2014 年 58 巻 2 号 p. 66-74
Experiments were conducted to assess and evaluate the effects of pigeon pea (Cajanus cajan) cover cropping and no-till practice on corn (Zea Mays) yield, surface runoff and soil erosion. The experimental site was a grassland with a uniform slope of 10% and low fertile clay loam surface soils located at the Soil and Water Conservation Station, Brgy. Baligatan, Ilagan, Isabela, Philippines. There were 3 treatments, namely; fallow + till (F+T), fallow + no-till (F+NT), and pigeon pea (Cajanus cajan) + no-till (PP+NT). Pigeon pea was grown during the period of February to May, 2008, then cut and mulched on the soil surface before corn planting. After corn harvest in September, the second corn cropping was conducted during the period of November, 2008 and February, 2009. Organic matter content in the PP+NT treatment increased significantly during the experimental period unlike that for the other treatments. PP+NT also led to a lower maximum soil temperature at a depth of 5 cm compared with the other two treatments. PP+NT also led to a soil water depletion behavior in deeper soil horizons during the lull period probably due to deep root penetration and active photosynthesis during the maturation period. The 20 hill-based corn yield for PP+NT was improved by almost 1 t ha-1 compared with that for F+T, although the values were not statistically significant, probably due to the nutrient contribution from pigeon pea biomass. PP+NT also contributed to reducing soil runoff and soil erosion, particularly during peak rainfall events. Hence, pigeon pea cover cropping in combination with no-till, with proper management, was found to be effective in ensuring sustainable corn production in sloping lands by improving crop yield, minimizing soil erosion and nutrient loss.
