广西石灰岩地区水土流失及其治理措施的探讨

Discussions on Water and Soil Erosion and Its Control Measures in the Limestone Areas in Guangxi

广西石灰岩分布较广,喀斯特现象发育,山多石头多,土地零散坡地多,成土缓慢,土层薄。石灰岩地区土壤允许流失量仅为68t/(km^2·a),而现在该区土壤流失量一般为100～200t/(k^2m·a),大大超过允许流失量。作者针对广西实际情况提出并论述了:1.造林绿化;2.封育恢复植被;3.修筑石坎梯田;4.增施肥料,深翻改土;5.建立生态目标责任制等水土保持措施。

Limestone is widely distributed in Guangxi. Karst is well-developed. There are more rock mountains with more sloping lands with thin soil layer scattered. Soil formation is slow. The soil loss tolerance in the limestone area is only 68 T/km^2·a, while the preseent soil loss in this region is 100—200T/km^2·a, being much higher than soil loss tolerance. Based on the existing conditions in Guangxi, the author sug gested and discussed some water and soil conservation measures including: 1. afforestation; 2: enclosure of the hills for natural afforestation and vegetation recover; 3. construction of stone-bank terraces; 4. increasing application of chemical fertilizers and soil improvement by subsoiling; and 5. establishment of the eco-objective responsibility system.