无机肥对生物复混肥活菌数的影响

采用平板计数法,研究不同氮、磷、钾无机肥类型、不同无机肥用量及无机肥不同配比对生物复混肥活菌数的影响.结果表明,硫酸铵、磷酸二氢铵和硫酸钾较适合作为生物复混肥的无机肥源;单加硫酸铵可显著降低肥料中的活菌数,添加w=2%的纯氮时对活菌数的影响相对较小;单加磷酸二氢铵对活菌数的影响较复杂,以添加w分别2%、4%的P2O5为宜;单加硫酸钾可显著增加肥料中的活菌数,以添加w=6%的K2O为宜;同时添加无机氮、磷、钾肥可显著降低生物复混肥中的活菌数,无机氮、磷、钾较适宜的添加配比(w)为4%N 4%P2O5 4%K2O.

Effects of Inorganic Fertilizer on the Living Microbial Numbers in Microbial-Organic-Inorganic Compound Fertilizers

The effects of inorganic fertilizer on the living microbial numbers in microbial-organic-inorganic compound fertilizers were studied by indoor simulated experiment with plating count.The results showed that ammonium sulfate((NH_4)_2SO_4),ammonium dihydrogen phosphate(NH_4H_2PO_4) and potassium sulfate(K_2SO_4) were suitable inorganic fertilizers as N,P and K sources respectively for making up microbial-organic-inorganic compound fertilizer.The numbers of living microbe in microbial-organic-inorganic compound fertilizer were decreased significantly by adding(NH_4)_2SO_4,but there was less influence in the fertilizer receiving a low dose N(2%).Adding 2% to 4% P_2O_5 in form of NH_4H_2PO_4 was relatively appropriate as living microbial population in the fertilizer was larger.The addition of K_2SO_4 increased the amount of living microbes in the fertilizer,and 6% K_2O in form of K_2SO_4 was optimal.The numbers of living microbes were remarkably reduced by adding N,P,K inorganic fertilizer simultaneously,and the suitable proportion of inorganic N,P,K fertilizer was 4%N,4%P_2O_5 and 4%K_2O.