灌溉模式和供氮水平对水稻氮素利用效率的影响

Effects of water management patterns and nitrogen fertilizer levels on nitrogen use efficiency of rice

以Ⅱ优838为材料,湖北潮土为供试土壤,通过2年稻麦轮作柱栽试验研究了2种灌溉模式(FW:土表淹水3 cm;CW:保持土壤湿润但土表不积水)和4个供氮水平(N 0、126.0、157.5、210.0 kg/hm2)对水稻地上部干物重、氮素积累量、氮素利用效率的影响。结果表明,灌溉模式和供氮水平对水稻产量、地上部氮素积累量和氮素利用效率均有显著(P<0.05)或极显著影响(P<0.01)。其中,淹水处理下水稻产量、地上部氮素积累量、水稻氮素农学利用率、氮肥吸收利用率、氮肥偏生产力和氮素生理利用率显著高于控水处理;地上部生物量及氮素积累量随供氮水平的提高而增加趋势明显;氮肥农学利用率、氮肥偏生产力和氮素生理学利用率均表现为随施氮量提高而下降的趋势,但减氮25%处理(N 157.5 kg/hm2)与常规施氮量处理(N 210.0 kg/hm2)间的差异并不显著。综合分析水稻产量与氮素吸收利用效率的各项指标,在8个供试处理中,淹水灌溉模式并减氮25%的处理为值得推荐的稳产高效水氮运筹模式。

A two-year pot-culture experiment of rice cultivar, II You 838, with alluvial soil from Hubei was conducted to investigate the effects of two water management patterns and four nitrogen （N） fertilizer levels （ N 0, 126.0,157.5,210. 0 kg/ha）on the aerial part biomass, N accumulation, N use efficiency. The results show that the aerial part biomass, N accumulation and N use efficiency of rice are obviously affected by the water management patterns, and the rice grain yield, N accumulation, N agronomic efficiency, N recovery efficiency, partial factor productivity and nitrogen physiological efficiency under the water-logging irrigation pattern are higher than those of the water-controlled irrigation pattern. The biomass and N accumulation of rice aerial parts are increased with the increase of nitrogen level, while the nitrogen agronomic efficiency, partial factor productivity of the applied N and N physiological efficiency are reduced. However, there are no significant differences between the 25 % N saving from conventional nitrogen application rate （ N 157.5 kg/ha） and the conventional nitrogen application rate （ N 210.0 kg/ha）. In general, the water-logging irrigation pattern combined with the 25% N saving from conventional nitrogen application rate is recommended as a better water and nitrogen application patterns due to its higher grain yield and nitrogen utilization.