高产小麦耗水特性及干物质的积累与分配

Water Consumption Characteristic and Dry Matter Accumulation and Distribution in High-Yielding Wheat

在2005—2006年和2006—2007年小麦生长季降水量分别为128.0mm和246.4mm条件下,采用不同灌水量处理,研究了高产条件下冬小麦的耗水特性和小麦干物质的积累与分配。结果表明,底水和拔节水分别灌溉60mm处理(W2)在两个生长季获得了最高的籽粒产量,2005—2006年生长季其水分利用效率和灌溉水的利用效率均显著高于其他灌水处理;2006—2007年生长季,其水分利用效率较高,降水量、灌水量和土壤供水量分别占农田耗水量的47.32%、23.04%和29.64%;与不灌水处理(W0)相比,灌水处理显著提高开花后干物质的积累量和开花后干物质积累量对籽粒的贡献率,以W2处理最高,分别达8241.59kghm-2和84.18%。灌水量过多显著减少光合产物向籽粒的分配,使产量降低。随灌水量增加,小麦全生育期耗水量显著增大,灌水量占农田耗水量的比例增加,降水量和土壤供水量占农田耗水量的比例均降低,以土壤供水量所占比例降低最大。综合考虑小麦的籽粒产量和水分利用效率,在本试验条件下,以底水和拔节水各60mm的灌溉量为最优。在小麦生长季降雨量为246.4mm条件下,仅灌60mm底水亦可获得较高的籽粒产量,其土壤供水量占农田耗水量的比例和灌溉水的利用效率高于底水和拔节水处理。

Water resource deficiency is one of major problems in wheat （Triticum aestivum L.） production in North Plain of China. Irrigation plays an important role to obtain high grain yield and quality. Currently, many reports on the basis of different experiments and cultivars have suggested several irrigation regimes in wheat, but no consistent conclusion is available due to interactions between eco-environment and cultivar. In this study, two winter wheat cultivars were used under high-yielding cultivation in 2005-2007 growing seasons （with precipitations of 128.0 and 246.4 mm, respectively） to reveal the effects of irrigation amount on water consumption characteristics and dry matter accumulations in various organs. The results showed that the yield of treatment W2 （irrigated each 60 mm before sowing and at jointing） was the highest and the WUE of treatment W2 was significantly higher than that of other irrigation treatments in 2005-2006 and 2006-2007 wheat growing seasons. And when the precipitation was 246.4 mm from sowing to maturity in 2006-2007, the ratios of precipitation, irrigation amount and soil water amount to water consumption amount in treatment W2 were 47.32%, 23.04%, and 29.64%, respectively. Compared with in treatment W0, dry matter accumulation amount after anthesis and contribution of dry matter accumulation amount after anthesis to grains in irrigated treatments increased significantly with the highest of 8 241.59 kg ha^-1 and 84.18% respectively in W2. However over-irrigation significantly reduced the photosynthate and grain yield. Water consumption amount increased significantly with increasing irrigation amount, and the ratio of irrigation amount to water consumption amount increased too, but the ratio of precipitation to water consumption amount and the ratio of soil water amount to water consumption amount both decreased. The variation in the ratio of soil water amount to water consumption was larger than others. As far as grain yield, WUE and WUE of irrigation concerned in the experiment, the most appropriate treatment for recommendation was treatment W2, which was irrigated 60 mm before sowing and at jointing stage respectively. The ratio of soil water amount to water consumption amount and the WUE of irrigation were higher in treatment W1 than in treatment W2, and the grain yield in treatment W1 was 8 797.73 kg ha^-1 when the precipitation was 246.4 mm. The results can offer a useful reference for formulating water-saving cultivation techniques in the areas with different water resources.