钱塘江附近农田土壤磷的积累及其流失的潜在风险

应金耀; 阮弋飞; 邬奇峰; 谢国雄; 章明奎

文章摘要

钱塘江附近农田土壤磷的积累及其流失的潜在风险

Accumulation and runoff loss potential risk of soil phosphorus in agricultural land near Qiantang River

Received:March 05, 2018

DOI：10.13254/j.jare.2018.0051

中文关键词: 钱塘江，农田，磷，积累，释放

英文关键词: Qiantang River, farmland, phosphorus, accumulation, release

基金项目:国家自然科学基金项目（41071145）

Author Name	Affiliation	E-mail
YING Jin-yao	Xiaoshan Agricultural Technology Promotion Center of Hangzhou, Xiaoshan 311203 China
RUAN Yi-fei	Lin'an Agricultural Technology Promotion Center of Hangzhou, Lin'an 311300, China
WU Qi-feng	Lin'an Agricultural Technology Promotion Center of Hangzhou, Lin'an 311300, China
XIE Guo-xiong	Hangzhou Plant Protection and Soil-fertilizer Station, Hangzhou 310020, China
ZHANG Ming-kui	College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China	mkzhang@zju.edu.cn

Hits: 2579

Download times: 2889

中文摘要:

为探讨钱塘江周边农田土壤磷流失风险，采集了181个代表性农田土壤，分析了土壤藻类可利用磷、植物有效磷（Olsen P）、水溶性磷和磷零吸附时的磷平衡浓度（EPC₀）。结果表明，土壤藻类可利用磷在5.89~932.65 mg·kg^-1之间，平均为105.30 mg·kg^-1；植物有效磷在1.00~444.76 mg·kg^-1之间，平均为30.57 mg·kg^-1，达到较高水平；蔬菜地土壤磷素积累明显高于一般农田。土壤水溶性磷含量和EPC₀值随土壤中植物有效磷积累而增加，当土壤中植物有效磷超过60 mg·kg^-1时，土壤水溶性磷含量迅速增加；土壤中植物有效磷>60 mg·kg^-1的样品比例达11.60%。土壤EPC₀可作为评价土壤磷素向水体释放磷的强度指标，根据土壤EPC₀值与植物有效磷之间的线性关系，估算得到的径流中磷达到Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ类地表水环境质量标准上限值相应的土壤植物有效磷临界值分别为7.9、13.7、20.9、28.2 mg·kg^-1和35.4 mg·kg^-1，研究区大约有35.9%的农田磷积累可能产生的地表径流磷含量在Ⅳ~劣Ⅴ类的范围。研究认为，钱塘江近江地段部分农田土壤中磷素已有明显积累，存在较高的流失风险。建议把植物有效磷为30 mg·kg^-1和60 mg·kg^-1分别作为这一区域农田磷肥限量施用和禁止施用的参考值。

英文摘要:

In this paper, 181 representative soil samples were collected from farmlands near Hangzhou section of the Qiantang River for characterizing algae available P, plant available P(Olsen P), water soluble P, and phosphorus equilibrium concentration at zero phosphorus adsorption(EPC₀), and evaluating its potential runoff loss risk. Results showed that accumulation of soil phosphorus in the study area reached a high level, and contents of soil algae available P ranged from 5.89 to 932.65 mg·kg^-1, with average of 105.30 mg·kg^-1. Contents of plant available P ranged from 1.00 to 444.76 mg·kg^-1 with mean of 30.57 mg·kg^-1. Soil phosphorus accumulated in vegetable soil was higher than that of other farmland. Content of soil water soluble P and EPC₀ increased with increasing the plant available P. Soil water soluble P increased rapidly when the plant available P was over 60 mg·kg^-1. About 11.60% of the soil samples had plant available P over 60 mg·kg^-1. The EPC₀ could be used as a threshold to evaluate release potential of soil phosphorus. From the linear relationship between the EPC 0 value and the plant available P of the soils, it was estimated that the critical values of plant available P were 7.9, 13.7, 20.9, 28.2 mg·kg^-1 and 35.4 mg·kg^-1, respectively, when phosphorus concentration in runoff from the agricultural lands reached at the upper limit of the environmental quality standard of Ⅰ, Ⅱ, Ⅲ, Ⅳ and Ⅴ for the surface waters. About 35.9% of the farmlands in the study area had soil phosphorus accumulation as high as it could product high runoff P concentrations which were equivalent to the range of P from Ⅳ to inferior Ⅴ surface waters. It was concluded that some of the farmlands had obvious P accumulation in the soils, and had high risk of phosphorus runoff loss. It was suggested that application rate of phosphorus fertilizer should be controlled in the agricultural lands when the plant available P was over 30 mg·kg^-1, and phosphorus fertilization should be banned when the plant available P was over 60 mg·kg^-1.

HTML View Full Text View/Add Comment Download reader