Distribution characteristics of soil available Cu and its affecting factors in West Henan

Distributing characteristics of and factors contributing to soil available Cu in the farmland in the West Henan were studied.Results showed that total soil Cu was mostly within the range of 23.60~52.70 mg·kg-1,with an average of 30.17 mg·kg-1,and available Cu was mostly within the range of 0.24~4.13 mg·kg-1,with an average of 0.89 mg·kg-1.Available Cu in soil increased with the order of mountain areahilly areaplain area.In this area,content of soil available Cu among 15.93% of total samples was below the minimum threshold,accounting for60.44%.parameters including content of organic matter,total nitrogen,pH was related with soil available Cu,with apositive relationship between soil available Cu and organic matter,and a negative relationship between soil pH and available Cu.The soil available Cu content was 1.18 mg·kg-1,with corn being the preceding crop.By contrast,it reduced to 0.63 mg·kg-1,with sweet potato as the preceding crop.