| Based on the developmental status of greenhouse cultivation in Yellow River irrigation area, the study was conducted in greenhouse soil collected from Yongjing, Honggu, Gaolan, Yuzhong, Baiyin, Jingyuan county, located in central Gansu Province, China. By field investigation and laboratory analysis, under different patterns of vegetable cultivating spatial change of soils nutrient, the characteristics of salt accumulation and acidification in the soils were investigated by compared with open field soil, involving in heavy metal contents such as Cd, Pb, Cr, Cu, Zn and Ni in soils were monitored and further assessed using methods combing single quality index and comprehensive quality index. The main results were as the bellowing:(1) There is a big blindness for application of organic manure and chemical fertilizer as well as the amount of irrigation water under greenhouse cultivation. Large amounts of organic manure and chemical fertilizer were applied. Application rates of organic manure was added from 60～337 t·hm-2, nitrogen fertilizer was applied from 1165～4865 kg·hm-2, phosphorus fertilizer was from 1079～2960 kg·hm-2 and potassium application rates was about from 631～3321 kg·hm-2.(2) Soil EC was higher in greenhouse cultivation than in open field. The EC value in soils of greenhouse vegetable production from Honggu, Gaolan, Jingyuan had exceeded the threshold value of vegetable growth (0.4 mS·cm-1). Nitrate and available K accumulation in soil increased soil EC. Soil pH was lower in greenhouse cultivation than in open field.(3) The contents of nitrate-N, available P and available K in each profile of greenhouse soil were significantly accumulated than those in open field soil, especially, an increased available P and K concentrations in greenhouse soils were noted, and moved down the depth of soil profile. The average content of nitrate-N is 93.90 mg·kg-1 in 0-20cm soil layer,50.68 mg·kg-1 in 20-40cm layer and 37.91 mg·kg-1 in 40-60cm layer in greenhouse. Nitrate-N contents in 0-40cm soil layer of greenhouse are higher than that of open field. The content of available-P exceeded 90 mg·kg-1 in topsoil by over 90%. This value is generally at high levels. The contents of available P in 40-60cm soil layer of greenhouse from Gaolan, Yuzhong, Baiyin and Jingyuan were higher many times than that of topsoil in open field collected. The potassium supply is excessive. The contents of available K in each soil profile were significant higher than in that of open field. The average contents of available K were 477.96 mg·kg-1 in 0-20cm soil profile, 400.09 mg·kg-1 in 20-40cm layer and 326.66 mg·kg-1 in 40-60cm soil layer in greenhouse.(4) Different levels polluted by Cd were found in all of greenhouse soils collected except from Yongjing. The concentrations of Cd in greenhouse topsoil collected from Baiyin, Gaolan, Yuzhong and Jingyuan exceeded the standard threshold set for greenhous vegetable production HJ333-2006. The concentrations of Cd in 20-40cm greenhouse soils from Baiyin, Gaolan, and Jingyuan were higher than the second- class limit value set in the national Soil Environmental Quality Standard (0.60 mg-kg-1) (GB15618-1995). The mean concentrations of the heavy metals except Cd were lower than the standard threshold set for greenhouse vegetables production HJ333-2006. According to the single quality index and comprehensive quality index of soil heavy metals, the soil collected from Yongjing belonged to the first class, and was clean. The soil from Honggu and Yuzhong belonged to the second class, and was considered to be clean. By contrast, the soils collected from Gaolan, Baiyin and Jingyuan belonged the third class, exceeding the threshold, and was considered to be not suitable for the cultivation of pollution free vegetables.
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