Yield maximization in cotton through targeted yield approach and omission plot techniques in Vertisols of Karnataka

A study was undertaken in the Bt cotton growing farmer fields of Raichur district with the following objectives 1. To know the effect of targeted yield approach on growth, yield and quality of Cotton in Vertisols 2. To study the effect of fertilization on crop nutrient uptake, soil nutrient status, nutrient balance sheet and efficiency of applied fertilizers 3. To workout the economics of cotton cultivation under fertilization levels and omission plots

IPNI-2015-IND-533

29 Apr 2016

2015 Annual Interpretive Summary


Two sets of on-station experiments, one at the Agricultural Research Station (ARS), Hebbali farm and the other at the main agricultural research station (MARS) at the University of Agricultural Sciences, Dharwad, Karnataka were conducted to assess the nutrient contribution towards yield of Bt cotton using the omission plot technique. The experiment consisted of four treatments: a) ample NPK treatment (180-70-80 kg N-P2O5-K2O/ha), b) -N, c) -P, and d) -K. Transgenic Bt cotton (First Class BG II) was planted at both the sites on June 19, 2015 at ARS and on June 22, 2015 at MARS.

Observations on growth and yield parameters at ARS recorded 2,953 kg/ha seed cotton yield (SCY) with ample NPK treatment, and the omission of N, P and K resulted in 32, 9.5 and 15% reduction in SCY as compared to ample NPK application. Whereas, at MARS, the SCY in ample NPK treatment was 2,721 kg/ha and the yield reduction due to omission of N, P and K was 50, 10 and 17%, respectively. The data further indicated that N and K followed by P are the most limiting nutrients in the cultivation of transgenic cotton and the application of the right rates of those nutrients are key for producing higher SCY. Increased net returns were measured at both the centers (Rs. 72,400/ha at ARS and Rs. 52,000/ha at MARS) due to ample NPK treatment. The data on nutrient uptake and post harvest soil properties are currently being investigated.

The information generated from this study will be utilized for developing the Nutrient Expert® (NE) decision support tool for cotton and help in providing individual field-specific fertilizer recommendations for improving the productivity and profitability of farmers growing cotton.