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全球气候变化最令人担忧的问题是干旱 ,而水分又是影响小麦产量的重要因素之一 ,农田水分的管理与有效利用已经受到人们的高度重视。作者以春小麦为实验材料 ,采用盆栽和小区试验相结合的方法 ,针对黄土高原半干旱地区的有限水分环境 ,研究了有限供水的高效利用问题。盆栽条件下 ,采用 3种肥力水平与拔节期、孕穗期和灌浆期有限供水组合处理。对生长发育、产量构成和水分利用效率等指标测定的结果表明 ,施肥可以显著增大叶面积 ,促进根系生长 ,提高子粒产量 ;而施肥条件下 ,拔节期有限供水能够显著增加穗粒数和粒重。小区试验结果表明 ,满足春小麦最大产量所需的灌水量约为 2 0 0 m m ,获得作物水分利用效率最高时的适宜灌水量约为 10 0 m m ,而拔节期 60 m m的灌水量可以使灌水利用效率接近最大值。拔节期 60 m m灌水条件下 ,耗水量、作物水分利用效率和灌水利用效率同步增长 ,同时土壤的贮存水也得到了有效利用。根据以上结果可得出 :在黄土高原缺水地区 ,春小麦有限灌溉的适宜灌水量下限应不低于 60 m m,一次性补充灌溉的最佳时期为拔节期
The most worrying issue of global climate change is drought. Water is another important factor that affects wheat yield. The management and effective utilization of farmland moisture have drawn great attention from people. Taking spring wheat as experimental material and pot and plot experiment, the author studied the limited water supply in the semi-arid area of the Loess Plateau. Under potted condition, three kinds of fertility levels were used to deal with the limited water supply at jointing stage, booting stage and filling stage. The results of growth and development, yield components and water use efficiency showed that fertilization could significantly increase leaf area, promote root growth and increase grain yield. However, the limited water supply at jointing stage could significantly increase grains and grains weight. The plot test results showed that the irrigation volume needed to meet the maximum yield of spring wheat was about 200 mm, and the optimum irrigation rate was about 100 mm at the highest crop water use efficiency, while irrigation at the jointing stage of 60 mm could make irrigation use The efficiency is close to the maximum. Water consumption, crop water use efficiency and water use efficiency increased simultaneously with 60 m irrigation at the jointing stage, and soil water storage was also effectively utilized. Based on the above results, it can be concluded that the lower limit of suitable irrigation amount for spring wheat limited irrigation should be not less than 60 m m in the areas lacking water on the Loess Plateau. The best period of one-time supplementary irrigation is jointing period