Terminating forage stands in preparation for seeding annuals

As time passes, productivity of tame hay and pasture declines because of changes in species caused by winterkill, disease, overutilization, or invasion of lower-yielding plant species. If your land is of suitable quality for annual crop production and 50 per cent or more of your production comes from weeds and/or undesirable plants, it may be time to terminate the stand and reseed to an annual crop.

The effectiveness of forage stand termination is dependent on the termination method, timing, stand composition, and environmental conditions. Hay or pasture can be converted to annual crops by using tillage, herbicides, or a combination of both.

Termination can occur in the summer, fall or spring. However, regardless of your chosen termination method, yields of subsequent crops are better if the stands are terminated in the summer or fall of the previous year instead of the spring of the year of seeding.

If you use herbicides to terminate the stand, you need to consider grazing or feeding restrictions, and reseeding restrictions.

Depending on the method, costs will vary and must be calculated on a case-by-case basis. Direct seeding of annual crops into herbicide-terminated forages is possible and can be cost effective if the following conditions are met:

1. Forage termination is initiated in the summer or fall of the previous year (apply herbicides three to seven days prior to last cut);
2. Effective forage kill and weed control are achieved at the time of termination through the proper application and rate of herbicide under growing conditions that allow for adequate herbicide translocation; and
3. An effective in-crop weed management strategy is implemented in the subsequent crop for the control of volunteer forages (alfalfa, grasses) and other annual and perennial weeds.