Effect of Organic Waste Incorporation and Nitrogen Fertilization on Transplanted Rice and Associated Weeds

Cyperus, iria, and Echinochloa crusgali were the dominant weeds associated with transplanted flooded rice variety Himalaya 1. The incorporation of Lantana and Eupatorium each at 5 t/ha at the time of puddling increased the growth of Cyperus iria and decreased the population of Panicum psilapodium at harvest. The grain and straw yields of rice increased significantly when Lantana and Eupatorium were incorporated whereas the effect of wheat straw was non-significant. Nitrogen fertilizaation increased the density of andv dry weight of individual weed species as well as that of <otal weeds. The response of rice to nitrogen was upto -100 kg N/ha and each kg N applied resulted in 10.6, 9.4 and 9.0 kg rice from 50, 75 and 100 kg N/ha, respectively when averaged over two crop seasons.