我国农田土壤污染状况及防治对策

THE CROPLAND POLLUTION IN CHINA: STATUS AND COUNTERMEASURES

关键词:  农田土壤污染 重金属污染 土壤修复 耕地质量 防治对策 中国

Key words:  cropland soil pollution  heavy metal pollution  soil restoration  cultivated land quality  countermeas- ures  China

摘要:

我国农田土壤污染日趋严重，农田受污染率从20世纪80年代末期的不足5%，上升至目前的 19.4%;污染物主要来自工矿业三废（废水、废气、废渣），并通过大气沉降、洪水冲积和不合理的农业生 产过程3个路径进入农田，其中不合理的农业生产过程，尤其是污水灌溉是污染物进入农田的首要路径; 不仅化肥会污染农田，有机肥同样也会污染农田。通过调节Cd超标农田土壤的PH值可以降低Cd的活性， 减轻对农作物的危害;不同作物对Cd的敏感性不同，通过调整农作物品种结构，可以降低危害;治理农田 土壤污染，首要工作是强化农田土壤污染防控，并因情而宜，走综合治理之路。该文首次量化了我国农田 土壤污染变化态势，明确提出了化肥在农田土壤污染中的3方面体现，概括出污染物进入农田土壤的3个 路径，首次将污水灌溉从过去的严重缺水区域有意识地利用污水灌溉扩展到有意识地利用污水灌溉和无意 识地利用了受到污染的水源进行灌溉两个方面，明确提出了有机肥同样会污染农田的结论，并提出了防治 土地污染的3项对策。

Abstract:

The pollution of cropland has become increasingly serious in China. At present， the ratio of polluted cropland is 19.4%，which was less than 5% in the late 1980s.The main pollutants in the cropland are from min- ing and industrial wastes（waste water， waste gas， waste residue），which entered into croplands by atmospheric deposition of pollutants， flood and irrational agricultural production process. The sewage irrigation is the primary route of pollutants entering into cropland. The chemical and organic fertilizer can both pollute cropland. The activi- ty of Cd can be reduced by adjusting the soil pH of the cropland which the content of Cd in soil is beyond the stand- ard level， and hence reduced the harm to crops. Due to the sensitivity of different crops on Cd is different， the damage of Cd to the cropland can be reduced by adjusting the structure of crop varieties. The most important meth- od to manage the pollution of the cropland is to strengthen the prevention and controlling of the cropland pollution， and it should follow the path of comprehensive management according to the situation to combat the pollution of soil. This paper quantified the current soil pollution situation in China for the first time， clearly pointed out the fer- tilizer can pollute the cropland by three aspects， summarized three paths of pollutants that entering into the cropland in China， analyzed the paths of the sewage irrigation which included the use of wasted water to irrigate cropland consciously and unconsciously， and pointed out the organic fertilizer can also pollute the cropland. At last， it put forward three countermeasures to prevent and control soil pollution.