典型黑土垄作区耕地沟蚀对土壤养分的影响研究

近年来东北黑土区沟蚀吞食耕地现象加剧,养分流失、耕地质量下降等问题凸显。以宾县的糖坊镇和三宝乡为研究区,综合"3S"技术和统计学的模型方法,对研究区沟蚀对土壤中有机质、全氮、全磷和速效钾含量的影响及不同垄向耕作下沟蚀对各养分的影响及差异展开研究。其中横垄种植指作物垄的方向和地块坡向方向成垂直的种植方式,顺垄种植是作物垄的方向和地块坡向方向平行的种植方式。结果表明:沟蚀对土壤养分含量影响较大,有机质和全氮含量较无侵蚀区分别减少33.43%和46.67%,速效钾与全磷含量则变化不明显,在沟蚀区进行秸秆覆盖能够有效减少土壤养分的流失。沟蚀在造成养分含量下降的同时,也影响了土壤的理化结构,降低了土壤中有机质和全氮含量之间的相关性。横垄沟蚀、顺垄沟蚀及无沟蚀对照组土壤有机质和全氮含量大小均表现为无沟蚀区顺垄沟蚀橫垄沟蚀。无侵蚀区土壤养分含量最高,沟蚀区顺垄耕作较横垄耕作更具保肥意义。

Effects of Gully Erosion on Soil Nutrients in Ridge Area of Typical Black Soil

In recent years, it has been an obvious phenomenon that the gully erosion cut up the cultivated land in the black soil region, the loss of nutrients, the decline in the quality of arable land and other issues were highlighted. Two towns in Bin County of the Heilongjiang province were selected as the study areas to explore the effect of gully erosion on soil organic matter, total nitrogen, total phosphorus, available potassium nutrient, the influence and difference of different cultivated ridge direction gully erosion on four nutrients with"3S" technology and statistical model method. The results indicated that: first, gully erosion has a great influence on soil nutrient content, the decline of organic matter and total nitrogen content was 33.43% and 46.67%, respectively. Available potassium and total phosphorus in two kinds of nutrients on the response of gully erosion was not obvious. Straw mulching could effectively reduce the loss of soil nutrients in gully erosion area. Second, gully erosion caused a decrease in nutrient content, but also affected the physical and chemical structure of the soil, reducing the correlation between the content of organic matter and total nitrogen content in the soil. Third, the content of soil organic matter and total nitrogen were no gully region, strike ridge gully and horizontal ridge gully in descending order, strike ridge tillage was the best cultivated model on reducing the loss of soil organic matter and total nitrogen than horizontal ridge tillage in this region on, so as to achieve fertilizer conservation.