在田间试验条件下, 以中穗型小麦(Triticum aestivum)品种‘山农15’和大穗型品种‘山农8355’为供试材料, 设置3个0-140 cm土层土壤相对含水量处理: W0 (拔节期65%, 开花期60%)、W1 (拔节期70%, 开花期70%)、W2 (拔节后8天70%, 开花后8天70%), 采用测墒补灌的方法补充土壤水分达到目标相对含水量, 对两个不同穗型小麦品种的耗水特性和干物质积累与分配进行了研究。结果表明: (1)两品种籽粒产量均以W0处理最低, ‘山农15’ W1和W2处理无显著差异, ‘山农8355’ W1处理显著高于W2处理; 两品种W1处理的水分利用效率和灌溉水利用效率均显著高于W2处理。‘山农15’ W1处理的籽粒产量和灌溉水利用效率分别显著低于和高于‘山农8355’的W1处理, 水分利用效率无显著差异; 两品种W2处理的籽粒产量、水分利用效率和灌溉水利用效率均无显著差异。(2)两品种总耗水量以W0处理最低, ‘山农15’ W1处理显著低于W2处理, ‘山农8355’两处理无显著差异; 两品种W1处理的土壤供水量及其占总耗水量的比例显著高于W2处理。‘山农15’ W1处理的总耗水量和灌水量占总耗水量的比例显著低于‘山农8355’, 土壤供水量占总耗水量的比例显著高于‘山农8355’; 两品种W2处理总耗水量, 土壤供水量及其占总耗水量的比例无显著差异。(3)两品种W1处理成熟期干物质积累量显著高于其他处理, W1处理提高了‘山农8355’开花后干物质积累量及其对籽粒的贡献率, 对‘山农15’无显著影响。‘山农15’ W1和W2处理成熟期干物质积累量显著低于‘山农8355’, 开花前贮藏同化物向籽粒的转运量和转运率、对籽粒的贡献率均显著高于‘山农8355’, 开花后干物质积累量及其对籽粒的贡献率低于‘山农8355’。综合考虑干物质积累与分配、籽粒产量、水分利用效率和灌溉水利用效率, W1处理是两品种节水高产的最佳土壤相对含水量处理。

Aims Our objective was to determine the effects of supplemental irrigation on water consumption characteristics and dry matter accumulation and distribution in different spike-type wheat cultivars under field conditions based on testing soil moisture.
Methods We conducted a field experiment using medium-spike (‘Shannong 15’) and large-spike (‘Shannong 8355’) cultivars. Three irrigation treatments were designed based on the contents of relative soil moisture at jointing and anthesis stages: 65% and 60% (treatment W0), 70% and 70% (W1), and 70% and 70% (delaying irrigation 8 d after the designated stages mentioned above; W2).
Important findings Grain yield in treatment W0 was the lowest in both cultivars. In ‘Shannong 15’, there was no significant difference between W1 and W2, whereas in ‘Shannong 8355’, W1 had higher grain yield than W2. Water use efficiency (WUE) and irrigation water use efficiency (IWUE) of W1 were significantly higher than those of W2 in both cultivars. Under W1, grain yield of ‘Shannong 15’ was lower than that of ‘Shannong 8355’, but IWUE was the opposite. There was no significant difference between ‘Shannong 15’ and ‘Shannong 8355’ in WUE. Under W2, grain yield, WUE and IWUE had no significant differences. The lowest total water consumption amount (TWCA) was obtained in W0 in both cultivars. In ‘Shannong 15’, W1 had lower TWCA than that of W2, while there was no significant difference in ‘Shannong 8355’ between the two treatments. Soil water consumption amount and its ratio to TWCA in W1 were significantly higher than those in W2 in both cultivars. Under W1 condition, TWCA and the ratio of irrigation amount to that in ‘Shannong 15’ were significantly lower than those in ‘Shannong 8355’, but the ratio of soil water consumption amount to TWCA was the opposite. Under W2, there was no significant difference between TWCA and the ratio of soil water consumption amount to it. Dry matter accumulation at maturity of W1 was significantly higher than that in other treatments in both cultivars, and it was significantly lower for W1 and W2 in ‘Shannong 15’ than in ‘Shannong 8355’. Treatment W1 increased dry matter accumulation amount after anthesis and its contribution to grains in ‘Shannong 8355’, but it did not change significantly in ‘Shannong 15’. Dry matter translocation after anthesis, its ratio and contribution to grains of W1 and W2 in ‘Shannong 15’ were significantly higher than those in ‘Shannong 8355’, while dry matter accumulation after anthesis and its contribution to grains were the opposite. In wheat production under conditions similar to this study, the optimal irrigation treatment in both cultivars was W1.