As urban sprawl continues and land becomes more and more valuable, horse facilities are finding it increasingly difficult to provide sufficient pasture for all of their horses. What can you do to maintain good pasture on small acreage?
What’s in Your Soil?
The first step in ensuring a healthy pasture is to test the soil. Grass can’t thrive where the nutrient levels are poor, and in an overgrazed pasture the grass will need all the assistance it can get to stay healthy. Contact your state or local county extension office to obtain a soil test kit. With an average cost of about $6, a soil test is something that every farm can afford. The test kit includes instructions on how to collect small samples from different areas of the field, which will create a representative sampling.
What, exactly, does a soil test evaluate? Normally, the pH level of the soil, as well as levels of phosphorus, potassium and nitrogen. The extension agency should also do a Cation Exchange Capacity test. “This indicates how many nutrients the soil can hold,” explains Dr. Marvin Hall of the Crop and Soil Sciences Department at Pennsylvania State University. “For example, a sand soil has a very low CEC, so if you add nutrients to it, they aren’t going to stick to anything. Heavy rains will just leach the nutrients through and they won’t be available for the plants. A loam soil with a lot more organic matter has a much higher CEC, which means a lot more nutrients are available for the plants. As opposed to the first soil, with this soil you can go several months without adding any nutrients.”
The test results should come with an explanation so you’ll know exactly what to apply (the fertilizers needed, the amounts, and frequency of application can vary greatly depending on soil type, the condition of the soil and where in the country you are located). It will spell out the levels of the various nutrients in your soil and how many pounds of nutrient per acre you’ll need to add to bring your soil up to proper levels. Your local garden supply or landscaping store should be able to help you mix up the right portions of fertilizer.
Once applied, how long should you wait until allowing horses to graze? “There are very few fertilizers that you have to worry about,” notes Dr. Hall. “Usually, by the following day it is safe. The morning dew breaks down the fertilizer so the animals can’t get high levels of them. The biggest concern would be with a nitrogen fertilizer, particularly if it is pelletized. If the pellets land on a leaf and the animal eats that leaf, it can give the animal a high nitrate content which can cause health problems.”
Manure build-up can become a huge problem when a lot of horses are crammed into a small pasture. Manure actually can provide too many nutrients for the soil and thus kill the grass, so you need to remove it on a regular basis. You may also run into environmental problems, because the nitrates from the manure can leach from the field into ground water or streams. Urine, too, can be a problem—although there is little that can be done. The nitrogen content in a spot where a horse urinates is equivalent to adding about 700 pounds of nitrogen per acre in that one spot (the normal application is about 35 pounds).
The one thing that seems to thrive when a pasture is overgrazed are the weeds. Why? The reason is simple. Grass is very palatable relative to weeds, so horses will select the grass. Then, the grass gets eaten again as soon as it starts to grow back. As a result, it never has a chance to build up a root reserve. Meanwhile, the weeds build up their roots as well as their carbohydrate reserves.
Herbicides will do a good job of controlling those annoying weeds, although many require 7 to 14 days post application before horses can be returned to the pasture. Look for herbicides that contain the chemical metsulfuron. It is effective and you don’t have to take the horses off the pasture when it is applied.
Make a Sacrifice
Ideally, there should be at least 1.5 acres of pasture for each horse. Unfortunately, this just isn’t possible at many farms. Consider creating a sacrifice area to give overgrazed pastures a fighting chance. Partition off a small portion of the pasture so that when it is too wet or the grass is too short, you have another place to put the horses. Basically, this area will get overgrazed, grass will die and mud may abound—but it gives the rest of your fields a fighting chance.
Keeping a lot of horses on a small amount of pasture is a constant uphill battle. There is no easy remedy, but good management can make the battle a little easier to fight.