玉米秸秆还田条件下冬灌时间与施氮方式对冬小麦生长发育及水肥利用效率的影响

为给玉米秸秆还田条件下冬小麦的水氮运筹提供依据,以小麦品种临优2069为材料,研究了山西省小麦-玉米一年两熟区玉米秸秆还田条件下冬灌时间和施氮方式对冬小麦生长发育及水氮利用效率的影响。结果表明,随着冬前灌水时间的推迟,小麦总茎数、单株分蘖数、成穗数、产量、籽粒水分生产率、氮肥表观利用率均呈先升高后降低趋势,以11月25日冬灌的最高。在施氮量相同条件下,氮肥一次性底施(N10∶0)的拔节期总茎数、成穗数、产量、籽粒水分生产率和氮素吸收量、表观利用率高于氮肥70%底施+30%拔节期追施(N7∶3)处理,冬前总茎数、单株分蘖数则相反。冬前灌水时间提前和氮肥一次性底施有利于提高小麦前期单株干重;冬前灌水时间推迟和后期追氮则有利于灌浆期穗部和总干物质的积累。因此,山西省小麦-玉米一年两熟区,秸秆还田条件下氮肥采取一次性底施,并于11月25日冬灌,可实现冬小麦的高产高效栽培。

Effects of Winter Irrigation Date and Nitrogen Fertilization on the Growth, Water and Nutrient Use Efficiencies in Winter Wheat under Straw Return to Field

In wheat maize rotation system of Shanxi, the effects of winter irrigation date and nitrogen fertilization on the growth, water and nutrient use efficiencies in winter wheat variety Linyou 2069 were studied, under maize straw returning to field. Results showed that, total tillers, tillers per plant, spike number per plant, grain yield, water use efficiency (WUE), and nutrient use efficiency (NUE) were increased when irrigated before November 25, and then were decreased while the irrigation date postponed. Under the same level of N rate, total tillers, spike number per plant, grain yield, WUE, nitrogen uptake rate, and NUE were all higher in the treatment of all N application as basal than that in the treatment of 70% of N as basal and 30% of N as topdressing at jointing stage, while total tillers before winter and tillers per plant were less. Dry weight per plant was increased by winter irrigation earlier and total N application as basal. While ear dry weight and total dry weight at filling stage were increased by winter irrigation time postponed and N topdressing at later growth stage. So in wheat maize rotation system of Shanxi, under maize draw returning to field, total tillers, grain yield and WUE were increased by total N application as basal and irrigation on November 25. High yield, high efficiency of winter wheat could be realized by these two measures.