Effect of different cultivation years on nutrients accumulation and environmental impacts of facilities cultivation soil | 不同种植年限对设施栽培土壤养分累积及其环境的影响

Chinese. 探讨不同种植年限对设施栽培土壤养分累积及其环境的影响，为设施栽培土壤的养分管理提供依据。以农田和菜地土壤为对照，测定了陕西杨凌地区5个不同种植年限(1，3，5，7，10年)的25个大棚不同土层深度(0~10，10~20，20~40 cm)土壤的pH、电导率及养分含量，通过分层聚类分析筛选出最有代表性的土壤养分指标。相对于农田和菜地土壤，种植1~5年的设施栽培土壤的速效氮、速效磷、速效钾、有机质及有效态锰、铜、锌含量均随种植年限的增长而升高，种植5~10年后各养分含量则趋于稳定，其含量均随土层深度的增加而降低。种植1~3年时,土壤硝态氮含量及电导率均随种植年限的增加而显著升高；各种植年限各层土壤硝态氮含量与电导率均呈极显著正相关(P＜0.01)，说明设施栽培土壤的硝态氮累积形成了一定的硝酸盐淋溶和次生盐渍化的风险。随种植年限的增加，设施栽培土壤pH呈下降趋势，且与土壤硝态氮和速效磷含量均呈极显著负相关(P＜0.01)，说明硝态氮和速效磷的累积是导致土壤pH下降的主要原因。提出以pH、有机质、速效磷和有效锌为典型指标，来表征土壤养分随栽培年限的变化状况。与农田和菜地土壤相比，设施栽培土壤pH下降、电导率上升且养分含量相对较高，存在一定的环境风险，应提倡合理施肥，以保证设施栽培的持续发展和利用。

English. 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. Soil pH, EC and various kinds of soil nutrients of different depths in 25 greenhouses with 5 cultivated 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. 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. 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.