不同水质滴灌与施氮措施下土壤盐分及关键离子变化研究

The Combined Effect of Drip Irrigation Quality and Nitrogen Fertilization on Soil Salinity and Na^(+)and Ca^(2+)Concentration in Soil Water

【目的】探明不同滴灌水质和施氮量对土壤盐分及关键离子变化的影响。【方法】基于棉花盆栽试验,设置3个施氮水平,分别为:F1(255 kg/hm^(2))、F2(315 kg/hm^(2))和F3(375 kg/hm^(2));3个滴灌水质,分别为:Q1(矿化度为1.27 g/L),Q2(矿化度为3.03 g/L)和Q3(矿化度为4.90 g/L),分析不同滴灌水质与施氮水平下的土壤盐分及关键离子的响应差异。【结果】棉花生育末期,微咸水与咸水滴灌下的土壤总盐量与Na^(+)、Ca^(2+)物质的量浓度分别相比地下水滴灌高14%~78%、42%~197%与58%~253%;土壤钠吸附比(SAR)与可交换性钠百分比(ESP)相比地下水滴灌提高了5%~109%与48%~90%;较高施氮量(315、375 kg/hm^(2))下的土壤总盐量、Na^(+)、Ca^(2+)物质的量浓度相比低施氮量(255 kg/hm^(2))降低了11%~70%、6%~42%与21%~138%,土壤SAR与ESP分别降低了5%~27%与3%~19%。【结论】土壤盐分总量随着滴灌水质矿化度的增加而增加,适宜的施氮量(315kg/hm^(2))能够降低土壤盐分总量和关键离子量,缓解土壤盐碱化。

【Objective】Drip irrigation using brackish water is a way to relieve water shortage in arid regions such as Xinjiang,but it needs a good management to reduce its detrimental consequence.The aim of this paper is to investigate the combined effect of irrigation water quality and nitrogen fertigation on changes in soil salinity and Na^(+)and Ca^(2+)concentration in soil water with cotton planted.【Method】A pot experiment was conducted from June to October 2020 at Alaer in Xinjiang.There are three nitrogen treatments:255 kg/hm^(2)(F1),315 kg/hm^(2)(F2)and 375kg/hm^(2)(F3),and three irrigation water quality treatments:1.27 g/L(Q1),3.03 g/L(Q2),4.90 g/L(Q3).Irrigation with groundwater was taken as the control.In each treatment,we measured soil salt content,and concentration of Na^(+)and Ca^(2+)in soil water.【Result】Depending on nitrogen fertigation,saline water irrigation increased total soil salt content and Na^(+)and Ca^(2+)concentrations by 14%~78%,42%~197%and 58%~253%,respectively,compared to groundwater irrigation.It also increased soil sodium adsorption ratio(SAR)and exchangeable sodium percentage(ESP)by 5%~109%and 48%~90%,respectively.Increasing nitrogen application to 315 kg/hm^(2)and 375 kg/hm^(2)reduced soil salinity and Na^(+)and Ca^(2+)concentrations by 11%~70%,6%~42%and 21%~138%,respectively,and reduced soil SAR and ESP by 5%~27%and 3%~19%,respectively,compared to the control.【Conclusion】Soil salinity increased with the increase in irrigation water salinity,but increasing nitrogen application to 315 kg/hm^(2)could reduce soil salinity and Na^(+)and Ca^(2+)concentrations in soil water,thereby alleviating salinity stresses.