玉米调亏灌溉节水调控机理研究

20012003年对玉米进行了调亏灌溉试验研究。结果表明,苗期重度、中重度、中度及轻度水分调亏灌溉可使玉米株高分别降低35.7%,29.9%,22.7%和14.2%;叶面积分别降低43.4%,34.7%,31.4%和26.3%;根数分别减少40.0%,31.2%,18.7%和12.5%;根系长度分别降低11.0%,10.0%,2.0%和1.0%;根系重量分别降低32.0%,19.0%,5.0%和-1.4%;根冠比分别增加29.3%,39.9%,33.6和36.5%;根系长/株高分别增加38.4%,28.4%,26.8%和15.4%。苗期经受不同水分调亏处理的植株,拔节期恢复正常供水后其株高、叶面积和干物质重量的相对增长率较苗期提高6.8%19.8%,5.5%18.5%,25.8%2.5%;随调亏程度加大其补偿作用越明显。对玉米生理指标的测定结果表明,适宜的水分调亏可增加玉米抵御干旱的能力,提高水分利用效率,改善作物品质。

Study on the mechanism of saving water of egulated deficit irrigation in maize

In this paper,the data of maize experiment on regulated deficit irrigation were analyzed and the following results were achieved.The serious water deficit,secondary water deficit,medium water deficit and less water deficit during seedling stage reduced the stem length by 35.7%,29.9%,22.7%,14.2%,the leaf area by 43.4%,34.7%,31.4%,26.3%, the root number by 40.0%,31.2%,18.7%,12.5%,root length by 11.0%,10.0%,2.0%,1.0%, the root weight by 32.0%,19.0%,5.0%,-1.4%,respectively,and increased the root/shoot ratio by 29.3%,39.9%,33.6,36.5%,the ratio of root length/stem length by 38.4%,28.4%,26.8%,15.4%,respectively.Compared with those during seedling,water deficit at seedling stage and rewatering at jointing stage increased relatively the stem length by 6.8%-19.8%,leaf areas by 5.5%-18.5%,dry matter weight by 25.8%-2.5%,suggesting that compensatory growth occurred after rewatering.With the enhancement of water deficit,the compensatory effect became more obvious.Moreover,physiological attributes showed some water deficit could enhance the drought resistance of maize and water use efficiency,and improve seed quality as well.