Avanços na ciência e tecnologia agrícola

Abstrato

Determination of Nitrogen and Phosphorous Fertilizer Rates on Low Land Rice Production

Tilahun Tadesse

Nitrogen and phosphorous fertilizers application experiment was conducted on rainfed lowland rice production at Fogera plain in two cropping seasons. The treatments were comprised of factorial combinations of five nitrogen (0,92,184, 276 and 368 kg/ha) and four phosphorous levels (0, 23, 46, and 69 P2O5 kg/ha). Data was collected on plant height. panicle length, number of total tillers/m, number of effective tillers/m, panicle length, number of fertile spiklets/panicle, thousand seeds weight, grain yield, straw yield and harvest index. All collected data were subjected to analysis of variance. Economic analysis was also carried out by following CIMMYT procedures. The results of the experiment indicated that the main effect of nitrogen application was significantly affecting plant height, panicle length, total tillers/m, effective tillers/m, filled spiklets/panicle, grain yield, straw yield, thousand seeds weight and harvest index while phosphorous was affecting only grain and straw yields. The interaction of nitrogen and phosphorous was affecting grain yield, straw yield and harvest index. With respect to the interaction effect, the highest grain yield (7.0 t ha^-1) was obtained at 276-69 N- P₂O₅ kg ha^-1. The economic analysis has exhibited that the combined application of 184-46 N-P₂O₅ kg ha^-1 is the most profitable treatment. It is thus concluded that application of nitrogen and phosphorous fertilizers at rates of 184-46 N- P₂O₅ kg ha^-1 is the best recommended for rainfed lowland rice production in Fogera plain and other similar agroecologies.