Study on distribution of available copper content in soil of navel orange orchards in Southern Jiangxi Province

【Objective】The aim of this study was to obtain the distribution of soil available copper content in navel orange orchards in Southern Jiangxi province.【Method】1405 soil samples were collected from 477 orchards in 18 counties,and the contents of available copper were analyzed.【Result】The results showed that differences in soil available copper content between different counties were significant,ranging from 0.84 mg·kg-1 to 2.15 mg·kg-1,with the average 1.55 mg·kg-1. 76.45% of soil samples were sufficient in available copper. The soil available copper content varied with the soil types,and the highest was found in paddy soil,and the lowest was found in yellow soil. The p H values,the organic matter contents,and the available zinc contents were highly significant positive correlation with the soil available copper contents,especially the correlation coefficients of the available zinc contents and available copper contents reached 0.431. The soil available copper contents increased obviously during the first ten years after planting,and flattened out.【Conclusion】Most of the soil available copper were sufficient in navel orange orchards in southern Jiangxi province,however,it is obvious that the soil hasn't been polluted by copper,and keeping the soil available copper levels in the orchards were suggested.