拔节后补灌对不同穗型冬小麦耗水和籽粒产量的影响

为探究拔节期和开花期不同补灌方案对不同穗型冬小麦耗水特性、籽粒产量和水分利用效率的影响，于2017-2019年在山东省泰安市以大穗型品种山农23和中多穗型品种山农29为试验材料，以拔节后无灌水(T1)为对照，设置拔节期补灌目标为0~20 cm土层相对含水率达100%田间持水率(T2)、拔节期和开花期补灌目标为0~20 cm土层相对含水率达100%田间持水率(T3)和拔节期补灌目标为0~40 cm土层相对含水率达100%田间持水率(T4) 3种补灌方案。结果表明，拔节后不同补灌方案对大穗型和多穗型小麦品种影响基本一致。与T1处理相比，T4处理显著提高了0~100 cm土层土壤相对含水率，使60~100 cm土层土壤相对含水率在开花期仍保持较高水平；T3处理显著提高了拔节期0～60 cm和开花期0~40 cm土层土壤相对含水率。与T3处理相比，T4处理的拔节至开花阶段耗水量增加了28.9%，其中对上层土壤总供水的表观消耗量增加了66.4%；T4处理在开花至成熟阶段对深层土壤总供水的表观消耗量增加了68.0%，对上层土壤总供水的表观消耗量降低了37.4%。在开花至成熟期降水较多(121.2 mm)的年份，T4处理的开花至成熟阶段耗水量、开花后旗叶净光合速率和籽粒产量相对于T3处理均无显著变化，但总耗水量较高，水分利用效率显著降低；在开花至成熟期降水较少(45.2 mm)的年份，T4处理的开花至成熟期的阶段耗水量、开花后旗叶净光合速率、籽粒产量和水分利用效率较T3处理均显著降低。因此，在小麦全生育期降水量为111.6~220.2 mm、开花后降水量为45.2~121.2 mm的条件下，大穗型和中多穗型小麦品种均以在拔节期和开花期将0~20 cm土层补灌至100%田间持水率的补灌方案最优，可同时实现高产和高水分利用效率。

Effect of Supplemental Irrigation after Jointing on Water Consumption and Grain Yield of Wheat Cultivars with Different Spike-Types

This study was carried out to investigate the effect of different supplemental irrigation(SI) schedule on water consumption characteristics,grain yield and water use efficiency(WUE) of different spike-type wheat cultivars. Field experiments was conducted during the wheat growing seasons of 2017-2019,using two different spike-type wheat cultivars(large-spike type,cv. Shannong 23 and medium/multi-spike type,cv. Shannong 29). Four SI treatments,no SI at jointing and anthesis(T1),SI with the plan wetting layer depth 20 cm at jointing(T2),SI with the plan wetting layer depth 20 cm at jointing and anthesis(T3),SI with the plan wetting layer depth 40 cm at jointing(T4),were established. The target relative soil water content in the plan wetting layer was set at 100% of field capacity.SI methods showed the same effect on two different spike-type wheat cultivars. T3 increased the relative soil water content(RSWC) in 0-60 cm and 0-40 cm soil layers at jointing and anthesis,respectively. T4 increased the RSWC in 0-100 cm at jointing,and maintained higher RSWC in 60-100 cm soil layers at anthesis. Compared with T3,water consumption and apparent consumption of total water supply in the subsoil layers under T4 during jointing to anthesis was increased by 28.9% and 66.4%,respectively. From anthesis to maturity,consumption of total water supply under T4 was increased by 68.0% in the depth,but decreased by 37.4% in the subsoil layers. T4 was similar with T3 on grain yield,net photosynthetic rate and water consumption from anthesis to maturity in growing season with plenty precipitation(121.2 mm) after anthesis but was decreased in growing season without much precipitation(45.2 mm) after anthesis. With precipitation ranging form 111.6-220.2 mm in whole growing season and 45.2-121.2 mm after anthesis,the optimal SI brought SRWC in the 0-20 cm profile to 100% field capacity at jointing and anthesis,and achieved high yield and WUE in different spike-type wheat cultivars.