Mid-April, Northern Larimer County pastures may have received the best drought-proofing ever — 1 to 2 feet of snow! Now we hope for a slow, nurturing melt that allows moisture to infiltrate into the soil, to be held by soil particles and absorbed by plant roots. To maximize the benefits of moisture on your pasture, increase what soaks into the soil and decrease runoff.
The best way to increase infiltration is to make sure you have adequate vegetative cover, plant litter on the soil surface and organic material in the soil.
A pasture that has been grazed heavily during a drought may have had most of its vegetative cover removed. The grazing itself is not necessarily injurious to the pasture; however in a drought, with minimal precipitation during the growing period, the plants will not have a chance to recover or replenish leaf area and roots. If these plants are grazed again without a chance to re-grow their leaves (vegetative cover and future plant litter) and roots (organic material) is further diminished. The soil becomes more compact and moisture is more likely to run off than soak in. A pasture that has been used heavily during a drought is less able to make use of moisture when it comes.
The best way to drought-proof your pasture is to be proactive. Realize that you will need to graze less to protect the leaf material and roots of your pasture plants. Plan on harvesting 20- to 30 percent less forage from your pasture as in a normal year. If your animals remove too much from any individual plant, it becomes debilitated, less vigorous, and unable to compete with undesirable plants, or even survive. Your pasture will gradually become sparser, with more bare ground between plants and hotter and drier at the soil surface. The excessive defoliation of plants during a drought only serves to amplify the effect of the drought. A drought-stressed pasture will produce less forage, and is more easily invaded by weeds.
How do you determine when to graze and how long to graze, especially during periods of drought or recovery from drought? You will want to develop an awareness of the condition of the plants, empathy for your pasture. It is important to understand a little about grass grows. The plant’s leaves are solar collectors; they convert sunlight to stored energy. When an animal removes these leaves by grazing, the plant uses stored energy from its roots to replace the leaves that were removed. These new leaves then go to work capturing sunlight, and producing energy to replenish the roots and to grow more leaves. It is critical that the energy removed from the roots be replaced, just as it is important for you to replace money in your bank account after you withdraw to meet monthly budget needs. If you continually withdraw, but never replace, your financial state will rapidly become very unhealthy. The same is true for the grass plants in your pasture.
For maximum plant vigor, the plant should not be grazed again until it has had adequate time and opportunity to regrow what was grazed. Re-growth can occur in as little as two to three weeks when there is adequate moisture, but during drought, it could take as long as three to four months. During severe drought, or in very dry areas, a pasture may need to be rested an entire year before it can be grazed again. A guideline for how long to graze is the second bite rule: remove stock from pasture before they have the opportunity to take a second bite of the same plant, and allow a plant that has been grazed adequate time to regrow before it is grazed a second time.
On small acreages, and especially during drought, it may be wise to plan on purchasing most of your forage, and to use your pasture as a turnout for limited periods. Another approach is to divide your pasture into several smaller pastures and rotate stock through these smaller pastures allowing pastures not in use to recover. But remember, without moisture, the plants are not recovering, no matter how much time passes. The best way to have a healthy stand of grass is to understand how your grass grows and to manage how your livestock graze.
If you would like help identifying plants in your pasture, or want some advice on managing the weeds, contact the Larimer County Weed District at 970 498-5768, or visit the website at http://larimer.org/weeds.