间歇灌溉对北方水稻生理生态需水的影响

Effects of intermittent irrigation on ecological and physiological water requirement of rice in north China

通过田间试验研究了间歇灌溉 (IT)条件下北方水稻生理生态需水变化特性 .试验于 2 0 0 2年在中国科学院沈阳生态实验站水田试验区进行 .分别采用非称重式蒸渗仪和小型蒸渗仪对间歇灌溉和淹灌(CSF)条件下的稻田蒸散量和棵间蒸发量进行了测定 .结果表明 ,间歇灌溉条件下的水稻蒸腾量与淹灌相比没有达到显著差异 ,而稻田棵间蒸发量和渗漏量则分别减少了 16 %和 2 4 % ,水分利用效率提高了10 % ,在显著减少用水量的情况下并未对水稻产量造成不良影响 .针对本地区土质而言 ,与淹灌相比 ,尽管间歇灌溉可以有效地减少稻田用水量 ,但仍有近 6 0 %的稻田用水通过渗漏损失掉 .为此 ,本文提出着眼于提高稻田水分利用效率、降低渗漏量和土壤水蒸发量的相应对策 .

The ecological and physiological water requirement of rice was studied in a paddy field of north China,and the field experiment was conducted at Shenyang Experimental Station of Ecology,Chinese Academy of Sciences.Under continuous flooding irrigation(CSF) and intermittent irrigation(IT) conditions,the evapotranspiration and soil evaporation of paddy fields were measured by non-weighing lysimeters and micro-lysimeters,respectively.The results showed that compared with continuous flooding irrigation,the transpiration under intermittent irrigation condition was not significantly reduced,but 16% and 24% of water amounts were reduced by decreasing the water losses through soil water evaporation and percolation,respectively.The water use efficiency of intermittent irrigation was increased 10%,without any adverse effects on biomass and grain yield of rice.Although the amount of water requirement under IT treatment was reduced significantly compared with CSF treatment,about 60% of total water requirement was still lost through deep percolation.Based on the results obtained,the corresponding countermeasures to reduce the amounts of soil water evaporation and percolation and to increase the water use efficiency were put forward in this paper.