4种填闲作物对天津黄瓜温室土壤次生盐渍化改良作用的初步研究

通过夏季填闲的方式来解决设施农业次生盐渍化在20世纪初就已被提出，但相关研究在天津黄瓜温室土壤次生盐渍化改良方面还没有开展。通过盆栽试验研究了4种填闲作物（毛苕子、苏丹草、甜玉米和苋菜）对天津地区黄瓜温室土壤次生盐渍化的改良作用。结果显示，与对照土壤相比，4种填闲作物均能显著降低土壤可溶性盐分和Na^＋的含量（P〈0．05），显著降低土壤养分和有机质的含量（P〈0．05）；毛苕子、甜玉米和苋菜能显著增大土壤K^＋／Na^＋的比值；高种植密度对次生盐渍化土壤的改良效果更为突出；4种填闲作物相比，毛苕子对黄瓜温室土壤次生盐渍化的改良效果最佳。既为改良天津黄瓜温室土壤次生盐渍化提供实践参考，也为延长设施土壤使用年限，促进天津设施蔬菜产业发展提供一种可行途径。

Study of the Improvement Effects of Four Catch Crops on the Secondary Salinization of Tianjin Cucumber Greenhouse Soil

Greenhouse vegetable production has been widely applied in North China due to its higher economic and social benefit. However, the special ecological environment and unreasonable irrigation or fertilizing often result in secondary salinization of greenhouse soil, that would directly do harm to crop growth, reduce crop yield and quality, and also affect human health or ecological environment. Among the methods of salt elimination, biological treatment has been paid more attention because of its predominant performance in operation and cost. Since cucumber is an important cash crop in Tianjin and the secondary salinization of cucumber greenhouse soil has been more and more severe, thus a pot cultivation experiment was designed to study the improvement effects of four catch crops on the secondary salinization in this paper. In middle July of 2007, the soil/substrate was collected from one cucumber greenhouse of Xiaobian Village, located in Nanhe Town of Xiqing District in Tianjin. Four catch crops, respectively Vicia villosa Roth., Sorghum s udanense （Piper） Stapf., Zea mays L. saceharata Sturt, A maranthus mangostanus L., were selected as experimental plants. The experiment was carried out at the campus experiment site of Tianjin Agricultural University. The seeds were sown in the pot soil on 20 July 2007, and after 10 days the seedlings were thinned to form three plant densities. A randomized block design was used with five blocks （replicates） and twelve pots （treatments） per block. On 10 September 2007, the above ground materials of each pot were harvested and the dry matter accumulation was subsequently determined. Additionally, 0 -20 cm soil was sampled from each pot and stored in aluminum cases after air drying for soil nutrient measurement. The results indicated that after planting these four plants, soluble salinity, Na^＋ content, soil nutrient and organic matter content significantly decreased compared with CK. Vicia villosa, sweet corn and A maranthus mangostanus could significantly increase