发酵床养猪过程中垫料P素和K素物质流分析

选取3种垫料(40%稻壳+60%菌糠、40%稻壳+60%锯木屑、40%稻壳+60%酒糟)为研究对象,分别在育肥猪进栏前和出栏后对垫料和表层土壤进行采样分析,采用物质流分析的方法分析了一个养猪周期内3种垫料TP和TK的损失途径。结果表明:P素在发酵床养殖过程中主要的损失途径为猪采食与淋溶损失,总损失量分别为(FJ:40%稻壳+60%菌糠组合)15.69 kg、(FD:40%稻壳+60%锯木屑组合)16.61 kg、(FW:40%稻壳+60%酒糟组合)14.37 kg;而3种发酵床分别有(FJ)80.74 kg、(FD)52.48 kg、(FW)84.65 kg的总P库存在垫料中,75%~85%的P素会滞留在垫料中,损失率均超过14%。K素的主要损失途径也为猪采食与淋溶损失,总损失量分别为(FJ)45.95 kg、(FD)33.95 kg、(FW)63.95 kg;总库存的K素分别为(FJ)158 kg、(FD)107 kg、(FW)136 kg,68%~78%的K素会留存在垫料中,损失率均超过22%。养殖过后发酵床下部表层土壤会出现P素和K素累积现象,为了防止元素通过淋溶作用渗漏损失,建议发酵床垫料厚度要超过50 cm。

Material flows of phosphorus and potassium in deep litter of swine biobeds

In this study, material flows of phosphorus(P) and potassium(K) in deep litter of swine bio-beds were examined using three kinds of deep litter, i.e., 40% rice husk+60% mushroom bran(FJ), 40% rice husk+60% sawdust(FD), and 40% rice husk+60% vinasse(FW). Phosphorus and K transformations in deep litters and top soils during a feeding period were determined. Results indicated that phosphorus lost mainly via leaching and pig feeding, in which the losses were 15.69, 16.61 and 14.37 kg, respectively, for FJ, FD, and FW. Residual P were 80.74, 52.48, and 84.65 kg in deep litter of FJ, FD and FW, respectively, which accounted for 75%~85% of total P. The rest 14% of P was lost via foraging and leaching. The K losses were 45.95, 33.95, and 63.95 kg, in FJ, FD, and FW, respectively. The residual amount of K was 158, 107 and 136 kg, respectively in FJ, FD and FW, indicating that more than 68%~78% of K was retained in the litter. The loss rate was over 22% due to foraging and leaching. Accumulation of P and K in top soils was found at the bottom of biobed. In order to prevent nutrient losses through leaching, the litter depth of biobed should be more than 50 cm.