Abstract
An experiment was conducted at the research farm of Indian Agricultural Research Institute, New Delhi, during 2001-02 and 2002-03, under irrigated conditions to study the effect of different sources of nitrogen viz., prilled urea, farmyard manure (FYM) and Azotobacter on growth, yield and NPK removal by cotton (Gossypium hirsutum L.) and their residual effects on a succeeding wheat (Triticum aestivum L.) crop. The results indicated considerable improvement in growth, yield attributes and NPK removal by cotton with addition of higher doses of fertilizer N through prilled urea. The performance of cotton with application of FYM 12 t ha-1 was found to be intermediate between 30 and 60 kg N ha-1 applied through prilled urea. Highest growth, yield (2333 kg kapas ha-1) and NPK removal was observed with integrated application of 30 kg N ha-1 applied as prilled urea and FYM 12 t ha-1 along with Azotobacter (M4). The same treatment combination also gave maximum residual effect on the succeeding wheat crop realized in terms of higher growth and yield attributes. Direct application of 120 kg N ha-1 through prilled urea to succeeding wheat resulted in 67.4 and 17.7 % increase in mean grain yield of wheat over no N and 60 kg N ha-1, respectively. Combined and judicious applications of organic and inorganic fertilizers are therefore recommended for realizing higher yield potential of the cotton - wheat cropping system on Ustochrepts of Indo-Gangetic plain.
