干旱区生态环境知识资源中心

High boron content is a key factor limiting the reclamation of arid region soils. The objective was to determine spatial variability of soil properties in a boron-toxic field irrigated by pivot sprinklers prior to the development of a proper management strategy. Top soils (0-30 cm) and sub-soils (30-60 cm) were separately sampled at each of 56 predetermined sampling points based on 100*100 m regular grid in 43 ha area. Soil samples were analyzed for physical and chemical properties to determine the spatial distributions. The major constraints in plant production were high pH and boron content. Soil pH showed the lowest variability (CV=3.60%), and boron concentration showed the highest variability (CV=67.94%) in surface soils. Boron concentration in surface soils had high significant positive correlations with EC (r=0.737, P<0.01) and clay content (r=0.520, P<0.01), but negative correlations between sand content (r=0.575, P<0.01) and aggregate stability (r=-0.378, P<0.01), whereas no significant correlation occurred between boron and any of the textural components in subsurface soils. The results indicated that geostatistical methods are useful in understanding the heterogeneous nature of soil salinity as well as soil boron levels, and developing site-specific reclamation techniques for the purpose of increasing crop yields on arid zone soils.