Farming systems in the tropics of Province, China

摘要

The Yunnan tropics is an area with rich biodiversity. There are advantages and disadvantages in developing tropical agriculture. People living in tropical areas follow traditional agriculture, but with the increase in population accompanied by economic development and environmental change, farming systems have changed. This paper introduces agro-forestry, shifting, cultivation, cash crop plantations and predicts development trends. The Yunnan tropics include two climate zones (the northern tropics and southern sub-tropics) which are mainly distributed in the southern part of Yunnan province and adjoining Laos, Myanmar and Vietnam. Their area is 81,000 km~2 (21 percent of the area of the province), or 10,000 km~2 for the northern tropics and 71,000 km~2 for the southern sub-tropics; 95 percent of the area consist of mountains. The main meteorological indices are as follows: daily temperature higher than 10°C throughout the year; annual accumulated value of temperature (>10°C) is 7,500 to 8,000°Cin the tropics, and in the southern subtropical, 285-365 days and 5,000-7,50Q°C respectively. The climate is divided into the rainy season (mid- May-October); and dry (November-early May), with annual rainfall at 1000-1500 mm. The Yunnan tropics is divided into humid /moist regions, semi-humid and semi-arid regions, with 58,431 km~2 for humid/moist region; 19,686 km~2 for semi-humid; and 7,883 km~2 for semi-arid. This area is inhabited by different entities who live on the natural resources and develop their traditional farming systems. With population growth and economic development, farming systems have changed. This paper summarizes the farming systems and analyzes changing trends.