菜田种养复合系统氮/磷平衡分析

通过田间试验，设置菜田种养复合模式（VE）和常规菜田单一种植模式（对照，CK）两个处理，采用投入?产出法，于蔬菜收获后对种植（种养）系统内土壤、水体和产品（包括花菜和水产动物）中氮磷含量进行测定，研究VE模式下土壤（耕作区、底泥、边沟）、蔬菜（花菜）、水产（螃蟹、黄鳝、鱼）和水体内氮、磷平衡和循环特征。结果表明：系统内总氮/总磷（TN/TP）含量均以肥料输入最大，VE模式和CK模式肥料氮、磷输入分别占TN/TP总输入量的89.09%、99.73%和89.20%、99.86%，收获季花菜花球氮、磷输出分别占TN/TP总输出量的37.74%、33.69%和38.26%、34.50%。VE模式中的系统TN/TP输出/输入比分别为67.01%和39.51%，均高于CK模式，VE模式降低了系统氮、磷表观损失35.19kg和24.38kg。当前投入水平下，两种模式的系统TN/TP盈余量均为负，说明均需投入适量肥料以利于作物产出和系统平衡。研究结果有助于为菜田种养复合模式氮、磷循环和平衡管理提供参考。

Analysis of the Nitrogen and Phosphorus Balance in the Integrated Ecosystem in Vegetable Field

In this study, a field experiment was conducted to study the balance and cycling characteristics of nitrogen(N) and phosphorus(P) under the integrated planting and breeding system in the vegetable field(VE mode) using an input-output method, with the conventional singly planting system as the control(CK mode). And the corresponding parameters were determined and analyzed: farming soil, ditch bottom mud, side ditch soil, cauliflower, aquatic products(crab, eel, fish), and water in the ditch. The results showed that the total nitrogen(TN) and total phosphorus(TP) were the largest in the fertilizer input, accounting for 89.09% and 99.73%(VE mode) and 89.20% and 99.86%(CK mode) of the total input, respectively. In the harvest season, the TN and TP of cauliflower curd, of the total output, accounted for 37.74% and 33.69% in the VE mode and 38.26% and 34.50% in the CK mode. The TN and TP input/output ratios of VE system were 67.01% and 39.51%, which both were higher than those of CK system(66.75% and 38.82%), indicating that VE mode decreased the apparent loss of N and P in the system(35.19kg and 24.38kg). Under the current input levels, the apparent balance of both TN and TP in the whole VE and CK systems were in deficit, so appropriate amount of fertilizer was needed for the two modes to guarantee crop yield and system balance. The research will be helpful to provide references for N and P cycling mechanism and balance management of the integrated plantation and breeding system in the vegetable field.