Act Now to Keep Pastures Growing the Entire Grazing Season

– Chris Penrose, Professor and Extension Educator, Agriculture and Natural Resources, OSU Extension, Morgan Co.

It’s never too early to consider which fields could be stockpiled for fall and winter grazing.

The warm February temperatures caused some of our forages to break dormancy early but the cooler March temperatures slowed down progress. We are now at a stage where our forage management decisions can affect forage availability for the entire season. Depending on the season and your location, perennial forages typically go through the reproductive stage in late April into May. After they set seed, these plants quickly transition from the reproductive stage into the vegetative stage. Up to this transition, energy of the plant moves up from the roots to the seeds, but with the transition, energy movement will primarily move from the leaves to the roots. As we move through summer this will help build up root reserves to help the plant survive the winter. What can we do to help keep plants vegetative and productive as long as possible?

First, removing the seed heads will stimulate new leaf development to build root reserves and provide more growth for grazing. Some of this can be accomplished by grazing livestock, but we may also need to clip some fields. If livestock have been out of a field for a period of time, planning to cut a portion of those pastures for hay is an excellent option. The other option is to clip or rotary cut the fields. Either one of these options will stimulate more leaf growth than no seed head removal at all.

Next, the height at which we clip the fields will make a difference. Have you ever noticed after a field is clipped and has a chance to grow that livestock will tend to not graze below the cutting height unless they are left in a field too long? This is a tool we can use to encourage certain types of plant production. For example, if I am trying to encourage orchardgrass growth, I would want to clip my field high, say five inches. If I am trying to encourage bluegrass growth, I would cut much closer.

Clipping pastures higher has another advantage. Removing the seed heads and leaving more leaf will provide shade for the soil and reduce evaporation. The additional leaves will gather more energy for the roots. If we receive one of those heavy rains in July, the additional cover will allow much more moisture to soak into the soil and not run off, providing more growth for the plants.

If forage growth is more than what your animals can use right now; consider removing some of the paddocks for hay. Then they can go back into the grazing rotation after pasture growth slows down or if hay needs are still short, one can take an additional cutting of hay.

Continue to monitor fields frequently as growth will likely start slowing down as summer approaches and we do not want to overgraze pastures. Letting them grow to proper heights and not grazing too close will allow for more forage availability for the entire season. If growth slows down too much, we are better to put cattle in a sacrifice lot and feed stored forages than to let them graze all of the paddocks down. If animals are removed prior to plants being grazed too close, new growth will start from the leaves without a reduction in root reserves. If they are grazed too close, root growth will stop and new growth will need to start from root reserves, weakening the plant.

Root growth does not cease until 50% of the leaf is removed. This is one of the reasons we recommend taking half and leaving half in pastures.

So, how tall should the pasture be before we graze and how close can we graze it? Tables 1 and 2 provide guidelines for grazing height.

Table 1: Managing Grazing Height for Pure Grass Stands

* You may want to graze closer to four inches during summer months as the endophyte can accumulate more at the base of the plant and graze closer in the winter months.
(Source: Ohio Integrated Forage Management Team)

Table 2: Managing Grazing Height for Grass/Legume Mixtures

(Source: Ohio Integrated Forage Management Team)

Finally, it’s never too early to consider which fields could be stockpiled for fall and winter grazing. After our first cutting of hay, we should have a good idea of what our winter feed needs will be. If quantity will be our biggest need, we can start stockpiling forages, especially fescue, in July. If quality is a more pressing need, we can wait to stockpile in August. In either scenario, 50 pounds of nitrogen should increase yields by 1000 pounds/acre and may increase protein content.

As spring progresses, there are several things we can do to influence the quality and quantity of our pasture fields for the rest of the season. We simply need to evaluate our needs, plan accordingly, keep looking down the road to get a sense of what is coming, and take action.