肥水优化管理对寒地水稻群体质量的影响

Effect of water-fertilizer optimization on rice population quality in cold area of northeastern China

采用田间小区试验方法,在25和30穴.m-2的密度条件下,比较农民习惯肥水管理(FFP)和肥水优化管理(OPT)的群体质量指标。结果表明,FFP-25产量为8.95 t.hm-2,FFP-30通过增加密度使抽穗期粒重/叶面积提高11.4%(P<0.01),但是分蘖成穗率降低,因此增产不显著;与FFP-25相比,OPT-25通过肥水优化管理使分蘖成穗率提高4.8%,抽穗期粒重/叶面积提高14.8%(P<0.01),产量提高8.5%(P<0.05);OPT-30在优化施肥的基础上增加密度,与FFP-25相比,抽穗期叶面积指数提高10.8%,粒重/叶面积提高15.7%(P<0.01),产量提高15.5%(P<0.01)。试验结果表明,增加密度产量增加不显著,增加密度的同时降低总氮量,增加穗肥中氮素的比例,并采用以水带氮的追肥方式,能够改善水稻群体质量,提高了抽穗期粒叶比,显著提高水稻产量。

A field experiment with 2 water and fertilizer management methods under 2 plant densities（25 and 30 plants.m-2）,optimal fertilization practice under controlled irrigation（OPT） and farmer＇s fertilization practice under traditional irrigation（FFP）,was conducted to study their effects on rice population quality.Yield of FFP-25 was 8.95 t.hm-2,FFP-30 increased grain weight/leaf area by 11.4%（P0.01） by increasing density at heading,but decreased the earbearing tiller rate,therefore,the increase of yield was not significant.Compared with FFP-25,OPT-25 increased earbearing tiller rate,grain weight/leaf area and yield by 4.8%,14.8（P0.01） and 8.5%（P0.05）,respectively;OPT-30 improved LAI and grain-leaf ratio at heading by 10.8% and 15.7%（P0.01）,therefore,yield was increased by 15.5%（P0.01） compared with FFP-25.The results indicated that the increase of the density could not improve yield,but OPT,decreased total N rate and applied N at later growth under controlled irrigation,significantly enhanced rice yield under higher density because of improving rice population quality and grain-leaf ratio at heading.