盐渍化土壤改良措施的作物生产效应

河西灌溉农业区的土壤盐分随水而迁移到低洼地聚集，导致土壤呈盐渍化而不宜种植牧草作物等。为修复这一土地资源，在土壤（0～10 cm）含盐量为18%～42%的土地上开挖排盐沟洗盐后种植牧草和农作物，研究其生产能力。结果表明：在排盐沟间距240 m地段种植的紫花苜蓿Medicago sativa比同等条件下种植的啤酒大麦Hordeum vulgare的生物量高0.53倍，蛋白质产量高3.57倍；比在排盐沟间距350 m地段种植的啤酒大麦生物量和蛋白质产量分别高1.38倍和5.60倍；比未改良地段（天然草地）相应高4.82倍和16.31倍。改良盐渍化草地、种植紫花苜蓿生产不仅为动物带来了营养丰富的食物，而且作为极有价值的草产品资源纳入了干草销售体系。此外，还使原本退化严重的天然草地，变成了高产、稳产的紫花苜蓿栽培草地，对恢复草地生态具有极其重要的推广意义。

Effect of salinity soil improvement on crop production

Soil salinity accumulated in lower areas with the water movements and high evaporation in Hexi irrigated agricultural region. The accumulation of salinity resulted in the unsuitable conditions for forage and crop growing. The objective of this study was to test the productivity of forages and crops that were cultivated on the plots where the original salt content (0 to 10 cm) was about 18% to 42% and the salt was removed through washing channels. The results indicated that the grass and protein yields of alfalfa (Medicago sativa) were increased by 0.53 times and 3.57 times compared with beer barley (Hordeum vulgare) under 240m distance between two washing channels. They were 1.38 times and 5.60 times, 4.82 times and 16.31 times higher than the yields of beer barley under 350m distance between two washing channels and the yields of the untreated area (natural grassland), respectively.