陕西省子长县沟道土地的土壤肥力评价

通过野外实地考察和对土壤垂直剖面样品的采集和测试,分析了黄土丘陵沟壑区沟道内的台地、滩地、坝地、草地等几种主要土地利用类型的土壤肥力状况,并与沟道内新造耕地进行了对比研究。同时,在分析土壤有机质、全氮、全磷、全钾、速效氮、速效磷及速效钾等7个土壤肥力指标测定数据的基础上,对不同土地利用类型的土壤肥力进行了综合评价。结果表明,斑块状分布于沟道内的5种不同土地利用类型条件下,其土壤肥力指标存在一定差异。对比陕西省土壤肥力划分标准,黄土丘陵沟壑区沟道内各种土地类型土壤有机质含量均处于低水平,其中新造耕地的土壤有机质含量处于最低的第8级;各地块的土壤全氮、速效氮、全磷含量也处于较低水平,其中草地、滩地和台地的速效磷含量相对较高,可达到4或5级肥力水平;各地块全钾和速效钾含量等级相对其他肥力元素较高,速效钾含量以新造耕地和低龄坝地较低。由于有机质、氮、磷等肥力元素含量水平低,从而导致新造耕地和低龄坝地的综合土壤肥力质量也较低。因此,对沟道新造耕地不仅要做好复垦、平整、侧蚀水毁防治等工程,同时还应重视后期土壤肥力培育工作,采取科学措施,提高土地的生产力。

Evaluation of Soil Fertility Under Different Landuse in Valleys and Gullies in Zichang County of Shaanxi Province

Based on the analytic hierarchy process and fuzzy mathematics theory,the integrated evaluation of soil fertility quality was studied at ravine regions of loess plateau in Zichang County of Shaanxi Province. And seven indexes,including soil organic matter,total N,total P,total K,available N,available P and available K were investigated in 5different types of land use.The results showed that there was significant heterogeneity in seven soil fertility indexes.According to soil fertility quality level standard of Shaanxi Province, soil organic matter contents in all the 5different land types were relative low,especially in the new manmade farmland,which was the lowest(level 8).The other indices such as total N content,soil rapidly available N and soil available P were relative low as well.The grass land and flood land held higher soil available P(level 4-5),compared with the other land use types.The content of soil total and available K were the highest among all the indices,especially in new cultivated land and dam land.As the low content of organic matter, N and P in soil,more attention need to paid in sustainable soil fertility development in Loess Plateau.