Context: The Tamil Nadu government has recently distributed Dhaincha (green manure) under the Chief Minister’s Mannuyir Kaathu Mannuyir Kaappom (MKMK) Scheme. Farmers receive 20 kg of green manure per acre at a 50% subsidy to improve soil health.

About Green Manuring

• Green Manuring: Involves growing and incorporating leguminous plants into the soil. Benefits include improved soil structure, increased water retention, reduced erosion, weed control, and enhanced soil microorganism activity.

About Dhaincha

• Dhaincha, scientifically known as Sesbania bispinosa, is a tall, branched herb commonly used as a green manure crop in India.

• It is renowned for its ability to enhance soil fertility and manage nitrogen levels, making it a valuable component in sustainable agriculture.

How does Dhaincha Work?

• Dhaincha can produce up to 8-10 tonnes of biomass per acre, and is rich in organic matter and nutrients.

• The plant forms root nodules that fix atmospheric nitrogen into the soil, increasing nitrogen availability for subsequent crops.

• When decomposed, Dhaincha secretes weak organic acids that help improve soil conditions and nutrient availability.

Preparation and Cultivation

• The ideal time for sowing is from the last week of May to mid-June, best planted when fields are fallow during the Kharif season.

• The seeds are broadcasted after light irrigation and field plowing.

• After growing for 45 to 50 days, Dhaincha is plowed back into the soil, to enhance its physical, chemical, and biological properties.

• Dhaincha thrives in black loamy soil but can be grown in various types of land, also suitable for waterlogged conditions and does not require specific climatic conditions.

Benefits of Dhaincha as Green Manure

• Dhaincha enhances soil aeration and overall health, making it beneficial for crop growth.

• As a legume, Dhaincha fixes atmospheric nitrogen into the soil, enriching it with essential nutrients. It also adds organic matter, which improves soil structure.

• It is particularly effective in flood-prone and lowland rice cultivation areas, providing a sustainable option for enhancing soil fertility.

• The green manure from Dhaincha contributes to reducing dependency on chemical fertilizers, thus lowering cultivation costs and environmental impact.

• Dhaincha can also be used as feed for livestock, adding another layer of utility to its cultivation.

• Using Dhaincha reduces weed growth and minimizes the need for herbicides, which lowers overall cultivation costs.