土壌および肥料成分の流出抑制を目指したヤシ殻濾過帯による保全対策 Palm Shell Filter Strips as a Conservation Strategy in Mitigating Soil and Nutrient Losses
This study was conducted to evaluate the effects of palm shell filter strips on mitigating soil and nutrient losses under simulated tropical rainfall. Humic Acrisol of sandy loam soil was compacted in four small scale plots of stainless steel with 0.11 m wide, 0.15 m high and 1.30 m long at 1.56 ± 0.05 g/cm<SUP>3</SUP> being similar to the field condition at Bertam River watersheds in Cameron Highlands of Malaysia. The first plot was control <I>C</I> without any conservation strategy, the second and third plots had fine <I>FP</I> and coarse palm shell filter strips <I>CP</I> of 20 cm wide at slope toe respectively, and the fourth plot had 20 cm wide <I>Ophiopogon japonicus</I> (Tamaryu) grass buffer strips <I>VG</I> at slope toe. Tropical rainfall pattern having higher rainfall intensity at 53.20 mm/h in the beginning for an hour and then followed by 23.00 mm/h for 3 hours was repeated 4 times. Overland and percolating discharge was measured and both water was sampled at certain intervals for analyzing the losses of soil, total nitrogen and total phosphorus components. The experimental results indicated that soil loss from <I>CP</I> was significantly 236.28, 62.59 or 136.53 times lower than those from other three plots of <I>C</I>, <I>FP</I> or <I>VG</I>, respectively. The same tendency as soil loss was observed for nitrogen and phosphorus losses. The losses of nitrogen or phosphorus from <I>CP</I> were significantly 2.08, 1.56, 1.54 or 9.37, 7.05, 9.00 times lower than those from <I>C</I>, <I>FP</I> and <I>VG</I> plots, respectively. Through this study, it was concluded that coarse palm shell filter strips can be an alternative conservation strategy for mitigating soil and nutrient losses effectively at farm level.
- Eco-engineering = 生態工学
Eco-engineering = 生態工学 20(2), 59-65, 2008-04-30