CHENNAI: The State government’s impact assessment of Tamil Nadu’s green manuring programme shows that the practice was adopted by nearly all farmers who received seeds, with many reporting improved soil condition, higher yields and reduced fertiliser use. The assessment, however, points to uneven outcomes across districts.

The study assessed the green manuring component of the Chief Minister’s Mannuyir Kaathu Mannuyir Kaappom Scheme, implemented during the 2024-25 agricultural year across 34 districts.

Under the programme, crops such as dhaincha (thakkai poondu) and sun hemp (sanappai) were grown for a short period and ploughed back into the soil before the main crop. These are nitrogen-adding crops that enrich the soil naturally, improving fertility and moisture retention while reducing the need for chemical fertilisers.

Adoption was reported to be highest in the Cauvery delta districts, including Thanjavur, Tiruvarur, Cuddalore, Tiruchy and Mayiladuthurai, which together accounted for the largest share of surveyed farmers. In these districts, farmers reported better soil moisture retention and visible improvement in crop growth.

Overall, 99.7% of surveyed farmers sowed the seeds they received. Non-adoption was reportedly limited to a small number of farmers who cited delayed supply, poor rainfall or overlap with the main crop season.

Seed performance, however, varied across districts. Germination was reported to be better in districts such as Dharmapuri, Madurai, Nagapattinam and Theni, while lower performance was noted in parts of Virudhunagar, Pudukkottai and Ariyalur, with complaints of poor-quality seed batches.

The assessment reports positive yield outcomes across most regions. Across agro-climatic zones, 94% of farmers said crop yields improved, while 93% reported better soil fertility. Reduced use of chemical fertilisers was reported by 88% of farmers, and 85% said cultivation costs had come down.

Field-level discussions indicated yield increases of up to 15% per acre, with income gains estimated at around Rs 17,500/acre, particularly in parts of Thanjavur, Cuddalore, Virudhunagar and Madurai.

While most farmers reported timely seed distribution, delays were more frequently flagged in the North Eastern Zone, including Tiruvannamalai, Villupuram and Kancheepuram. Erratic rainfall in parts of the Cauvery Delta and southern districts affected sowing windows and delayed ploughing back of the green manure crop.

The assessment also flagged gaps in reaching out. Only 48% of farmers surveyed had attended training programmes related to green manuring. In the Southern Zone, nearly half the farmers said they would not continue the practice without government subsidies, raising concerns about long-term adoption.