By Dwayne Summach MSc, PAg, Livestock & Feed Extension Specialist, Kindersley
Are you going to fertilize that old hay field? If so, with what? Old grass fields are very likely to be deficient in a range of nutrients, but the largest response is likely going to be to nitrogen. The rule of thumb is that an old grass stand will produce ten to fifteen pounds of grass for every pound of nitrogen applied. The application of fifty pounds of nitrogen should result in an additional 500 to 750 pounds of dry hay, as long as moisture is not limiting. Applying 50 pounds of nitrogen, at the current price of urea fertilizer ($563.68/T) of five and a half cents a pound of nitrogen, and valuing the hay produced at eight cents a pound, results in a net benefit of $15.70 per acre, if forage production increases by 500 pounds. If the same application results in an increase of 750 pounds of forage, the net benefit is $32.20 per acre. Increased forage productivity also improves harvest efficiency of the equipment involved, spreads out the land ownership cost over more production, and allows for greater livestock productivity.
Broadcasting fertilizer is the most common method of applying nutrients to an established forage stand. This results in less than ideal placement of the fertilizer, so extra emphasis needs to be placed on timing the application to coincide with environmental conditions that allow the forage to make the best use of any applied nutrient. In short, apply fertilizer to cool (not frozen) soils just in advance of a half inch or better precipitation event to move the nitrogen into the soil. Additional information on fertilizing forages can be found at Fertilizing Seeded Forages in Saskatchewan.
Feed production is an expensive endeavour, but when feed supplies are tight, additional investment in soil fertility may improve the overall position of a livestock operation. To discuss various aspects of forage fertility and feed production, contact your nearest Agriculture Regional Office or the Agriculture Knowledge Centre.