土壤有机质对坡耕地土壤侵蚀及作物产量的影响

土壤有机质是形成土壤结构的重要因素.采取定位试验的结果表明,在10°～12°的黄土坡耕地上每公顷施厩肥30000、45000、75000kg,年径流量比对照区分别减少13.3%、20.5%、34%,年泥沙流失量分别减少32.3%、33.7%、35.4%,其减少率随施肥量的增加而提高;第4年各施肥水平下的耕层土壤有机质增加量分别为69.7%、65.0%和140.1%;一种作物在一年中的产量随施肥量的增加而增加,3种施肥水平可分别增产26.7%、25.5%和43.3%.在10°左右的坡耕地上,每年施入一定数量的有机肥,使土壤有机质增加,土壤结构得到改善,并达到减少水土流失、提高作物产量的目的.

Influence of Soil Organic Matters on Soil Erosion and Crop Yield of Cultivated Slope Land

Soil organic matters are an important factor affecting the formation of soil structure. The result of experiment on the spot indicated that when 30 thousand, 45 thousand and 75 thousand kg of barnyard manure per hectare are applied on the cultivated loess land with slope of 10 ~ 12 degree, the annual runoff amount decreased by 13.3%, 20.5% and 34% and the annual soil loss amount decreased by 32.3%, 33.7% and 35.4% respectively in comparison with the contrast area, the decrease rate increased positively with the manure amount applied; in the fourth year, the increments of soil organic matter in tilling layer for each manure level were 69.7%, 65.0% and 140.1% respectively. The annual yield of a crop increased positively with the manure amount, the output could increased by 26.7%, 25.5% and 43.3% respectively for the three manure levels. Applying a definite amount of organic manure on the cultivated land with slope of 10 degree could make the soil organic matters increase and soil structure improve, soil loss decrease and crop yield increase.