Effects of burning on upland rice crop yields and soil properties following a Leucaena leucocephala fallow on the Island of Mindoro, Philippines

An experiment was conducted in an upland rice field to test rice crop response to burning in a Leucaena leucocephala (Lam.) De Wit fallow. No significant differences (P < 0.05) were detected between the burned and unburned treatments in grain or straw yield, or in soil or foliar nutrients, although foliar P concentration was lower in the unburned treatment at P = 0.06. No differences were detected between soils sampled before burning and those collected 182 days after burning. Weeding requirements were greater in the unburned treatment. Stump survival was higher in the unburned treatment (41%) than in the burning treatment (4%). The number of leucaena seedlings at the end of the rice harvest was greater in the unburned treatment. The advantages of the unburned treatment were only in the enhanced regeneration from stumps and seedlings. Advantages of the burned treatment included reduced labour for weeding and greater P availability as evidenced by higher foliar P levels.