Fed hay can be an import fertilizer for pastures By John Lory

High fertilizer costs make it imperative that cattle producers maximize the benefits of all fertilizer sources on their farm. Often farmers overlook the fertilizer value of fed hay. A ton of fescue hay contains approximately 40 pounds of nitrogen, 15 pounds phosphate and 40 pounds potash. Many of those nutrients pass through the cattle; non-lactating cows return the equivalent of almost all fed nutrients back to pasture. Some of the nitrogen is lost so ultimately approximately 25% of the fed nitrogen and all the fed phosphate and potash have fertilizer value. The nutrients in a ton of hay are enough to match the phosphate and potash nutrient removal rates for one acre of pasture. Fertilizer value of nutrients in a ton of hay is about $15 assuming $0.40 for nitrogen, $0.30 for phosphate and $0.20 for potash.

This source of fertilizer only has value if your manure spreader, the cow, does a good job of distributing its manure around a field. Cattle naturally tend to deposit most of their manure near feeders and water sources in a pasture. The following practices help improve the distribution of manure in pastures:

• Spread the wealth! Frequently move feeders and feeding areas around the pasture.
• Increase the stocking density of animals but move animals from area to area more frequently to prevent over use of areas in the pasture.
• Do not use the same pastures for supplemental feeding every year but move winter feeding areas each year to distribute the nutrient benefits around the farm.

To protect water quality, maintain a setback area between winter feeding areas and streams and lakes. Frozen and saturated soil promotes the movement of manure nutrients in runoff. Nutrient losses in runoff will have little impact on the fertilizer value of manure but can have a big impact on stream and lake water quality.

John Lory
Commercial Agriculture Program
and Division of Plant Science