Featured Research

from universities, journals, and other organizations

Why crop rotation works: Change in crop species causes shift in soil microbes

Date:
July 18, 2013
Source:
Norwich BioScience Institutes
Summary:
Shift in soil microbes triggers cycle to improve yield, plant nutrition and disease resistance. New research could help explain the dramatic effect on soil health and yield of crop rotation.

Crop rotation has been used since Roman times to improve plant nutrition and to control the spread of disease. A new study to be published in Nature's The ISME Journal reveals the profound effect it has on enriching soil with bacteria, fungi and protozoa.

"Changing the crop species massively changes the content of microbes in the soil, which in turn helps the plant to acquire nutrients, regulate growth and protect itself against pests and diseases, boosting yield," said Professor Philip Poole from the John Innes Centre.

Soil was collected from a field near Norwich and planted with wheat, oats and peas. After growing wheat, it remained largely unchanged and the microbes in it were mostly bacteria. However, growing oat and pea in the same sample caused a huge shift towards protozoa and nematode worms. Soil grown with peas was highly enriched for fungi.

"The soil around the roots was similar before and after growing wheat, but peas and oats re-set of the diversity of microbes," said Professor Poole.

All organisms on our planet can be divided between prokaryotes (which include bacteria) and eukaryotes (which include humans, plants and animals as well as fungi). After only four weeks of growth, the soil surrounding wheat contained about 3% eukaryotes. This went up to 12-15% for oat and pea. The change of balance is likely to be even more marked in the field where crops are grown for months rather than weeks.

Analysis has previously relied on amplifying DNA samples. This limits scientists to analysing one taxonomic group at a time such as bacteria. It also means that everything present in that group is analysed rather than what is playing an active role. Every gram of soil contains over 50,000 species of bacteria so the task is enormous.

There are relatively fewer actively expressed genes, or RNA. It is now possible to sequence RNA across kingdoms so a full snapshot can be taken of the active bacteria, fungi, protozoa and other microbes in the soil. The research was carried out in collaboration with the University of East Anglia and The Genome Analysis Centre on Norwich Research Park.

"By sequencing RNA, we can look at the big picture of active microbes in the soil," said PhD student Tom Turner from the John Innes Centre.

"This also allows us to work out what they are doing there, including how they might be helping the plants out."

"Our work helps explain the experience of farmers in the field," said Professor Poole.

"The best seed needs to be combined with the best agronomic practices to get the full potential benefits."

"While continued planting of one species in monoculture pulls the soil in one direction, rotating to a different one benefits soil health."

Seeds can be inoculated with bacteria before planting out, just like humans taking a dose of friendly bacteria. But this does not achieve the diversity or quantity of microbes found in this study.

The scientists also grew an oat variety unable to produce normal levels of avenacin, a compound that protects roots from fungal pathogens. They expected the soil to contain higher levels of fungi as a result, but instead found it contained a greater diversity of other eukaryotes such as protozoa.

The findings of the study could be used to develop plant varieties that encourage beneficial microbes in the soil. John Innes Centre scientists are already investigating the possibility of engineering cereal crops able to associate with the nitrogen-fixing bacteria normally associated with peas.

"Small changes in plant genotype can have complex and unexpected effects on soil microbes surrounding the roots," said Professor Poole.

"Scientists, breeders and farmers can make the most of these effects not only with what they grow but how they grow it."


Story Source:

The above story is based on materials provided by Norwich BioScience Institutes. Note: Materials may be edited for content and length.


Journal Reference:

  1. Thomas R Turner, Karunakaran Ramakrishnan, John Walshaw, Darren Heavens, Mark Alston, David Swarbreck, Anne Osbourn, Alastair Grant, Philip S Poole. Comparative metatranscriptomics reveals kingdom level changes in the rhizosphere microbiome of plants. The ISME Journal, 2013; DOI: 10.1038/ismej.2013.119

Cite This Page:

Norwich BioScience Institutes. "Why crop rotation works: Change in crop species causes shift in soil microbes." ScienceDaily. ScienceDaily, 18 July 2013. <www.sciencedaily.com/releases/2013/07/130718101236.htm>.
Norwich BioScience Institutes. (2013, July 18). Why crop rotation works: Change in crop species causes shift in soil microbes. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2013/07/130718101236.htm
Norwich BioScience Institutes. "Why crop rotation works: Change in crop species causes shift in soil microbes." ScienceDaily. www.sciencedaily.com/releases/2013/07/130718101236.htm (accessed July 23, 2014).

Share This




More Plants & Animals News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Michigan Plant's Goal: Flower and Die

Michigan Plant's Goal: Flower and Die

AP (July 22, 2014) An 80-year-old agave plant, which is blooming for the first and only time at a University of Michigan conservatory, will die when it's done (July 22) Video provided by AP
Powered by NewsLook.com
San Diego Zoo Welcomes New, Rare Rhino Calf

San Diego Zoo Welcomes New, Rare Rhino Calf

Reuters - US Online Video (July 21, 2014) An endangered black rhino baby is the newest resident at the San Diego Zoo. Sasha Salama reports. Video provided by Reuters
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
$23.6 Billion Awarded To Widow In Smoking Lawsuit

$23.6 Billion Awarded To Widow In Smoking Lawsuit

Newsy (July 20, 2014) Cynthia Robinson claims R.J. Reynolds Tobacco Company hid the health and addiction risks of its products, leading to the death of her husband in 1996. 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