To get an optimal irrigation regime and planting density for simultaneous improvement of grain yield (GY) and water use efficiency (WUE) in winter wheat, we examined the responses of 'Tainong 18' (with bigger ears) and 'Shannong 22' (with medium-sized ears) under four irrigation regimes, including 0, 45, 60, and 75 mm. Those two cultivars were planted at four densities: Tainong 18 at 135×104, 270×104, 405×104, and 540×104 plants·hm-2 and Shannong 22 at 90×104, 180×104, 270×104, and 360×104 plants·hm-2. The interactive effects of irrigation regimes and plant densities on GY, water consumption characteristics, and WUE were investigated. The results showed that GY, evapotranspiration, soil water consumption, and WUE were significantly affected by irrigation regime, plant density, and their interaction. The optimal irrigation regime was 45 mm for both cultivars, while the optimal plant density was 405×104 plants·hm-2 for Tainong 18 and 270×104 plants·hm-2 for Shannong 22, as indicated by the highest GY, the lowest ratio of soil evaporation to evapotranspiration after jointing, and higher WUE and the ratio of soil water consumption below 1 m to total soil water consumption. The rational combination of plant density and irrigation could reduce unnecessary water consumption and improve WUE.
为明确协同提高冬小麦产量和水分利用效率的适宜灌水量和种植密度,选用大穗型品种‘泰农18’(T18)和中穗型品种‘山农22’(S22)为试验材料,设置4个灌溉水平(不灌水、每次灌水45、60、75 mm)和4个种植密度,其中泰农18选用135×104、270×104、405×104、540×104 株·hm-2,山农22选用90×104、180×104、270×104、360×104株·hm-2,研究了籽粒产量、麦田耗水特性和水分利用效率对灌水量和密度互作效应的响应。结果表明: 籽粒产量、总耗水量、土壤贮水消耗量和水分利用效率均受到灌溉水平、种植密度及两者互作效应的显著影响。每次灌水量为45 mm,泰农18种植密度为405×104株·hm-2、山农22种植密度为270×104株·hm-2时,两品种籽粒产量均达到最高,拔节后棵间蒸发量占阶段农田总耗水量的比例最小,1 m以下土壤水消耗比例、水分利用效率高。种植密度与灌溉量合理组合,有利于降低水分无效损耗,提高水分利用效率。.
Keywords: evapotranspiration; grain yield; irrigation regime; plant density; water use efficiency; winter wheat.