山西吕梁黄土丘陵沟壑区坝地土壤养分分布特征研究

以山西黄土高原丘陵沟壑区吕梁4县的6座骨干坝为研究对象,对坝地0~40 cm土壤有机质、全氮、全磷、全钾及速效养分进行了分析。结果表明,坝地土壤养分分布不均匀,整体土壤养分含量较低,特别是有机质和有效氮、磷,0~20 cm分别为5.13 g.kg-1、28.89 mg.kg-1和5.06 mg.kg-1,20~40 cm分别为4.05 g.kg-1、27.67 mg.kg-1和4.55.06 mg.kg-1;坝地土壤养分存在着一定的变异性,0~20 cm土壤全钾和速效磷为弱变异性,有机质、全氮、全磷、碱解氮、速效钾属中等变异性,20~40 cm土壤全氮和速效磷为中等变异性,有机质、全磷、全钾、碱解氮、速效钾为弱变异性,且不同流域坝地土壤养分的变异性大于坝地内不同水平方向上的变异性。因此,通过平衡施肥,科学管理,提高坝地生产潜力还很大。

Distribution Characteristics of Soil Nutrients of Dam Fields in Loess Hilly and Gully Region in Lüliang,Shanxi

This article analyzed soil OM,total N,total P,total K and available nutrient(0~40 cm)of the dam fields focusing on the six backbone dams in the hilly and gully regions on Loess Plateau in four counties in Lüliang,Shanxi.The results showed that the imbalance of soil nutrients was very serious in dam fields,and the content of its soil nutrients were very low,especially soil OM,available N and P.The content of soil nutrients,soil OM,available N and P is 4.05 g·kg-1,27.67 mg·kg-1 and 4.55.06 mg·kg-1,respectively,in 0~20 cm,and 4.05 g·kg-1,27.67 mg·kg-1 and 4.55 mg·kg-1,respectively,in 20~40 cm.There was a variability in soil nutrients on dam fields and the variability of different dam fields in different watersheds was greater than that of fields in different level directions on the same dam.It is little variability to total K and available N,medium variability to soil OM,total N,total P,alkali-hydrolytic nitrogen in 0~20 cm;it is medium variability to soil total N,available N,and little variability to soil OM,total P,total K and alkali-hydrolytic nitrogen,available K in 20~40 cm.There was a great potential for increasing the yield on the dam fields through scientific management,balanced fertilization and making full use of water resources.