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Accelerating the Adoption and Implementation of Proven Cover Crop Technolog

CIG Projects in PIA | Pacific Islands Area NRCS
 CIG Projects in the Pacific Islands Area:

Accelerating the Adoption and Implementation of Proven Cover Crop Technologies in Hawaii

Grantee: Crop Care Hawaii, LLC

Although the benefits of cover cropping to improve soil and reduce erosion have a long and proven history very few farms in Hawaii employed this cultural practice prior to 2000. Since the mid-1990�s, large monoculture plantations have been replaced by smaller, diversified, agricultural operations (short term row crops including seed, vegetable, and melon production). The new crops have used bare ground fallow as a way of managing soil borne pests and weed competition, however, this practice has elevated the risk of soil erosion and increased the probability of soil runoff off into adjacent surface water bodies. Soil sediment from eroded fields contains nitrogen (N) and phosphorus (P) which are considered to be non-point source pollutants. The soil sediment itself also serves as a source of turbidity when it is eroded into streams and coastal waters.

In 1992, Hawaii Sugar Planters� Association began to examine the use of cover crops for erosion control. Since that time interest in and support for cover crops for erosion control and as green manure has grown considerably in both agricultural research and grower support organizations. Numerous single and multi site-studies have been conducted to examine the utility of cover crops to combat nematodes, improve soil quality, reduce soil erosion and suppress weeds in Hawaii. The results of these studies confirm that the benefits reported nationally and internationally can be realized in Hawaii�s agriculture environment.

Sunn hemp has been the most widely tested legume for cover crops in Hawaii. The cultivar �Tropic Sun�, a joint release by the University of Hawaii (UH) and the USDA Soil Conservation Service (now NRCS), has been shown to be effective as a green manure, in reducing root knot and other nematodes, in preventing soil erosion, in suppressing weeds and even as a short-term windbreak because of its vigorous growth.

The overall goal of this proposal is to accelerate the adoption and implementation of proven cover crop technologies in Hawaii. To accomplish this, we propose these innovative objectives to overcome the barriers to adoption and implementation of cover crop technologies:

  1. Demonstrate the cost effectiveness of cover crops and/or cover crop combinations as an alternative to bare ground fallow to growers through 2 field day events and educational outreach activities.
  2. Demonstrate the effectiveness of the five cover crop options alone and in combination with Tropic Sun for weed suppression, nematode suppression (if nematodes are present), and increase in soil nitrogen and organic matter and between the three different sites.
  3. Examine the utility of Mung bean as a cover crop.

   � Project Summary: Crop Care in Hawaii - Final Report (PDF; 682 KB)