Add soil fertility to your pasture management kit
There are many ways to determine forage and soil health, and soil fertility is a great tool in our management kit. Collecting information from a soil test, yield, and general observations can put you on the right track to productive fields.
Proper fertility is a key factor for healthy productive pastures and hay fields. Every good fertility management plan should start with a soil test, it is difficult to diagnose problems or anticipate a deficiency without establishing a clear baseline.
A soil test offers a place to begin, and regular testing will allow you to note changes over time.
Soil samples should be taken anytime from 2 to 6 months before you plan to apply amendments to allow time for planning, ordering inputs, and making any other changes.
Key Nutrients
Nitrogen is usually the most limiting nutrient for grass pastures. Because of its mobility in the soil, nitrogen should be applied annually in some form.
Forages respond to nitrogen when applied during cool temperatures and adequate soil moisture, spring application sees the greatest response followed by a late summer application.
Nitrogen applied in mid-summer yields the poorest response. Keep in mind that large applications of nitrogen will require careful management and may need to be applied in split applications.
Legumes in pasture mixes can provide additional nitrogen to the system. Nitrogen applications should be limited in pastures with greater than 40% legumes to avoid overcrowding by grasses.
Phosphorus and potassium are key to legume success in pastures.
Both can be applied during spring or fall to established fields. A good liming program will result in a good phosphorus program. The University of Kentucky’s AGR-1 offers lime and nutrient recommendations for pastures and hay fields.
Soil pH affects nutrient availability and interactions with each other. Maintaining the correct pH will ensure overall nutrient availability for your fields. The suggested baseline pH is between 6.0 and 7.0 for grass-mixed pastures and 6.5 to 7.0 for legume pastures. If pH is not corrected, then applied nutrients may not be available to the plants, and deficiency symptoms will persist.
Chapter 8 of the Illinois Agronomy Handbook offers suggested limestone applications based on your soil and pH.
Take Home Messages for Forage Fertility
Both hay fields and pasture grow forages for livestock feeds, but there are some key differences to consider when building a fertility management plan for each.
Hay fields will need yearly fertilizer applications and close monitoring, because of the removal of nutrients.
Pastures with livestock can recycle 80% of nutrients consumed by grazing through manure and urine.
Fields with short-lived perennials will be periodically renovated with tillage and replanting, while pastures may remain undisturbed for long periods of time.
Soil tests should be taken every three to five years in any cropping system. Use soil tests and observations to make informed decisions about fertilizer applications and field renovation.
A healthy soil will yield quality forage production and result in the best quality livestock feed.
How To Take Forage Brix Test
About the video: Brix scoring is important because it tells us how much sugar content is in our forages and the nutrition density in our dry matter. Plants high in brix are more resistant to drought, cool temperatures, pests, and disease. The higher the brix, the higher the quality of the forage you're feeding livestock. A refractometer is used to determine the sugar levels in pastures. Logan Karcher, director of producer programs with Illinois Grazing Lands Coalition, demonstrates how to conduct a forage brix test.
How to Use a Refractometer
About the video: A refractometer is used to measure brix, the sugar content in plants. Understanding the quality of your forages will help you adjust the forage options for your livestock. Logan Karcher, director of producer programs with Illinois Grazing Lands Coalition, demonstrates how to use a refractometer.
Source: Katie Lynn Bell, University of Illinois Extension Local Food Systems and Small Farms Educator