Assessing Pastures in Preparation for Fall Pasture Renovation

Amanda Grev, Pasture and Forage Specialist
University of Maryland Extension

With the current warm temperatures it may feel like fall is still far away, but the end of summer will be here before we know it and now is the time to be thinking ahead about plans for pasture renovation this fall. Despite our best managerial efforts, many of our forage stands will eventually require some form of renovation. Whether we have simply let our fertility slip, lapsed a little in our harvest management, allowed some fields to become overgrazed, or some weeds have taken over and outcompeted the desirable forages, an unproductive pasture is often the result. Couple this with the severe drought and extreme wet conditions that Mother Nature has all too often thrown our way in recent years and we may find ourselves scratching our heads and wondering how we got here and what to do about it.

The first step is to recognize that poor forage stands are often a symptom of an underlying cause. More often than not, the major causes of poor pasture productivity include a lack of adequate fertilization and/or poor grazing or harvest management. If this is the case, keep in mind that if a stand is thin as a result of poor soil fertility or overgrazing, the problem will not correct itself just because you’ve added more seed. To achieve real success, these underlying issues will need to be corrected. If environmental conditions such as flooding or drought are at fault, we can work to overcome those by selecting species or varieties that will be more resilient to those conditions moving forward.

Along those lines, one other point of note is that renovation does not always require completely starting over with a full reseeding. Renovation can also occur in the form of improvements in management, better fertilization and weed control, the addition of legumes into grass pastures, or overseeding into thinner areas.

When deciding whether or not renovation is needed, take some time to assess the current condition of your pastures. Are they performing as well as you would like? Has there been excess damage from environmental conditions? How well have you been managing the stand? Are there a lot of undesirable species or weeds present? In addition to asking yourself these questions, an objective assessment of the pasture stand can be helpful. One such assessment is the step-point method, which involves walking through each pasture in a random pattern and noting the forage species (or lack thereof) at various locations throughout the pasture (see specific steps below). Recording these observations allows you to objectively calculate the vegetative cover and percent desirable forages for a given field. In addition, take note of other key indicators such as forage diversity, plant vigor, presence of insect or disease damage, signs of erosion, or other observations as you walk.

If damage is light and there is a high proportion of desirable species and a low proportion of bare ground or undesirable weeds, then some rest, fertility, and weed control might be all you really need. If the damage is more moderate, perhaps frost seeding in some clovers or overseeding the worst areas would also help. If you have a low proportion of desirable species and a higher proportion of bare ground or undesirable weeds, you may want to consider terminating the existing stand and reestablishing the field with a suitable forage species based on your farm, your system, and your needs.

If you do decide to fully renovate, you have several options. The renovation process is a chance to upgrade your forage system and to capitalize on new and improved forage genetics. You may decide to do a rotation or two with an annual forage as a smother crop to help suppress weed populations, prevent soil erosion, build soil fertility, mitigate soil compaction, and provide a high quality forage source during the renovation process prior to planting the field back into a perennial stand. Either way, there are several steps you should follow to make sure the reseeding process goes smoothly, so start thinking ahead on some of the necessary steps moving forward. Think about forage options that will work for you and look for good quality seed to purchase. If you don’t have a recent soil test, take some soil samples and begin correcting any soil pH or fertility deficiencies. If weeds are a problem, be sure to allow adequate time to achieve good weed control and still be able to plant in a timely manner. Recognize that in some situations a single herbicide application may not always be enough, and be mindful of any herbicide carryover that might affect seeding.

No matter how you decide to proceed, now is the time to be thinking ahead and making plans for this fall. Stay tuned next month for an overview of the key steps for optimum forage establishment and some common establishment mistakes to avoid.

The Step-Point Method for Pasture Vegetative Cover Assessment
Step 1 Denote or mark a specific spot on the tip or edge of a shoe or boot.
Step 2 Based on the major species present in your pasture, determine which forage species to include as categories. As an example, you could include tall fescue, orchardgrass, Kentucky bluegrass, white clover, red clover, other legume, other grass, undesirable species (weeds), and bare ground.
Step 3 Walk through the pasture in a random zig-zag pattern stretching from one end of the field to the other. Avoid walking near gates, waterers, laneways, or other heavily used areas. Every 10 to 20 steps (depending on pasture size), stop and take note of what is directly under the designated spot on your shoe. The spot will fall directly on top of a specific plant species, make a mark for or write down which forage species (or bare ground) is present based on your pre-determined categories.
Step 4 After recording 50-100 stops, add up the number of marks for each forage species or category and calculate the percentage of each species.
Step 5 Repeat the above steps for each pasture.