Victor Shelton, NRCS State Agronomist/Grazing Specialist
I’m
glad that May has finally arrived. For me, it’s been a wet and somewhat stormy spring so far. If you haven’t done it already, it’s a really good idea to walk your pastures before grazing them for the first time. You can use your ATV if you prefer, but I’d rather see you walking and observing closely rather than taking quick glances and a joyride. It wouldn’t hurt to take some pictures to compare current conditions to other time periods.
First, assess how much new growth is actually present in each paddock or field. The amount can be deceiving unless you actually step into it. Ideally, take a yardstick with you and measure the average height of the new forage. For most cool-season forages, I like to see at least 8-10 inches of growth prior to grazing. I don’t want to sound like a broken record, but it’s important to rebuild green vegetative “solar panel” and ensure energy is returning to the roots, as much of the initial spring growth has already used it.
You’ll typically notice some differences in growth from field to field. This is perfectly normal, and we’ve recently discussed some of these differences. Fields that were grazed harder last fall, especially before dormancy, are often a bit delayed in their spring growth. This is expected because grazing reduced energy storage for spring green-up. However, this can be useful if you’re interseeding or frost-seeding clovers because there’s less competition.
Fields that are grazed later in the fall or early winter typically experience more growth in the spring, unless they were grazed very short, especially during the winter. When grazed heavily, the plants rely on their energy reserves to regrow, but they also need to use those reserves to grow new roots along with new leaves. Prolonged close grazing can damage the roots, leading to root dieback. As a result, these fields need time to recover and regenerate both their roots and leaves.
The amount of live roots at any given time is roughly equivalent to the amount of live or dormant leaf matter left above ground (residual). Taller, well-maintained plants typically have deeper root systems, while shorter, closely grazed plants have more shallow roots. Early in the year, especially with plenty of moisture, you may not think about the potential issues with short roots. But when the hotter, drier days of summer arrive, the deeper roots will play a critical role in accessing moisture and nutrients lower in the soil profile.
Fields that were stockpiled last fall, grazed post-dormancy, and not grazed too short generally respond very well in the spring and are often among the first fields ready for grazing. These stockpiled fields can take the abuse of wet weather better than fields that were grazed too closely early on and continued grazing under wet conditions. Short, tight grazing in wet conditions often increases compaction, which negatively impacts new growth in the spring. If this happens regularly, these fields may begin to transition to forages that are more tolerant of close grazing and compacted soils, such as bluegrasses and white Dutch clover. In fact, if compacted, you may notice bluegrass going to seed earlier than usual. Take the time to observe and reflect—what has been happening in a particular field?
Fields that were not stockpiled but were not grazed much in the fall and allowed to recover over the winter will likely have the most new spring growth. These fields had ample time to rebuild reserves last fall—perhaps from mid-October on or longer. Even though some areas were drier than usual, the long recovery relieved much of the stress on those forages and allowed them to send energy reserves to the roots. The “solar panel” left throughout fall continued to pump energy into the roots, helping them grow. When you look at these fields this spring, the forage should be dense, rich, and growing well. If you dig down, you’ll find plenty of live roots extending deep into the soil profile. These fields will not only be productive for early grazing but will also be in better shape to handle the hotter, drier conditions that will come later—as long as we don’t overgraze them in the meantime.
I encourage you to take a close look at your pastures. This is a good practice whether you’ve not started grazing yet this year, already have, or never stopped. Think about what you can do to improve forage growth and quality this growing season. Adequate recovery before grazing is typically beneficial for increased productivity.
If you frost-seeded clover into established stands earlier this year, light to moderate grazing can help release the interseeded legumes and reduce competition from dominant grasses. Careful grazing management helps the clover establish, integrate into the pasture system, and boost nitrogen fixation, which enhances overall pasture productivity and soil health. You want to remove just enough competition to open up the sward and allow more light to reach the young clover seedlings, being careful not to overgraze or remove the newly seeded legumes.
Spring is a critical time for controlling weeds in your pastures. Weeds can quickly take hold when pastures are grazed too short or are stressed from overgrazing. Dense, healthy forage will naturally help suppress weed growth, but you should be proactive in identifying and dealing with problem weeds early. Spot grazing can help manage weed patches, and targeted herbicide application is useful if you have particularly aggressive species. Always be mindful of your overall pasture health and ensure that weed control methods don’t harm beneficial plants or soil quality.
Look for common problem weeds like thistles or perennial broadleaf weeds that can outcompete your desired forage. If you catch them early, you can prevent them from seeding and spreading throughout the pasture. However, it’s important not to over-graze areas with weeds, as it can make the problem worse. Healthy pasture management, along with smart weed management practices, will reduce weed pressure while promoting strong, productive pastures.
Grass tetany (hypomagnesemia) is a serious condition that can affect livestock in the early spring, especially when they begin grazing lush, new growth. Rapidly growing grass is often high in potassium and low in magnesium, which can disrupt magnesium absorption and lead to tetany. To prevent grass tetany, it’s a good idea to provide a high-magnesium mineral supplement (typically 10-20%) until the flush of new forage is past. If you have concerns or need further advice, reach out to your local Extension service or veterinarian for more information on effectively managing grass tetany.
It’s not about maximizing a single grazing event but optimizing the entire grazing season. Observe, plan ahead, and keep on grazing!