【作者】 彭里；

【导师】 魏世强；

【作者基本信息】 西南大学 ， 农业环境保护， 2009， 博士

【摘要】 畜牧业是农业甚至整个国民经济的重要组成部分,世界上许多国家的畜牧业产值超过农业总产值的50%。然而,随着近年来畜牧业特别是规模化养殖业的迅猛发展,由畜禽养殖带来的环境污染问题日益显现。我国现阶段畜禽养殖环境污染的一个新趋势是,面源污染日趋严重,已经对生态环境的安全,特别是水环境安全构成了威胁。世界上的一些发达国家如日本、芬兰、美国等在上世纪七十年代就开始了畜禽粪便对环境的污染治理工作,我国在上世纪九十年代初一些城市（上海、北京等）也开始进行了畜禽粪便的区域治理,并取得了一些成果。重庆市自从1997年直辖以来,在包括社会、经济的各个方面做了大量工作来防治环境污染,全市环保投入逐年增加。全市环境保护工作总体上取得了明显的成效,但作为近年农村面源污染主要来源的畜禽粪便污染治理却收效甚微。在此以前,我市还没有对全市畜禽粪便污染特征及其时空动态变化进行过全面系统的调查研究。多年以来,我国畜禽粪便的主要处理途径是作为有机肥施入农田。畜禽粪便施入农田不仅为作物提供养分、改良土壤,同时还是一种简便的废弃物处理途径。然而,快速增长的畜禽粪便在一定的时空范围内没有足够的农田加以消纳,造成农牧脱节,打破了原有良性循环的生态模式,加上化肥的大量使用限制了畜禽粪便的出路,使得畜禽粪便在一定区域内超过土地承载能力,对农田以及环境带来了巨大的压力。因而畜禽粪便的合理利用对于农业生产和环境保护都具有重要意义。但是,如何合理利用畜禽粪便?每年单位面积的土壤施用多少畜禽粪便为宜?农民群众在实践中总结有“一头猪,一亩田”之说,也就是说常年养殖一头猪,其间产生的粪便可以供一亩田作为肥料种植作物,作物能维持生长,而粪便也不会因此产生环境污染。但是其科学性如何,没有人对其进行深入的研究。且实际生产中,不可能只养殖猪,还需养殖其它种类的畜禽。于是就给人们提出了这样一个问题,一亩田每年究竟需要多少畜禽粪便才合适,即土壤的畜禽粪便适宜负荷量是多少。基于此,本研究以重庆市为研究对象,根据物质平衡原理,以满足作物氮素需求为前提,首先将整个重庆市定为有养分输入和输出的开放系统。其次通过大量调查研究和资料收集等从宏观的和微观的方面获得基础数据资料,确定输入和输出的项目。最后,根据物质平衡原理,在重庆市范围每年氮输入和输出的差值等于系统内氮的净积累。从而可以从理论上计算出每年单位面积作物的对氮需求量。这些氮假设全部来自畜禽粪便,根据畜禽粪便的含氮量,可以换算为相应的猪粪当量,再除以当年的耕地面积,就可以计算出重庆市每年单位土壤面积的畜禽粪便理论负荷量,也就是重庆市单位作物满足氮需要的土壤面积的畜禽粪便理论适宜负荷量。实际上,畜禽粪便的土壤适宜负荷量受多方面的因素影响,如农田养分水平、不同的养分需求、不同种类畜禽粪便的养分含量、及粪便施用的区域条件（土地利用类型、土壤质地、地形、季节、气候、经济、人口等）,这些因素均是一个动态的变化量。因而畜禽粪便的适宜负荷量也是一个动态的变化量。以氮平衡为基础的理论分析获得的重庆市畜禽粪便的理论适宜负荷量是否适宜作物生长,需对这一理论值在实际中的真实性进行检验。本研究以窝笋为材料,以理论研究的适宜理论负荷量为基准,根据土壤面积大小换算为相应的猪粪量,分别增加和减少100克猪粪为不同试验水平,共设8个处理水平,在温室进行盆栽实验。每天观察窝笋的生长情况,种植85天时进行收获,分别测量窝笋的生物量,土壤和窝笋中氮磷等营养元素和铜、铁等重金属元素含量。并对这些数据进行分析处理,得出盆栽实验的结果。畜禽粪便施入土壤后,增加了土壤中氮、磷、钾及金属元素的含量,由于其中的金属元素在土壤中易累积,长期施用畜禽粪便会产生金属元素对土壤和作物污染,所以即使土壤按适宜负荷量施用畜禽粪便,也应控制畜禽粪便连续施用于同一地块的时间。本研究中以金属元素铜为基准,找出土壤中铜的环境容量、土壤背景值、猪粪中铜的含量值,再通过一定的数学公式,可以算出猪粪便连续施用于同一地块土壤的时间。由于畜禽养殖结构的差异,不同区域和不同时期畜禽粪便的排放量不一致,对环境的影响不一样,这也就产生了重庆市畜禽粪便的时间和空间分布差异。本研究中以重庆市2007年的39个区县为空间区域单位,以重庆市养殖的主要畜禽猪、牛、家禽（鸡、鸭、鹅）、羊为研究对象,时间从1995年开始至2007年共13年以年为单位。根据重庆市单头畜禽日排放粪便量及粪便中主要成分的测定,结合国内外的研究,选取重庆市畜禽的排放参数。再根据重庆市畜禽年养殖数量,可计算出重庆市各类畜禽的年排放粪便量及粪便中的成分量。以畜禽粪便中的主要营养物氮为基准,按照重庆市养殖的主要畜禽猪的排放量为单位,换算为猪粪当量。有了这些数据,就可以从1995年起至2007年止,研究每一年重庆市畜禽粪便排放量的变化,从而得出重庆市畜禽粪便的时间变化特征。在空间分布上,选定最近的2007年为研究对象,结合地理信息系统的空间分析方法进行了分析,研究各区域畜禽粪便排放的空间分布特征。最后,根据确定的重庆市畜禽粪便土壤适宜负荷量值和重庆市禽粪便的时间和空间分布,进行重庆市畜禽养殖的环境影响评价,并提出重庆市畜禽养殖布局建议。结果表明,重庆市畜禽粪便的理论适宜负荷量为44.37t·hm^-2.a^-1,也就是4.437kg.m^-2.a^-1。作物盆栽实验检验后证明,这一负荷值是作物最适宜生长的畜禽粪便负荷值。因而可以认为重庆市畜禽粪便的土壤适宜负荷量为44.37t·hm^-2.a（-1）。这个值与“一头猪负担一亩田”基本吻合。畜禽粪便施入土壤后,经过作物正常生长,土壤中氮、磷、钾及金属元素铜、铁、锌等的含量明显增加,并且随着畜禽粪便施入量的增加,土壤中氮、磷、铜、锌等物质含量呈线性增大。猪粪便连续施用于同一地块的时间最长应控制在42年以内为宜。重庆市主要畜禽粪便（猪、牛、家禽等）都是随时间的变化排放量增大,而重庆市各类畜禽粪便的总量和也是随时间的变化而增加。变化最大的是家禽粪便1995年到2007年增加了4.85倍;变化最小的是牛粪便,1995年至2007年的年仅增加了1.23倍;重庆市畜禽粪便排放总量在1995年时为8600.27万t,2007年为10974.45万t,增加1.28倍,但以家禽的发展最为突出。重庆市猪粪当量的变化与排放总量的变化有相同的趋势。猪粪当量播种面积负荷的值在21.343t.hm^-2a^-1—27.74t.hm^-2a^-1之间波动,变化相对比较平稳,但总体趋势是随着时间的推移,负荷在逐年增大,相关性也达到了极显著水平。重庆市年畜禽粪便中的养分排放量及负荷量也在逐年增大。有机质年排放量最大的是2007年,为1151.96万t,最小的是1995年,为935.57万t,波动值为216.39万t。氮年排放量较有机质小得多,最大的是2007年,为61.31万t,最小的是1995年,为47.26万t。畜禽粪便的这四种物质中磷的年排放量最小,每年仅24.33至31.05万t间,约相当于当年有机质的四十分之一。重庆市年畜禽粪便中氮的负荷在0.13—0.17t·hm^-2之间波动,磷负荷在0.06—0.08 t·hm^-2之间变化,钾负荷在0.15—0.19 t·hm^-2之间波动。氮、磷、钾负荷变化大致趋势是一致的,都是随时间的变化负荷在增大,磷的负荷变化相对较小,变化趋势线近乎直线。各类畜禽粪便排放呈现出较强的区域化特征。猪粪便集中在合川、巴南、武隆、涪陵、开县等地。最大区域是合川464.13万t.a^-1,最小区域是双桥5.91万t.a^-1。羊粪便集中在酉阳、奉节、城口等地,最大的区域是云阳为21.14万t.a^-1,最小的区域是南岸为0.014万t.a^-1。牛粪便集中在铜梁、渝北、南岸等地,最大的区域是酉阳为220.75万t.a^-1,最小的区域是双桥为0.18万t.a^-1。家禽粪便则集中在壁山、永川、铜梁、长寿等地。重庆市猪粪当量负荷区域分布差异较大。猪粪当量最大的区域均处于近郊,如大渡口、九龙坡等;而最小的均位于边远的山区,如城口、巫溪、巫山等县。有机质负荷大的区域主要集中在位于三峡库区的酉阳和渝西走廊荣昌及主城的江北、九龙坡等区域;氮负荷大的区域主要集中于主城区的江北、沙平坝、九龙坡和渝本走廊的荣昌、合川及三峡库区的酉阳。磷负荷大的区域主要集中渝西走廊的荣昌、合川及主城区的江北。重庆市畜禽养殖环境评价表明,重庆市有2.6%的区县畜禽养殖对环境没有任何污染,有68.4%的区县畜禽养殖对环境稍有污染,有23.7%的区县畜禽养殖对环境有污染,只有5.3%的区县畜禽养殖对环境污染较严重。根据现有的养殖量核算,已经有荣昌县和江北区的养殖量超过了耕地的适宜载畜量,这两个区域应限制畜禽养殖数量和控制养殖结构,其它区域均还有一定的养殖发展空间。以养殖猪为标准,可以再发展200万头以上的区县有涪陵、合川等6个区县占重庆市区县数量的15.8%;可以发展100万头以上的区县有綦江、长寿等15个区县占重庆市区县数量的39.5%;可以发展100万头以下的区县有北碚、南岸等15个区县占重庆市区县数量的39.5%。更多还原

【Abstract】 Animal husbandry is an important part in agriculture and also in the whole national economy.In many countries in the world,the output of animal husbandry surpasses more than 50%of the total output of agriculture.In recent years,however,with the development of animal husbandry,especially the rapid development of large-scale livestock farming,the problems of environmental pollution caused by livestock and poultry breeding have become increasingly apparent.A new trend of livestock pollution in China at this stage is the growing-point source pollution,and it has been a threat to the safety of the ecological environment,in particular a threat to the water environment.Some of the world’s developed countries,such as Japan,Finland and the United States,began their environmental pollution control work caused by livestock and poultry manure in the seventies of the last century.In China,in the early nineties of the last century,a number of cities（Shanghai,Beijing,etc.） have begun to carry out regional governance of livestock and poultry manure,and have achieved some results.Directly under the Chongqing Municipality since 1997,a lot of work,including in the social and economic aspects,have been done to combat environmental pollution,and the city’s environmental protection investment has increased year by year.The city’s environmental protection work in general has made remarkable results,but,as a point source pollution in rural areas,the main source of animal waste pollution has little effect in recent years.Meanwhile little research has been done in this area in the city.Prior to this,comprehensive and systematic study and investigations have not been carried out from the aspects of the pollutional features of livestock and poultry manure and its temporal and spatial dynamics of the city’s.Over the years,the main way to proceed our livestock and poultry manure is to put it into the fields as an organic manure.Applied into fields,livestock and poultry manure not only provides nutrients for crops and improves the quality of the soil,it is also a simple means of waste disposal.However,within a certain time and space,the rapid growth of livestock and poultry manure does not have enough farmland to digest and absorab it, resulting in agricultural and pastoral touch,breaking the original ecological model of a virtuous cycle,and coupled with heavy use of fertilizers,finally limiting the way of livestock and poultry manure,so that within a certain region,livestock and poultry manure surpasses the carrying capacity of farmland and great pressure has been brought on the environment.Therefore,the rational use of livestock and poultry manure is of great significance for agricultural production and environmental protection.But questions are: how to make rational use of it? How much livestock and poultry manure is appropriate for per unit area of soil each year ? In practice,the peasants have summed up a saying "One pig,one mu of fields.",which means that by breeding a pig all year round,its manure can be used as fertilizers for each mu of fields of crops,so the growth of crops can be maintained,and no environmental pollution being resulted in.But how is it in science? No one has made an in-depth study on it.And in the real practice,not only pigs are bred,other types of livestock and poultry are also bred.So such a problem has been proposed:how much livestock and poultry manure on earth is appropriate for each mu of land a year,that is:what is the load of livestock and poultry manure suitable fort the soil.For this reason, taking Chongqing as the research object,based on the principle of material balance,to meet crop needs for nitrogen as the premise,this study first regards the whole city of Chongqing as an open system with nutrient input and output.Second,through extensive research and data collection,basic data can be obtained from the macro and micro aspects to determine the input and output items.Finally,under the principle of material balance, within the Chongqing municipality,the difference between nitrogen input and output in each year is equal to the net accumulation of nitrogen within the system.Thus,nitrogen demand of crops per unit area per year can be theoretically calculated.Suppose that all nitrogen comes from livestock and poultry manure,and according to the amount of livestock and poultry manure,nitrogen can be converted to the corresponding pig equivalent,and then divide the year’s farming area,we can calculate the theoretical load of livestock and poultry manure each unit area of the soil per year in Chongqing,that is the theoretical load of livestock and poultry manure suitable for soil to meet the needs of crops of Chongqing Municipality for nitrogen In fact,the suitable soil load of livestock and poultry manure is affected by a wide range of factors,such as nutrient levels of the farmland,the different nutrient needs,the nutrient contents of different types of livestock and poultry manure,and regional conditions of manure application（types of land use,soil textures,topographies,seasons,climate,economy,population,etc.）.These factors are a dynamic variation.And therefore the appropriateness of livestock and poultry manure is also a dynamic load variation.Based on and obtained from the theoretical analysis of nitrogen balance,whether the theoretical suitable load of livestock and poultry manure in Chongqing is suitable for crop growth,should take the value the theory to test the authenticity in practice.This study takes asparagus lettuce as materials,and is based on the suitable load of theoretical study, and according to the size of basins,pig manure is converted into the corresponding amount and then increases and decreases respectively 100 grams of pig manure for different test levels,with the total of 8 treatment levels,pot experiments are carried out in a greenhouse. The growth of asparagus lettuce is observed every day,and after 85 days it is harvested. The biomass is measured,so is nitrogen and phosphorus and other nutrients and iron and copper and other heavy metals in soil and asparagus lettuce.And analysize and process these data to obtain the results of pot experiments.Applying livestock and poultry manure into the soil increases in it the contents of nitrogen,phosphorus,potassium and metallic elements.As one of the metallic elements in the soil is easy to accumulate,a long-term application of manure will produce contamination of metallic elements on the soil and crops.So even if the soil is applied appropriate amount of manure,livestock and poultry manure should be controlled not to be continuously applied to the same plot during a period of time.In this study,metal element copper is taken as a benchmark to identify the environmental capacity of copper in the soil, the soil background value,the value of copper content in pig manure,and through a certain mathematical formula,the time amount that the pig manure could be applied continuously to the same block of soil can be figured out.Due to the differences in the structures of livestock and poultry breeding,in different regions and during different periods,the livestock manure emissions are variable,and have not the same impact on the environment,which also results in the differences in the emporal and spatial distribution of livestock and poultry manure in Chongqing.This study takes 39 districts and counties in Chongqing City in 2007 as its space units,and such main animals bred in Chongqing as pigs,cattle,poultry（chickens,ducks,geese）,and sheep as the research object,with a total of 13 years from 1995 until to 2007.According to the amount of emissions by a single head of livestock and poultry,manure and its major components are to be measured.Combined with the studies at home and abroad,the emission parameters of livestock and poultry in Chongqing are selected.Then according to the number of livestock and poultry bred in Chongqing each year,the annual emissions from various types of livestock and poultry manure and its composition can becalculated. The major nutrient of nitrogen in livestock and poultry manure is taken as the benchmark, and the main livestock-the pigs’ emission as units,pig manure equivalent can be converted.With these data,a study can be carried out about the changes in emissions from livestock and poultry manure in Chongqing from 1995 until 2007 each year,and thus comes to the time-varying features of livestock and poultry manure in Chongqing.In spatial distribution,the latest year 2007 is selected as the research object.Combined with geographic information systems,the method of spatial analysis is analyzed to study regional spatial distribution characteristics of emissions from livestock and poultry manure.Finally,according to the established value of suitable soil load of livestock and poultry manure and the emporal and spatial distribution of livestock and poultry farming in Chongqing Municipality,the assessment of environmental impact by breeding livestock and poultry is to be conducted,and the layout of livestock and poultry breeding in Chongqing is proposed.The results show that the theoretical suitable load of livestock and poultry manure in Chongqing is 44.37 t·hm^-2.a^-1,which is 4.437 kg.m^-2.a^-1.After the examination of crop pot experiments,it is proved that the load value is the most suitable load value of livestock and poultry manure for the growth of crops.Thus,it can be considered that the suitable load of soil for livestock and poultry manure in Chongqing Municipality is 44.37 t·hm^-2.a^-1.This value is basically consistent with the " A pig burdens an acre of fields".Poultry manure being applied into the soil,after normal growth of crops,the levels such as nitrogen,phosphorus,potassium and metal elements,copper,iron,zinc in the soil increase significantly,and with the increase in the amount of manure applied into in the soil,nitrogen,phosphorus,copper,zinc and other substances increases linearly.It is appropriate for the same land to be applied to pig manure continuously within 42 years.In Chongqing,the emissions from the main livestock and poultry manure（pigs,cattle, poultry,etc.） are increasing with the changing of time,while the total amount of various types of livestock and poultry manure is also increasing with the changes over time.The biggest change is poultry droppings,an increase of 4.85 times from 1995 to 2007;the smallest change is cattle dung,only an increase by 1.23 times between 1995 and 2007; livestock and poultry manure in Chongqing is 8600.27 million tons in 1995,and 10974.45 million tons in the year of 2007,with an increaseof 1.28-fold,but the development of poultry is the most prominent.The pig equivalent of changes and the changes in the total emissions in Chongqing have the same trend.The value of equivalent load of pig manure ranges between 21.343t.hm^-2a^-1.and 27.74t.hm^-2a^-1,the changes being relatively stable,but the overall trend is that as time goes by,the load increases year by year,and the correlation has reached an extremely significant level.The amount of nutrient emissions and loads of livestock and poultry manure in Chongqing are increasing year by year.The biggest annual emissions of organic matter is in 2007,1151.96 million tons,and the smallest in 1995,935.57 million tons,the fluctuation value being 216.39 million tons.Annual emissions of nitrogen is much smaller than the organic matter,the largest being in 2007,to 61.31 million tons the smallest in 1995,to 47.26 million tons.Among these four substances from livestock and poultry manure,the smallest annual emission is phosphorus,only from 24.33 to 31.05 million tons each year,equivalent to about one fortieth of organic matter of the year.The nitrogen load of livestock and poultry manure in Chongqing per year fluctuates between 0.13--0.17t·hm^-2,the phosphorus load 0.06--0.08 t·hm^-2 and the potassium load 0.15--0.19 t·hm^-2. The general trends of load changes of nitrogen,phosphorus,potassium are almost the same, the load incrasing with the changes of time.The load change of phosphorus is relatively small,the changing trend line almost being straight.Emissions from various types of livestock and poultry manure have shown a strong regional characteristics.Pig manure is concentrated in Hechuan,Banan,Wulong,Fuling, Kaixian and so on.The maximum area is Hechuan,with 464.13 million tons,the smallest area is Shuangqiao,with 5.91 million tons Sheep manure is concentrated in Youyang, Fengjie,Chengkou and other places.The largest region is Yunyang for 21.14 million tons, and the smallest area is Nanan 0.014 million tons.Cattle manure is concentrated in Tongliang,Yubei,Nanan and other places.The largest region is Youyang for 220.75 million tons,and the smallest region is Shuangqiao for 0.18 million tons.Poultry droppings are concentrated in Bishan,Yongchuan,Tongliang,Changshou and so on.Large differences in Chongqing exist among the pig manure equivalent load of regional distribution.The largest pig equivalent region lies in the suburbs,such as Dadukou,Jiulongpo,etc.;while the smallest are located in the remote mountainous areas, such as Chengkou,Wuxi,Wushan and other counties.Large Organic load areas are mainly located in the Three Gorges reservoir area such as Youyang,Rongchang,the main corridors of the West Chongqing,and Jiangbei City,Jiulongpo and other areas;large nitrogen load areas are mainly concentrated in the main city of Jiangbei,Shapingba, Jiulongpo and Rongchang,Hechuan and Youyang--the Three Gorges reservoir area.Large phosphorus load areas are focused on Rongchang,Hechuan,and Jiangbei.The environmental assessment of Chongqing’s livestock and poultry breeding shows that with livestock and poultry breeding,2.6%of Chongqing’s districts and counties have no pollution on the environment,68.4%of them have a little pollution on the environment, 23.7%of them have environmental pollution,and 5.3%of them have more serious environmental pollution.Under the existing amount of aquaculture,in Rongchang and Jiangbei District,the breedings have already been more than the carrying capacity of arable land.These two regions should be limited in quantity and be controlled of livestock and poultry breeding structure,and other regions still have a certain degree of culture space for development.To take breeding pigs as the standard,districts and counties which can further develop more than 2 million pigs include Fuling,Hechuan and other six districts and counties,accounting for 15.8%of the number of districts and counties in Chongqing; Those which can develop more than 1 million include 15 districts and counties such as Qijiang,Changshou,accounting for 39.5%of the number of districts and counties;Those which can develop no more than 1 million have 15 districts and counties of Chongqing: Beibei,Nanan,and so on,accounting for 39.5%of the number of districts and counties.更多还原