低丘红壤开发与复合农林业对土壤侵蚀的影响

Impact on the Soil Erosion by Development of Red Soil and Farm Forestry on Hillock

在低丘红壤的开发利用中,通过复合农林业技术达到植树种草、增加地面覆盖率、发展当地经济植物促进畜牧业发展,探索低丘红壤开发利用的新模式,科学合理地开发红壤资源,实现开发中保护。经过2年的试验表明:选择适宜的植物种类对于有效地发挥生物措施与复合农林技术的功效是极其重要的,各试验块的植被覆盖度分别是湿地松18%,茶叶23%,柑橘34.6%;覆盖度大小顺序依次为柑橘>茶叶>湿地松;低丘红壤开发的第1年土壤侵蚀量一般都超过土壤允许侵蚀量500t/km2.a,第2年就减小到350t/km2.a左右,各类型的土壤平均侵蚀量次序为柑橘>湿地松>茶叶;各处理的平均N素流失量为湿地松138.8 kg/km2,茶叶450.1 kg/km2,柑橘182.4 kg/km2;N素流失大小顺序为茶叶>柑柑橘>湿地松。在试验区采样分析结果表明:随着土壤侵蚀的逐步升级,土壤容重、田间持水量、土壤粉粒、土壤团聚体、土壤pH、土壤盐基饱和度、土壤盐基交换量均相应降低,而土壤交换性酸对应增加。验证了水土流失直接导致土壤结构、土壤物理性状退化、变差的结果。

After two years＇ experiment, the result shows that the selection of suitable plants is very important on the effectively exerting of bio - measures and farm forestry technology. The vegetation coverage degrees in different experimental plots are as follows： 18% in the Pinus elliouii land, 23%in tea garden and 34.6% in the citrus orchard, while the coverage is sized down as citrus 〉 tea 〉 Pinus elliouii. In the first year＇s red soil development in the hillock, soil erosion usually exceeds the pennitamount of 500 t/km^2, a, while it is reduced to 350 t/km^2, a in the second year. The average soil erosion amounts are listed in sequence as citrus 〉 Pinus elltouii 〉 tea. The average N element loss amounts in different plots are recorded as 138.8 kg/km^2 in the Pinus elliouii land, 450.1 kg/km^2 in the tea garden and 182.4 kg/km^2 in the citrus orchard. While the N element loss amounts in different plots are sized down as tea 〉 citrus 〉 Pinus elliouii. The sampling results in the experimental plots show that following with the gradually increase of soil erosion, the soil volume, field moisture capacity, soil silt, soil aggregate, soil pH value, soil base saturation degree and soil base exchange capacity will be reduced accordingly, while the soil soil exchangeable acid will be increased. This proved that soil erosion will directly result in the degradation of soil structure ＆ physical behavior.