions: Soil management practices for healthy soils and food security

T D F E T D F E

Radish Mustard

Turnip Rape

Cranfield University PhD study (Agnese Mancini): Cover crops for soil erosion and runoff control in forage maize

4. Possible solutions: Soil management practices for healthy soils and food security

3. Soil (organic) amendments – Green manures (cover cropping) – Composts – Mulches – Sewage sludge – Digestate from AD plants

Increase organic matter content, carbon, soil biota

Improve soils structure and resilience

Effects will be specific to materials used and sites (weather, soil type, etc)

http://www.biogen.co.uk/The-Biogen-Difference/The-Closed-Loop

Case study: Application of organic waste to restore soil health and productivity of a degraded soil Benedict Unagwu

Increase crop yield?

Poultry manure

Mushroom compost

PAS compost (green waste)

Anaerobic digestate

Improve Soil Quality?

Amendment effects on maize height and biomass

20

control

10 t ha-1 PM

At 3 weeks after planting

10 t ha-1 MC

At tasseling (9 weeks after planting)

5. Evidence needed to inform policy: Research priorities

• What is the extent, magnitude and frequency of soil degradation processes both now and in the future, given the uncertainties associated with climate change, extreme weather events, land use competition, and population growth and urbanisation?

• To what extent are other ecosystem goods and services affected by soil degradation?

• Can land management practices control and even reverse soil degradation processes?

• Where should these mitigation practices be targeted?

• What social, economic and political conditions are needed to facilitate the adoption and retention of soil protection measures for ‘soil security’?

6. Soil and food security: Take home messages

• Healthy soils deliver many goods and services, including food production, but can be irreversibly degraded

• Soil management can improve soil productivity and control degradation processes

• Cost effectiveness of practices will be site specific and must fit into current farming practices

• Ultimate goal is economically, socially and environmentally acceptable food production

= “sustainable intensification”

ORGANIC MATTER

BIOTA

NUTRIENTS STRUCTURE

WATER BIOTA

In conclusion…..

“The challenge for global agriculture is to grow more food, on not much more land, using less water, fertiliser and pesticides than we have historically done”

Sir John Beddington, former UK Government Chief Scientific Adviser, 2011.

Thank you for your attention

Professor Jane Rickson j.rickson@cranfield.ac.uk

+44 1234 750111 ext. 2705