The Perfect Time to Evaluate Your Pasture

Posted: October 1, 2013

Autumn's quick approach and with cooler weather ideal conditions are present for inspecting a pasture which should reveal important information for the farm manager.

Why Inspect Your Pastures in the Autumn?

This inspection can assist in pasture management for the next growing season. Forage that grows in a pasture should be desirable, such as forage grasses or legumes. Undesirable forage consists of weeds, which develop in any pasture environment. There are different methods to evaluate a pasture and all calculate the total forage coverage and specifically identify desirable and undesirable forages.

Pasture Consistency

  • Pastures consist of two types of grasses; warm-season and cool-season grasses, which can be annuals or perennials.
  • Pastures can contain weeds which can be annual or perennial and just like grasses grow at different seasons. Weeds can be categorized into winter and summer weeds. If a pasture becomes over-grazed or stressed the weeds have an opportunity to become established.
  • If the desirable grasses are strong and healthy they can hinder the weed’s growth. If the desirable grass is weak and stressed the weed becomes stronger and overcomes grass growth.

Warm-Season Grasses

  • The warm-season grasses grow best in climates where the summers are hot, dry and/or humid and winters are traditionally mild.
  • Warm-season grasses often lose their green color and stop growing during the winter season or in cooler temperatures. The catalyst for the slow growth of warm-season grasses is exposure to air or soil temperatures below 50 - 55 F.
  • Often if warm-season grasses are exposed for long periods of time to sub-freezing temperatures they will die.
  • Some types of warm-season grasses are Bermuda, Prairie, bluestem, switch, Teff, crab (weed grass), and foxtail (weed grass) grasses.

Cool-Season Grasses

  • Cool-season grasses grow in northern and coastal climates that have mild summers and cold winters.
  • These grasses grow best in early spring and during the fall seasons. As the summer months become hot and humid, these grasses will not exhibit strong growth.
  • These grasses will remain green year round unless the temperature falls below a constant freezing temperature.
  • Common cool-season grasses are annual and perennial rye, fescue, Kentucky, orchard, timothy, reed canary and festulolium grasses.

It would be so simple if one only has to consider the climate and type of grass to grow a desired grass for forage

  • Grasses thrive successfully when the climate is compatible and rainfall and sunlight are adequate, but will not strive if the soil is not fertile.
  • To successfully analysis soil fertility a soil test must be taken. The test can detect if the acidity in the soil is below, at or above (basic) an optimum of 7. If the soil is below a 7, soil test results will encourage applying lime to reduce acidity.
  • Fall is a good time to test your soil and apply lime if recommended. Typically soil test and application of lime are done once every three years. Soil test results can also recommend fertilizer applications to address nitrogen, potassium and phosphorus levels.

Other Considerations

  • Another consideration in maintaining a desirable forage pasture is the length of time and the number of livestock that are grazing.
  • A pasture manager must adapt the length of time that livestock are allowed to forage as the grasses go through the stages of growth.
  • Pastures grasses should not be grazed below a 3-4 inch level. Horses especially tend to “spot” grass and nip the grass down to soil level. This makes those grasses especially vulnerable and the grass becomes unable to compete with weed growth. When this occurs it is very important to rest the pasture for a period of time to enable the grass to re-grow. A 21 to 27 rotational grazing plan can assist forages in staying healthy and give time for regrowth. This rotational plan would mean that a pasture is rested and idle of livestock and animals for at least 21 days.

To evaluate your pasture follow these steps:

  1. Take a soil test and follow recommendations
  2. Evaluate (identity) desirable and undesirable forages within the pasture
  3. Rest and limit use of pastures for ultimate growth.

County Extension offices, the District Conservation offices and/or Natural Resource Conservation Services (USDA) offices can assist pasture managers in successfully evaluating and managing their pastures. The ultimate goal is for a pasture to provide nutritional and exercise needs for the livestock, eliminate weeds (often toxic) and maintain forage coverage that abides within the PA Manure Management requirements.