Pasture management is vital to profitability. When the cow harvests its own “groceries,” the better the bottom line. Pasture management involves maintaining the fertility of land, grazing management of land, stocking rate and taking into consideration Mother Nature when we have less rainfall or other weather challenges.
I have observed lots of pastures this year with tremendous weed pressure. Weeds are usually an indicator of issues. If a field is left unmanaged, it will revert to weeds and then to a forested area over time. That is known as succession. Weed proliferation can also be the result of low fertility, overgrazing and overstocking. Often, it happens before realizing the damage has been done. Overgrazing remains the single biggest mistake in a forage-livestock system.
Grazing guru Jim Gerrish, when asked what he thought was the most common mistake still made by those who have implemented rotational grazing strategies, replied, “grazing pastures too short and returning too soon.” Overgrazing is easier to avoid in the spring when pastures are growing faster than the livestock can consume them, but as mid- and late-summer roll around and forage growth slows, grazing pastures too short is hard to avoid
The consequences of grazing pastures too short are long lasting. The following are reasons why:
• Removing too much of the photosynthetic factory or leaves severely limits the plant’s ability to recover and regrow. Remove the leaves or blades and the plant cannot capture sunlight to replenish its source of energy.
• The plant’s ability to grow new tillers is compromised. “Some species keep their carbohydrate reserves in structures below ground, others keep them in the lower one-third of the canopy Removing these storage structures limits the plant’s capacity to generate new tillers and persist long term. Hence the loss of fescue and other cool season plants in our pastures. Another culprit in this issue is setting the mower to low and scalping the plants.
• Weeds proliferate when overgrazing happens. Slowed plant growth and more exposed soil can easily lead to higher populations of undesirable weed species. This scenario can drive pastures with high populations of broomsedge and other weeds that are less competitive if good desirables grasses are growing. Someone once said the “best weed control is having an abundance of desirable grasses growing.”
• Research studies show overgrazed pastures result in plants that have less root mass, also much shallower. This limits the plant’s ability to take up both water and nutrients, especially during periods of dry weather. Not leaving enough forage biomass can cause drought-like conditions even where adequate amounts of rainfall are received.
• Overgrazing exposes more of the soil surface allowing for a higher degree of runoff, less water infiltration, more soil erosion and elevated levels of evaporation. Adequate forage cover intercepts raindrops, which slows impact at the soil interface and enhances water infiltration. Research has shown that soil temperature is very important to having productive, healthy soils.
• Animal performance suffers as forage intake declines when pastures are overgrazed. Milk production and rate of gain can be impacted both short and long term if pastures are not given an adequate recovery period after being overgrazed. Overgrazed plants are a poor source of nutrition if they do have adequate amounts of energy.
It seems there are lots of reasons to take care of your resources and pasture is your main resource if a livestock producer.
For more information, contact the UT-TSU Extension Office in Wilson County at 615-444-9584. You can also find us on Facebook or visit extension.tennessee.edu/wilson. Ruth Correll, UT Extension-TSU Cooperative Extension agent in Wilson County, may be reached at 615-444-9584 or [email protected]