Agriculture and Polluted Runoff

Agriculture: With Opportunities Come Responsibility

Photo of coffee beans.

Coffee arrived in Hawai`i in the early 1800s and by the early 1900s it was grown on all of the major Hawai`ian islands. Hawai`i has roughly 6,500 acres of coffee statewide. Hawai`i Coffee Association

NRCS in Hawai`i

The Natural Resources Conservation Service (NRCS) provides conservation grants and technical advice to private landowners. Their main goal is to protect, enhance and preserve soil, water, air, plants and animals using sound science and expertise. NRCS has offices located throughout the Hawai`ian Islands.

For an example of how a farmer can benefit from a NRCS partnership, view the video “Hawai`i Farmer Cuts Chemicals” that describes how Wei Chong Ho was able to reduce his use of chemicals on his Oahu farm. The story of the Ho’s success can also be found in the NRCS Success Stories.

Technical documents related to animal waste management, comprehensive nutrient management plans, pests, water quality and more can be found on the NRCS Pacific Islands Area Technical Resources site.

Hawai`i, with its year-round growing season and isolation, supports a variety of agricultural products. Long known for sugarcane and pineapple, Hawai`i’s farm economy is in transition to a much more diversified product mix with many smaller operations. Hawai`i now leads the nation in sales of several tropical commodities.

With the great opportunities that Hawai`i has to offer its farmers, it also brings a responsibility to protect Hawai`i’s water resources. EPA’s Agriculture Strategic Plan for the Pacific Southwest Region notes that agriculture is the nation’s leading source of pollution for ground, surface and coastal waters. Livestock and crop farming practices can contribute pollutants such as sediments, nutrients from fertilizers and animal waste, pesticides, herbicides, and bacteria from animal waste to local waterways. By choosing sustainable farming practices, farmers can reduce the amount of polluted runoff from their farms. Several examples of sustainable farming practices are described below.

Develop a Conservation Plan

Working with local Soil and Water Conservation Districts (SWCDs), farmers and ranchers can develop a unique plan for their property that will improve water efficiency, decrease erosion and minimize their environmental impact. A conservation plan addresses pollutants in farm runoff with nutrient and pest management strategies. Conservation cover and mulching recommendations address the quantity of farm runoff. Conservation plans also provide information about soils and nearby streams, aquifers, ditches and other water resources. To find the SWCD in your area, visit the Hawai`i Association of Conservation Districts Web site.

Conserve and Protect Water Resources

It is important for farmers to adopt practices that will keep rain and irrigation water on their property to prevent polluted runoff from entering nearby streams and rivers. These practices will protect local waterbodies and also prove helpful during times of drought and water shortages. Farmers can conserve water resources by using water more efficiently, improving on-farm retention of water, reducing water demand, and increasing soil content and soil moisture. EPA’s Sustainable Water Infrastructure Web site provides links and suggests ways that farmers can conserve water.

For livestock farmers, it is important to have access to an adequate supply of water that is clean enough to support healthy animals. Livestock farmers need to be careful that animal wastes do not contaminate drinking water sources for livestock and wildlife. Guidance on how to implement proper techniques for managing animal waste can be found at:

Properly Apply and Time the Application of Fertilizers, Pesticides and Herbicides

Photo of a man harvesting taro.

Taro was brought to Hawai`i by Polynesian settlers about 1500 years ago. Taro can be grown as wetland in a series of ponds (pictured above) called lo’i or in dry, upland areas where watering is supplied by rainfall or supplemental irrigation. The bulk of taro is made into poi. Other processed uses for taro include a traditional Hawai`ian dessert called Kulolo (a mixture of taro and coconut cream and/or shredded coconut meat) and chips. USDA

Fertilizers, herbicides and pesticides are often applied to improve production, but when applied improperly, these nutrients and chemicals often enter our waterways. Before fertilizers are applied, a soil test should be administered to determine exactly which, if any, fertilizers should be applied. Hawai`i’s Cooperative Extension Service provides information on how to conduct a soil test in its paper “Testing Your Soil: Why and How to Take a Soil-Test Sample “. Fertilizers should be used sparingly and applied when rain is not in the immediate forecast. Organic fertilizers are also known to release nutrients more slowly, allowing a longer treatment of the soil.

Pesticides are chemicals that are intended to kill or repel a pest such as unwanted insects, weeds, rats, germs and fungus. It is important to properly use and dispose of pesticides in order to keep these harmful chemicals out of Hawai`i’s waterways. All pesticides should be carefully applied per the label’s instructions. Old and unused pesticides require special disposal and should not be thrown out in the trash or poured down the drain. To learn where pesticides can be properly disposed of, visit the Hawai`i Department of Agriculture site. The Hawai’i Department of Agriculture’s Plant Pest Control Branch also provides updates of the latest pests that are affecting Hawai`i on their Pest Advisory Web page.

Protect Soil Resources: Plant Cover Crops

Exposed soil can be easily washed away by rain and irrigation water into nearby waterbodies. Sediment clouds the waters and aquatic animals (including corals) can be smothered. It is important to keep soil on the land and out of waterways. After harvesting, cover crops should be planted. Range and grazing lands should also be planted year-round.

Past Agricultural 319 Projects

319 Grants have been used to address polluted runoff from agriculture. Examples of past projects are listed below.

Kauai Watersheds

Oahu Watersheds

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Pili grass (above) is mostly grown on the island of Moloka’i, Maui and the big island. For some restoration projects, pili grass is bundled into bales and used for erosion control (below). The bales are made by picking the seeds of the mature grass and rolling them into a hay bale. The seeds are still viable. When the seeds come in contact with water, they “dig” into the ground and become established.

Photo of pili grass bundles.

Pili grass bundles.

Maui Watersheds

Hawai`i Watersheds (The Big Island)

State-wide

Agricultural Resources