硫酸亚铁和过磷酸钙对牛粪秸秆混合堆肥氮损失和腐殖化的影响

Effects of Ferrous Sulfate and Calcium Superphosphate on Nitrogen Loss and Humification During Co-Composting of Cattle Manure With Straw

通过表征堆肥过程温度变化和堆肥产品化学性质、腐殖质组成等,研究过磷酸钙(物料干重的4.4%)和硫酸亚铁(物料干重的4.1%)对牛粪秸秆混合堆肥氮损失和腐殖化的影响。结果表明:经过55 d堆肥后,过磷酸钙和硫酸亚铁处理组均达到腐熟要求,堆肥产物C/N比分别为11.61和13.71,胡敏酸光密度(E4/E6值)分别为1.96和1.57,NH4^+-N含量分别为34.19和35.74 mg·kg^-1,种子发芽指数分别为143%和144%,过磷酸钙和硫酸亚铁对堆肥产品的植物毒性无不利影响;添加硫酸亚铁具有较好的保氮效果,对照组和硫酸亚铁组的氮损失率分别为40.78%和25.18%,而添加过磷酸钙则无明显保氮效果;添加过磷酸钙和硫酸亚铁降低了堆肥过程有机物的降解损失量,对照组、过磷酸钙和硫酸亚铁组的有机物降解率分别为58.59%、49.44%和34.67%;添加过磷酸钙和硫酸亚铁可提高堆肥产品腐殖质的品质,过磷酸钙和硫酸亚铁组的胡敏酸占比分别为45.23%和51.60%,均高于对照组的36.85%。添加硫酸亚铁可显著降低牛粪秸秆混合堆肥的氮损失,并有效提升堆肥的腐殖酸品质。

Effects of calcium superphosphate(SP,4.4%dry weight)and ferrous sulfate(LF,4.1%dry weight)on nitrogen loss and humification were studied during co-composting of cattle manure with straw.Changes in temperature during composting,the chemical properties and humus compositions of the compost products were characterized.The results show that SP and LF groups both met the maturity requirements after 55 days of composting.The C/N ratios of compost products were 11.61 and 13.71,E4/E6 ratios were 1.96 and 1.57,and NH4^+-N contents were 34.19 and 35.74 mg·kg^-1,the seed germination indices were 143%and 144%,respectively.The addition of calcium superphosphate and ferrous sulfate had no adverse effect on the phytotoxicity of compost products.The addition of ferrous sulfate had a good nitrogen retention effect(the nitrogen loss of the control group and the LF group were 40.78%and 25.18%,respectively),while the addition of calcium superphosphate had no obvious nitrogen retention effect.It was found that the degradation of organic matter was inhibited in the presence of calcium superphosphate and ferrous sulfate,the loss of organic matter in the control group,SP and LF groups were 58.59%,49.44%and 34.67%,respectively.The addition of calcium superphosphate and ferrous sulfate could improve the quality of humus.The percentages of humic acid in SP and LF groups were 45.23%and 51.60%,respectively,which were higher than 36.85%in the control group.Therefore,the addition of ferrous sulfate can significantly reduce the nitrogen loss during co-composting of cattle manure with straw,and improve the humus quality of the compost effectively.