调亏对玉米生态特性及产量的影响

简要介绍玉米不同生育期实行不同调亏等级时对其生态特性及产量的影响。结果表明,玉米苗期及拔节期经受适度水分调亏可促使水分和营养供给向根系倾斜,增强了植株后期的调节和补偿能力,节水效益显著且对产量影响不大。与充分供水处理相比,苗期重度调亏、中度调亏、轻度调亏处理的根冠比分别增大了11.5%,23.14%和6.36%;分别节水14%,11%和7%;产量则分别相差5%,5%和3%。拔节期重度调亏、中度调亏、中轻度调亏及轻度调亏根冠比分别增大了6.25%,24.2%,40.29%及43.00%;分别节水12%,6%,4%及3%;产量则分别相差18%,9%,3%及1%。玉米苗期调亏下限以50%田间持水量为宜,拔节期以中轻度亏水为宜(60%田间持水量),低于50%田间持水量的调亏下限则减产幅度大于节水幅度。抽雄期以后不宜进行调亏。

The effect of regulated deficit irrigation on ecological characteristics and yield of corn

The effects of different levels of Regulated Deficit Irrigation (RDI) in different growth stages of corn on its ecological characteristics and yield were studied.The mild water deficit in seedling and elongation stages of corn could stimulate more water and nutrition moving to root system,which could strengthen the ability of regulation and compensation in the late part of growing season and has obvious profit and small bad effect on yield.Compared with the full water supply,the root top ratio treated with severe RDI,middle RDI and light RDI in seedling stage increased 11.5%,23.14% and 6.36%,saved 14%,11% and 7% of water use,reduced 5%,5% and 3% of crop yield,respectively.In severe RDI,middle RDI,light and moderate RDI and light RDI in elongation stage,6.25%,24.2%,40.29% and 43.00% of the ratio of root top ratio increased,12%,6%,4% and 3% of water use saved,and 18%,9%,3% and 1% of crop yield reduced,respectively.The low limit of RDI in seedling stage of corn should be 50% of field capacity.In elongation stage,light and moderate RDI (60% of field capacity) was appropriate.If the water content was lower than 50% of field capacity in elongation stage,the degree of yield reduction was greater than that of water saving.It was unsuitable to apply RDI after elongation stage.