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Forage Focus: Early Season Pasture Management
As we near the end of winter and move towards spring, many livestock producers are anxiously awaiting pasture green up and growth. However, due to last year's drought and short forage supplies, many of these same pastures were overgrazed and abused last fall. Remember that fall is a critical time for the forage plant to buildup and store carbohydrate root reserves. These carbohydrate reserves are used for initial plant growth in the spring until the plant has enough leaf tissue to sustain its own growth through photosynthesis. Plants that are overgrazed in the fall of the year must over winter with diminished carbohydrate root reserves. This can lead to plant death over the winter in severe cases, but most commonly slow spring green up and reduced growth rates or lower production are seen. In this article I want to look at 3 possible pasture scenarios and discuss some management options for each.
1) Pasture is thin with large bare areas: This might also be called the worst case scenario and for any livestock producer facing this scenario and absolutely needing early grazing because there is no more hay, this is a nightmare. Unfortunately I don't know of any great management options for this scenario.
It is possible that a small grain such as oats or wheat planted early, before mid-March if at all possible, could provide some grazing by mid to late April. There is very little information available about using small grains seeded in the early spring to provide spring grazing. In my search, I did find a couple of references to early spring planted oats in Kansas and Nebraska being recommended to provide spring grazing. The Nebraska article stated that oats planted by mid-March would provide oats 6 to 8 inches tall in 5 to 6 weeks. Recommended planting rates were 2 to 3 bushels an acre. Nitrogen should be applied at 30 to 60 pounds/acre. This should work for any of the small grains, but oats may respond best to the cool soil temperatures in early spring. The advantage of winter wheat seeded in the spring over oats is that the winter wheat will stay in vegetative growth, while the oats will go into reproductive growth and form a seed head. I would only advise trying this planting of a small grain for spring grazing where the pasture is in such bad shape that re-seeding is necessary and the producer can't wait for a typical cool season grass/legume seeding to get established before grazing. Even if this does provide some grazing in the late April through May period, a perennial grass/legume seeding will have to be done in late summer to re-establish a sod base.
If there are other spring forage options or spring pastures that can be utilized, then this type of pasture paddock should be seeded back into a perennial pasture mix. This should be done before mid-April to have the best chance of success. It takes a forage plant 6 to 8 weeks after germination to become established, so during this time livestock must be removed. Once plants have grown to a 6 to 8 inch height, a light, quick grazing that removes only the top couple of inches can be allowed. Subsequent grazing passes should follow the "take half - leave half" principle and allow enough time between grazing passes to allow the stand to re-grow to grazing height.
2) Overgrazing has weakened pasture plants but the sod base is still in moderately good shape, with few bare spots. Depending upon how "open" this sod is and how few the bare spots are, this could be a good candidate for frost seeding some clover seed into this pasture paddock. In our area, frost seeding generally should be done by mid-March. Consider rates of 8 lbs/acre for red clover and 2 lbs/acre for white clover. See the section on soil fertility later in this article. Another option would be to thicken up the stand by using a no-till drill. This increases the cost of the seeding, but insures better seed and soil contact and increases the chance of seeding success. It also provides a larger window of opportunity, as no-till seeding could be done until that mid-April time frame.
In order to allow the clover the opportunity to survive in a grass stand after it germinates, allow livestock to do several light grazing passes that eat down the grass plants without grazing the young clover plants. This will allow sunlight to get down to the young plants and help them to get established.
If sod thickness is satisfactory, and the goal is earlier spring growth, this is the spot for an early season nitrogen application. Early season nitrogen can lead to quicker growth and increased yields. Dr. Ray Smith, a University of Kentucky Extension forage specialist who spoke at the Ohio Forage and Grasslands Council Conference in Reynoldsburg in early February, addressed this topic. Research done at the University of Kentucky that looked at the spring growth response of tall fescue to top-dressed nitrogen demonstrated that early season forage production could be increased. An application of 40 pounds of nitrogen/acre in mid-March resulted in a 1.07 ton yield response compared to 0 nitrogen when yields were measured in mid-May. This figures out to almost 54 pounds of extra grass produced per pound of nitrogen applied. The yield response dropped off after the 40-lb/acre-application rate, so the biggest bang for the buck is up to this 40-lb/acre rate. Even at today's nitrogen prices, this is a paying proposition. At this return, if grass is worth $0.05/pound ($100/ton hay), the breakeven price (point at which expense = return) of nitrogen is $2.70/pound!
3) Pasture was not overgrazed, sod is thick and root system is healthy. If you have pastures in this condition after last year's drought, you are to be congratulated. Either you had very few livestock on lots of acres, or you did an excellent job of managing. On these paddocks continue to practice good rotational grazing management by holding to the take half, leave half principle and providing adequate rest periods before making another grazing pass.
I need to touch on a final point when discussing pasture management options and that is soil fertility. I'm going to include soil pH in this. Soil fertility is the base of forage production. Yes we have forage species that are better than others at tolerating low pH and low soil nutrient levels. However, there is a difference between tolerating and achieving maximum production. Good soil fertility produces better forage yields and offers better returns for your pasture management efforts. Aim for the following minimum soil fertility goals: soil pH > 6.0, soil phosphorus (P) of 15 ppm (grasses), or 25 ppm (legumes) and soil potassium (K) of 100 ppm or better depending upon your soil cation exchange capacity.
For more information about pasture management, renovation, reseeding or fertility, contact your local Ohio State University Extension office.
Source: Rory Lewandowski, Extension Educator, Athens County
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