炭基辅料对羊粪好氧堆肥中氮素损失的影响

养殖废弃物(羊粪)的堆肥化处置是现代"草-羊-田"农牧循环生产的重要环节,为探讨羊粪高温好氧堆肥中氮素损失的有效控制技术,研制了一种炭基辅料,与羊粪和稻草混合后进行了34 d的堆肥试验。试验设置2个处理:羊粪与稻草高温好氧堆肥(CK)、CK基础上添加质量比15%的炭基辅料(CA)。监测了堆肥体的温度、NH_3挥发速率、N_2O排放通量、各形态氮素含量等参数变化情况,分析了炭基辅料对羊粪堆肥过程中氮素转化及损失的影响。结果表明,与CK处理相比,添加炭基辅料促进了堆肥后第1～7 d堆肥温度快速上升,对堆肥后第8～34 d的堆温影响较小;堆肥34 d后,CK、CA处理的NH_3挥发累积量分别为368.38、175.63 mg·kg-1,N_2O排放累积量分别为50.38、88.94 mg·kg-1,CA处理的NH_3挥发累积量显著小于CK处理(P0.05),而2个处理之间的N_2O排放累积量差异性不显著(P0.05),羊粪堆肥过程中NH_3挥发是氮素损失的主要途径;CK、CA处理的氮素损失率分别为50.49%、32.63%,添加炭基辅料显著降低了羊粪堆肥体的氮素损失率(P0.05),炭基辅料应用于羊粪有机肥生产,氮素损失率可减少35.37%。

Effect of carbonaceous amendment on nitrogen loss during the aerobic composting of sheep manure

The composting of livestock residue (sheep manure) plays an important role in grass-sheep-field of modern agriculture and animal husbandry recycling production. In order to develop an effective material for controlling nitrogen loss in the aerobic composting process of sheep manure, a carbonaceous amendment mixed with sheep manure and rice straw was adopted in a 34-day composting experiment. And to aim to determine the effect of carbonaceous amendment on nitrogen loss in the aerobic composting process of sheep manure, the temperature, NH₃ volatilization rate, N₂O emissions flux, and nitrogen content of the composting body were monitored. In the current study, two treatments, i.e., (i) aerobic thermophilic composting of mixing sheep manure and rice straw (CK), (ii) on the basis of CK, adding 15% (m/m) carbonaceous amendment (CA) were conducted. Compared with the CK, the carbonaceous amendment rapidly increased the composting temperature from 1st to 7th day, while did not significantly increased composting temperature from 8st to 34th day. After 34 days of composting, the total amount of NH₃ volatilization was 368.38 mg·kg^-1 in the CK and 175.63 mg·kg^-1 in the CA. The total cumulative N₂O emission flux was 50.38 mg·kg^-1 in the CK and 88.94 mg·kg^-1 in the CA. Significant difference on the total amount of NH₃ volatilization between the CK and the CA was obtained (P<0.05). However, no evident difference on the total cumulative N₂O emission flux between the CK and the CA (P>0.05) was detected. The results indicated that NH₃ volatilization was the main ways of nitrogen loss in the aerobic composting process of sheep manure. The nitrogen loss was 50.49% in the CK and 32.63% in the CA. The carbonaceous amendment significantly decreased the nitrogen loss of sheep manure compost (P<0.05). The nitrogen loss can be decreased by 35.37%.