黄土高原肉牛集约化养殖产排污系数及温室气体排放季节动态研究

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	黄土高原肉牛集约化养殖产排污系数及温室气体排放季节动态研究
	丁学智
学位类型	博士
导师	龙瑞军
	2010-05-26
学位授予单位	中国科学院研究生院
学位授予地点	北京
学位专业	生态学
关键词	肉牛粪便产排污系数甲烷排放
摘要	伴随畜牧业的高度集约化发展，畜禽产生的废弃物对环境污染等问题也随之凸现出来。畜禽粪便和有害气体的排放是环境污染的主要来源之一。畜牧业生产过程中产生的粪尿排泄物及瘤胃甲烷等畜牧业废弃物对水、土、空气以及大气层的影响已受到世界各国的高度关注。本试验通过大量的试验和实地调查，较为系统地研究了黄土高原肉牛集约化养殖业生产过程中的产排污系数以及主要温室气体排放的季节变化动态，为有效控制畜禽废物排放及对畜禽粪便资源进行无害化、资源化利用提供了基础依据。从集约化养殖场(出栏率≥200 头)选取50 头育肥架子牛(秦川牛，平均体重为 431±13kg)，分四季(2007 年10 月、2008 年1 月、4 月、7 月)对其粪尿产量及总磷(TP)、总氮(TN)、化学需氧量(COD)、铜(Cu)、锌(Zn)等主要的污染物进行监测。结果表明：不同季节粪便有机质含量一般在35%，TN、TP 随季节的变化趋势较为相似，平均含量分别为1.98%和0.69%。Cu、Zn 含量受季节影响较大，分别在2.31-20.51μg/g 和24.69-986.28 μg/g 之间变化，其平均含量分别为12.33 和229.93 μg/g。尿液中COD 含量在不同的采样期差异较大，依次为秋季>夏季> 春季>冬季。TP 含量季节差异显著(P<0.05)，秋季显著高于其他季节。各季节肉牛尿液中铜、锌含量差异显著(P<0.05)。对全年数据进行测算，肉牛集约化养殖其粪便、尿液的平均产生量分别为12.10 kg/head· d 和8.29 kg/head· d。产污系数分别为：COD 2235.21 g/ head· d (其中粪便、尿液中COD 分别为2052.8 g/ head· d 和182.41 g/ head· d)、氨氮(NH3-N) 2.28 g/ head· d、TN 104.10 g/ head· d、TP 10.17 g/ head· d、Cu 29.32 mg/ head· d、Zn 236.89 mg/ head· d；排污系数分别为：COD 305.84 g/ head· d、NH3-N 2.27g/ head· d、TN 60.13 g/ head· d、TP 4.12 g/ head· d、 Cu 2.32 mg/ head· d、Zn 20.58 mg/ head· d。结合饲料样品的检测与分析表明：肉牛粪便中氨氮、磷、铜、铁、砷、汞、镉7 个污染物均与饲料因子存在高度线性关系，饲料中影响粪便污染物的主要因子为总氮、总磷、铜、砷均为饲料配方元素，表明通过调控饲料配方可有效调控肉牛粪便中氨氮、总磷、铜、铁、砷、汞、镉等污染物排放；粪便总氮与饲料氮之间不存在线性关系，单位体重耗料量的影响不显著，经曲线拟合未现显著性曲线模型。因此，降低饲料总氮水平不一定减少禽畜粪便中总氮含量。用静态箱法对自然堆放、覆盖玉米秸秆和鲜粪/稻草(70/30)三种不同堆放方式的肉牛粪便温室气体排放速率季节动态进行了观测，结果表明：各个季节三种处理的温室气体排放速率变化趋势基本一致，但各季节间排放速率有明显差异。三种处理温室气体的排放速率与牛粪温度相关极显著。70%鲜粪+30%稻草可减少二氧化碳(CO2)、氧化亚氮(N2O)的排放，而且春季(2008 年4 月14 日~5 月14日)CO2 的排放速率和夏季(2008 年6 月2 日~7 月30 日)N2O 的排放速率与自然堆放的均差异显著；不同季节覆盖对甲烷(CH4)的排放影响不同，夏季覆盖处理的 CH4 排放速率上升，并且与自然堆放的差异显著(P<0.05)；其他季节三种处理温室气体的排放速率无显著差异(P>0.05)。非分光红外(NDIR)探测技术能快速有效的测定反刍动物的CH4 和CO2 排放。肉牛夏季CH4 排放显著高于其他季节(P<0.05)，其CH4 日排量为274.2 L/d；冬季CH4 排放较少，为192.6 L/d。春、秋两季肉牛的CH4 日排放量分别为244.3 和228.1 L/d，差异不显著(P>0.05)。不同季节肉牛CO2 各季节差异较大，且其累计排放量约为CH4 的10 倍。春、夏、秋和冬季CO2 的排放量分别为2546.4 L/d、3202.5 L/d、2728.3 L/d 和1981.2 L/d，其变化范围分别为520-1660 L/d、1070-2030.1L/d、950-1727.1 L/d 和450-1190.5 L/d。夏季CO2 排放显著高于其他季节(P<0.05)，其冬季CO2 排放相对较少，春、秋两季差异不显著(P>0.05)。相关性分析表明，不同的季节CH4 和CO2 呈极显著的正相关关系，随CH4 排放量的增加，CO2也呈上升趋势。春夏秋冬各季节甲烷能的转化率分别为8.04%、7.33%、7.09%和6.38%。CH4 排放量与肉牛日粮各成分的日摄入量之间有显著的相关关系，预测肉牛CH4 排放的最佳因子为干物质摄入量(DMI)，同时总能摄入量(GEI)也可以很准确地预测出甲烷排放量，对应的回归方程分别为： CH4(L/d)=16.238DMI(kg/d)+49.47 (r=0.9418，P<0.01) CH4(L/d)=1.139GEI(MJ/d)+97.421 (r=0.9527，P<0.01)
其他摘要	Environmental issues continue to be one of the biggest challenges faced by intensive livestock husbandry. Specifically, contaminations of air, water and soil related to manure handling and utilization from feedlot, and greenhouse gas (GHG) emission from ruminants are serious environmental problems, which attract great concerns from governments of many countries. In 2007, the Chinese government started the first national census on pollution sources. This provided the golden opportunity to systematically study on production and emission of contaminants from beef cattle in feedlots and seasonal dynamics of GHG emission from enteric fermentation. This research provided accurate techniques to quantify and evaluate the real effects of animal excretions and GHG emission from ruminants, which would supply sound knowledge to develop strategies to use animal wastes more efficiently with less pollution and mitigate GHG emission. The main results and conclusions from this research were summarized as follows: Animal manures contained 80-90% moisture with 1.98% total nitrogen (TN) and 0.69% total phosphorus (TP). No differences were detected for organic matter content among seasons. However, manure had significantly higher copper (Cu) content in summer than any other seasons (P<0.05). The contents of Cu and zinc (Zn) ranged from 2.31-19.68 μg/g and 24.69-986.28 μg/g, respectively, based on 300 samples of eef cattle manures. There was no difference for the contents of copper and zinc urine amples between seasons. The average value of COD (chemical oxygen demand) in rine was 13.46, 11.43, 7.06 and 4.36 g/L for spring, summer, fall and winter. It was stimated that each beef cattle produced 12.10 kg manure and 8.29 kg urine per day, ontaining COD 2235.21 g/head· d (2052.8 g/ head· d and 182.41 g/ head d in manure and urine, respectively), NH3-N 2.28 g/ head·d, TN 104.10 g/ head· d, TP 10.17 g/head d, Cu 29.32 mg/ head d, Zn 236.89 mg/ head d. The wastes exported to farmyard(excretion coefficient) contained COD 305.84 g/head·d, NH3-N 2.27g/head·d, TN60.13 g/head· d, TP 4.12 g/head·d, Cu 2.32 mg/head·d, Zn 20.58 mg/head·d.Organic matter and inorganic minerals in manure was affected by many factors,such as N concentration in diet, degradability, microbial community, and their interactions with other nutrients. There was a strong linear relationship for NH3-N, P, Cu, Fe, As, Hg and Cd in feed and manure wastes, indicating that NH3-N, P, Cu, Fe, As, Hg and Cd in manure can be controlled efficiently by altering the diet. Results showed that reducing crude protein in diet to conserve N during the final stage of the finishing phase in feedlot could decrease N excretion into the environment without reducing animal performance. The GHG emission fluxes from beef cattle manure were measured using static chamber method over 4 seasons. The treatments were manure covered by cornstalk, mixed manure with straw (70:30) or no cover. Results showed that there were significant difference in GHG emission between seasons. The emission of GHGs was significantly correlated with manure temperature. Manure covered with cornstalk reduced the emission of CO2 and N2O compared with manure mixed with straw and no cover. The emission of CO2 in spring and N2O in summer from manure were significantly lower for the 70% manure+30% cornstalk mixture than those without cover. As for the emission of CH4, cornstalk cover increased rate of CH4 emission in summer, but no difference was found in other seasons in comparison with other two treatments.Greenhouse gass (CH4 and CO2) from rumen were continuously recorded using the flow-through chamber method. A new type of Nor-disperse Infrared (NDIR) gas sensors based on pulsable IR source was introduced, where the high performance pyroelectric IR sensor with built in interference filter and the ‘single light and two wavelengths’ technology were used. Methane production in summer was significantly higher than that in other seasons (P<0.05). The daily CH4 production from rumen was 274.2 L in summer and 192.6 L in winter, and intermediate in spring (244.3 L) and fall (228.1) with no significantly difference between spring and fall. The amount of CO2 produced was 10 times higher than CH4. The CO2 emission in 24-h was 2546.4, 3202.5, 2728.3 and 1981.2 L/head with a range of 520-1660, 1070-2030.1, 950-1727.1 and 450-1190.5 L/head d for spring, summer, fall and winter, respectively. Results also showed that CO2 and CH4 emission were positively correlated with R2 0.70 (P<0.01). The methane conversion rate (MCR) was 8.04%, 7.33%, 7.09% and 6.38% for spring, summer, fall and winter, respectively. Methane emission value increased when energy intake and dry matter increased. Enteric fermentation methane emission rates can be estimated from daily intake of general energy (GEI) and dry matter (DMI) with following equations: CH4 (L/d)=16.238DMI (kg/d)+49.47 (r=0.9418，P<0.01) CH4(L/d)=1.139GEI(MJ/d)+97.421 (r=0.9527，P<0.01)
学科领域	生物科学
语种	中文
文献类型	学位论文
条目标识符	http://210.75.249.4/handle/363003/3391
专题	中国科学院西北高原生物研究所
推荐引用方式 GB/T 7714	丁学智. 黄土高原肉牛集约化养殖产排污系数及温室气体排放季节动态研究[D]. 北京. 中国科学院研究生院,2010.

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