长期定位施不同氮源有机肥替代部分含氮化肥对陇东旱塬冬小麦产量和水分利用效率的影响

摘要

在陇东黄土旱塬覆盖黑垆土大田,利用陇鉴301进行了连续10年的定位试验,观测长期施用不同氮源有机肥(发酵有机肥、农家肥)或小麦秸秆还田各处理对冬小麦产量相关性状和水分利用效率的影响.结果显示,小麦产量和水分利用效率年际间变化较大,与降雨量有直接关系;不同有机氮源替代部分含氮化肥处理对提高冬小麦产量和水分利用效率具有明显作用.在干旱、平水和丰水年型,较不施肥对照分别增产53.1%~103.7%、40.3%~79.3%和73.1%~94.8%,较单施化肥对照分别增产6.6%~41.8%、7.0%~36.8%和-2.9%~9.3%.以发酵有机肥做替代物处理的产量和水分利用效率最高,增产幅度最大,10年平均产量较不施肥和单施化肥对照分别增加88.9%和25.4%,水分利用效率和边际水分利用率也最高,分别为10.8 kg mm–1 hm–2和1.03 kg m–3;并且产量构成因素和植株生理指标也优于其他处理.因此,发酵有机肥是陇东半湿润偏旱雨养农业区(年降水量约550 mm)冬小麦生产上替代部分含氮化肥的首选有机氮源.%The objective of this study was to find the possibility of organic fertilizers replacing partial chemical fertilizer continu-ous winter wheat cropping system through evaluating yield and water use efficiency (WUE). Using winter wheat variety "Long-jian 301", we carried out a ten-year field experiment in the Loess Plateau of eastern Gansu province with two controls (no-fertilizer and chemical fertilizer) and three treatments of organic fertilizer (fermented organic fertilizer, farm manure, and wheat straw) replacing partial chemical fertilizer. The yield and water use efficacy of winter wheat varied greatly across years, with a direct effect of precipitation amount on them. Organic fertilizer replacing partial chemical fertilizer had positive effects on winter wheat yield and WUE, and the yield-increased rates were 53.1%–103.7%, 40.3%–79.3%, and 73.1%–94.8% over the no-fertilizer control and 6.6%–41.8%, 7.0%–36.8%, and -2.9% to 9.3% compared with chemical fertilizer control in dry, normal and wet year, respectively. Among all treatments, the fermented organic fertilizer treatment showed the highest yield and WUE, as well as the largest yield-increased rate. In this treatment, the average yield of 10 years increased by 88.9% and 25.4% compared with no-fertilizer and the chemical fertilizer controls, respectively, and WUE and marginal water use efficiency were 10.8 kg mm-1 hm-2 and 1.03 kg m-3, respectively. Meanwhile, the yield components and plant physiological parameters in this treatment were also superior to those in other treatments. As a result, we suggest fermented organic fertilizer replacing partial chemical fer-tilizer in the semi-humid rain-fed area of eastern Gansu province, where annual precipitation is around 550 mm.