Featured Research

from universities, journals, and other organizations

Prior herbicide use -- not irrigation -- is critical to herbicide efficacy

Date:
May 5, 2010
Source:
USDA/Agricultural Research Service
Summary:
Crop and herbicide use history are more critical to herbicide efficacy and environmental safety than the timing and amount of irrigation water used, according to agricultural scientists.

ARS plant physiologist Dale Shaner has found that, while the herbicide atrazine breaks down more quickly in fields that have been previously treated with the herbicide, the amount of irrigation does not affect the degradation rate at all.
Credit: Photo by Peggy Greb

Crop and herbicide use history are more critical to herbicide efficacy and environmental safety than the timing and amount of irrigation water used, according to Agricultural Research Service (ARS) scientists.

ARS plant physiologists Dale Shaner and Lori Wiles made this discovery from ongoing experiments on two irrigated fields at Colorado State University (CSU) at Fort Collins, Colo. Shaner and Wiles work in the ARS Water Management Research Unit at Fort Collins.

In collaboration with CSU colleague Neil Hansen, Shaner and Wiles compared the behavior of the herbicide atrazine in conventionally tilled corn grown continuously year after year versus corn grown in three different crop rotations. They tested various levels of tillage and irrigation, including no irrigation.

The amount of irrigation used -- including a total absence of irrigation -- had no impact on the rate of degradation of atrazine by soil microbes in the top foot of soil. The only factors that made a difference were prior herbicide use and the choice of crop sequences, with prior herbicide use the most important factor by far.

Earlier studies, including one by Shaner, have shown that previous applications of atrazine can predispose soil to more quickly degrade later applications of the herbicide. But until now, it was not clear if other factors such as cropping history and quantity of irrigation played a role.

There are two consequences of the more rapid dissipation of atrazine in the plots with a history of use. The first consequence is a loss in weed control. In the plots with the most rapid dissipation, weeds began to re-infest the plots within four weeks after treatment, while the plots with the slowest rate of dissipation remained weed-free through the growing season.

The second consequence is that atrazine leached more deeply in the soil in the plots where it did not dissipate rapidly, but the herbicide did not move below the top three inches of the soil in the plots where it was degraded rapidly.

This research was published in the Journal of Environmental Quality.


Story Source:

The above story is based on materials provided by USDA/Agricultural Research Service. The original article was written by Don Comis. Note: Materials may be edited for content and length.


Journal Reference:

  1. Dale L. Shaner, Lori Wiles, and Neil Hansen. Behavior of Atrazine in Limited Irrigation Cropping Systems in Colorado: Prior Use Is Important. Journal of Environmental Quality, 2009; 38 (5): 1861 DOI: 10.2134/jeq2008.0463

Cite This Page:

USDA/Agricultural Research Service. "Prior herbicide use -- not irrigation -- is critical to herbicide efficacy." ScienceDaily. ScienceDaily, 5 May 2010. <www.sciencedaily.com/releases/2010/03/100317101353.htm>.
USDA/Agricultural Research Service. (2010, May 5). Prior herbicide use -- not irrigation -- is critical to herbicide efficacy. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2010/03/100317101353.htm
USDA/Agricultural Research Service. "Prior herbicide use -- not irrigation -- is critical to herbicide efficacy." ScienceDaily. www.sciencedaily.com/releases/2010/03/100317101353.htm (accessed July 29, 2014).

Share This




More Plants & Animals News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
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

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