Effect of different cultivation years on nutrients accumulation and environmental impacts of facilities cultivation soil

【Objective】The impacts of different years of facility cultivated soils on nutrients accumulation and environment were studied to provide scientific guidelines for soil nutrients management in facility cultivation.【Method】Soil pH,EC and various kinds of soil nutrients of different depths in 25 greenhouses with 5cultivated years(1,3,5,7 and 10 years)were measured,soils from grain field and normal vegetable land were taken as control.Soil nutrients parameters were classified by Hierarchical Cluster to select the most representative index.【Result】Available phosphorus,nitrogen and potassium,organic matter,available manganese,copper and zinc content in facility cultivation soil increased during the first 5 years and then leveled off from 5th to 10th years,and which decreased with the increase of soil depth.Soil nitrate and EC content raised significantly with the increase of cultivation year.There was a significant correlation between soil nitrate content and EC in different soil depths,and this indicated that nitrate accumulation formed a risk on nitrate leaching and secondary salinization in soil.Soil pH declined significantly with the increase of cultivation years.The decrease of soil pH resulted from the accumulation of nitrate nitrogen,available phosphorus and organic matter.Soil pH,organic matter,available phosphorus and available zinc were the sensitive indexes to characterize the variation of soil with cultivation years.【Conclusion】Soil pH decreased while EC increased and soil nutrients accumulated significantly in facility cultivation soil compared with grain field and vegetable land,and it formed certain environment impacts.Advocating rational fertilization is necessary for sustainable development of facility cultivated soil.