浙江省规模养猪场沼渣液养分特征和农田利用适宜性分析

为明确浙江省规模养猪场沼渣液养分含量特征,为沼渣液农田合理利用提供指导,分别在2016年5月和8月采集全省62个规模养猪场的沼渣液样品,测定沼渣液养分含量指标。结果表明,5月和8月采集的沼渣液样品平均pH分别为7.39和7.47,总有机碳平均含量分别为5.01 g·L~(-1)和4.79 g·L~(-1),全磷平均含量分别为0.34 g·L~(-1)和0.47 g·L~(-1),全钾平均含量分别为0.57 g·L~(-1)和0.81 g·L~(-1),全盐平均含量分别为3.06 g·L~(-1)和1.76 g·L~(-1)。铵态氮是沼渣液中主要的氮素形态,5月和8月沼渣液样品的铵态氮平均含量分别为689.2 mg·L~(-1)和1 235.5 mg·L~(-1),占沼渣液全氮含量的69.6%和81.2%。2次取样的沼渣液样品总有机碳变异幅度分别为126.2%和182.1%,全磷的变异幅度分别为86.7%和222.6%,全氮、全钾、铵态氮和全盐的变异幅度在44.5%～87.8%。不同区域沼渣液养分含量间没有明显差异,但5月和8月2次取样时间沼渣液样品含量差异极显著。沼渣液中铵态氮含量与全氮、总有机碳、全磷、全钾、含盐量等指标间都表现为显著线性相关。5月和8月全省沼渣液总养分含量(N+P_2O_5+K_2O)分别为1.91 g·L~(-1)和2.81 g·L~(-1),N∶P_2O_5∶K_2O分别为1∶0.31∶0.6和1∶0.35∶0.59。沼渣液养分指标间存在明显的相关性,氮、磷、钾的比例和作物需肥比例相似,农田利用时可以根据沼渣液铵态氮含量测定结果确定沼渣液施用量。

Nutrient characteristics and cropland utilization suitability of biogas slurry from large-scale pig farms in Zhejiang Province,China

The aim of this study is to clarify the nutrient characteristics of biogas slurry (BS) from large-scale pig farms and to promote the rational use of BS in farming systems. BS samples were collected from 62 large-scale pig farms in Zhejiang Province in May and August 2016, and their pH, total organic carbon (TOC), total phosphorus (TP), total potassium (TK), total salt (TS), and ammonium-N levels were measured. The results showed that the average pH, TOC, TP, TK, and TS of the pig BS were 7.39 and 7.47, 5.01 and 4.79 g·L^-1, 0.34 and 0.47 g·L^-1, 0.57 and 0.81 g·L^-1, and 3.06 and 1.76 g·L^-1 in May and August, respectively. Ammonium-N was the main form of N in the BS. The mean ammonium-N was 689.2 and 1 235.5 mg·L^-1 in May and August, respectively, which accounted for 69.6% and 81.2% of total nitrogen in the BS. The variable coefficient of TOC was 126.2% and 182.1% in May and August, respectively, and those of TP were 86.7% and 222.6%. The variable extents of TN, TK, ammonium, and TS ranged from 44.5%~87.8%. No significant differences in the nutrients were observed among the regions. However, there were significant differences between sampling times. Ammonium of BS was significantly correlated with TN,TOC, TP, TK, and TS. The main nutrient concentrations (N + P₂O₅ + K₂O) were 1.91 and 2.81 g·L^-1 in May and August, respectively. The N:P₂O₅:K₂O was 1:0.31:0.60 and 1:0.35:0.59 in May and August, respectively. Significant relationships were observed among the nutrients in the slurry. The N:P:K ratio in the BS was similar to the crop demand in the field. The application rate of BS could be confirmed according to the ammonium-N concentration in the BS when it was applied in farming systems.