Analysis of Soil Secondary and Trace Elements and Organic Matter in Rapeseed-growing Areas of Henan Province

In order to comprehensively understand the situation of soil secondary trace elements and organic matter in rapeseed-growing areas of Henan province,the soil samples at different development stages of rapeseed were collected and analyzed.The results indicated that the organic matter in rapeseed-growing areas was sufficient,with 22.35 g/kg in average and reaching the first class.The available secondary element sulfur(S) was also sufficient.Its average content was 26.87 mg/kg,higher than mid-standard.The available copper(Cu) was rich.Its average content was 4.65 mg/kg,also higher than mid-standard.Manganese(Mn) and iron(Fe) were all not deficient in different locations and different growth stages.Their average contents were 139.94 mg/kg and 205.27 mg/kg,respectively,up to the middle or upper standards.The content of effective zinc(Zn) in different soil samples was quite different,and part of locations was seriously deficient.Its average content was 2.79 mg/kg,belonging to moderate type generally.The contents of available Cu,Mn and Zn were gradually decreased with growth period,especially the contents of available Zn and Mn,which were sharply decreased.Therefore,Zn and Mn fertilizers as base fertilizers must be increased in rapeseed production,especially for the shortage soil.