Effects of supplemental irrigation at key growth stages on soybean yield and water productivity in arid area of northern Shaanxi
To investigate the effects of supplementary irrigation during critical growth stages on the growth,yield,and water productivity of soybeans in the dryland farming areas of northern Shaanxi,a two-year field experi-ment was conducted with six treatments:irrigation to 80％of field capacity(θ)at branching stage(BI80),irriga-tion to 100％θf at branching stage(BI100),irrigation to 100％θfat flowering stage(FI100),irrigation to 80％θf at branching stage followed by irrigation to 100％θf at flowering stage(BI80+FI100),irrigation to 100％θf at branching stage followed by irrigation to 100％θf at flowering stage(BI100+FI100),and rainfed control(CK).The effects of branching and flowering stage irrigation on soybean plant height,leaf area index(LAI),soil water storage(SWS),evapotranspiration,biomass accumulation and translocation,yield(SY),water productivity(Wp),and irrigation water use efficiency(IWUE)were examined.The results showed that compared to the rainfed control,BI80+FI100 treatment resulted in appropriate plant height and LAI,along with increased pre-flowering and post-flowering bio-mass translocation.SY was significantly increased by 28.03％to 38.71％compared to CK(P＜0.05),and Wp was increased by 3.80％to 13.51％compared to CK.Increasing the upper limit of irrigation from 80％θf to 100％θf at branching stage led to prolonged LAI,accelerated soil water consumption,decreased post-flowering SWS and evapo-transpiration,and reduced post-flowering biomass accumulation and translocation.Compared to BI100+FI100,there was no significant difference in SY for BI80+FI100.However,Wp increased by 1.23％to 9.33％,and IWUE signifi-cantly improved by 37.69％to 60.20％(P＜0.05),with irrigation water reduced by 18.54％to 20.21％compared to BI100+FI100.Under the BI80+FI100 treatment,LAI ranged from 6.66 to 7.48,ETa/ETb stabilized between 0.85 and 1.04,and the post-flowering biomass contribution rate remained steady at 80.78％to 81.07％.These values were within suitable ranges,resulting in the highest SY,Wp,and IWUE of the season.The BI80+FI100 treatment effective-ly balanced water supply and demand for both the nutritional and reproductive growth of soybeans,creating a more stable and efficient production environment.This approach is recommended for adoption in dryland farming areas of northern Shaanxi.
soybeansupplementary irrigationevapotranspirationdry matter accumulation and translocationyieldwater productivity
万方数据
维普
