Featured Research

from universities, journals, and other organizations

Large amounts of nitrogen stored beneath selected agricultural areas

Date:
May 3, 2010
Source:
American Society of Agronomy
Summary:
Scientists used a new version of the Root Zone Water Quality Model to estimate unsaturated zone nitrogen mass balances at four agricultural fields. The new version of the model can make predictions down to 30 meters, enabling estimation of water quality effects well beyond the root zone.

Large amounts of nitrogen are stored in the soils of agricultural areas in Nebraska and Maryland, according to a new study by the U.S. Geological Survey (USGS) and the U.S. Department of Agriculture (USDA). Once in the soil, nitrogen can be converted to nitrate, which can readily move to groundwater.

"We expected to find nitrogen stored in organic matter in these soils, but didn't realize how much," said Tom Nolan, USGS hydrologist, who led the study. "If mobilized, the large reservoirs of nitrogen could significantly impact water quality."

Nitrogen occurs in soil, plants, and groundwater, and it is difficult to account for all of the various forms it can take. For this study, scientists at the USGS National Water Quality Assessment Program and the USDA Agricultural Research Service used a new version of the Root Zone Water Quality Model to estimate unsaturated zone nitrogen mass balances at four agricultural fields. The study was reported in the May/June 2010 edition of the Journal of Environmental Quality, published by the American Society of Agronomy, the Crop Science Society of America, and the Soil Science Society of America.

The mass balances were expected to reveal the predominant forms of nitrogen in important agricultural settings. The four sites had variable climate, soils, and management practices, and included: an almond orchard in central California; a cornfield that is about 0.6 kilometers from the almond orchard; a corn-soybean crop rotation in eastern Nebraska; and a corn-soybean rotation in eastern Maryland.

The model predicted that large amounts of organic nitrogen are stored in the soil beneath fields in Nebraska and Maryland on which corn and soybean crops are grown. The model also showed that nitrogen came primarily from inorganic fertilizer or from nitrogen fixation by soybeans, and that most nitrogen was removed from the soil through uptake by crops. After crop uptake, leaching accounted for most of the nitrogen lost from the soil, particularly in irrigated areas of California. Denitrification, a process where nitrogen is removed from the soil when it is converted to its gaseous phase, occurred only sporadically at the four sites because soils generally were sandy and well-drained.

The work is novel in that the model was autocalibrated to measured data comprising soil moisture, soil water tension, bromide and nitrate concentrations, and soil organic matter. Also, previous versions of the model were limited to the rooting depth of plants (typically three meters or less). The new version of the model can make predictions down to 30 meters, enabling estimation of water quality effects well beyond the root zone. More study is needed to better understand the conditions required to mobilize and transport the stored nitrogen to groundwater.


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. B. T. Nolan, L. J. Puckett, L. Ma, C. T. Green, E. R. Bayless, R. W. Malone. Predicting Unsaturated Zone Nitrogen Mass Balances in Agricultural Settings of the United States. Journal of Environmental Quality, 2010; 39 (3): 1051 DOI: 10.2134/jeq2009.0310

Cite This Page:

American Society of Agronomy. "Large amounts of nitrogen stored beneath selected agricultural areas." ScienceDaily. ScienceDaily, 3 May 2010. <www.sciencedaily.com/releases/2010/05/100503074247.htm>.
American Society of Agronomy. (2010, May 3). Large amounts of nitrogen stored beneath selected agricultural areas. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2010/05/100503074247.htm
American Society of Agronomy. "Large amounts of nitrogen stored beneath selected agricultural areas." ScienceDaily. www.sciencedaily.com/releases/2010/05/100503074247.htm (accessed July 28, 2014).

Share This




More Plants & Animals News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com
Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com
Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Newsy (July 27, 2014) The satellite is back under ground control after a tense few days, but with a gecko sex experiment on board, the media just couldn't help themselves. 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:
from the past week

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