Composition and mineralization of organic compost derived from composting of fruit and vegetable waste

ABSTRACT Fruit and vegetable waste can be used for the production of organic compost, which when mineralized can increase the availability of nitrogen. The objectives of this study were: (a) to produce compost from different ratios of fruit and vegetable waste, rice husk and poultry manure that meets the legislation on organic fertilizers and (b) to assess the mineralization of N in substrates prepared with different ratios of compost. In experiment 1, the following treatments were prepared using (fruit and vegetable residue: rice husk: poultry waste) (v:v): Treatment 1 (2:1:0), T2 (1:1:1), T3 (1.5:1:0) and T4 (1.2:1:0). All the treatments were subjected to composting for 95 days, were subjected to analysis of nutrients, organic carbon, C/N, CEC/C, pH and moisture content. The composts were compared in regards to the parameters required by legislation. In experiment 2, the treatments consisted of eight blends of agricultural peat, carbonized rice husk and organic compost pre-selected from experiment 1. The NO3 --N and NH+ 4-N contents were analyzed in the substrate at time zero and at 7, 14, 28, 56, 112 days after incubation. Compost (C2) met the parameters required by legislation and the use of 40% in the substrate composition promoted the mineralization of N.摘要：果蔬废弃物可用于制备有机堆肥（organic compost），其经矿化作用可提升氮素的生物有效性。本研究的目标为：(a) 以不同配比的果蔬废弃物、稻壳与家禽粪便制备符合有机肥料法规标准的堆肥；(b) 评估以不同配比堆肥制备的基质中氮的矿化情况。 实验1中，按照（果蔬残渣:稻壳:家禽废弃物）的体积比（v:v）设置如下处理组：处理组1（2:1:0）、T2（1:1:1）、T3（1.5:1:0）及T4（1.2:1:0）。所有处理组均进行95天堆肥发酵，并对其养分含量、有机碳（organic carbon）、碳氮比（C/N）、阳离子交换量与有机碳的比值（CEC/C）、pH值及含水率开展检测分析。依据有机肥料法规规定的相关参数，对各堆肥样品进行对比评价。 实验2中，处理组由8种混合基质构成，这些基质由农用泥炭、碳化稻壳与实验1中预筛选得到的有机堆肥混合制成。在培养初始时刻（0天）及培养后7、14、28、56、112天，对基质中的硝态氮（Nitrate Nitrogen, NO3--N）与铵态氮（Ammonium Nitrogen, NH4+-N）含量进行测定。 经筛选的堆肥C2符合法规规定的各项参数标准，且在基质配比中添加40%的该堆肥可有效促进氮的矿化作用。