Performance and nitrogen use efficiency of rice under different fertilizer and water management practices in bangladesh

Abstract

Studies were conducted to determine appropriate water management practices to maximize rice yield and to quantify nitrogen use eefTiciency in Bangladesh during 1991 and 1992 dry season. N applicaiton in continuous standing water produced highest rice yield of 3.71 and 5.21 t ha'1 in 1991 and 1992 respectively. Lowest rice yield of 2.37 and 2.85 t ha'1 were obtained from continuous stnading water but no fertilzier N applied (T5, control) in 1991 and 1992, respectively. The management practice of fertilzier N applicaiton at field capacity followed by irrigaiotn at 10-15% soil moisture depletion (Tl) produced the lowest rice yield among the N treated plots, agronomic efficiency of N under T3 and T4 management practices were 45.38 and 46.38 kg rice kg'1 N applied in 1991 and the same efficiency under to same management practicews in 1992 were 64.13 and 65.13 kg rice kg'1 N applied. Physiologifcal efficiency of absorbed N ranged from 54.2 to 58.9 and from 58.7 to 65.9 kg rice kg'1 N absorbed in 1991 and 1992 respectively. Rice plants used two-thired of total absorbed N for gain production one-third for straw production. The studies indicated that fertilzier N applicaiton in continuous standing water and continuous standing water with drainage up to saturaiton before N applicaiton were the better management practices for rice yield, nitrogen use efficiency and apparent recovery of applied fertilizer N.