Pasture and forage minute
After we receive soil tests back from the lab, the next step is developing a plan for pasture fertility. The main nutrients to consider are nitrogen, phosphorus, potassium, and sometimes sulfur. Today, let’s take a look at phosphorus.
Phosphorus plays a critical role in many plant processes, including root development, N-fixing ability in legumes, plant strength, and a central role in the photosynthetic process. Research in Nebraska and other states has shown that the combined effect of nitrogen and phosphorus fertilization often produces higher yields than application of either nutrient alone, especially when phosphorus is low.
In addition to soil test results, phosphorus application will depend on whether or not the pasture is irrigated and how many legumes are present. If legumes make up 25% or more of the pasture’s production, phosphate should be applied at 50% more than for grass alone.
Soil phosphorus can be tested in three ways, Bray, Mehlich, and Olsen. All three tests give results in parts per million (ppm), but values for the Bray or Mehlich test will differ from those of the Olsen. It is important to know what test you are using before making a fertilization plan. For the Bray and Mehlich tests, values over 25 ppm do not need any phosphate applied for both dryland and irrigated pastures.
• 0-5 ppm apply 60 lb. P2O5/acre for irrigated or 40 lb. P2O5/acre for dryland
• 6-15 ppm apply 40 lb. P2O5/acre for irrigated or 20 lb. P2O5/acre for dryland
• 16-25 ppm apply 20 lb. P2O5/acre for irrigated or 10 lb. P2O5/acre for dryland
Phosphorus is fairly immobile, so fertilizing can be done yearly or every other year, as long as applications match recommendations for the length of time desired. The NebGuide G1977: Fertilizing Grass Pastures and Hayland is a great resource if you want more information, and as always, for additional help or information, contact your local extension office.
WINTER HAY ACCESS
With Nebraska forecasts for the next few weeks looking to be dry, getting hay to animals in the field or pasture may not be a concern, but if conditions change to snow and mud, will current placement allow for easy access?
While only Mother Nature knows what lay in store for the winter months ahead, long periods of cold and snow turning into a wet and muddy spring are not out of the norm for Nebraska. If this winter does take a turn for the worse, are you prepared? The principles of bale storage are fairly straight forward and easy to implement while dry weather holds.
First, mitigate the impact of moisture. Move bales away from areas where snow will drift making access difficult. Tree lines, low areas, and fence rows are all natural snow catches, and while convenient, are poor locations for winter bale storage. Additionally, areas where snow collects often become muddy during the spring thaw. While we may be able to plow through drifts and get access while the ground is frozen, bales stored across plowed fields or along minimum maintenance roads may be unusable later on due to mud.
The second concept to keep in mind is organization. Hopefully by now, you have taken some forage tests and have a good idea of the nutrient value of the bales on hand. Higher quality hay may be needed later during late gestation and peak lactation, while right now lower quality forage will suffice for spring-calving cows. Plan accordingly.
Hay that might be higher in nitrates should be noted as well. Feeding high nitrate hay during a storm when animals are hungry and no other feed is available is the story behind many winter cases of nitrate poisoning. Know where these bales are feed them out in a manner and time will mitigate the nitrate risk.
Proper bale storage this winter can mean a better and easier feeding program if the need arises. Avoid storing in areas that collect snow or might be muddy later on, organize hay by quality, and keep a special eye on those that may have nitrate issues.
Fresh spring growth is a welcome sight for producers looking for animal forage. However, this lush growth may also be the perfect set of conditions for a case of grass tetany.