A survey was undertaken to study dry matter production, nutrient uptake and yield of Bt cotton grown in soils belonging to three different orders (inceptisols, alfisols and vertisols) in Kurnool district of Andhra Pradesh. There is no much variation in dry matter production of Bt cotton grown in inceptisols, alfisols and vertisols. Bt cotton grown in vertisols recorded the maximum mean uptake of N, P and K as compared to Bt cotton grown in alfisols and inceptisols. Similarly,Bt cotton grown in vertisols exhibited maximum mean uptake of Mg and S as compared to Bt cotton grown in inceptisols and alfisols. However, Bt cotton grown in inceptisols showed maximum mean uptake of Ca. The highest seed cotton yield was observed in Bt cotton grown in vertisols.

https://www.chemijournal.com/archives/2018/vol6issue5/PartAX/6-5-456-765.pdf

Impact of Bt cotton on soils of Kurnool district, Andhra Pradesh

A study was conducted at Research Farm, Department of Agronomy, CCS Haryana Agricultural University, Hisar during kharif 2010. The soil of experimental field was sandy loam in texture and slightly high in pH. Soil was tested low in organic carbon and available nitrogen and medium in available phosphorus and high in potassium. The experiment was conducted in split plot design with three replications. The combination of three spacings (100 x 40 cm, 100 x 50 cm and 100 x 60 cm), two times of N fertilizer application viz., T 1 : 50% at flowering and 50% at square formation and T 2 : 25% as basal, 37.5% at flowering and 37.5% at square formation, were kept in main plots, while three nutrient levels viz., F 1 –131.2 : 45 : 45 NPK (kg/ha) F 2 –175.0 : 60 : 60 NPK (kg/ha) and F 3 – 218.7 : 75 : 75 NPK (kg/ha) were kept in sub-plots. Maximum plant height was recorded at closer spacing of 100 x 40 cm. Maximum sympods/plant were recorded in wider spacing (100 x 60 cm) which were significantly higher than closer spacing (100 x 40 and 100 x 50 cm). Weight/boll (g) was recorded non-significant in spacing manure. Time of N fertilizer application had a significant effect on plant height and sympods/plant. Maximum plant height and sympods/plant were recorded with three split applications of N fertilizer. Maximum plant height was recorded at a NPK fertilizer dose of 218.75 : 75 : 75 (125% RDF) kg/ha followed by 175 : 60 : 60 (100% RDF) kg/ha. Spacing (100 x 60 cm) exhibited significantly higher available N, P and K in soil than closer spacing. The maximum available N, P and K in soil was observed with two split doses of N application as compared to three split doses of N application. Significantly higher available N, P and K in soil after harvest of crop was found with 125% RDF, which is significantly superior over 75 and 100% RDF. Total cost of cultivation, gross returns, net returns and benefit : cost ratio were significantly higher with spacing of 100 x 40 cm followed by spacing of 100 x 50 cm with three split applications of N fertilizer and 100% of recommended dose of fertilizers. Cost of cultivation was significantly better in fertilizer levels with 125% of recommended dose of fertilizers.

R. V. S. Chauhan

Papers

Effect of different nutrients on growth, yield attributes and yield of cotton under varying cotton cultivars.