再生水与黄河水灌溉对宁夏引黄灌区土壤环境及玉米生长的影响OA

To clarify the safe and efficient utilization mode of reclaimed water in the Ningxia Yellow River irrigation district and alleviate the shortage of agricultural water resources,a two-factor completely randomized design was adopted in this study.We investigated the effects of two water sources,namely Yellow River water(Y)and reclaimed water from constructed wetlands(R),and two irrigation regimes on soil environmental quality and maize growth.The irrigation regimes were defined as:W1(irrigation quota of 1 800 m³/ha with two irrigation events)and W2(irrigation quota of 1 200 m³/ha with three irrigation events).The TOPSIS(technique for order preference by similarity to ideal solution)model was employed to screen the optimal irrigation mode.The results showed that irrigation regimes had a significant impact on the accumulation of soil heavy metals;specifically,the W2 treatment significantly reduced soil cadmium and zinc contents compared to W1,and reclaimed water irrigation performed comparably to Yellow River water in controlling cadmium and zinc.Furthermore,the W2 treatment significantly increased soil cation exchange capacity and total phosphorus content,thereby enhancing soil fertility preservation and supply capabilities.In terms of promoting maize growth,increasing yield,and improving water use efficiency,reclaimed water irrigation proved superior to Yellow River water.The yield of RW1 treatment was 4.11%higher than that of YW1 treatment,and the yield of RW2 treatment was 6.77%higher than that of YW2 treatment,with an an irrigation water use efficiency of 5.12 kg/m³.Regarding maize quality,the YW2 treatment increased protein and fat contents by 21.52%and 21.62%,respectively,compared to YW1;similarly,the RW2 treatment increased protein and fat contents by 17.58%and 44.44%,respectively,compared to RW1.Pearson correlation analysis indicated that soil pH value,total salt content,total nitrogen content,copper content and zinc content were the core factors influencing maize yield and quality.The TOPSIS comprehensive evaluation revealed that the RW2 treatment achieved the highest score,identifying it as the optimal irrigation mode.In summary,RW2(reclaimed water combined with an irrigation quota of 1 200 m3/hm2 and three irrigation times)is the suitable model for the safe and efficient utilization of water resources in the Yellow River irrigation district of Ningxia.