Cereal/Pea or Spring Cereal/Winter Cereal Intercropping - Frequently Asked Questions

 
 
Subscribe to our free E-Newsletter, "Agri-News" (formerly RTW This Week)Agri-News
This Week
 
 
 
 What feed crops are normally intercropped and why?
Peas and oats, barley or triticale, or a combination of spring cereals with winter wheat, winter triticale or fall rye, are the two common types of intercropping. Peas are usually included in mixes to improve the quality of the feed. Fall or winter cereals are often intercropped with spring cereals to provide grazing after the initial crop is harvested, but may also be grown for feed quality reasons.

What kind of protein content is realistic with pea/cereal mixes?
Pea silage could be 13-18% protein so theoretically a pea/cereal mix should have higher protein than a cereal silage alone which is usually about 10% protein. In reality however, the potential protein benefits of peas in silage mixtures often are not attained because of the competitive effects of the cereal crop. Pea/cereal mixtures can produce better quality silage than cereals alone (Table 1), but the success of these intercrops is highly dependent on the seeding rates for both crops and making sure that there are enough peas in the mixture to influence feed quality.

Table 1. Dry matter yield, protein content and protein yield of peas seeded at seven plants per square foot with various rates of barley at Edmonton and Barrhead.
Peas
Peas + 22 lb/ac BarleyPeas + 44 lb/ac BarleyPeas + 67 lb/ac Barley67 lb/ac
Barley
Dry tons/ac
3.21
3.49
3.53
3.57
3.42
Protein %
13.4
12.0
11.4
11.3
9.5
Protein Yield lb/ac
860
837.6
804.8
806.8
649.8
Source: Adapted from Lopetinsky and Blade as used in the Silage Manual, AAFRD.

What are recommended seeding rates for pea/cereal combinations for silage and greenfeed?
In wetter areas of the province (gray, black, and thin black soils) pea plant densities of 7-8 plants per square foot are optimal for both pure stands of peas or cereal-pea blends. The seeding rate for the cereal component of these mixed crops should be about 25-50% of what is normal for the area. In drier areas of the province, cereal seeding rates are usually lower than in wet areas so pea stands of about 4 plants per square foot with a normal cereal seeding rate should work fairly well.

An adequate pea seeding rate will be a significant input cost but the pea stand density should not be compromised. Reducing the pea seeding rate usually results in the cereal crop out-competing the peas, producing minimal or non-existent feed quality gains even though the peas that were seeded increased production costs.

What are recommended seeding rates for spring cereal/winter cereal mixes?
Generally, spring and winter cereals should both be seeded at about 75% of what is normal for the area to balance silage/greenfeed yield with regrowth and pasture production. Increasing the relative proportion of the winter crop will give better regrowth and fall grazing potential but lower silage yield. Conversely, more spring cereal than winter cereal will increase the silage yield potential but at the expense of grazing production.

Additional Resources:
Using 1000 Kernel Weight for Calculating Seeding Rates
Seeding Rate Calculator

An updated silage manual was published by Alberta Agriculture in 2004 and is an excellent resource.
Information for Purchasing New Silage Manual


Prepared by Ag-Info Centre, Alberta Agriculture & Forestry
 
 
 
 
For more information about the content of this document, contact the Ag-Info Centre.
This information published to the web on April 21, 2004.
Last Reviewed/Revised on July 6, 2015.