||Cover Crops for Erosion Control in Ko'olaupoko
||December 1999 to June 2002
Hawaii Agriculture Research Center (HARC)
99-193 Aiea Heights Drive, Suite 300
Aiea, Hawaii 96701
|The shift from large-scale plantation agriculture to diversified
agriculture and forestry is occurring with clean-tilled site preparation
as a standard practice. This can lead to runoff of sediments, nutrients,
and herbicides into surface and ground waters. At present, there
is no recommended groundcover for use in the establishment of agroforestry
systems or tree farms in Hawaii.
||To provide soil protection using cover crops. Specifically, the
project’s goal was to identify effective ground cover species
to reduce soil erosion and other impacts for established Acacia
koa demonstration sites located in Koolaupoko Watershed.
||This project was successful in showing the benefits of establishing
effective cover crops as a means to reduce soil loss from agroforestry
lands. Nine ground covers (grasses and legumes) were examined during
the trial periods. Native grasses (Pili and Emoloa) proved to be
the most effective cover crops. Thirty days after the establishment
of these ground covers, it was estimated that the soil loss from
each trial was reduced by more than 90% using Pili grass and 50%
using Emoloa grass instead of standard weed cover. When compared
to bare ground, these grasses reduced soil loss by more than 97%.
After 60 days, the Pili grass remained an effective cover crop
continuing to reduce soil erosion by more than 34%. Also, Koa tress
grown in conjunction with Pili and Emoloa grass were much taller
and heartier after 60 days.
||Koolaupoko Watershed and Kaiaka-Waialua Watersheds,
island of Oahu