关键词: 甘肃省, 甘肃省, 区位塌陷, 战略地位, VAR模型

Abstract: The author used biological bacterial manure to improve a 2 hm2 greenhouse which was abandoned for a long time. The soil heavy metal contents, the pesticide residue condition, the soil basic physical and chemical properties before the test, and soil pH, EC, organic carbon, available P and nitrate-N changes after the test were measured. The author analyzed the soil nutrient improvement effect and nitrate-N accumulation after different treatments. The results showed that the contents of heavy metal were lower than the secondary limit level of“Environmental Quality Standard for Soils”and the“Controlling Standards for Pollutants in Agricultural Sludge” . The contents of pesticide residue were also lower than the secondary limit level of “Environmental Quality Standard for Soils” . Soil pH in 0-5 cm layer of CK, organic fertilizer and biological bacterial manure treatments increased. Soil EC and soil nutrient of organic fertilizer treatment, microorganism fertilizer and organic fertilizer treatment and biological bacterial manure treatment increased. They all had differences with CK. The contents of nitrate-N in topsoil in those 3 treatments increased and showed a surface aggregation phenomenon. But the contents of nitrate-N in 5-30 cm layer were less than before in this test. From the results we could come to the conclusion that this plot was not polluted by heavy metal and pesticide residue. The organic fertilizer and biological bacterial manure treatment could increase soil pH, organic carbon, available P content and decrease nitrate-N content in 5-30 cm layer.