The effect of legume cover crop Mucuna bracteata on soil physical properties, runoff and erosion in three slopes of immature oil palm plantation

Abstract

This study determined the effect of legume cover crop Mucuna bracteata (MB) on soil physical properties, runoff and erosion on three slopes of immature oil palm plantation. This research used split plot design with three slopes as main plot consisted of: S1=slope 0-8%, S2=slope 8-15% and S3=slope 15-25%. The use of MB as subplot consisted of: M0=unovergrown with MB and M1=overgrown with MB. The measuring runoff and erosion used small plot method. The research showed that the oil palm plantation which overgrown by MB had the soil physical properties such as field moisture content, bulk density, total pore space, permeability, infiltration and organic matter better than without MB. The higher slope level decreased the soil physical properties; (2) the use of MB decreased the runoff and erosion compared to the unovergrown MB. The higher level of the slope induced the greater runoff and erosion; (3) the combination of slope with the MB resulted the lower runoff and erosion even at the steeper slope; (4) There is a positive correlation between rainfall intensity and runoff, and runoff with erosion. Thereby, the more rainfall intensity, more runoff as well, and the increase of runoff followed by the increased erosion.