[目的]为探究适宜于干旱、半干旱区番茄大田栽培的灌溉水盐度和盐分组成.[方法]在宁夏银北灌区开展3年番茄膜下滴灌野外田间试验,设置3种不同盐分浓度(1,2,3 g/L)和5个Na:Ca摩尔浓度比(1,3,5,7,9)的灌溉水源.[结果]在较低的灌溉水盐度(1 g/L)下,适当增加灌溉水Na:Ca摩尔比有利于番茄植株的干物质和氮磷钾素积累;番茄单果重、商品果产量和总产量随灌溉水Na∶Ca摩尔比增加而线性下降,且灌溉水Na:Ca摩尔比每增加1,番茄商品果产量下降5 761.7~6 036.7 kg/hm2;"高盐度(2,3 g/L)、低Na:Ca摩尔比(1,3)"的灌溉水较"低盐度、高Na:Ca摩尔比"的灌溉水,更有利于番茄增产;膜内表层40 cm 土壤钠吸附比和表层100 cm 土壤积盐量随灌溉水Na:Ca摩尔比的增加线性增加.[结论]为在宁夏银北灌区大田栽培番茄生育期内减少积盐并获得相对高产,推荐土壤基质势控制下限-20 kPa下膜下滴灌的适宜灌溉水盐度为2 g/L且Na:Ca摩尔浓度比为5.
Effects of Irrigation Water Salt Compositions on Tomato Growth and Soil Salinization
[Objective]To explore the optimal salt composition and salt concentration of irrigation water suitable for tomato field cultivation in arid and semi-arid areas.[Methods]Three salinity levels(1,2,and 3 g/L)and five Na∶Ca molar concentration ratio levels(1,3,5,7,and 9)of irrigation water were used in a 3-year field experiment of drip irrigation under tomato film in Yinbei irrigation district of Ningxia,China.[Results]The experiment found that with lower irrigation water salinity(1 g/L),appropriate increases in the Na:Ca molar ratio of irrigation water were beneficial for the accumulation of tomato plant dry matter and nutrients.Tomato fruit weight,marketable yield,and total yield decreased linearly with the increase of irrigation water Na∶Ca molar ratios.Moreover,with each increase in Na:Ca molar ratio of irrigation water,the tomato marketable yield decreased by 5 761.7 to 6 036.7 kg/hm2.Irrigation water with"high salinity(2,3 g/L)and low Na:Ca molar ratio(1 and 3)"was more profitable for tomato yield increase than irrigation water with"low salinity and high Na:Ca molar ratio".The soil sodium adsorption ratio in 0-40 cm and the amount of soil salt accumulation in 0-100 cm increased linearly with the increase of irrigation water Na∶Ca molar ratio.[Conclusion]To alleviate the soil salt accumulation and obtain a relatively high fruit yield during the growth period of field cultivated tomatoes in Yinbei irrigation area of Ningxia,irrigation water with salinity of 2 g/L and Na∶Ca molar concentration ratio of 5 was recommended for mulched drip irrigation,under the control limit of soil matrix potential at-20 kPa.
saline watermulched drip irrigationdry matter accumulationmarketable yieldsodium adsorption ratio