Water Status And Nutrient Leaching In Purple Soils On Slope Under Different Cropping Modes

Soil and water loss results in soil thin layers and nutrient loss as well as fertility reduction, which attributes directly to land productivity depression. It is thus important to reasonable planting modes to prevent soil erosion and improve land productivity of purple croplands on slopes. It is vitally significant to find efficient cropping ways to prevent the losses of soil and water and to increase the productivity of soils. Massive field spot experiments together with chemical analysis were carried out to investigate the water status and nutrient leaching from soils in runoff plots in Chongqing Beibei and Fuling. The main arms were to realize the characteristics of soil water and nutrient loss, and to open out the factors affecting these variations in soils with different planting modes, and to provide some information to improve cropping modals in these soils in practices.The dynamic variations of soil water contents from April to May were related to the amount of seasonal rainfall on purple cropping soil on slope. The heavy rainfall, however, didn't benefit the increment of soil water. Water conservation and storage capacity were higher in the cross-plowing plots than the traditional straight-plowing plots.The variation coefficients of water content in soils trended to increase with soil depth increased in the natural grass plots and in the cross-plowing plots, while they behaved otherwise in the straight-plowing plots.Water content in slop soils different plots changed in the sequence: upper > medium > lower. Largest increment of water contents were observed in soils with the straight-plowing plot.Soil nutrients, principally total nutrient elements, were lost mainly in clay and sand sediments in runoff under different planting modes. The nutrient and organic matter loss in quantities varied in the order: straight-plowing corn plot > mulberry hedgerow intercropping plot > cross-plowing corn plot > natural grass plot (nutrients); natural grass plot > straight-plowing corn plot > mulberry hedgerow intercropping plot > cross-plowing corn plot (organic matter). It seems thus reasonable to suggest...