花岗片麻岩地区坡耕地改造途径及其效益分析

Analysis on Conrol Measures and Their Benefits for Slope Land in Granite—gneiss Areas

通过对花岗片麻岩山丘区坡改梯方法进行实验研究,结果表明:采取一次性窄面水平梯田治理坡耕地,施工简便,费省效宏。如5°与10°坡改梯较传统方法省工25%左右,省料30%左右;较坡耕地水保效益提高75%以上,土壤养分损失明显减轻,汛期土壤含水量增加15%～20%,粮食增产20%～35%,提高土地利用率40%～50%。

The experiments to transform slope land into terrace have been made in mountain and hilly areas of granite-gneiss. The results show that the narrow-level terrace which is built up in one time can easily control slope land,save on investment and achieve good benefits. Compared with the usual one in slope land of 5°and 10°,the aboveway can save on labour forces and investment by 25 percent and by 30 percent respectively. The narrow-level ter-race can enhance the benefits of soil and water conservation by more than 75 percent,the soil moisture by 15 to 20percent in rainfall season,the crop yield by 20 percent to 35 percent,and land utilization by 40 percent to 50 per-cent. The fertility loss on narrow-level terrace is little compared with that one on slope fields.