Intercropping and Sources of Nitrogen on Biological Efficiency in Cotton

Field experiments were conducted at Tamil Nadu Agricultural University, Coimbatore, during winter (August-January) 2002-03 and 2003-04 in Cotton to evaluate the effect of intercropping and sources of nitrogen involving organic and inorganic sources. The treatments in the main plot consisted of Sole cotton, Cotton+Onion, Cotton+Blackgram, Cotton+ Greengram and Cotton +Lucerne. The subplot consisted of combinations of inorganic and organic manures namely, 100% recommended inorganic N, 75% inorganic N+ 25% N through poultry manure, 75% inorganic N+25% N through sunnhemp, 75% inorganic N+25% N through farm wastes and 75% inorganic N+25% N through weed compost. The experimental results revealed that cotton+blackgram intercropping with 75% inorganic N+25% N through poultry manure recorded lower weed density, higher cotton yield, cotton equivalent yield, better economics and higher post harvest nutrient status.