Abstract :
A field experiment was conducted to determine the productivity and economics of rice influenced by crop establishment methods, varieties and nitrogen levels on growth, phenology and yield of rice cultivars in the sub-tropical climate of Chitwan, Nepal. Three factors Strip-split plot experimental design using establishment methods (conservation and conventional agriculture) in vertical plots; varieties (hybrid Gorakhnath 509 and high yielding Sabitri) in horizontal plots and four nitrogen levels (0, 60, 120 and 180 kg N ha-1) in sub-sub plots was laid out with three replications. The research result revealed that, grain yield of rice along with nitrogen use efficiencies, net return and B:C ratio was significantly higher in conservation agriculture than conventional agriculture. The higher grain yield in CA plots was because of higher number of effective tillers per square meter as compared to conventional agriculture. The grain yield of both hybrid and high yielding varieties were statistically similar whereas nitrogen level of 180 kg ha-1 produced the highest grain yield which was statistically similar to 120 kg ha-1 N but significantly higher than 60 kg ha-1 N. Higher N application increased the effective tillers per square meter and number of grains per panicle which resulted in higher grain yield. Net return and B:C ratio were higher at 120 and 180 kg ha-1 N applied plots. Thus for sustainable rice production, conservation agriculture with high yielding variety and nitrogen level of 120 kg ha 1 are best.
Keyword :
Conservation agriculture, conventional agriculture, nitrogen levels, effective tillers