长期不同施肥模式对日光温室土壤硝态氮时空分布及累积的影响

Effects of long-term fertilization modes on spatio-temporal distribution and accumulation of soil nitrate nitrogen in solar greenhouse

通过连续7年的定位试验,研究了日光温室生产中不同施肥模式(常规模式、无公害模式和有机模式)对土壤NO3--N时空分布及累积的影响。结果表明,随着种植年限的增加,3种施肥模式土壤剖面各层次NO3--N含量均呈上升趋势,年增加量顺序为常规施肥模式>无公害施肥模式>有机施肥模式。受氮素输入量(施肥)的影响,NO3--N主要分布在0～40 cm土层,0～60 cm土层NO3--N含量总体呈作物生长前期低、中期高、后期低的趋势;与上层土壤相比,100 cm以下土层NO3--N含量有不同程度的增加。0～200 cm土体NO3--N平均累积量有机施肥模式比无公害施肥模式低33.8%,比常规施肥模式低45.9%;无公害施肥模式比常规施肥模式低18.3%。3种施肥模式下,NO3--N都有向2 m以下土体淋洗的趋势。与施用化学肥料相比,施用有机肥能明显降低土壤剖面NO3--N含量,控制其累积峰的下移,但不合理施用有机肥也会产生NO3--N淋洗而污染环境。

Continuous localization experiment was conducted for seven years to study the spatio-temporal distribution and accumulation of soil nitrate nitrogen in solar greenhouse.The study showed that nitrate nitrogen content increased through soil profile with increasing planting time.The order of annual increment in soil nitrate nitrogen in relation to fertilization mode was as follows：conventional fertilization low-input fertilization organic fertilization.The main nitrate nitrogen distribution soil layer was 0～40 cm.Nitrate nitrogen content in the 0～60 cm soil layer was low at the early stage,high at the middle stage and low at the late stage of crop growth.Compared with the upper soil layers,nitrate nitrogen content in soil layers below 100 cm was increased.Average nitrate nitrogen accumulation in the 0～200 cm soil layer was 33.8% and 45.9% less in organic fertilization mode than in low-input and conventional fertilization modes.It was also 18.3% less in low-input fertilization mode than in conventional fertilization mode.Nitrate nitrogen leaching tendency to soil layers below 200 cm was observed in all three fertilization modes.Compared with conventional fertilization mode,organic fertilization mode obviously reduced nitrate nitrogen content in the soil profiles and retarded downward movement of nitrogen.However,improper application of organic fertilizer induced soil nitrate nitrogen leaching which led to environmental pollution.