采用径流小区定位观测法测定广西桂平市金田林场马尾松工程林林地的水土及养分流失量。结果表明 , 挖大穴整地造林林地年平均水流失量比荒坡地的低 15.2%, 泥沙流失量比全垦和带状整地造林的分别低 76.2 %和 46.7 %, 养分流失量依次低 75.3 %和 46.3 %。 林地径流系数年度差异显著, 随造林时间推移而逐年下降。 林地泥沙流失量的季节分配规律与降雨量的季节分布一致, 多雨季节(5～ 7 月)的流失量大, 少雨季节(1 ～ 4 月和 8～ 12 月)的流失量小。
 

The inspection method of fixed position of runoff plots was used to study the loss amounts of soil, water and its nutrient elements of Pinus massoniana Lamb. engineering forests in Jintian Forest Station of Guiping City , Guangxi. The results show :The yearly mean water loss amount of dig cave ploughing was 15 .2 % lower than that in wasteland , the loss amount of soil from dig cave ploughing was 76 .2 % and 46.7 % lower than that in overall ploug hing and band ploughing respectively and the loss amount of nutrient elements was 75 .3 % and 46 .3% lower respectively .The year diversity of runoff coefficient was outstanding, and there are smaller runoff coefficient, there are leng ther forestplanting date.The seasonal distributed regularity of soil loss amount was of the same as the regularity of rainfall , the maximum soil loss was in the rainy season (M ay ～ July)and the minimum was the dry season (January ～ A pril and August ～ December).