Many forage stands begin to decrease in productivity after three to five years. Soil moisture, nutrient availability, plant species density and management history all combine to determine a forage stand’s health and potential productivity. The factors below can help you determine the health of your forage stand.
(1) Assess forage plant population and density
The first step in evaluating a mature stand is to identify the plant species present and their densities by counting plants of each species per square foot or per square metre. Ideal plant densities will vary by region depending on growing conditions. Dry regions require a lower plant density to reduce competition for available moisture. In areas with high annual precipitation, a higher plant density is targeted to maximize forage production and minimize weed intrusion. The desired plant species will also vary by region and end use. In hay stands, a higher alfalfa population is typically desired than in pasture stands. Intensively grazed pastures require different species than conventionally grazed pastures.
(2) Identify weeds and bush present
Weed and bush plants compete with forage plants for sunlight, moisture and space. They can also discourage grazing and prevent livestock from getting to available forage. Over-grazed, unhealthy forage stands are susceptible to weed infiltration. Assess the weed and brush contamination across the field, and determine if chemical or mechanical control is needed.
(3) Assess litter/ground cover present
A healthy forage stand has a good amount of litter, with little bare soil showing. Litter is dead plant material that covers the soil between plants. Like plant density, the appropriate amount of litter will change with location, as well as species. Low amounts of litter in a forage stand are symptomatic of an unhealthy stand and often over-grazing.
(4) Evaluate soil damage/nutrient cycling
Soil damage can be seen in areas of erosion (due to wind or water), compaction, or hoof damage. Soil damage is often seen in areas where cattle source water. Nutrient cycling is important on pasture stands, as livestock return nutrients to the soil through manure and urine. Uniform distribution of nutrients throughout the forage stand is a sign of good herd and pasture management. Frequently moving mineral and water sources as well as restricting livestock from areas where they tend to linger will improve nutrient distribution across the field. Uneven distribution of urine and manure will lead to patchy forage production.