北京市设施蔬菜施肥状况及减施潜力分析

通过对北京市352 个设施蔬菜地块的施肥状况进行实地调研，查明设施蔬菜施肥现状及存在问题，估算肥料减施潜力。结果表明，北京市设施蔬菜养分投入量普遍超过推荐施肥量（养分超标率＞72%）。不同设施类型施肥量差异较大，其中日光温室每季蔬菜平均氮磷钾（N、P₂O₅ 和K₂O）投入总量分别为858 、409、572 kg · hm^-2，明显高于塑料大棚每季蔬菜平均氮磷钾投入总量593、317、438 kg · hm^-2。设施蔬菜养分主要来源于有机肥基施，对日光温室和塑料大棚养分投入总量的贡献分别为66% 和52%。不同蔬菜种类肥料减施潜力巨大，其中甘蓝、黄瓜和茄子总养分相对减施潜力分别为61%～62%、43%～48% 和18%～47%。日光温室和塑料大棚氮磷钾养分投入比例（N∶P₂O₅∶K₂O）分别为1∶0.47∶0.66和1∶0.53∶0.73，表明钾肥比例相对不足。建议加快设施蔬菜水肥一体化技术的推广应用，加强设施蔬菜施肥技术指导，尤其要降低日光温室的氮、磷肥投入量，避免过量施肥带来的资源浪费和环境污染。

Analysis on Fertilization Status and Potential of Fertilizer Reduction in Greenhouse Vegetable Fields in Beijing

Through proceeding field investigation on the fertilizer application of 352 greenhouse vegetable fields in Beijing，this paper aimed to find out the fertilization status in greenhouse vegetable fields and existing problems，so as to estimate the potential for fertilizer reduction．The results showed that the nutrients input to greenhouse vegetable fields in Beijing（nutrients over standard rate＞72%）were generally exceeded the recommended fertilizing amount．There were significant differences in fertilizing amount between different kinds of greenhouses．The average input quantities of nitrogen，phosphorus and potassium（N，P₂O₅ and K₂O）were 858，409，572 kg · hm^-2 in solar greenhouses，which were significantly higher than those in plastic-covered tunnels．The average input quantities of N，P₂O₅ and K₂O were 593，317，438 kg · hm^-2，respectively．Nutrients in greenhouse vegetable fields mainly came from basally applied organic fertilizers．The total nutrients input amount in solar greenhouses and plastic-covered tunnels were 66% and 52%，respectively．There was huge potential in fertilizer reduction for different vegetable varieties．Potentials of fertilizer reduction for total quantities of N，P₂O₅ and K₂O were 61%-62% for brassica，43%-48% for cucumber，and 18%-47% for eggplant，respectively．The input ratios of N∶P₂O₅∶K₂O were 1∶0.47∶0.66 and 1∶0.53∶0.73 in solar greenhouses and plastic-covered tunnels，respectively，indicating that the potassium fertilizer input was relatively insufficient．We suggested to accelerate the popularization and application by integration of water and fertilizer technology in greenhouse vegetable production and reinforce technical guidance for greenhouse vegetable fertilization，especially to reduce N and P₂O₅ inputs in solar greenhouses，so as to avoid waste of natural resources and environmental pollution caused by excessive fertilization．