Emergy Analysis Based On Different Treatments Of Livestock Excrements Of The Agricultural Ecosystem

Today the environmental pollution problems are more and more severity,which is caused by that the total livestock excrement output has increased drastically, therefore, the government pays great attention to the pollution of the livestock excrement. Through field survey and literature reference the author discovered that the two kinds of planting breeding agricultural ecosystem(livestock excrement manufacture manure and livestock excrement manufacture methane) are the most reasonable approach to solve the pollute problem of livestock excrement and develop the planting breeding industry.The paper has a study on Jinhua Animal Husbandry(using the technology of livestock excrement manufacture manure to achieve planting breeding agricultural ecological model) and Dadi Animal Husbandry(using the technology of livestock excrement manufacture methane to achieve planting breeding agricultural ecological model),the main mean in the paper was emergy analysis theory and method. Firstly, this paper researched the change of emergy about the two company that the operation pattern developed from previous pure breeding to present planting breeding ecological and used some important emergy indexes to estimate it, secondly, the author had a transverse compare between the present planting breeding model of the two company, the author gets several research results finally in the following:(1)For the study of Jinhua Animal Husbandry, the results show that, after Jinhua Animal Husbandry employs planting breeding agricultural ecosystem that is based on livestock excrement manufacture methane, the natural resources emergy self-supporting ratio rises from 0 to 0.11, the system self-supporting ratio rises from 0 to 0.30, the waste utilization is 15%, the environmental loading rate reduces from 0.44 to 0.37, the emergy yield ratio rises from 1.32 to 1.47, the emergy index of sustainable development rises from 3.00 to 3.97, the date can tell us that the present operation model of Jinhua Animal Husbandry has a higher level of modernization, responds environmental protection policy of our country, realizes zero pollution emissions in the system of agricultural production, and improves the agricultural productivity and sustainability.(2)For the research of Dadi Animal Husbandry, the following results are obtained, after the technology that the livestock excrement manufactured methane was used in the planting breeding agricultural ecosystem,the natural resources emergy self-supporting ratio rises from 0 to 0.14, the system self-supporting ratio rises from 0 to 0.58, the waste utilization is 20%, the environmental loading rate reduces from 0.17 to 0.12, the emergy yield ratio rises from 1.37 to 1.57, the emergy index of sustainable development rises from 8.06 to 13.08, the dates show that after Dadi Animal Husbandry introduces the planting breeding agricultural ecosystem it improves the level of agricultural modernization, works better on waste disposal, recycling and environmental protevtion, and improves the agricultural productivity and sustainability.(3)The author had a compare and analysis between Jinhua Animal Husbandry and Dadi Animal Husbandry about the emergy investment ratio, and gets the following conclusions,(1)the proportion for the natural resources emergy input in the total emergy input between model Ⅱ and model Ⅳ has a small different, the date is 8.03% and 8.22%, shows the natural resources emergy utilization is the same in the two kinds of planting breeding agricultural ecological model;(2)the system feedback emergy of model Ⅱ is 9.68 * 1015 sej, proportion for 21.23% of the total emergy input, the system feedback emergy of model Ⅳ is 72.55 * 1015 sej, proportion for 33.68% of the total emergy input. The difference of two kinds of proportion is more apparent, the feedback emergy of model Ⅱ is mainly used to improve soil quality and production of vegetables, not bring obvious auxiliary function for the breeding link, the feedback emergy of model Ⅳ not only is used to planting, but also supplied a significant portion auxiliary for breeding;(3)the proportion of renewable organic emergy in total emergy input is 50.65% in model Ⅱ, the proportion of renewable organic emergy in total emergy input is 51.40% in model Ⅳ,not only the category of energy but also the proportion, they has no significant differences;(4)the proportion of nonrenewable industrial ememgy is 20.09% in total emergy of model Ⅱ, the proportion of nonrenewable industrial ememgy is 6.70% in total emergy of model Ⅱ, there was large difference between the two, the main reason of the difference is that the generated methane of mode Ⅳ is used to produce electric energy and thermal energy for breeding, which makes the energy input greatly reduce, there is no in model Ⅱ(4)The paper also had a compare between Jinhua Animal Husbandry and Dadi Animal Husbandry about some important emergy indexes, which showed that the indexes of Dadi Animal Husbandry such as the natural resources emergy self-supporting ratio, the system self-supporting ratio, the waste utilization, the emergy yield ratio and the environmental loading rate are superior to Jinhua Animal Husbandry, so the inner structure of planting breeding agricultural ecosystem and the sustainable development of Dadi Animal Husbandry is more perfect.