Soils and Pulses: symbiosis of life

Eduardo MansurDirector, Land and Water Division

Healthy soils are the basis for healthy food production

Soils are the foundation for vegetation cultivated or

managed for feed, fibre, fuel and medicinal products

Soils support our planet’s biodiversity; they host a

quarter of the total

Soils help mitigate and adapt to climate change; plays a key role

in the carbon cycle

Soils store and filter water, improving resilience to floods

and droughts

Soil is a non-renewable resource, its preservation is

essential for food security and a sustainable future

Our soils are under threat!

Nutrient imbalance• Lack of soil nutrients (especially nitrogen

and phosphorus) is one of the greatest obstacles to improving food production in degraded landscapes.

• In Africa, all but a few countries take more nutrients from the soil every year than are returned through use of fertilizer, crop residues, manure, and other organic matter.

• In some industrialized countries, oversupply of nutrients contaminates soil and water resources and contributes to greenhouse gas emissions.

• In 2010, nitrogen oxide emissions from agricultural soils caused by the addition of synthetic fertilizers were the equivalent of about 680 million tones of CO2.

Nutrient availability in soils

Pulses: important for humans and soils

Pulses are:

Soils and Pulses• Since millennia farmers have been aware of the positive link between pulses

and soil health. Pulses require healthy soils, which in turn get healthier.

• The Roman publication Rerum Rusticarum (Varro 37 BC) recommended to plant pulses because of their benefits to soil health.

• Native Americans have been using for centuries the so-called Three Sisters (cultivating beans, maize and squash together

• In many countries, pulse crops have been displaced to marginal environments, mostly by cereal crops

• In many regions of the world yields are very low due to the lack or low bioavailability of soil nutrients.

• Many smallholder farmers cannot afford to use fertiliser.

• Remarkable feature of pulses: ability to form symbiosis with some soil bacteria.

• Pulses have the potential to improve soil health through:1. Nitrogen input from Biological Nitrogen

Fixation (BNF).

2. Phosphorous input from P-mobilizing pulse species.

3. Recovery of nitrate from deep soil layers (pulse trees like Pigeon pea).

Soils and pulses: symbiosis of life. Why?

• 50 Million metric tonnes of nitrogen are fixed annually through BNF

• Around 30% of the nitrogen input in Africa and South America comes from BNF

• Especially important for farmers who cannot afford the use of fertilizers.

Soils and pulses: symbiosis of life, why?

• Pulses, when cultivated in rotation/intercropping, are responsible for increasing soil microbial populations.

• Pulses improve structure, composition and diversity of soil biota.

• Pulses are crucial component of multiple cropping systems (e.g., intercropping, crop rotations); therefore, these systems need to be promote as soil friendly.

Integration between International Years

Healthier soils and more pulses for:

• Food security and nutrition

• Climate change adaptation

• Poverty alleviation

• Provision of ecosystem services and biodiversity.

• In recognition of their contribution to sustainable development, the UN General Assembly declared 2016 as the International Year of Pulses.