Infiltrated Water and Runoff at Four Gradient Slopes at Smallholder Oil Palm Plantation in Dry Season in Jambi, Indonesia

摘要

Since water balance is considered as a major constituent in the environmental issue for sustainability of oil palm production system, particularly as significant biomass contributor, runoff water as water loss and infiltrated water for oil palm consumption play the most significant role for the explanation of water status and should be exposed comprehensively. In case of water inefficiency in oil palm cultivation system, problem-solving solutions are to be identified and recommended. The purpose of the experiment was to approach the value or infiltrated water at smallholders oil palm plantation in Jambi at 4 gradient slopes category i.e. plain(0-5%), slight(6-10%), moderate(11-21%)and heavy slope(24-33%). The experiment was conducted at dry season from June to October 2013 in 4 replications. Water throughfall from September-October amounted to 35-39 mm from the total precipitation value of 97.1 mm. Infiltrated water from the water throughfall amounted to 32.3 mm at the slight gradient slope and 6.8 mm at the heavy gradient slope. Runoff rate at heavy gradient slope reached the value of 82.7 mm per 100 mm of total throughfall value. Canopy covering rate measured by sunlight transmission ranging from 11.9% -13.5% had no significant effect on throughfall value at all of gradient slopes category.