沼渣和沼液总称为沼肥,是生物质经过沼气池厌氧发酵的产物。沼液中含有丰富的氮、磷、钾、钠等营养元素。沼渣是由部分未分解的原料和新生微生物菌体组成,分为三部分:一是有机质(20%～30%)、腐殖酸(10%～20%),对改良土壤有重要作用;二是氮(0.8%～2.0%)、磷(0.4%～1.2%)、钾(0.6%～2.0%)等营养元素,满足作物生长需要;三是未腐熟原料, Biogas residue and biogas slurry are collectively referred to as biogas, which is the product of anaerobic fermentation of biomass through biogas digesters. Biogas slurry is rich in nitrogen, phosphorus, potassium, sodium and other nutrients. Biogas residue is composed of some undissolved raw materials and new microbial cells, and is divided into three parts: one is organic matter (20% -30%) and humic acid (10% -20%), which plays an important role in soil improvement; The second is nitrogen (0.8% -2.0%), phosphorus (0.4% -1.2%), potassium (0.6% -2.0%) and other nutrients to meet the needs of crop growth; third is not decomposed raw materials,