村级养殖种植园区碳素物质流分析——以北京市平谷区西柏店村为例

Material flow analysis on carbon cycle in planting and breeding park of village scale: A case study of Xibaidian village in Pinggu District, Beijing

将西柏店村畜禽养殖规模折合为1.5万头猪场当量污染负荷,并将整个园区生产工艺分为养殖、废弃物处理和种植3个阶段,不考虑隐藏流的情况下,以1年为系统边界,通过数据调查、已有资料研究和小区种植试验,采用物质流分析方法分析了西柏店村养殖种植园区在整个生产工艺的碳素流动,以期为村级养殖种植园区大力发展低碳经济提供新的方法和视角,为村级区域循环经济及可持续发展提供减少环境压力解决方案的科学依据。通过园区养殖种植过程的C素分析表明,养殖阶段年输入C素总量为112.52×104 kg,其中猪身总固碳量为40.04×104 kg,粪碳和尿碳总量为49.29×104 kg,以CO2形式代谢排出的C为23.19×104 kg。废弃物处理阶段输入的碳主要为粪碳和尿碳,其总量为49.29×104 kg,其中9.79×104 kg尿碳直接进入种植阶段,39.50×104 kg粪碳进入沼气站处理,沼气转化出的碳为11.02×104 kg,其中CH4为8.43×104 kg,CO2为2.59×104 kg,养殖污水中通过CH4排放再加上其他途径释放的碳约有23.66×104 kg,占粪碳量的59.89%。进入种植阶段的碳素主要为尿碳、沼渣和沼液的碳素,合计为14.61×104 kg,假设该村43 hm2耕地能全部施用沼肥,不计其他作物种植,1季玉米种植土壤可库存有机碳为60.50×104 kg,为进入种植阶段碳素14.61×104 kg的4倍,还可增加植物有机碳27.31×104 kg。由C素流动分析可知,西柏店村具有可容纳该村养殖废弃物的环境容量,有较好实现养殖废弃物循环利用的条件,但需大力加强畜禽废弃物的管理和处理,提高园区养殖废弃物循环利用效率。

In this paper,the case study area is Xibaidian village in Pinggu District,Beijing which is a representative planting and breeding park（PBP） of village scale.The pollution load of Xibaidian village’s livestock breeding quantity is equivalent to a scale swine farm with 15 000 pigs,and the production in this village is divided into breeding stage,waste treatment stage and planting stage.Taking one year as the system boundary and without considering hidden flow,through data investigation,the previous research and plot experiments,a material flow analysis（MFA） method is applied to analyze carbon flow of Xibaidian village’s production.The aim is to provide a new method and perspective for PBP of village scale to develop low-carbon economy and sustainable development and to provide a feasible solution for PBP of village zone to decrease the environmental pressure.Through the analysis of carbon flow,the total amount of C annual input is 112.52×10^4 kg during the breeding stage,among which the amount of C sequestration in swine body is 40.04×10^4 kg,the amount of C in feces-carbon and urine-carbon is 49.29×10^4 kg,and the amount of C in the form of CO2 emissions is 23.19×10^4 kg which is metabolized by swine.The total amount of C annual input including feces-carbon and urine-carbon is 42.29×10^4 kg during the waste treatment stage,in which the urine-carbon 9.79×10^4 kg enters into planting stage directly,and the feces-carbon 39.50×10^4 kg enters into biogas plant.The amount of C of biogas converted by feces-carbon is 11.02×10^4 kg,among which the amount of C of CH4 and CO2 is 8.43×10^4 kg and 2.59×10^4 kg respectively.And the amount of C releases from CH4 by wastewater discharging together with other means of carbon emission is 23.66×10^4 kg,which takes up 59.89% of the total amount of feces-carbon.The total amount of C annual input including urine-carbon and the C in biogas slurry and residue is 14.61×10^4 kg during the planting stage,assuming the 43 hectares arable land in the village could spread the biogas slurry and resi-due,without considering other crops planting,the organic carbon stored in soil could be 60.50×10^4 kg during a quarter of corn planting,which is 4 times of C input quantity 14.61×10^4 kg,and the organic carbon of plant could increase 27.31×10^4 kg.From the above analysis,Xibaidian village has the environmental capacity to accommodate the breeding wastes,and has the conditions to carry out the recycling use the breeding wastes.But the attentions should be paid to strengthen the management and treatment of the breeding wastes,and to increase the efficiency of wastes reuse.