Energy input and output of a rural village in China - the case of the "Beijing Man village"/district of Beijing.

The rapid development of the economy has created an increasing demand for energy in China. The limited resources of fossil energy are a risk for the development of China. Sustainable agriculture like organic farming (Green AAA in China) with biomass energy - as done in developed countries like Germany - is an option to reduce these risks. In China, agriculture is not energy efficient, and the intensive farming is not sustainable. The scientific challenge is to develop sustainable farming systems which can fulfill national food security, food safety and considerable renewable energy production without harming the environment, and are acceptable to the people and the economy. The protection and intelligent utilization of resources is the core of rural village development. To explore the potential of recent Chinese agriculture for the development towards a multi-functional farm for food and energy production, a village in the adjacent area of Beijing has been selected: the “Beijing Man village”. About 1,900 people live in the village and 140 hectares of the 240 hectare total land are available for farming. The major agricultural activity is pork production (capacity of 10,000 pigs per year) and dairy farming (40 dairy cows). In 2004, the energy input and output of this village was evaluated and taken as a basis for a model of sustainable farming for food and biogas production. The study explored that the gross energy production from crops in the “Beijing man village” was about 19,103 GJ/year. It was obvious that the crop production was not sufficient for the feed demand of the animal husbandry (pigs and cows). 60% of the corn used as feed stuff was purchased on the market. The reason was, that the purchasing of corn was cheaper than the own production. The low competitive crop production due to the low efficiency resulted in the decrease of cultivated crop land from 140 ha to 80 ha in the past four years (two harvests per year). On the other hand, there was much more manure produced as suitable and applicable for crop production. Therefore manure was exposed in open air in a pond like waste. This is risky for public hazards like ground water contamination and zoonosis diseases. Therefore the farming system is not sustainable, risky and not efficient. There is a potential of the optimization of the cropping and animal husbandry interaction as well as the development of renewable energy production in the village. The main development chains are the improvement of the energy efficiency of crop production, the reduction of animal husbandry to a sustainable animal-land-ratio and the introduction of biogas production with manure and cropping by-products.