- DTN Headline News
Underground Movement - 17
Wednesday, March 29, 2017 8:23AM CDT
By Dan Crummett
Progressive Farmer Contributing Editor

A little field diplomacy can go a long way toward maintaining healthy, resilient crops -- and that means taking care of billions of helping hands busy at work in the topsoil of your farm.

Kristine Nichols, chief scientist at the Rodale Institute, said naturally occurring mycorrhizal fungi that live in and around roots supply crops with nutrients and water, and serve as the plant's extended root system. In addition, they secrete soil-building glycoproteins and defend against soil-borne pathogens that otherwise could attack the crop. In exchange for all this, the plant shares 40% to 50% of its sugars and starches through its roots to feed the fungi.

PIPELINES

Nichols is a veteran soil microbiologist, formerly with USDA at the Northern Great Plains Research Laboratory. She said mycorrhizal fungi are probably the most critical organisms in crop production because they form supplemental pipelines for water and nutrients mineralized by other bacteria and fungi from the soil.

"The rapid-growing mycelium of these fungi extend well beyond the plant's root system and provide a means to gather water that otherwise would be out of the roots' depletion zone," she explained. "Also, the hair-like structures, or the mycelium, transport mineralized phosphorus, zinc, copper, etc., that wouldn't be available to the plant otherwise."

INTO THE CELLS

Arbuscular mycorrhizal fungi (AMF) penetrate the cell walls of the root and reside there, preventing pathogens from harming the root system. They also function symbiotically with specialized bacteria that fix nitrogen (N) on the roots of legumes -- in the case of natural prairie, forests or in fields managed with leguminous cover-crop species.

Research shows mycorrhizal networks provide significant reductions in the need for applied fertilizer in no-till fields grown with cover crops, Nichols said.

"In undisturbed conditions, these networks can include miles of fungal hyphae in a handful of soil," Nichols explained. "In an annual crop system, the networks won't be as complex, but a large part of them will survive from season to season if conditions are right.

"Anytime the soil is disturbed by a plow or other tillage operation, the networks are disconnected, forcing them to regrow instead of tapping into the soil's moisture and nutrient reserves," she continued. "This is particularly true when a moldboard plow is used to invert the soil. With plowing, many segments of the networks are buried so deeply they cannot reattach to roots. This results in a population decline in beneficial fungi."

DO NOT DISTURB

Nichols said minimizing tillage with no-till, strip-till or occasional rotational tillage is the best way to ensure healthy populations of soil fungi. Also, managing with cover crops allows farmers to make the most of the help the fungi provide.

"With a multispecies cover crop, you have grasses and legumes which live symbiotically with nitrogen-fixing bacteria and all are linked through hyphal networks," she said. "Through this network, the grass [corn, wheat, grain sorghum, etc.] can signal the fungus it needs N and P [phosphorus] from the soil. The fungus then signals a legume that it needs N. The legume says, 'I'll do it because I have excess N, but I need your phosphorus.'

"Fungus and bacteria need carbon provided by the plant, while plants need nitrogen and phosphorus. So everybody wins," she said.

(ES/BAS)


blog iconDTN Blogs & Forums
DTN Market Matters Blog
Editorial Staff
Monday, March 27, 2017 10:34AM CDT
Friday, March 24, 2017 10:19AM CDT
Monday, March 20, 2017 11:07AM CDT
Technically Speaking
Darin Newsom
DTN Senior Analyst
Monday, March 27, 2017 9:22AM CDT
Monday, March 27, 2017 9:21AM CDT
Monday, March 27, 2017 8:49AM CDT
Fundamentally Speaking
Joel Karlin
DTN Contributing Analyst
Friday, March 24, 2017 7:38AM CDT
Wednesday, March 22, 2017 9:25AM CDT
Thursday, March 16, 2017 9:30AM CDT
DTN Ag Policy Blog
Chris Clayton
DTN Ag Policy Editor
Thursday, March 30, 2017 10:27AM CDT
Tuesday, March 28, 2017 8:58PM CDT
Tuesday, March 28, 2017 7:21AM CDT
Minding Ag's Business
Marcia Taylor
DTN Executive Editor
Tuesday, March 28, 2017 2:14PM CDT
Tuesday, March 7, 2017 3:34PM CDT
Tuesday, March 7, 2017 3:33PM CDT
DTN Ag Weather Forum
Bryce Anderson
DTN Ag Meteorologist and DTN Analyst
Tuesday, March 28, 2017 2:45PM CDT
Friday, March 24, 2017 9:53AM CDT
Thursday, March 23, 2017 1:58PM CDT
DTN Production Blog
Pam Smith
Crops Technology Editor
Friday, March 17, 2017 3:51PM CDT
Tuesday, March 7, 2017 10:37AM CDT
Tuesday, February 28, 2017 12:18PM CDT
Harrington's Sort & Cull
John Harrington
DTN Livestock Analyst
Friday, March 24, 2017 4:48PM CDT
Friday, March 17, 2017 1:38PM CDT
Friday, March 3, 2017 5:46PM CDT
South America Calling
Alastair Stewart
South America Correspondent
Wednesday, March 29, 2017 12:27PM CDT
Monday, March 6, 2017 4:07PM CDT
Tuesday, February 28, 2017 3:22PM CDT
An Urban’s Rural View
Urban Lehner
Editor Emeritus
Friday, March 24, 2017 6:25PM CDT
Friday, March 17, 2017 8:00AM CDT
Thursday, March 16, 2017 12:34PM CDT
Machinery Chatter
Jim Patrico
Progressive Farmer Senior Editor
Monday, March 20, 2017 11:34AM CDT
Wednesday, March 15, 2017 1:23PM CDT
Tuesday, February 28, 2017 12:58PM CDT
Canadian Markets
Cliff Jamieson
Canadian Grains Analyst
Wednesday, March 29, 2017 4:23PM CDT
Tuesday, March 28, 2017 4:18PM CDT
Thursday, March 23, 2017 4:31PM CDT
Editor’s Notebook
Greg D. Horstmeier
DTN Editor-in-Chief
Tuesday, March 7, 2017 3:28PM CDT
Friday, February 24, 2017 1:51PM CDT
Wednesday, February 22, 2017 12:23PM CDT
 
Copyright DTN. All rights reserved. Disclaimer.
Powered By DTN