Project Report

 

 

AB-1:  Cover crops not the key to successful forage establishment
The Challenge.
Demonstrating perennial forage stand establishment without the use of cover crops.

Project Applicant.
Battle River Research Group, Forestburg, Alberta.

Funding Allocation.
The Greenhouse Gas Mitigation Program for Canadian Agriculture (GHGMP) has allocated $2.1 million for projects in the beef sector. The GHGMP has contributed $10,800 over three years towards this project.

Using cover crops to establish forage stands is not the best choice as an Alberta applied research group found through a demonstration project.

The Battle River Research Group (BRRG) in Forestburg set out to promote the successful establishment of forages and to explain the impact of the use of cover crops in perennial forages. “Our goal was to clear any misconceptions regarding the use of cover crops and to increase producer’s awareness of the potential for carbon sequestration in perennial forage crops,” says Jenifer Heyden, a forage and livestock agronomist with the BRRG.

The demonstration project received funding from the Greenhouse Gas Mitigation Program for Canadian Agriculture (GHGMP). The federal program is designed to promote the awareness of agricultural practices that reduce atmospheric levels of greenhouse gas or increase carbon storage in soil. The Canadian Cattlemen’s Association administers the delivery of the beef sector component of the program.

The project involved three demonstration sites – one in the County of Beaver and two in the County of Paintearth. Heyden says they used barley, oats, triticale and annual ryegrass as cover crops seeded with meadow brome, smooth brome, tap rooted alfalfa and creeping rooted alfalfa as forage crops. Each plot was monitored throughout the summer of 2003 and data was collected. Heyden says the demonstration project was modeled on a previous project in Saskatchewan involving cover crops and short-to medium-lived grasses and legumes.

Competing crops

Results showed using cover crops to establish perennial forages can be detrimental to the health of the forage and the soil, says Heyden. The Battle River Research Group demonstrated that cover crops compete with the forage stand for water, light, nutrients and space making the forage less productive and less vigorous.

“In our demonstration plots, forage plants that were established with a cover crop tended to be spindly and had few leaves,” says Heyden. The plots with cover crops showed lower forage plant counts compared to the plots with no cover crop.

However, plots with no cover crops were initially more susceptible to weeds, says Heyden. The financial impact of this has yet to be determined. Once the forage stand is more established, mowing and crop competition suppress weed production, and over time, weed seeds in the soil will decompose.

Carbon sequestration advantage

Successfully establishing lush, healthy forage crops can go a long way in mitigating greenhouse gas emissions.

“Forage plants are able to capture carbon dioxide from the atmosphere and store a portion of that as carbon in plant tissue and in the soil,” says Heyden. “Proper establishment and management of healthy forage stands will allow them to be long-lived as well. This is important since breaking the stand results in a tremendous release of the stored carbon, not to mention the economic costs of breaking and re-seeding.”

Establishing and maintaining a perennial forage stand not only increases the amount of stored carbon in the soil, it improves soil fertility and productivity and protects the soil from wind and water erosion. Compared to annual crops, perennial forages, especially those containing legumes, can require lower annual fossil fuel input costs such as fuel, fertilizer and machinery wear and tear, she adds.

Livestock industry benefits

An improved forage crop will benefit the livestock industry by providing a sustainable feed resource, says Heyden. Initial establishment of a vigorous forage stand is important in maintaining long term yield and forage quality. She adds that improvements in production efficiencies associated with highly productive forage crops also reduce the amount of greenhouse gas emissions per pound of beef produced.

“Producers should appreciate the added benefits of having a healthy forage crop,” says Heyden. “Good management practices improve production efficiency and that is good news for people looking to run efficient operations.”

© Canadian Cattlemen's Association, 2004,

 

© Canadian Cattlemen's Association, 2003,
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