农田土壤磷的环境指标研究进展

Research Advances on Environmental Indicator of Soil Phosphorus in Farmland

为了研究农田土壤磷的环境指标,综述了国内外1984—2014年农田土壤磷的环境指标研究,发现对于农田土壤磷的环境指标研究不断深入,虽然起步晚,但是进展较快。从研究农田土壤磷的流失途径和流失形态着手,发现土壤水溶性磷、颗粒态磷等不同形态的有效磷含量与地表径流中的磷含量呈现显著相关,流失至水体的磷含量与土壤Olsen-P含量具有较高的相关性,把土壤Olsen-P作为农田土壤磷的环境指标具有准确性及可靠性。综述国内外农田土壤磷的环境指标研究表明:目标水体为湖库和河流的土壤Olsen-P环境阈值分别为25 mg/kg和75 mg/kg。超过该临界值时,土壤径流、排水和渗漏液中磷含量将明显增加,加大农田中土壤磷进入水体的风险,造成水体富营养化,对水环境产生破坏。农田土壤磷的环境指标研究还存在不足,今后还需要研究农田土壤磷素在流失过程中的削减系数,以及农田土壤磷素通过地表径流与土壤侵蚀淋溶之间的交互作用机理。

The paper aims to study the environmental indicators of soil phosphorus in farmland. Bysummarizing the researches on the environmental indicators of soil phosphorus from 1984 to 2014, it was foundthat the research on the environmental indicators of soil phosphorus in farmland had a rapid progress eventhough it started late. Through the researches on the loss pathways and erosion forms of the soil phosphorus inthe farmland, it showed that the available phosphorus content in different forms such as water solublephosphorus and particulate phosphorus in soil had a significant correlation with surface runoff phosphoruscontent. The phosphorus content of the water body had a high correlation with the content of soil Olsen-P. Itwas accurate and reliable to regard the soil Olsen- P as the environmental index of soil phosphorus in thefarmland. Domestic and foreign research results showed that the Olsen-P environment threshold of the targetwater body as lake and river was 25 mg/kg and 75 mg/kg, respectively. Exceeding the critical value, thephosphorus content in soil runoff and drainage and fluid leakage would significantly increase, which led to therisk of increasing soil phosphorus loss from farmland into the water. The pollution and eutrophication of waterbodies would emerge. However, the research on the environmental indicators of soil phosphorus in the farmlandstill has many deficiencies. In the future, we need to study the reduction coefficient of the soil phosphorus inthe process of loss, as well as the interaction mechanism of the soil phosphorus in farmland through surface runoff and soil erosion.