As a result of last summer's drought, I am getting questions about pasture and hayfield renovation. What can be done to thicken up forage stands that have been thinned out?
The first step is to evaluate the forage stand to determine renovation options. Use a one-foot square as a tool to help quantify the stand density. Take 10 to 15 random one-foot square samples per hayfield or pasture to provide an estimate of the average stand condition. If the stand is a grass or grass legume pasture or hayfield, evaluate the stand based on the percentage of bare or open soil plus the presence of legumes if the stand is a mixed grass/legume stand. There should be less than 10% open or bare soil. There should be 2 legume plants per square foot in a grass/legume mixture. If these conditions are not met, then partial renovation should be considered. In the case of an alfalfa hay stand, there should be 10 to 15 plants per square foot in a second year stand and at least 5 to 6 plants per square foot in a 3rd year and older stand.
A partial renovation can be defined as adding forage seed to an already existing forage stand with the goal of increasing the stand density of desirable forage plants. No-till seeding is the typical method used for partial stand renovation; however March often offers an opportunity to utilize frost seeding as a renovation method if certain conditions are met. Frost seeding involves broadcasting seed over a pasture or hayfield area and letting the natural freeze/thaw cycles of late winter and early spring help to move the seed into good contact with the soil.
A basic requirement for frost seeding success is to make sure that the sod cover has been opened up, so that some bare soil is exposed. Last year's drought may have caused the loss of enough desirable plants that there is sufficient bare or open soil without any additional preparation.
Another twist to frost seeding that sheep producers can use to their advantage is to combine frost seeding with hoof action. Under this seeding scenario, let your sheep begin to graze the paddock or hayfield that is to be frost seeded. Let the sheep graze down the forage, scuff up the soil and open up bare areas in the sod. At this point, broadcast the forage seed across the paddock. Keep the sheep in the paddock another couple of days and let them continue to graze and trample or hoof in the seed. This method seems to work well with sheep because they don't trample in the seed too deep as could happen with cattle.