Many of Kauai’s soils are depleted of nutrients, and a major challenge for Kauai farmers is improving fertility and moisture retention, and increasing the amount of organic matter in their soils.
It’s an issue for farmers in many places, organic or conventional, as well as for home gardeners. And interestingly, many of these diverse farming approaches are using very similar techniques to improve the quality of the land on which they grow their crops.
At Steve Frailey’s northeast Kauai organic noni farm, Kaakaaniu Plantation, amending soils is a constant job.
He manufactures his own compost, turning the piles every day to add oxygen to make a more potent compost. He pays tree trimmers to bring vegetative matter to the certified organic noni farm, to increase the amount of compost, which he uses to improve soil consistency and fertility.
He brews up compost tea through an aeration method and applies it as a foliar spray to feed his trees.
Frailey also grows worms, and collects worm castings that are spread around trees to help build topsoil. He and other farmers use cover crops of pigeon pea, cow pea and the nitrogen-fixing tree gliricidia.
It is, in Frailey’s view, a mimicking of what nature has done for millennia in the forests. Frailey offers free educational noni farm tours Mondays, Wednesday and Fridays by reservation. Call (808) 651-6457 to attend.
On the West Side, Syngenta’s Allan Smith said that his firm uses cover crops of oats, pigeon pea and sun hemp to improve soil fertility and to reduce wind and water erosion.
At Kauai Coffee, there has not been a lot of natural soil amendment being done in the past, but that’s now changing. General manager Fred Cowell is a lifelong coffee farmer, and said the big coffee farm is beginning to use cover crops of grasses and nitrogen-fixing plants and plans a major composting program.
We took a tour of the fields between Kalaheo and Eleele. Cowell said much of the knowledge about improving the quality of the soil comes from a range of sources, some from university-trained experts, but also from organic and no-till farming industries.
“There is knowledge to be gained from outside the coffee industry and outside conventional agriculture,” he said.
“Right now, we’re feeding nutrients directly to the root system to provide necessary growth, but I know that we can produce coffee cheaper and of better quality with improved soils,” Cowell said.
By properly composting four million pounds per year of pulp waste from his coffee milling operations, “we expect to be able to dramatically boost the amount of organic material in our fields,” he said.
“Our biggest weed problem is the maunaloa vine, which covers and kills our trees and gets carried back to the factory in harvesting, and it is in the waste stream,” he said.
If composting is not done properly, the maunaloa seeds are carried back into the field where they create additional problems. One of the keys to successful composting is to get the compost pile’s internal heat high enough to kill the weed seeds and to break down organic material swiftly.
Kauai Coffee is also working to improve the water permeability of soils by both adding organic matter and mowing rather than herbiciding the spaces between rows of coffee trees. The roots of the grasses and other plants between the rows help allow rainfall to seep into the soil instead of evaporating or running off.
And the organic matter helps keep the moisture in the soil.
“Every 1 percent increase in organic matter results in a tenfold increase in moisture retention,” Cowell said.
Kauai’s very diversified agriculture ventures are holding on, and in some cases growing. At the same time, they are growing increasingly attuned to the health of our island’s soils.
Our island’s agricultural industry is supported by a number of organizations, among them the Kauai County Farm Bureau and the Family and Friends of Agriculture.
Jan TenBruggencate is a communications consultant, author and retired newspaper reporter who lives on Kauai. He is also a canoe paddler, beekeeper and volunteer.