Evaluations and Influencing Factors of Soil Available Fe,Mn,Cu and Zn Concentrations in Major Wheat Production Regions of China
[Objective]It is of great importance to clarify the current regional distributions and influencing factors of soil available iron(Fe),manganese(Mn),copper(Cu)and zinc(Zn)concentrations.This will improve understanding of the soil micronutrient supply abilities and guarantee high-yield and high-quality wheat in major wheat production regions of China.[Method]During 2016 to 2021,a successive 6-year in situ farm survey was conducted in combination with the collection of topsoil(0-20 cm)samples from 1 314 randomly selected farmland fields in 17 major wheat production provinces and regions in China.The soil-available Fe,Mn,Cu and Zn concentrations were determined to evaluate their abundance and deficiency status based on China's classification criteria for soil-available micronutrients.Also,it was quantified the contribution of main soil chemical properties on Fe,Mn,Cu and Zn availabilities by random forest analysis.[Result]Results showed that the soil available Fe ranged from 1.8 to 612 mg·kg-1,with an average of 49.1 mg·kg-1,and 8.9%of samples had lower soil available Fe than the Fe deficiency threshold of 4.5 mg·kg-1.Soils with relatively low available Fe were usually observed in the provinces of Shanxi,Shaanxi and Gansu in northern and northwestern wheat production regions,while high-Fe soils were found in southwestern and middle and lower Yangtze River wheat regions.Also,soil available Mn ranged from 0.1 to 176 mg·kg-1,with an average of 22.1 mg·kg-1,and 6.9%of samples exhibited lower soil available Mn than the Mn-deficient threshold of 5.0 mg·kg-1.Mn-deficient soils were mainly distributed in Shanxi,Shaanxi,Gansu provinces and Inner Mongolia Autonomous Region in northern and northwestern wheat growing regions,while soils with high and very high available Mn often occurred in southwestern and middle and lower Yangtze River wheat regions.Soil available Cu ranged from 0.1 to 10.8 mg·kg-1,with an average of 1.9 mg·kg-1,and only 1.8%of samples had lower available Cu than the Cu-deficient critical value of 0.5 mg·kg-1.Soil available Zn ranged from 0.1 mg·kg-1 to 26.0 mg·kg-1,with an average of 1.4 mg·kg-1,and 14.3%of samples'available Zn was lower than the Zn deficiency threshold of 0.5 mg·kg-1.Zn-deficient soils were mainly found in Shanxi,Shaanxi,Gansu provinces and Inner Mongolia Autonomous Region of northern and northwestern wheat production regions,and higher Zn concentrations were mainly observed in soils of Yunnan and Guizhou provinces of southwestern wheat regions.Among the investigated soil chemical properties,the pH was the most important influencing factor to available Fe and Mn,and available Fe contributed to the highest Cu availability,and available phosphorus,followed by Cu,was found to be the leading factor for soil available Zn in major wheat production regions of China.[Conclusion]There were large regional variations in the soil-available Fe,Mn,Cu,and Zn concentrations in China's wheat fields.Deficiencies of soil available Fe,Mn and Zn were serious problems on calcareous soils in the northern part,and higher supplies of these micro-elements occurred in the southern part,while almost all of the wheat fields were not identified as Cu-deficient soil in China.
万方数据
维普
