Bai Yongfei

Scientific basis and practical ways forsustainable development of China’s pasture regions

Great changes have taken place in the dietary structure of urban and rural residents in China since the country’s reform and opening starting from the end of 1970s. During the past three decades, grain consumption has reduced and animal food consumption has increased significantly, causing a sharply increased demand of forage. However, the country’s cropping structure has not been adjusted timely, resulting in a large number of grain to be used as forage. Although China has a grassland area of 4×10 8 hectares, which should play an important role in the country’s ecological security and food security, its forage grass and livestock production are considerably low, with different levels of degradation across the grasslands, so that it is far not satisfied with a need of animal husbandry development, because of its extensive management and less input of prataculture. Our analysis showed that developing artificial pasture, which grass yield can be more than 10 times higher than natural grassland, is an effective way to promote the production of forage grass in China. We thus developed the “animal-husbandry development” model, which uses a small area (less than 10% of the grassland) with high quality site to develop intensive artificial pasture to enhance forage grass production, and prevents a large area of the natural grassland (more than 90% of the grassland) from degradation and over-grazing. In order to implement “animal husbandry development” model, we proposed to construct an “eco-animal husbandry experimental zone” in the grassland areas. The “experimental zone” is planned and designed as a coupled system of nature-economy-society complex in a considerably large area, to promote production of artificial pasture and animal husbandry and improve ecological functioning of natural grassland. This paper also discusses the bottleneck issues about socio-economic development in pasturing areas, and proposed seven principles for the development of pasturing areas, including grass breeding, artificial grassland planting, efficient harvesting, efficient use of water, protection and better use of natural grassland, trade-off between grass production and ecological functioning, and system development.

Fundamental theories and technologies foroptimizing the production functions and ecological functions in grasslandecosystems

Optimizing the production functions and ecological functions in grassland ecosystems is of fundamental importance to grassland ecology and management. Here we summarize the progresses in pratacultural systems worldwide, with an emphasis on major limitations of the pratacultural systems in China. We propose six important hypotheses and theories that can be used to guide grassland management, including grazing optimization hypothesis, intermediate disturbance hypothesis, accelerating nutrient cycling hypothesis, decelerating nutrient cycling hypothesis, forage supply-demand balance theory, and grassland-agriculture system theory. We also propose a framework with three major aspects of technologies in eco-pratacultural systems, including how to restore the degraded grasslands, how to sustainably use the natural grasslands, and how to establish artificial grasslands. Finally, we put forward the rules for establishing eco-pratacultural systems with optimization of the production functions and ecological functions. This review has important implications for the management of eco-pratacultural systems in China and beyond.