AbstractA field experiment was carried out in sub-tropical climate of Bhimdattanagar, Kanchanpur to assess the effect of site specific nutrient management approach in productivity of spring rice. The experiment was carried in single factor randomized completely block design with four replication, in four different farmer’s field, each farmers’ field as single replication. The seedlings were grown in the mat nursery bed and transplanted in the experimental plots with different nutrient management practices. Nutrient management practices were Site Specific Nutrient Management with Nutrient Expert dose (SSNMNE)(109:28:38 kg NPK/ha), Government recommendation dose (100:30:30kg NPK/ha +6 ton FYM), Farmer’s field practice (FFP)(different among farmers) with three omission plots viz. omission of Nitrogen (0:28:38 kg NPK/ha), Omission of Phosphorus (109:0:38 kg NPK/ha) and Omission of Potassium (109:28:0 kg NPK/ha). SSNM-NE dose was obtained by household survey in the respective area and using nutrient expert model. The growth parameters, yield, yield attributing traits and total cost of production were recorded. Data were analyzed using Duncan’s Multiple Range Test (DMRT) in Genstat. Result indicates that the highest grain yield (5.81 t/ha) was obtained from SSNM-NE which was statistically at par with government recommendation (5.54 t/ha). Similarly, thousand grains weight, straw yield in the experiment 23.20g, 6.90t/ha were significantly higher in SSNM-NE respectively. Straw yield, grain yield and thousand grain weight of SSNM-NE were found to be statistically at par with government recommendation. The economic analysis revealed that higher B: C ratio (1.91), net return and gross return were higher in SSNM-NE.

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.