Effects of Retting Treatment on Coconut Husk Buffer Strips for Eliminating Nutrient Losses

抄録

Coconut husk has been applied as buffer strips for soil erosion control on slope upland fields in Bohol of the Philippines. However, attention has been paid to the losses of nitrogen and phosphorus components not only those leached from synthetic fertilizer applied in upland fields but also those components released from coconut husk buffer strips. Thus, pretreatment of coconut husk by retting before its installation into the field has been proposed. The objective of this study is to find out the effect of ret treating the coconut husk utilized as buffer strips on eliminating its releasing nitrogen and phosphorus components. Coconut husks were trimmed then minor pounding by hammer were applied to meet the desired porosity of the material as buffer. Retting treatment of 41.34 g in dry mass of coconut husk was carried out by soaking into 1,300 ml of distilled water for 10 days to extract its nitrogen and phosphorus components. Ret treated coconut husk were installed into stainless slope model plot filled with Philippine soil and set at 8 degrees in slope. Another plot was also prepared and installed with untreated coconut husk then rainfall simulation was carried out into both plots. The experimental results showed that the amount of nitrogen released from the plot installed with ret treated coconut husk buffer strip was significantly lower than that of untreated husk buffer strip at 99% significant level. Therefore, it was concluded that 10 days retting treatment of coconut husk for buffer strips was effective on eliminating the release of nutrient particularly on nitrogen from leaching.