Use rye cautiously before corn
When applying manure in late summer, there is a risk that nitrogen (N) in the manure will leach from the field before being taken up by a cash crop the next spring.
Read this paper in the Canadian Journal of Plant Science.
By planting service crops (SC) such as rye just after manure application, it is hypothesized that the SC will take up the manure N and hold it until the next spring when it can be released for the cash crop. Then the cash crop need for N fertilizer might be lower.
This study used four such SC treatments: (i) no SC, (ii) rye alone, (iii) rye plus three additional species, and (iv) the four species mixture plus eight other species. Each SC treatment was implemented after winter wheat harvest, with and without liquid hog manure. The next spring, SCs were terminated one week before planting corn. Later N fertilizer was either side-dressed or not.
SCs did not reduce soil mineral N nor partial plant available N over the growing season. Nevertheless, corn N accumulation and final grain yield were reduced up to 20% following the rye monoculture, in both years.
Furthermore, the side-dress N application did not overcome the yield loss associated with rye. Rye had a negative impact on corn, regardless of the amounts of plant available N.
The practical lessons are to select appropriate SC species and their proportions in polycultures, plant corn later than ten days after rye termination, and restrict living rye roots from touching emerging corn roots.
Read the paper — Corn yield and nitrogen recovery following rye (Secale cereale L.) in monoculture and polyculture service crops by Cameron M. Ogilvie, Laurent Van Arkel, Laura L. Van Eerd, John D. Lauzon, Bill Deen, and Ralph C. Martin.
