摘要：

为明确灌水量对玉米生产的影响,以郑单958为试验材料,以本地区多年来参考作物平均需水量(ET0)为基础,于2020,2021年在旱棚条件下设置T1(60%ET0)、T2(80%ET0)、T3(100%ET0)、T4(120%ET0)、T5(140%ET0)、T6(160%ET0)、T7(180%ET0)、T8(200%ET0)共计8种灌水处理,分析了灌水对玉米产量及构成、植株理化性状的影响。结果表明:增加灌水,玉米产量及构成、穗长、籽粒干物质分配比例、自由水含量、株高、穗位、穗高系数、光合势及结实率表现为增加趋势,其中产量和穗粒数随着灌水的增加显著增加,而叶片和穗轴中物质分配比例表现为下降趋势。高水处理(T5~T8)下VT与R6期玉米叶片的叶绿素、水势变化率较小,处理间株高、穗位高无显著差异,穗高系数稳定。与T3相比,灌水量减少20%和40%可引起产量显著下降,而增加同比例灌水,玉米产量变化低于减少灌水后的产量降低值,该条件下的结实率变化与产量变化一致,而供水效率随着灌水的增加而降低,灌水量超过T6处理的供水效率下降超过20%。相关分析表明,玉米产量与叶片叶绿素含量、开花期水势及含水量无显著相关性,与其他因素存在显著或极显著相关关系,因此,玉米可通过灌水改善穗部性状、籽粒干物质分配比例及植株发育理化性状等实现产量提升,在本区域生育期平均需水量基础上增加灌水40%~60%可实现产量和效率最大化。

关键词: 夏玉米, 灌水量, 产量, 理化性状

Abstract:

In order to clarify the impact of irrigation amount on maize production,using Zhengdan 958 as the main material and the local average reference crop water demand(ET0)was used as the basis of irrigation volume,a study was conducted under rain-protection shed in 2020 and 2021,which included eight irrigation treatments:T1,T2,T3,T4,T5,T6,T7 and T8 representing 60% ET0,80% ET0,100% ET0,120% ET0,140% ET0,160% ET0,180% ET0 and 200% ET0,respectively.The study aimed at analysing the effects of irrigation on yield and its components and plant physicochemical properties.The results indicated that the yield and its components,ear length,grain dry matter distribution ratio,free water content,plant height,ear position height,ear height coefficient,photosynthetic potential and seed setting rate of maize showed an increasing trend when irrigation was added.Specifically, the yield and grain number per ear increased significantly while the material distribution ratio decreased in leaf and corn cob.There was a small change rate of chlorophyll and water potential of maize leaves,no significant difference in plant height and ear position height among treatments and stable ear height coefficient at VT and R6 stages under high water treatment(T5—T8).Comparing with T3,a decrease of 20% and 40% in irrigation volume could cause a significant decrease in yield,but the lower yield increase rate appeared when irrigation volume had the same increase rate as the decrease rate. The seed setting rate also showed the same variation under the same condition. However,the water supply efficiency decreased with the increase of irrigation volume and declined more than 20% when the irrigation volume exceeded T6.Correlation analysis showed that correlation between maize yield and leaf chlorophyll content,water potential at anthesis and water content was not significant,but there was a significant or extremely significant correlation with other factors.Therefore,maize yield could be raised by improving ear traits,grain dry matter distribution ratio and physical and chemical properties of plant development through irrigation,an increased irrigation amount by 40%—60% on the basis of the average water demand should be suggested for maximizing the yield and efficiency during the growth period in the region.

Key words: Summer maize, Irrigation amount, Yield, Physicochemical character