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连续3年定点监测位于黄土高原南部陕西杨凌的10余个新建日光温室栽培蔬菜种类、产量及施肥情况,并在每季作物种植前及收获后测定0~100 cm土壤电导率、有机质、全氮、有效磷、速效钾及0~200 cm土壤硝态氮等理化性质。结果表明,过量施用有机肥及化肥导致新建温室土壤养分大量盈余,前3年土壤氮、磷、钾养分(以N、P2O5、K2O计)表观盈余量之和分别高达3 784、4 097及2 727 kg/hm2。种植前3年有机质、全氮呈线性增加,年均增加量分别为4.25、0.25 g/kg;土壤有效磷、速效钾累积更加突出,种植2年后,耕层有效磷及速效钾已达高或极高水平;随着种植年限的增加,土壤剖面硝态氮累积量显著增加,耕层以下土壤有效磷、速效钾含量也有所增加。说明新建日光温室在种植初期就存在施肥过量问题,由此引发的问题值得关注。
Three consecutive years of site-specific monitoring of the cultivation of vegetables in more than 10 new greenhouses in Yangling, Shaanxi Province in the southern part of the Loess Plateau, the yield, and fertilizer application. The soil electrical conductivity, organic matter, total nitrogen , Available phosphorus, available potassium and 0 ~ 200 cm soil nitrate nitrogen and other physical and chemical properties. The results showed that excessive application of organic manure and chemical fertilizers led to a large surplus of nutrients in newly-built greenhouses. The sum of apparent N, P2O5 and K2O nutrients in the first three years were as high as 3 784,4 097 and 2 727 kg / hm2. In the first three years before planting, the total organic nitrogen and total nitrogen increased linearly with an average annual increase of 4.25 and 0.25 g / kg, respectively. Soil available phosphorus and available potassium were more prominent. After two years of planting, available phosphorus and available potassium had reached a high level Or extremely high level. With the increase of planting years, the accumulation of nitrate nitrogen in soil profile increased significantly, and the contents of available phosphorus and available potassium in the soil below the topsoil also increased. It shows that the problem of over fertilization exists in the new solar greenhouse at the early stage of planting, and the problems caused by it are noteworthy.