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Handbook of Ecological Indicators for Assessment of Ecosystem Health - Chapter 11

Áp dụng chỉ số nhiệt động nông Các hệ sinh thái Một tiêu chí truyền thống cho việc đánh giá hiệu quả của công nghệ nông nghiệp khác nhau luôn luôn sản xuất cây trồng của họ liên quan đến năng lượng, phân bón, lao động, con người và động vật, đã dành. Trong tỷ lệ này nhiệm kỳ đầu tiên là thích hợp hơn. Nông hệ sinh thái sản xuất tối đa hoặc với tỷ lệ tối đa được coi là hiệu quả nhất. Để ước tính các hệ sinh thái nông nghiệp từ quan điểm của các tiêu chí. | CHAPTER 11 Application of Thermodynamic Indices to Agro-Ecosystems Y.M. Svirezhev A traditional criterion for the evaluation of efficiency of different agricultural technologies was always their crop production in relation to energy fertilizers human and animal labor spent. In this ratio the first term was preferable. Agro-ecosystems with maximum production or with maximal ratio were considered to be the most efficient. In order to estimate agro-ecosystems from the viewpoint of the latter criterion D. Pimentel 1973 1980 has developed the so-called eco-energetic analysis. However the agriculture intensification leads to degradation of both the agro-system and its environment. Moreover today this phenomenon acquires such a scale that in developed countries the conservation of environmental quality becomes the main criterion of efficiency for agriculture. We therefore need a universal index which could quantitatively estimate the impact of agro-system on the environment. From the physical point of view any degradation can be associated with an increase in entropy. Therefore if we know how to calculate the entropy balance for agro-ecosystem then the value of the entropy overproduction can be used as a measure index of the agro-ecosystem s degradation caused by the intensification of agriculture. In other words the entropy measure estimates the load of intensive technology on the environment Copyright 2005 by Taylor Francis that allows us to support and ensure ecological and sustainable public policies for agricultural land use. For this purpose a thermodynamic model of ecosystem under the anthropogenic pressure was developed. The pressure shifts the equilibrium of a natural reference ecosystem to a new equilibrium corresponding to an agro-ecosystem. In the course of the transition some quantity of entropy is produced which cannot be balanced by the natural processes. These are the main contents of the entropy pump concept. In this case the excess of entropy has to be .