TITLE:
Environmental Threshold of Phosphorus Infiltration in Red Soil under Different Land Use Patterns
AUTHORS:
Chunyu Dong, Haoyu Yang, Shiying Zhang, Hong Deng, Hongjiao Xu, Yunsheng Xia, Youbo Su, Xinxing Dong, Naiming Zhang, Li Bao
KEYWORDS:
Environmental Threshold, Leachate, Phosphorus, Red Soil
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.9 No.8,
August
12,
2021
ABSTRACT: The risk of soil phosphorus leaching increases in basin regions in light
of large-scale use of phosphorus fertilizers because of agricultural
modernization. In this study, we conducted an earth pillar simulation test on
the infiltration threshold of red soil, Vaseline-coated PVC pipe, intact soil
core, fine sand, and
nylon filter was used for Penetration test, which covers the largest area of
the Dianchi Lake Basin in China. Results showed that: 1) The contents of the total available phosphorus
in algae (NaOH-P) and dissolved labile phosphorus (CaCl2-P) in red
soil were consistent with the content of available phosphorus (Olsen-P) under
different use patterns manifested by the law of greenhouse > open field >
grassland. Grassland had the highest phosphorus sorption index (PSI), followed
by the greenhouse and then by the open field. 2) The leachate under the
same use pattern had the characteristics of total phosphorus (TP) > particle
phosphorus (PP) > total dissolved phosphorus (TDP) > dissolved organic
phosphorus (DOP) > molybdate reactive phosphorus (MRP). The TP
contents in the leachates of grassland, greenhouse, and open field were 0.46,
0.61, and 0.49 mg/L, respectively. DOP, TDP, PP, and MRP had similar contents,
and their distributions in the three land types were consistent with that of
TP. 3) Olsen-P had a significant correlation with TP, TDP, PP, and DOP in the
leachates. Olsen-P of 50 slightly influenced
eutrophication. Moreover, Olsen-P of >40 and 40 had minimal influence on the environment. Olsen-P of >70.90 mg/kg and
PSI of 26.09 mg/kg, the TP content in the leachate increased
sharply.