以肥调水提高水分利用效率的生物学机制研究

为揭示以肥调水作用的内在实质，充分发挥水肥的协同作用，我们于１９９５～１９９６年进行了大田和深桶栽培冬小麦氮、磷二因素五水平二次通用旋转组合设计施肥试验。采用中子法和石膏块法监测土壤水分，于灌浆初期用美国产ＬＩ—６２００型便携式光合作用系统测定光合、蒸腾速率，同时挖取土柱测定根系。研究表明合理施肥可显著增加冬小麦根量，提高根系活力，扩大作物吸收水分和养分的空间和动力；提高光合、蒸腾速率和蒸腾蒸散比（Ｔ／ＥＴ），降低土壤水分无效蒸发损失；增加有效穗数和经济产量。从而使冬小麦的水分利用效率得以大幅度地提高。

A Study on Biological Mechanism of Raising Water Use Efficiency by suitable application of Fertilizers

To explore the essence that soil water absorb and use are improved by suitable fertilizer application, and to bring fully the cooperative effects of water and fertilizers into play, a fertilizer experiment with nitrogen and phosphorus, based on quadratic rotation design of 2 factors and 5 levels, was conducted in field and deep pots simultaneously in winter wheat in 1995 1996. Experiment results show that suitable fertilization can improve root growth markedly, which will expand space and improve vigor of crop root system for water and nutrient absorption, and to raise photosynthetic rate, transpiration rate and transpiration/evaporation ratios, and furthermore to improve water use efficiency of winter wheat obviously.