休闲期覆膜与施氮量对旱地小麦水氮利用效率和籽粒产量的影响

为探寻旱地小麦休闲期覆盖下的适宜施氮量,在旱地小麦休闲期覆盖与不覆盖条件下,分别设置75、150和225kg·hm-2三个施氮量,分析了休闲期覆盖配施氮肥对旱地小麦水氮利用效率和籽粒产量的影响。结果表明,休闲期覆盖显著提高播种至孕穗期0~300cm土壤蓄水量,其中播种期土壤水分增加70~81mm,其蓄水保墒效果可延续至孕穗期,进而提高了小麦产量和水分利用效率。休闲期覆盖促进了小麦植株对氮素的吸收和积累,增加了植株花前氮素转运量、花后氮素积累量以及籽粒氮素积累量,提高了氮素收获指数和氮素生产效率。休闲期覆盖配施氮素150kg·hm-2时,蓄水、增产和水分高效利用、氮素积累与转运的效果最好。

Effects of Mulching in Fallow Period and Nitrogen Application Amount on Water and Nitrogen Use Efficiency and Grain Yield in Dryland Wheat

In order to explore the technological approach to increase yield under plastic film mulching in fallow period matching with nitrogen fertilization, field experiment was carried out in Wenxi, Shanxi with nitrogen application amounts of 75, 150 and 225 kg·hm^-2 under plastic film mulching and no mulching in fallow period to explicit the effect of mulching in fallow period and nitrogen application amount on water and nitrogen use efficiency, and grain yield in dryland wheat. The results showed that after mulching in fallow period, soil water storage during sowing to booting stage at the depth of 0~300 cm were significantly improved, which improved by 70~81 mm at sowing, and while combined with middle nitrogen, the effect on water retention could be extended to booting stage, yield and water use efficiency of wheat were improved. After mulching in fallow period, N accumulation at different growth stages was significantly improved, nitrogen accumulated before anthesis (NTBA) and nitrogen accumulated after anthesis (NAAA) were improved, so grain N accumulation was significantly improved, and the effects of mulching with middle nitrogen was better. Mean while, N harvest index and N productive efficiency were improved. In all, mulching in fallow period in dryland wheat had a better soil moisture conservation, improved soil water storage in earlier and interim stages, the effect on water retention could be extended to booting stage, finally improved water use efficiency; it was helpful to promote the absorption, accumulation and translocation of nitrogen, finally improved grain N accumulation, meanwhile mulching with N fertilization about 150 kg·hm^-2 was better for improving N harvest index and N productive efficiency.