MSU Extension reported yesterday as popularity grows for annual ryegrass cover crops, it’s important to be aware of the optimal conditions under which to control it, burning it down in the spring before planting corn or soybeans.

MSU conducted field tests on annual ryegrass, and the results are beneficial for soil health and for achieving conservation goals (less erosion, less nutrient loss off fields, deeper rooting, more crop access to moisture in dry years, etc.)

Here is a section of their report. Click here to read the entire document and see photos.

In the last several years annual ryegrass (AR) has become a popular cover crop in the Midwest. It has most often been used in no-till farming systems in Indiana, Illinois and Ohio. Michigan farmers have increased their use of annual ryegrass as new varieties have been released.

The root system for AR is massive and can grow up to three times deeper than its top growth. In other words, 10 inches of above ground growth can result in 30 inches of root growth. The fibrous root system for annual ryegrass can really enhance soil quality. When properly killed annual ryegrass is a great cover crop.

The best results for controlling annual ryegrass have been when annual ryegrass is actively growing and the air temperature is above 60° Fahrenheit.

Our study is looking at applying four different herbicide treatments at three different growth stages of annual ryegrass. These include annual ryegrass at: 6-8 inches, 10+ inches and after planting. Due to a cool spring, the best environmental conditions for controlling annual ryegrass were difficult. We actually had our best control of annual ryegrass when it was over 12 inches tall. We had better control of annual ryegrass on our higher sandier ground as compared to the lower high organic matter locations.