Many pastures that are presently unproductive can be improved with a little management. There are several methods that may apply to improving pastures.
Weeds can be controlled either by clipping or herbicide application.
Clipping pastures should be done at least once a year, but it’s better if two or three clippings a year are done. Clipping should be done when weeds are flowering and before seeds are developed. Clipping desirable plants will also improve their nutritional value since young plants are more digestible than mature forage. Caution: When you clip and drag pastures, you will also be spreading the manure piles. If this is done during warm, humid weather, you will be infecting the pasture with parasites. Clipping and dragging should be done in hot dry weather to kill the parasites.
Herbicides can also be used to control weeds. Banvel (one-half to 1 pint per acre), 2,4-D amine or ester (1 to 4 pt. per acre), or a combination of the two can be used without removing the horses from the pasture. These herbicides are effective against bull thistle, Canadian thistle, chicory, plantain, burdock, and dandelion and will help reduce ironweed infestation. Both of these herbicides will also kill any legumes (i.e., clovers, alfalfa) that are present in the pasture. Herbicides should be applied during rapid plant growth such as is common in the spring or in the early fall after rains.
Grasses need a soil environment that is 6.0 to 7.0 pH and the nutrients nitrogen (N), phosphorus (P), and potassium (potash, K). Legumes need a soil environment that is 6.5 to 7.0 pH and the nutrients P and K. Legumes do not need nitrogen since they are capable of making their own by absorbing it out of the air into nodules located on their roots. Often, adequate fertilization and good grazing practices allow pasture plants to increase in number and make the pasture more productive.
In general, the soil should contain 40 to 60 units of P and 220 to 260 units K. It takes about 10 units of P205 (P source in commercial fertilizer) to raise the soil one unit, and it takes 2.5 units of K2O (K source in commercial fertilizer) to raise the soil one unit. After the soil is brought up to these levels, then annual application would be as follows:
• If the pasture is at least 30% legume, add 40 lb. per acre of P205 and 80 to 100 lb. per acre of K2O.
• If the pasture is less than 30% legume, then nitrogen also needs to be added in addition to P and K as given previously. The amount of nitrogen will vary based on the amount of forage you wish to produce. Eighty pounds per acre will give production of less than two tons of dry matter per acre, and 120 lb. will give more than two tons per acre. In general, each 50 units of nitrogen will give an additional 1,000 lb. of dry matter and increase the crude protein value of the grass two units. However, there are limits to adding nitrogen because excessive nitrogen will actually burn or kill the vegetation if too much is applied at one time or a lot is applied in dry weather. Therefore, it is recommended that nitrogen be applied in split applications, the first being in late march or early April and the second in late August when fall rains are beginning.
Horses do not need to be removed when applying granular fertilizer. Just be careful to not have any spills of fertilizer where a horse could eat enough of the material to be toxic. When applying liquid fertilizer, the animals should be removed until rains come and wash the fertilizer off the plants.
To determine the fertility level of soil before planting a pasture, soil samples need to be taken and analyzed. Your local county Extension office or local fertilizer companies will provide this service. There is a small charge to have the soil analyzed.
This method involves dividing the total pasture area available into smaller pastures. Livestock are then moved from one pasture to another, which gives the previous pasture time to reestablish the plant root reserves. Ideally, after being grazed, plants should be given at least a 30-day rest to rebuild. Continual close grazing will cause the death of the plant. For maximum production, the animals are moved when the plants have been grazed to a height of 2 to 2-1/2 inches.
Some pastures are to the point that one needs to start over, or the owner wishes to establish a more productive pasture by using different plant species. In general, renovation is done by one of the following methods:
• Plowing and preparing a new, firm seedbed free of weeds.
• Surface tilling or disking up the surface to kill the present vegetation. To do this, the surface needs to be disked then time allowed for the plants to die and then additional diskings until all plants have died.
• No till, which involves using herbicides to kill the present vegetation and then using a no-till drill to plant seeds in the soil under the dead vegetation.
The herbicides used are 2,4-D at the rate of one pound of active ingredient per acre for broadleaf weed control, followed 10—14 days later with Gramoxone Super at the rate of one and one half pints per acre to kill remaining plants. The new seeding may be made just prior to or immediately after the Gramoxone Super treatment. With either of these methods, it is recommended that new seedings be made mid-April to early May or in August. It is also recommended that the soil fertility be corrected prior to renovation. Animals must be removed from new seedings until the plants are well-established (10 inches tall for tall grasses and six inches tall for Kentucky Bluegrass).