天津市设施蔬菜不同种植年限土壤及地下水养分特征

Characteristic of Soil and Groundwater Nutrient in Different Age Greenhouse Vegetable Cultivation in Tianjin

为了保护设施蔬菜土壤朝着健康的方向发展,针对不同种植年限的设施蔬菜土壤养分状况展开调查。结果表明,碱解氮、速效磷和速效钾在设施土壤中出现了大量的累积,并且随着种植年限的增加,累积强度增大,超过10年的土壤碱解氮和速效磷含量显著增加。天津市设施土壤碱解氮和速效磷累积强度与其他地区相差不多,速效钾累积强度高于其他地区;在设施蔬菜土壤中,硝酸盐在表层及深层土壤都出现了累积现象,地下水中硝酸盐的含量也较高,种植年限超过10年的设施蔬菜地下水硝酸盐含量已经达到149.1mg/L,而种植大田作物地下水硝酸盐含量仅为1.13mg/L;在种植不足10年设施土壤的pH未发生明显变化,超过10年则pH显著降低;种植年限超过10年的设施蔬菜表层土壤全盐含量显著增加;种植年限超过5年的设施土壤,有机质含量呈显著增加。从以上结果可以看出,种植设施蔬菜超过10年,土壤养分累积强烈,地下水污染也较为严重,应重点加以治理。

Recent ferent old greenhouses years,with the rapidly growth of greenhouse coverage area in Tianjin, soil nutrient status in dif- were investigated for the healthy development of greenhouses. The results showed that available nitrogen, available phosphorus and available potassium were heavy cumulated in soil of greenhouse vegetable. With the planting age increasing ,the cumulative intensity was the higher. The contents of soil available nitrogen and available phosphorus were significantly increased in the soil which planting years of greenhouses were more than 10 years. A- vailable nitrogen and available phosphorus accumulation were the same as other districts, but available potassium ac- cumulation was more intensity than other districts. Nitrate was also cumulated in surface layer and deep layer of the soil of greenhouse vegetable. At same time, the content of nitrate in the groundwater was higher. For example, if the greenhouse vegetable lasted more then 10 years,the content of nitrate in the groundwater was up to 149.1 mg/L;how- ever it was only 1.13 mg/L where filed crops were planted. The pH didn＇t change a lot in the soil where greenhouse vegetables were planted less than 10 years,but if more than 10 years it decreased remarkably. After 10 years of green- house vegetable planting, the salt contents of soil were increased obviously. The content of soil organic matter was also increased remarkable after 5 years planting of greenhouse vegetables. These results indicate that soil nutrients were cu- mulated intensively after 10 year planting of greenhouse vegetables. Simultaneity, ground water pollution was serious in these area, so effective measures should be taken to deal with it.