Effects of shifting cultivation on soil ecosystems in Sarawak, Malaysia

Abstract

Abstract Experimental shifting cultivation was conducted at two sites, Balai Ringin (B. Ringin) and Sabal in Sarawak, Malaysia. The soils at the B. Ringin site were clayey with strongly acidic nature while those at the Sabal site were sandy with a very low nutrient status. The plots (10 x 10 m2) were burned with vegetation biomass (fuel) amounting to 0 (control), 100,200, and 300 Mg ha-1 for the cultivation of upland rice. At both sites, the fire severity was found to range from moderate to high for the treatments with 200 and 300 Mg ha-1 fuel, and from low to moderate for the treatment with 100 Mg ha-1 fuel. At the B. Ringin site, the content of total C (T-C) of the soils decreased during rice cultivation which could be ascribed to the rapid decomposition of soil organic matter (SOM) and the loss of SOM due to soil erosion. One year after burning, the T-C content returned to the initial level before burning, suggesting that SOM was replenished by the addition of fresh organic matter derived from rice str...