RESEARCH ON THE PHYSIOLOGICAL MECHANISM FOR HIGH-YIELD AND WATER-SAVING OF SPRING WHEAT IN HETAO IRRIGATION DISTRICT OF INNER MONGOLIA | 河套灌区春小麦节水高产栽培生理基础研究

Chinese. 在内蒙古河套平原浅层地下水灌区,通过设计田间不同灌水处理试验,研究了不同供水条件下春小麦的耗水组成、水分利用效率及其与产量形成的关系,揭示了春小麦个体构型、群体结构、贮藏物质转运及籽粒灌浆等生理基础,为河套灌区春小麦节水高产技术体系的建立提供理论依据。结果表明,随着灌水量的增加,春小麦产量也相应增加,但水分利用效率和经济产量均以拔节和抽穗期灌2水处理最高;春小麦的水分利用效率与地下水补给量呈极显著正相关,即随着灌水量增加,地下水补给量减少,小麦生育期总耗水量增加,而群体水分利用效率相应降低。因此,在水资源紧缺的河套平原灌区,在秋季浇足底墒水基础上,春浇2水（拔节期＋抽穗期）是春小麦实现高产的最佳节水灌溉模式。在此节水灌溉模式下,小麦单株叶面积减少,开花期叶面积指数相应较低,此种株型和群体结构有利于改善群体内光照条件,灌浆期叶面积衰减慢,物质生产能力较高,且茎鞘贮藏物质的转运及籽粒灌浆速率快,粒重增加。同时,地上部较小的冠层结构又减少了水分的蒸腾消耗,提高了群体水分利用效率,这是节水栽培春小麦实现高产与高水分利用效率统一的生理基础。

English. A field experiment was conducted in 2007 to study the effects of water on grain yield,water components and water use efficiency（WUE） of spring wheat,and physiological mechanism on the the plant type,canopy structure,storage substance transfer and grain filling were determined for the establishment of the technical system of water saving and high yield of spring wheat in the Hetao irrigation district with shallow groundwater of Inner Mongolia.The results demonstrated economic yield of spring wheat increased with the increasing irrigation times,but the highest WUE and economic yield were observed under two-times watering condition.The WUE of spring wheat correlated significantly and positively with groundwater recharge.That is,water consumption during the whole growth season significantly increased while WUE and groundwater recharge reduced accordingly with the increasing irrigation rates on spring wheat.Under enough autumn irrigation＇s condition,the irrigation was performed two times before elongation and after heading stage that can be considered the optimal selection to maintain high-yield and water-saving.The leaf area per stem got small through controlling irrigation before jointing stage,leaf area index（LAI）at anthesis decreased under the two-times irrigation scheme in wheat,but these lead to better canopy structure,light transmission ratio increased significantly,high canopy photosynthetic efficiency,high transportation ratio of reserve in stems and sheaths to grains after anthesis,grain-filling rate rasining and grain weight increased.Meanwhile,root weight increased in deep soil layer when water supply decreased in the early stage,and smothered canopy cut down leaves transpiration loss,which contributed to high WUE for spring wheat under drought condition.