Study of variable nutrient responses in cotton grown in Vertisols of North-Eastern Karnataka
A study wan undertaken with the objective of To characterize and assess fertility status of soils in intensive cotton and soybean growing areas of North-Eastern region in Karnataka To study the response of cotton and soybean to major nutrients and assess the extent of spatial variability of yield responses in the study region To study the nutrient uptake pattern, nutrient use efficiency and residual soil fertility through nutrient omission technique To create awareness among farmers for optimized nutrient use and best nutrient management practices for cotton and soybean in Vertisols
IPNI-2015-IND-534
29 Apr 2016
2015 Annual Interpretive Summary
The current investigation was aimed at determining the variable nutrient responses in cotton grown on the Vertisols of north-eastern Karnataka. The study was initiated at 10 on-farm sites covering three villages in the Raichur District where the soils are medium black to deep black in nature. Soils of the experimental sites were alkaline in pH (7.5 to 8.4), low to medium in organic C (0.4 to 0.6%), low in available N (70 to 235 kg/ha), medium to high both in available P2O5 (42.6 to 82 kg/ha) and available K2O (295 to 675 kg/ha). Hybrid transgenic Bt cotton was planted at all the locations between July 17 to 27, 2015 and the experiments consisted of four treatments namely ample NPK (333-78-106 kg N-P2O5-K2O/ha) and three treatments with omission of N, P and K from the ample NPK treatment, respectively.
Data collected from two pickings revealed that the seed cotton yield (SCY) in the ample NPK treatment varied from 3.9 to 4.4 t/ha with an average of 4.1 t/ha. The average SCY in treatments with omission of N, P and K was 3.5, 3.8 and 3.6 t/ha, indicating a reduction in SCY to an extent of 16.3, 7.8 and 13.8%, respectively. Data from an additional picking is due for reporting the final SCY. The information pertaining to nutrient uptake and post harvest soil analysis is currently being analyzed.
The results from the above study will be helpful in developing Nutrient Expert for cotton as a decision-support tool for making better fertilizer recommendations to farmers growing cotton.