夏玉米苗期有限水分胁迫拔节期复水的补偿效应

以作物调亏灌溉原理为基础 ,对夏玉米苗期水分胁迫拔节期复水进行了试验研究。结果表明 ,复水增加了夏玉米叶片气孔导度和光合速率 ,提高叶片水平上的水分利用效率(WUE)。复水 2天后 ,叶片气孔导度和光合速率即恢复到对照水平 ,部分时段 ,特别在下午 ,复水处理表现出高于对照的“反冲”现象。复水使苗期受旱的夏玉米株高、叶面积、地上 (下 )部分干物重和根系生长发育都恢复到或接近充分供水的植株生长水平。使其产量及构成因子与对照接近 ,水分利用效率显著地提高了 2 4 7%。这为玉米中后期的水分管理 ,提高玉米水分利用效率 ,提供了一定的理论依据 ;也提供了一种便于广大农民掌握的简单易行的灌溉方式

Compensatory effects of re-watering on summer maize threatened by water stress at seedling period

Based on the theory of crop Regulated Deficit Irrigation (RDI), field experiments on compensatory effects of re-watering at jointing stage for summer maize threatened by water stress at seedling period were carried out.The results showed that re-watering can increase the stomatal conductance, photosynthesis rate, and WUE (Pn/Tr).The compensatory effect was evident.Two days after re-watering, the stomatal conductance and photosynthesis rate recorered to the level of CK.Sometimes in the morning and the whole afternoon, the "over-compensatory " effect under re-watering treatment was significant.In addition, the plant height, leaf area, shoot and root biomass of summer maize can improve to the plant growth status under well irrigation treatment.Thus, the yield and yield factors were close to the CK.The WUE (Y/ET) was improved to 24.7% significantly.It provided a theoretical reference for water management and improving water use efficiency of summer maize, and also provided a simple irrigation method that can be operated by farmers easily.