Differences in main processes to transform phosphorus influenced by ammonium nitrogen in flooded intensive agricultural and steppe soils

Shuo Chen; Shuai Zhang; Zhengjuan Yan; Yutao Peng; Qing Chen

doi:10.1016/j.chemosphere.2019.03.123

Differences in main processes to transform phosphorus influenced by ammonium nitrogen in flooded intensive agricultural and steppe soils

Chemosphere. 2019 Jul:226:192-200. doi: 10.1016/j.chemosphere.2019.03.123. Epub 2019 Mar 21.

Authors

Shuo Chen¹, Shuai Zhang¹, Zhengjuan Yan¹, Yutao Peng¹, Qing Chen²

Affiliations

¹ Beijing Key Laboratory of Farmland Soil Pollution Prevention-control and Remediation, College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian, Beijing, 100193, PR China.
² Beijing Key Laboratory of Farmland Soil Pollution Prevention-control and Remediation, College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian, Beijing, 100193, PR China. Electronic address: qchen@cau.edu.cn.

PMID: 30927671
DOI: 10.1016/j.chemosphere.2019.03.123

Abstract

Exogenous ammonium nitrogen (AN) fertilization/deposition and the subsequently induced soil acidification, might exacerbate soil phosphorus (P) transformation and mobility, whereas poor understanding in abiotic and biotic processes still existed between intensively cultivated soil with high proportion of legacy inorganic P (P_i) in comparison to natural steppe soil with high proportion of organic P (P_o). Column batch flooded experiment using vegetable (VEG) and steppe (STE) soils was conducted to investigate the P transformation and mobility influenced by 60-day intermittent elution with an (1500 mg N kg^-1) solution or an acid sulfate (107 mmol H⁺ kg^-1) solution. The results showed that AN elution significantly decreased the contents of all P_i fractions and strengthened P_i leaching, whereas acid elution increased the contents of Al-P_i, Fe-P_i, and reductant-soluble P_i and reduced P leaching in VEG soil. In contrast, AN elution increased the contents of soluble-P_o and Al-(P_i + P_o) and decreased Ca-P and Fe-P_i, no effects on P leaching, whereas acid elution increased the contents of soluble-(P_i + P_o), Al-(P_i + P_o), Fe-(P_i + P_o) and reduced P leaching in STE soil. Variances analysis showed that pH and microbial biomass carbon were the most important factors to predict the P composition of the VEG and the STE soil, respectively. This indicated that AN elution released the soil mineral-bound phosphate with ammonia oxidation coupled with Fe(III) reduction, besides the same chemical influences on Fe/Al oxides as acid elution in VEG soil; while predominantly affected biochemical/biological processes of soil P by changing microbial biomass and enzyme activities in STE soil.

Keywords: Acidification; Ammonium nitrogen; Enzyme activities; Phosphorus fractionation; Phosphorus leaching.

MeSH terms

Agriculture / methods*
Ammonium Compounds / chemistry
Biomass
Ferric Compounds / analysis
Ferric Compounds / chemistry
Floods*
Nitrogen / chemistry*
Phosphorus / chemistry*
Soil / chemistry*
Soil Microbiology
Vegetables

Substances

Ammonium Compounds
Ferric Compounds
Soil
Phosphorus
Nitrogen