基于发酵床养猪的秸秆垫料腐熟的微生物驱动机制研究

The straw bedding has been popularizing in pig biobed technology, because it can not only improve the growth of livestock and poultry and control environmental pollution of soil and water, but also solve the problem of burning straw pollution. Moreover, the waste can be used as organic fertilizer. Nevertheless, the study on the biobeds was mainly focused on the pig growth process, but less on straw litter decomposition and environmental pollution. In this study, we will use the straw from rice and wheat as the bedding of pig biobeds, which are the most widely planted crops in China. Through the static chamber and gas chromatograph method, we will determine the flux and correlation of material conversion and CH4 and N2O emission in the pig biobeds, with the different types of straws and the different breeding number of pigs. By adding the inoculum into the straw, we will assess its straw rotten degree and emission reduction capacity in the pig biobeds. Using molecular biology method, we will reveal the microbial community structure and function of gene driven factor with CH4 and N2O emission from the pig biobeds. It will provide rational evaluation of material conversion and CH4 and N2O emissions and emission reduction potential in the pig biobeds with straw bedding, and the scientific basis for the microbial driving mechanism of straw litter decomposition.

秸秆作为发酵床养猪垫料为秸秆等农业废弃物提供了新的去处，而且秸秆等垫料发酵完成后可作为有机肥，因此该模式具有广阔的推广前景。然而，发酵床养猪过程中垫料的腐熟过程及可能存在的环境问题研究较少。通过了解秸秆垫料在发酵床养猪过程中腐熟机理，为后续废弃垫料成肥提供技术支撑，加快废弃秸秆垫料肥料化利用。本项目以国内种植面积最广的粮食作物水稻和小麦秸秆作为养猪发酵床垫料，研究不同发酵床秸秆垫料在养猪过程中物质转换和CH4、N2O排放规律，发酵床菌剂对发酵床养猪过程中秸秆垫料腐熟度和CH4、N2O排放的影响及减排潜力，利用分子生物学方法揭示发酵床养猪过程中物质转换和CH4、N2O排放的相关微生物群落结构、功能基因驱动因子及微生物间协同作用，为合理评估发酵床养猪过程中秸秆垫料CH4和N2O的排放量及其减排潜力提供数据支持，为揭示发酵床养猪过程中秸秆垫料腐熟的微生物驱动机制提供科学依据。

本研究以秸秆作为养猪发酵床主要垫料，研究养猪过程中发酵床秸秆垫料腐解规律，为发酵床养殖的科学管理和后期垫料肥料化利用提供理论依据。研究结果表明，发酵床秸秆垫料虽然在养猪过程中经过一定的腐熟，也能够产生有利于植物生长的腐殖酸，但是其并未能完全腐熟，必须经过无害化处理才能作为肥料用于农田；发酵床秸秆垫料养猪过程中存在一定的温室气体排放，发酵床垫料早期温度气体排放较少，在一栏猪生长的中后期发酵床垫料温室气体排放量增多，中后期应通过合理的管理措施降低温室气体排放；发酵床随着时间的推移垫料中养分、盐分含量逐渐增加，其微生物群落结构也发生变化，对不同时间的垫料进行堆肥发现3个月的垫料微生物活性最高，时长1年的垫料微生物活性最低；通过外源添加有机物料能够有效促进发酵床垫料肥料化进程，有效提高高温期微生物多样性，加快有机物料的腐解进程，而发酵床垫料作为单一物料可能存在不能满足无害化处理条件。