中文摘要：

目的干旱、降水供需错位和春季低温是制约西北黄土高原丘陵沟壑区春小麦生产的主要因子，如何最大限度保蓄自然降水、实现水分的跨季节利用，则是该区春小麦产量稳定提高的根本途径。本文在大田定位观测的基础上，揭示全膜覆土穴播对西北黄土高原旱作春小麦季节性耗水特征、产量、水分利用效率和休闲期土壤水分补给的影响，并评判其年际土壤水分平衡效应。方法试验于2011—2013年在西北黄土高原半干旱区的甘肃省农业科学院定西试验站进行（104°36′E，35°35′N），以春小麦陇春27号为试验材料，设全膜覆土穴播（FMS）、地膜覆盖穴播（FM）和露地穴播（CK）3个处理，测定春小麦不同生育时期的土壤含水量、生物量、产量和产量构成因子，计算休闲效率、耗水量、水分利用效率、收获指数等指标。结果2011和2012年3个处理的春小麦耗水量无显著差异，但2013年FMS耗水量显著高于CK。FMS和FM可增加春小麦苗期到孕穗期耗水，且此阶段的耗水量在干旱年份分别较CK增加27.2%和9.6%，在丰水年份分别较CK增加52.2%和44.6%。虽然FMS和FM在各生育期的耗水量无显著差异，但FMS在丰水年（2012年和2013年）的耗水量较FM有增加趋势，且这一效果在2013年尤为明显。FMS和FM在休闲期可补充0—80 cm土层土壤水分25.4和18.3 mm，比CK分别低2.2和9.3 mm；补充80—200 cm土层土壤水分78.0和71.0 mm，比CK分别高30.0和23.1 mm；与2011年播前相比，种植3年春小麦后0—200 cm土层的土壤贮水量FMS增加了23.8 mm、FM增加了22.5 mm、CK增加了12.4 mm。FMS的休闲效率为30.5%—52.6%，比CK高12.8%—109.5%，比FM高4.5%—40.9%。FMS的穗粒数、千粒重等产量构成因子均显著高于CK（P＜0.05）；收获指数为0.4—0.5，比CK高32.5%。FMS的产量为1750—3180 kg·hm-2，水分利用效率为5.5—11.5 kg·hm-2·mm-1，分别比CK增加40%?

英文摘要：

[Objective]The main limiting factors which affect spring wheat productivity on Northwest Loess Plateau are drought, rainfall dynamics could not meet spring wheat water needs, and low temperature in spring. How to conserve the rainwater in soil efficiently, and use it at the spring wheat growth stage, is the most important method to increase spring wheat yield in this area. The aim of the study is to reveal the effect of whole field soil plastic mulching （i.e. the whole soil surface firstly mulched by plastic, and then spread around 1cm thick soil on plastic surface） on spring wheat seasonal water consumption, yield, water use efficiency and the soil water recharge in fallow period, further to assess its effect on inter annual soil water balance in semiarid region on Northwest Loess Plateau. [Method]The spring wheat （Triticum aestivum Lunchun 27） selected as test material, a field experiment was conducted from 2011 to 2013 on the Dingxi Experimental Station of Gansu Academy of Agricultural Sciences （104°36′E, 35°35′N） , which located on northwest Loess plateau. The designed three treatments are whole field soil plastic mulching and bunch seeded （FMS）, whole field mulching and bunch seeded （FM）, and uncovered and bunch seeded （CK）. The seasonal soil water content, spring wheat biomass, yield and spring wheat yield components were recorded, as well as the rainwater fallow efficiency, evapotranspiration, water use efficiency, harvest index, and reproduction allocation index were calculated.[Result]The evapotranspiration among the three treatments were not differed significantly in 2011 and 2012, but the evapotranspiration of FMS was significantly higher than CK in 2013. From seeding to jointing stage, the FMS and FM significantly increased spring wheat evapotranspiration by 27.2%and 9.6%in dry year, 52.2%and 44.6%in wet year, respectively, as compared with CK. The evapotranspiration of FMS and FM was not significantly different at each spring wheat growth stage. However, the evapotranspi