U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 close



Research
                Research Home
                            National Programs
                            Research Projects
                            Scientific Manuscripts
                            International Engagement
                            Scientific Software/Models
                            Databases and Datasets
                            Office of Scientific Quality Review
            Media
                News & Features
                            Multimedia
                            Briefing Room
                            Down on the Farm
                            Press Room
                            Science in Your Shopping Cart
                            Scientific Discoveries
                            Tellus
                            Under the Microscope
            About ARS
                About ARS Home
                            Staff Directory
                            Labs and Research Centers (Map)
                            Headquarter Offices
                            Organizational Chart
                            Employee Services (REE Employees Only)
                            Office of Outreach, Diversity, and Equal Opportunity
            Work With Us
                Work With Us Home
                            ARS Vacancies at USAJOBS
                            Careers at ARS Information
                            Scientific Collaborations
                            Extramural Agreements
                            1890 Faculty Research Sabbatical ProgramSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home News & Events News Articles Research News 2002





- ARS News & Events
- AgResearch Magazine
- Image Gallery
- News
- Search News & Events
- Pesticide Drift May Endanger Pollinators
- ARS Seeks a Fire Ant Fix
- Scientific Discoveries 2024
- ARS Featured Photos
- Down on the Farm
- Facebook Live Events
- Food and Nutrition Research Briefs
- News Archive
- Science in Your Shopping Cart
- Scientific Discoveries
- Social Media
- Under the Microscope
- AgResearch magazine
- ARS at Work
- ARS Memorial Lectures
- ARS Science Hall of Fame
- Citrus Disease (Huanglongbing)
- Contact Office of Communications
- Plant Hardiness Zone Map
- Mobile Apps
- Public Affairs Contacts
- Publications and Other Resources
- USDA Blog
- Videos

Archived Page
 This page has been archived and is being provided for reference purposes only. The page is no longer being updated, and therefore, links on the page may be invalid.
 Wood-Chip Trenches Keep Nitrate Runoff in Check By Luis PonsApril 25, 2002 Agricultural Research Service scientists have found that trenches filled with wood chips are a promising line of defense against nitrate seeping from fertilized cropland into waterways. Dan Jaynes, a soil scientist and research leader at the ARS Soil and Water Quality Unit in Ames, Iowa, is leading studies on how to curb the flow of nitrate from farm fields into streams and rivers. The study, which is concentrating on fields planted with corn and soybeans, found that wood-chip-filled trenches can cut nitrate losses to surface water by 70 percent. The wood chips create a carbon-based barrier that helps change the nitrate into nitrogen gas, a common atmospheric component. The system doesn’t require any management by the farmer. In the study, the 6-foot-deep trenches were filled with chips up to 1 foot below the surface and covered with soil. Drainage tiles speed the draining of cropland and release the excess water into waterways. They have played a significant role in the development of U.S. agriculture and are used on 30 percent of Midwest cropland, according to Jaynes. However, rapid draining allows nitrate to bypass the soil root zone, making it unavailable to plant roots and other natural processes that can remove it from soil. Once excess nitrate gets into waterways, it feeds the growth of aquatic plants. As the plants die and decompose, they use up all the oxygen in the body of water. This scenario has been cited as a cause of hypoxia--a deficiency of oxygen--in parts of the Gulf of Mexico. High nitrate levels have also caused problems for communities that use rivers for drinking water. The trenches in the study are 2 feet wide, laid out parallel to tile drains, and placed 10 feet apart. The wood-chip trenches are 2 feet deeper than the tile drains. Jaynes says the trench method works equally well for small and large farms. The study’s next phase will explore how long the wood chips in the trenches will filter nitrate before decomposing. ARS is the chief scientific research agency of the U.S. Department of Agriculture.


Return to top


Research
                            Media
                            About ARS
                            Work With Us


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov