Ecological study on the dynamics of soil organic matter and its related properties in shifting cultivation systems of northern Thailand
1997
Funakawa, S. (Kyoto Prefectural Univ. (Japan). Faculty of Agriculture) | Tanaka, S. | Shinjyo, H. | Kaewkhongkha, T. | Hattori, T. | Yonebayashi, K.
There is a large number of hill people in northern Thailand, who practices shifting cultivation. In order to analyze the soil ecological problems involved in the transition from traditional shifting cultivation to more intensive upland farming, the authors carried out comparative studies on the dynamics of organic matter and its related properties in soils both in the traditional shifting cultivation systems adopted by Karen people and more intensive upland farming practiced by thai and Hmong people in the area. The contents of organic matter and available N in the surface 10 cm layers of soil f rom the field continuously cultivated were lower than those in soils under prolonged fallow (more than 10 y) or natural forest. Based on the rate of soil respiration, the amount of organic matter decomposed within 1 y was estimated to reach nearly 10% of that stored in the upper 50 cm layers of the soil profile in the upland crop fields. These results indicate that the organic matter-related resources markedly decreased under continuous cropping
显示更多 [+] 显示较少 [-]