黄土高原南部坡地土地生产力衰退过程和恢复途径研究

使用PI模型对黄土高原坡地生产力的自然衰退过程,以及在水土保持和施肥管理措施下土地生产力的变化趋势进行了模拟,结果显示:在自然侵蚀环境中,土地生产力的衰退速度很快,平均每年以0.25%到0.5%的速度衰减,若采取水土保持措施则其衰退速度较自然侵蚀下年均减缓0.07%(水平梯田)、0.15%(坡式梯田)和0.21%(等高带状种植),而采用水土保持措施并结合施肥管理措施则可使土地生产力得到明显恢复;水土保持措施可以减缓土地生产力衰退的速度,但不能使其生产力得到有效恢复,只有采用水土保持措施并结合合理的施肥管理措施才能使土地生产力水平得到恢复和提高.

Study on the decline process and instauration path of land productivity on the sloping land in the Southern Loess Plateau

Using the PI model this paper simulates the changing trend of the land productivity under the natural process,soil conservation and fertilization on the sloping lands in the southern Loess Plateau.The results show as follows: the decline speed of the sloping land productivity under the nature process is very quick,the productivity annually reduces averagely by 0.25% to 0.5%;the decline speed under the soil conservation decreases by 0.07%(level terrace),0.15%(sloping terrace) and 0.21%(contour plant),compared with the nature erosion;the land productivity get obvious instauration as the measures of soil conservation and fertilizer are applied;The soil conservation measure can decrease the decline speed of the land productivity,but can't effectually recover the productivity;only application of the soil conservation measure along with fertilization can retrieve and enhance the land productivity.