Modeling circulation function in agroecosystems

Understanding the biophysical foundation of agroecosystems is critical to achieve sustainable results. This paper focuses on the efficient flow of materials within an agroecosystem from cropping to livestock-raising and endeavours to establish a functional model of the relationship between motive power and resistance with efficiency measured in terms of material flow within the system. An efficiency constant (K) was created by modeling five integrated factors in the cultivation-husbandry system: single-harvest yield, multiple crop index, waste of forage, feed conversion ratio and circulation volume. Results of a test modeling of K at three sites in north China indicate that small scale agroecosystems are sensitive to material flows and the resulting pressure such flows place on system efficiency.