三峡库区退化土壤的恢复与重建研究

THE RESTORATION AND RECONSTRUCTION OF DEGRADED SOILS IN THE THREE GORGE RESERVOIR AREA

三峡库区是一个生态环境背景较为脆弱且人口压力巨大的丘陵山区，由于人类长期的过垦与破坏，土壤退化十分严重。因此，加强对库区退化土壤的恢复与重建势在必行。土壤恢复与重建包括土壤结构、养分和环境的恢复三个方面内容。文中对库区土壤结构、养分与环境恢复与重建的标准进行了定量探讨。在库区，土壤厚度重建的标准应大于５０ｃｍ，土壤养分重建要以磷钾为主要对象；土壤环境重建包括增加地面覆盖度和森林覆盖率（其重建标准为４１％）、以及不同坡度和地形的改造和恢复。同时，文中提出了相应的恢复与重建工程技术措施与对策，主要包括：（１）加强基本农田建设，防止水土流失；（２）建立坡地复合农业生态系统；（３）优化肥料施用结构，增施有机肥；（４）实施移土重建工程。

Three gorge reservoir areas are typical mountainous regions with fragile eco environment and intense population pressure. Because of long term over burden, over cultivation and disturbance, soils in the area were degraded heavily. It is very necessary to restore these degraded soils in order to keep up sustainable development. The restoration or reconstruction includes the rehabilitation of recovery of soil structure, nutrients and soil environment. In this paper, the standards of soil structure, nutrients and environment for restoration are given. The thickness of soil should be more than 50cm; phosphor and potassium are main objects of soil nutrent restoration in the studied area; soil environment reconstruction includes the increase of the soil surface coverage and percentage of forest cover(the standard of forest cover ≥ 41%), and the reconstruction of relief and slope. On the other hand,the countermeasures for soil restoration are as follows: (1) strengthen the construction of basic farmlands to control water and soil loss; (2) establish complex agroecosystems for slope lands; (3) optimize the proportion of fertilizer application, increase organic fertilizer; (4) conduct the project of soil transfer from the land soon to be submerged by the reservoir water.