Furukawa Yuichiro, Hasegawa Hiroshi
International Rice Research Institute, Crop, Soil, and Water Science Division, DAPO Box 7777, Metro Manila, Philippines.
J Environ Qual. 2006 Sep 13;35(5):1939-47. doi: 10.2134/jeq2005.0482. Print 2006 Sep-Oct.
Recycling of kitchen garbage is an urgent task for reducing public spending and environmental burdens by incineration and/or landfill. There is an interesting regional effort in Ogawa, Saitama prefecture, Japan, in which source-separated kitchen garbage is anaerobically fermented with a biogas plant and the resultant effluent is used as a quick-release organic fertilizer by surrounding farmers. However, scientific assessments of fertilizer values and risks in the use of the effluent were lacking. Thus, a field experiment was conducted from 2003 to 2004 in Tohoku National Agricultural Research Center to grow spinach (Spinacia oleracea L.) and komatsuna (Brassica rapa var. perviridis L. H. Bailey) for evaluating the fertilizer value of the kitchen garbage effluent (KGE), nitrate, coliform group (CG), Escherichia coli, fecal streptococci (FS), and Vibrio parahaemolyticus concentrations of KGE and in the soil and the plant leaves. A cattle manure effluent (CME) and chemical fertilizers (NPK) were used as controls. Total nitrogen (N) and ammonium N concentrations of the KGE were 1.47 and 1.46 g kg(-1), respectively. The bacteria tested were detected in both biogas effluents in the order of 2 to 3 log CFU g(-1), but there was little evidence that the biogas effluents increased these bacteria in the soil and the plant leaves. At the rate of 22 g N m(-2), yield, total N uptake, apparent N recovery rate, and leaf nitrate ion concentration at harvest of spinach and komatsuna in the KGE plot were mostly comparable to those in the NPK and CME plots. We conclude that the KGE is a quick-release N fertilizer comparable to chemical fertilizers and does not cause contamination of CG, E. coli, FS, or V. parahaemolyticus in the soil and spinach and komatsuna leaves.
厨余垃圾的回收利用是一项紧迫任务，有助于减少通过焚烧和/或填埋处理带来的公共开支和环境负担。在日本埼玉县小川地区，有一项有趣的区域性举措，即对分类收集的厨余垃圾进行厌氧发酵处理，通过沼气厂生产出的废水被周边农民用作速效有机肥料。然而，此前缺乏对该废水肥料价值及使用风险的科学评估。因此，2003年至2004年在东北农业研究中心开展了一项田间试验，种植菠菜（菠菜属）和小松菜（不结球白菜变种），以评估厨余垃圾废水（KGE）的肥料价值、硝酸盐、大肠菌群（CG）、大肠杆菌、粪链球菌（FS）以及KGE、土壤和植物叶片中副溶血性弧菌的浓度。牛粪废水（CME）和化肥（NPK）用作对照。KGE的总氮（N）和铵态氮浓度分别为1.47和1.46 g kg⁻¹。在两种沼气废水中检测到受试细菌的数量为2至3 log CFU g⁻¹，但几乎没有证据表明沼气废水会使土壤和植物叶片中的这些细菌增加。以22 g N m⁻²的用量，KGE地块中菠菜和小松菜收获时的产量、总氮吸收量、表观氮回收率以及叶片硝酸盐离子浓度大多与NPK和CME地块相当。我们得出结论，KGE是一种与化肥相当的速效氮肥，不会导致土壤、菠菜和小松菜叶片中CG、大肠杆菌、FS或副溶血性弧菌的污染。
