Saving Soil for a Secure Future

In the previous article, we had discussed the importance of Adaptation measures in Agriculture, so that food security can be attained and the sector is shielded from the adverse effects of climate change. An important aspect of this Adaptation strategy will include soil conservation and regeneration. In addition to the long-practiced measures of soil conservation such as afforestation, control of overgrazing, better agricultural practices, contour and strip farming etc., there is a need to look at regenerating eroded soils and saline farmlands created by overirrigation. Not only does soil conservation and regeneration improve crop yields, it also increases carbon absorption and prevents carbon dioxide emissions. It thus offers Adaptation and Mitigation benefits. Let us discuss this further.

Soil Conservation and Regeneration

With each passing year, climate risks are increasing in general. This is true of climate risks to soil conservation and regeneration as well. In addition to the extreme heat and loss of soil moisture, there are increased instances of water logging, higher salinity, changes in pests and plant diseases, increased wind erosion and more wildfires. Accordingly, farmers have to go beyond the traditional conservation measures outlined above.

Some of the Adaptation measures that need to be taken are:

• Cover Crops: These are nitrogen-fixing crops that are introduced in the soil before planting the main crop. In addition to nitrogen-fixing, these crops (examples are legumes and oilseeds) also prevent runoff and soil erosion.
• Change cropping practices to include measures such as Crop Rotation and Intercropping, including Tree Intercropping. Crop Rotation involves planting a different crop on the same farmland each season. This replenishes soil nutrients (since different crops use different nutrients), improves pest control by disrupting their life cycles and prevents soil degradation associated with single crops. Intercropping involves growing 2-3 crops in close proximity on the same farmland and gives the same benefits as crop rotation. Tree intercropping is similar except that it involves planting trees, instead of other crops. The trees have an added advantage of working as windbreakers and preventing soil erosion. They also have deeper roots, which draws up more sub-soil minerals and nutrients as compared to crops.
• Better Water Management: Use of small earth dams to store water, watershed management, use of drip irrigation and sprinklers to conserve water, rainwater harvesting and use of micro-basins and micro-catchments to irrigate trees and bushes etc.
• Composting and Mulching: Vermicomposting and basket composting, which involve the breakdown of waste organic material to give bio-manure and mulching, use crop residue in the soil to reduce erosion.
• Nutrients and Supplements Such As Fertilizers and Manures: Use of mineral fertilizers and compost.
• Pest Control Management: Integrated pest control management by the use of bio-pesticides, use of disease- and pest-resistant crops, rotation of crops to provide disease breaks for susceptible crops, and use of non-chemical control practices (thermic, mechanical), including their genes or metabolites, for controlling pests.
• Ploughing Across the Slope, Contour Bunding and Terraces: Ploughing across the slope by following contour lines creates gullies that are perpendicular to the slope, rather than parallel, which prevents runoff of water; contour bunding involves the construction of stone bunds along contours that prevent erosion and improves water retention; terraces are built on steep slopes to prevent water runoff and erosion.

The Adaptation measures cited above have the additional advantage of being accessible to all sections of farmers, and involve technology that is easily accessible and easily applied, ensures the use of locally available resources, is not very expensive and generates employment. Since these measures require that farmers work together, they also increase local understanding among each other, leading to the building up of social capital.

Conclusion

Soil conservation and regeneration are key Adaptation measures in the Agricultural sector, which ensure that the adverse effects of climate change are minimised. Excessive and erratic rainfall, flooding, extreme heat conditions leading to drought: these take a toll on the soil by way of erosion, water runoff, loss of soil moisture, which, in turn, lead to a loss in agricultural productivity, ultimately affecting food security. The importance of soil conservation and regeneration can therefore be ignored at our own peril.

The writer is Additional Chief Secretary, Department of Cooperation, Government of West Bengal