Welcome to Chinese Agricultural Science Bulletin,

Chinese Agricultural Science Bulletin ›› 2022, Vol. 38 ›› Issue (29): 108-117.doi: 10.11924/j.issn.1000-6850.casb2021-0903

Special Issue: 生物技术 现代农业发展与乡村振兴 农业生态 耕地保护

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Spatial Distribution and Formation of Phosphorus in Typical Land-use Soils in Karst Agricultural Areas

YANG Miao1(), TIAN Yongzhu2, HAN Zhiwei1,3(), LUO Guangfei1, ZHAO Ran1, TIAN Yutong1, XIAO Han1   

  1. 1College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025
    2Bureau of Natural Resources Sinan County Guizhou province, Tongren, Guizhou 565100
    3Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang 550025
  • Received:2021-09-15 Revised:2021-11-08 Online:2022-10-15 Published:2022-10-14
  • Contact: HAN Zhiwei E-mail:yangmiao0916@qq.com;zwhan@gzu.edu.cn

Abstract:

A study on the spatial distribution, migration characteristics and influencing factors of phosphorus in vertical and horizontal soil under different land use types in karst agricultural areas was carried out. A total of 56 samples were collected from 9 soil profiles under typical land use types (grassland, riverside, paddy field, dry land, etc.) around Kaizhang reservoir, and the water content, pH, organic matter, exchangeable acid, total phosphorus, available phosphorus and inorganic phosphorus of each soil profile were determined. The results demonstrated that the total phosphorus content and available phosphorus content were measured to be over a wide range of 420.73-1669.53 mg/kg and 2.50-64.14 mg/kg, respectively, and the soil phosphorus activation coefficient was in the range of 0.34%-5.96%. It was found that available phosphorus content in the surface soil of agricultural land was more than 15 mg/kg, which was correlated with the overuse and waste of phosphate fertilizer. Meanwhile, the risk of phosphorus leaching downward into underground water was found in the surface soil of dry land in the agricultural area behind the dam (the average content of available phosphorus was 64.14 mg/kg). The soil inorganic phosphorus forms in paddy field and dry land were mainly Fe-P and Al-P, and in grassland and riverside were mainly Fe-P and O-P. The results indicated that soil pH was significantly and negatively correlated with available phosphorus, Fe-P and Al-P, and soil organic matter was significantly and positively correlated with total phosphorus, available phosphorus, Al-P, and Fe-P. It is concluded that the soil phosphorus content of agricultural area is generally higher than that of non-agricultural area because of different phosphorous distributions in different land use types. The study clarifies the spatial distribution of phosphorus and its forms in karst agricultural areas, which could provide a basis for the prevention and control of agricultural non-point source pollution caused by phosphorus.

Key words: karst agricultural area, phosphorus, soil profile, inorganic phosphorus form, distribution characteristics

CLC Number: