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为探讨栽培年限对日光温室土壤养分平衡状况及其动态累积特性的影响,以黄土高原南部陕西杨凌的13个日光温室为研究对象,连续4 a监测其养分投入量、蔬菜产量、土壤养分含量等变化,以评价温室栽培系统养分平衡状况及土壤养分的累积特性.结果表明:温室土壤每年N、P2O5、K2O的平均投入量分别为18.04、15.65和17.79 kg/km2,其中来自有机肥的N、P2O5、K2O分别占各养分投入总量的64%、58%、53%,氮、磷、钾投入过量问题突出;表层土壤w(有机质)、w(TN)、w(矿质氮)、w(速效磷)和w(速效钾)均随栽培年限的延长而不断增加;与建棚时相比,栽培第1年和第2年温室土壤各养分含量增幅迅速,第3年和第4年养分累积速度相对减慢.随着温室栽培年限的延长,土壤剖面硝态氮累积量显著增加;虽然研究区井水中ρ(NO3--N)平均值低于GB 5749—2006《生活饮用水卫生标准》标准,但随着温室栽培年限的延长,硝酸盐向深层土壤淋溶及进入地下水的风险值得关注.
In order to investigate the effects of planting years on soil nutrient balance and its dynamic accumulation characteristics in solar greenhouse, 13 solar greenhousehouses in Yangling of Shaanxi Province in the south of the Loess Plateau were selected as research objects. Nutrients input, vegetable yield, soil nutrient content The results showed that the annual average input of N, P2O5 and K2O in greenhouse soil were 18.04, 15.65 and 17.79 kg / km2, respectively, of which the N, P2O5 and K2O accounted for 64%, 58% and 53% of the total amount of each nutrient input, and the problems of excessive input of nitrogen, phosphorus and potassium were prominent. The contents of soil organic matter, w (TN), mineral N, Available phosphorus) and w (available potassium) all increased with the extension of the cultivation years. Compared with the greenhouse planting, the nutrient contents in greenhouse soil increased rapidly in the first year and the second year of cultivation, and the nutrients in the third and fourth years The accumulation rate of nitrate nitrogen in the soil profile increased slowly with the increase of the greenhouse cultivation years.Although the average ρ (NO3 - N) in the well water of the study area was lower than that of the standard of GB 5749-2006 "The standard, but with greenhouse cultivation years The extension of the limit, the nitrate leaching into deep soils and the risk of entering the groundwater are noteworthy.