甜玉米作为填闲作物对北方设施菜地土壤环境及下茬作物的影响

在北方设施菜地雨季休闲敞篷期种植填闲作物（甜玉米）,通过现场采样及室内分析测试,研究了正常施肥条件下休闲和填闲前后NO3--N的淋失状况、土壤电导率的变化以及对下茬作物产量和品质的影响。结果表明,种植填闲作物较休闲处理0～100cm土壤硝态氮表观损失量减少了28.4kg·hm-2,剖面NO3--N的累积峰也低于休闲处理;种植填闲作物可以显著降低表层土壤（0～20cm）的电导率,较正常休闲处理低41.4%;种植填闲作物并未造成下茬作物产量的降低,同时可显著降低下茬作物果实中硝酸盐含量,较休闲处理降低了28.9%。从降低NO3--N淋失的角度看,雨季敞篷休闲期种植填闲作物可以作为减少氮素淋失的一种有效手段,同时,对提高下茬作物品质,降低可食部分硝酸盐含量有明显的作用。

Effect of Sweet Maize as Catch Crop on Soil Environment and Following Vegetable in Greenhouse of Northern China

This study aim to reduce the NO-3-N leaching and the risk of the underground water pollution by planting the catch crop（Sweet Maize） which were planted in the greenhouse of North China when the land was fallow on the rainy season.We studied NO-3-N leaching,soil conductivity in forth and after of the fallow and catch crop season,and the effect of planting catch crop on yield and quality of following crop.The results indicated that,planting catch crop could reduce the apparent loss of nitrogen by 28.4 kg·hm-2,and,meanwhile,lead peak value of NO-3-N accumulation in the soil profile（0～100 cm） to lower than the follow.In addition,the soil conductivity in 0～20 cm soil layer was significantly decreased by 41.4% by planting catch crop.However,following crop yield was no significant different between follow and catch crop and,compared with normal fallow treatment,the nitrate content of vegetable for following crop was reduced by 28.9% after planting catch crop.Therefore,planting catch crop could be considered as one of the effective measures reducing NO-3-N leaching during the fallow.Meantime,this cultivation system could improve quality of following crop,especially reducing the nitrate content of the vegetable.