玉米苗期和拔节期调亏灌溉技术研究

Research on Regulated Deficit Irrigation in Maize Seeding Stage and Jointing Stage

以玉米吉单198为试验材料,利用盆栽试验研究了苗期和拔节期缺水对玉米植株性状、光合生理及产量的影响。结果表明玉米各缺水处理株高、叶面积、冠风干重和根风干重均低于CK,但苗期缺水处理根长高于CK。在子粒灌浆期苗期轻度、中度缺水处理光合速率高于CK,苗期重度缺水和拔节期各缺水处理光合速率均低于CK。苗期轻度缺水减产1.47%,苗期中度缺水增产1.90%,但与对照比差异不显著;其余处理均减产,并与对照相比均达到显著水平。苗期土壤含水量在田间持水量的50%以上时,起到蹲苗促根生长的作用,对产量影响较小,可以考虑不灌;拔节期植株的新陈代谢活动旺盛,水分胁迫既影响营养体生长,又影响内部幼穗的分化,造成营养体生长不良,土壤含水量低于田间持水量的70%应及时补水灌溉。

Using Jidan 198 as material, effects of different lacking water treatments on plant characters, photosynthesis physiology and yield were studied with pot cultivation at maize seeding stage and jointing stage. Results indicated that lacking water at seeding stage and jointing stage reduced plant height, leaves area, dry crown weight and root weight. But lacking water treatments at seeding stage increased root length. Photosynthetic rate increased in slight and medium lacking ,sater treatments at seeding stage and filling stage, but it decreased in serious lacking water treatments at seeding stage and lacking water treatments at jointing stage. Yield decreased by 1.47% and 1.90% in slight and medium lacking water treatments at seeding stage, but the differences were not significantly compared with the control. Yield of other treatments were significantly lower than the control. When the soil water content was more than 50% of field moisture capacity, irrigation was not needed because plant growth was inhabited but root growth increased and yield not largely influenced. At jointing stage, water stress influenced vegetative growth and young ear differentiation, so maize should be irrigated when soil water content was less than 70% of field moisture capacity.