Featured Research

from universities, journals, and other organizations

Straw residue helps keep nitrogen on the farm

Date:
July 26, 2010
Source:
American Society of Agronomy
Summary:
A research study evaluated the potential for straw residue to retain legume-derived nitrogen in a corn cropping system.

Scientists are exploring ways to reduce non-point pollution from agriculture. A new study finds that using straw residue in conjunction with legume cover crops reduces leaching of nitrogen into waterways, but may lower economic return.

Related Articles


Agriculture is the largest source of nitrogen non-point pollution to waterways in the United States, flowing into streams and rivers via erosion from farmlands, or through leaching of nitrate into groundwater. Once in aquatic systems, excess nitrogen leads to aquatic ecosystem degradation, including oxygen depravation that leads to fish kills and dead zones. If nitrates leach into drinking water supplies, they are a human health concern and have been linked to blue-baby syndrome, various cancers, and birth defects.

Legume cover crops, such as hairy vetch, have been considered as an alternative or supplement to synthetic nitrogen fertilizers that may improve the sustainability of agricultural systems. Such cover crops can contribute substantial amounts of nitrogen to subsequent crops, as well protect soils from erosion and promote overall soil quality. Legumes tend to release nitrogen more slowly than synthetic fertilizers, possibly being more synchronous with crop demand. That does not mean that nitrogen from legumes cannot be lost from the system.

One way to possibly minimize these losses may be to add more carbon to nitrogen-rich residues, such as those of cereal grain crops, during cover crop phase of the cropping systems. A research study conducted by Anna Starovoytov at Penn State evaluated the potential for straw residue to retain legume-derived nitrogen in a corn cropping system. Results from this study are reported in the May/June 2010 issue of the Agronomy Journal, a publication of the America Society of Agronomy. A portion of the research was also presented in New Orleans, LA at the 2007 International Annual Meetings for ASA, CSSA, SSSA on November 4-8, 2007.

The study revealed that adding straw residues to hairy vetch cover crops tended to lower soil inorganic nitrogen compared to treatments with strictly legume residues. On average, across sampling dates, soil inorganic nitrogen was 7.3% lower in the treatments with straw residue retention.

In this study, three different quantities of straw residue were spread on research plots that were later planted with to hairy vetch. A corn grain crop was later no-till planted into the vetch/straw residues. The type of residue present affected not only the magnitude of the peak of nitrogen in soil but also the timing of this peak, which is important when considering the synchrony of nitrogen availability to corn nitrogen demand.

However, the reduced availability of nitrogen in the soil also negatively impacted corn grain yields, which in one year of the study fell 16% below the county average. The straw residue left of the field is often sold, contributing to the economic value of the overall grain crop. The study did not show that using the straw residue to help retain nitrogen would offset this loss of income from harvesting the straw.

The scientific study concluded that partial retention of small grain residues prior to a hairy vetch cover crop can reduce legume nitrogen losses, but may result in reduced crop yields in some years. Further research is needed to help better predict legume nitrogen availability and how to best integrate legume cover crops with synthetic fertility management systems.


Story Source:

The above story is based on materials provided by American Society of Agronomy. Note: Materials may be edited for content and length.


Journal Reference:

  1. A. Starovoytov, R. S. Gallagher, K. L. Jacobsen, J. P. Kaye, B. Bradley. Management of Small Grain Residues to Retain Legume-Derived Nitrogen in Corn Cropping Systems. Agronomy Journal, 2010; 102 (3): 895 DOI: 10.2134/agronj2009.0402

Cite This Page:

American Society of Agronomy. "Straw residue helps keep nitrogen on the farm." ScienceDaily. ScienceDaily, 26 July 2010. <www.sciencedaily.com/releases/2010/05/100524072908.htm>.
American Society of Agronomy. (2010, July 26). Straw residue helps keep nitrogen on the farm. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2010/05/100524072908.htm
American Society of Agronomy. "Straw residue helps keep nitrogen on the farm." ScienceDaily. www.sciencedaily.com/releases/2010/05/100524072908.htm (accessed October 25, 2014).

Share This



More Plants & Animals News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins