黄丘区坡耕地土壤退化及防治措施的研究

Study on Soil Deterioration of Sloping Farmland and Its Prevention and Control Me- asures in rolling loess Area

研究认为,侵蚀是坡耕地土壤退化的主要原因。侵蚀使耕层物理性状恶化,沙粒增多,粘粒减少,质地变劣,趋向沙化;侵蚀还使土壤中水稳性团粒下降;碳酸盐含量增加,抑制了土壤中微生物的活动。同时,广种薄收,开荒扩种等不合理的耕作制度加剧了土壤退化。经测算,黄丘—副区每年流失的氮磷钾肥相当于我国目前年产化肥的7.5％。坡地修梯田,推行保土耕作措施和草田轮作,可防治其退化。

The research indicates that soil erosion is the key cause leading to soil deterioration of sloping farm land. Soil erosion makes the physical characteristics of the plaughing layer deteriorate, sand increase, clay particles decrease and the texture of soil turn into inferiority .Soil erosion also leads to derease of water-stablizing aggregation, increase of carbonatite and restrain of the activity of microorganisms in the soil, meanwhile, the unreasonable cultivation systems such as low output in large areas and great reclaiming of barren land also aggravate soil deterioration. Through calculation, the annual loss of fertilizer N,P, K in the first subregion of rolling loess areas equals 7.5% of yearly chemical fertilizer output made in our country .Terracing the sloping farmland, spreading the conservation cultivation and rotation of grass and grain can prevent the soil from deterioration.