The fertilizer prescription equations were developed for rainfed Bt cotton on Pielamedu series (Typic haplusterts) by adopting the inductive cum targeted yield model, and fertilizer requirements were quantified for Bt cotton based on soil test and yield target. The validity of fertilizer prescription equations was done by conducting test verification trials at four locations in Perambalur district of Tamil Nadu developed for rainfed Bt cotton. The fertilizer prescription equations were used to calculate the fertilizer doses for STCR treatments. The percent achievement of the targeted yield was within ±10% variation in all the locations for both the yield targets under nitrogen, phosphorus, and potassium (NPK) alone and IPNS, proving the validity of the equations. STCR-IPNS based fertilizer recommendations for a yield target of 32 q/ha has recorded the highest yield, nutrient response ratio, and percent yield achievement in all the locations.

For evaluating the effect of STCR-IPNS (soil test crop response-integrated plant nutrient supply) equations for targeted yield of rice under sodic soils developed by department of Soil Science and Agricultural Chemistry, AICRP-STCRunit, TamilNadu Agricultural University, Coimbatore, TamilNadu, demonstrations based on targeted yield in rice were conducted at farmers’ fields by Krishi Vigyan Kendra, Vamban, Pudhukottai, Tamil Nadu at different locations of sodic soil areas with rice varieties CO43 Sub1 (medium fine grained) and TRY 3 (bold grain) during rabi 2020–2021. The STCR-IPNS technology was used for computation of fertilizer doses based on soil test values and targeted yield of 60 q/ha and compared with farmers’ practice. The demonstrated STCR-IPNS technology was able to increase yield of rice over farmers’ practice under sodic soil to the tune of 41.68 and 38.34 per cent for medium fine and bold rice varieties respectively. Value of net return from demonstrated STCR-IPNS technology was observed to be Rs 42,000 and 44,000 in comparison to farmers’ practice ie Rs 21,000 and Rs 17,500 for medium fine and bold rice varieties respectively. The benefit-costratio of STCR technology with farmers'practice was 2.16 and 2.25 and 1.55 and 1.46 for medium fine and bold rice respectively. The STCR-IPNS technology ie application of fertilizer doses based on initial soil test values with FYM @ 12.5 tonnes/ha along with gypsum application was effective in changing attitude, skill and knowledge of farmers and can be recommended for achieving higher yield (ie up to 6 tonnes/ha), response ratio and BCR for rice on Alathur series (Vertic Ustropept) and allied soil series especially sodic soils of Tamil Nadu. This also improved the relationship between farmers and scientists and built confidence among the farmers.

Developing and distributing crop production technologies that promote sustainable crop intensification is crucial for ensuring food and nutritional security for the growing global population. This challenge remains one of the most pressing issues for governments in the twenty-first century. According to the Ministry of New and Renewable Energy, India produces approximately 500 million tons of crop waste annually. Conservation agriculture offers a promising solution to manage crop residues by maintaining a permanent soil cover through mulching and incorporating crop residues into the soil. Soil is fundamental to agricultural productivity and plant growth. However, the fraction of arable soil is limited and requires careful management to prevent nutrient depletion. Soil fertility depends significantly on organic matter and soil carbon content, which are key indicators of soil health. Crop residues enrich the soil with essential nutrients, improving crop yields and altering soil characteristics. They influence water infiltration, flow and runoff and help regulate soil temperature by shielding the surface from direct sunlight. Increased residue cover reduces evaporation rates, conserving soil moisture. Agricultural residues typically contain vital nutrients up to 80 % nitrogen, 25 % phosphorus, 20 % potassium and 50 % sulphur. Incorporating these residues into the soil enhances fertility, maintains health and supports sustainable agriculture, ensuring long-term productivity.