微咸水非充分灌溉对冬小麦生长发育及夏玉米产量的影响

Effect of deficit irrigation with brackish water on growth and yield of winter wheat and summer maize

为实现微咸水替代淡水,缓解环渤海地区淡水资源紧缺的目的,采用桶栽和大田试验相结合的方法,研究了不同矿化度咸水非充分灌溉对冬小麦产量、产量构成、生理指标及其后茬玉米产量的影响。桶栽试验表明,小麦产量灌2水>灌1水>旱作,产量差异主要由千粒重变化引起;两种灌水处理中灌水的矿化度对产量无明显影响。大田冬小麦试验设越冬后不灌水(A0),越冬后拔节期灌淡水(A1)、2 g.L-1微咸水(A2)和4 g.L-1微咸水(A3)4个处理。结果表明,微咸水灌溉降低了小麦离体叶片的失水速率,提高了小麦的比叶重;微咸水灌溉引起了小麦千粒重降低,但对穗粒数和穗数无显著影响;不同处理小麦产量为A2>A3>A1>A0。微咸水灌溉增加了0～40 cm土壤含盐量;随着灌溉水矿化度的增加,土壤含盐量呈增加趋势,且主要增加了0～40 cm土层的K++Na+含量。虽然后茬玉米季未进行微咸水灌溉,但土壤积累的盐分对玉米形成了减产效应,A2和A3处理的玉米产量比A1分别降低11.8%和18.8%,A3比A2处理的玉米减产8.0%;全年产量为A2>A1>A3>A0。因此,在冬小麦-夏玉米一年两熟种植区,利用2 g.L-1及以下的微咸水灌溉小麦,对全年产量无显著影响。

Pot and field experiments on deficit irrigation with brackish water were conducted.The objective of the experiments was to substitute fresh water of irrigation with brackish water,which could relieve water shortage in the Bohai Rim of China.The effects of deficit irrigation with brackish water on winter wheat yield,yield components and physiological characters were studied.The yield of the later crop,summer corn,was investigated too.The pot experiment showed that the order of irrigation for optimum wheat yield was double irrigation single irrigation rain-fed.Change in yield was mainly caused by the 1000-gain weight variation.The effect of salt levels of irrigation water on wheat yield was insignificant.In the field experiment,four treatments were analyzed-no irrigation after winter（A0）,irrigation at jointing stage with fresh water（A1）,2 g·L？1（A2） and 4 g·L？1（A3） brackish water irrigation.The field experiment showed that brackish water irrigation decreased excise-leaf water loss,increased specific leaf weight and leaf area of winter wheat.No significant change was observed in kernel number per spike and spike number.The 1000-grain weight,however,decreased under brackish water irrigation.The order of yield for winter wheat under the treatments was A2A3A1 A0.Salt content in the 0～40 cm soil layer was enhanced under brackish water irrigation.It increased more obvious under higher salt concentration of irrigation water.Among the cations in the 0～40 cm soil layer,K＋ ＋ Na＋ increase was most significant.Although there was no irrigation during the growth period of summer maize,maize yield under A2 and A3 treatments dropped by 11.8% and 18.8%,respectively,compared with A1.The yield drop in A2 and A3 was due to the accumulation of salts in the soil during the growth period of winter wheat.Yield under A3 was 8.0% lower than that under A2.The order of the total yield for winter wheat and summer maize was A2A1A3A0.The results suggested that irrigation with 2 g·L？1 brackish water had no significant effect on annual yield of winter wheat and summer maize in the winter wheat/summer maize double cropping system.