Want to save money on corn fertilizer?

Start by accurately comparing prices, suggest Paul Johnson and Gregg Carlson, South Dakota State University plant scientists.

You want to compare the cost of the nutrient on an actual pound for pound basis.

Anhydrous ammonia usually costs the most per ton, they say, but is usually the cheapest per unit of N, because it is 82% N. If you look at urea, it is 46% N and  liquid is usually 28%.

If anhydrous ammonia costs $749/ton, 44-46% urea costs $562/ton and 30% lquid solution costs $351/ton, calculate the $/lb actual N as follows.

Save money on fertilizer

Focus on providing N, P, and K first, Johnson says, and then attend to micro nutrients. In the case of corn, zinc is the one micro nutrient that is most commonly needed. If you are zinc deficient, its application usually produces good return on investment, he says.

You also want to look at the time you are buying the products. Nine years out of 10 fertilizer is cheaper in the fall than in the spring. Most years the difference in cost will cover any interest charges that may be incurred before the product is needed., Johnson says.

As an example, if the fall N price is at $0.60/ lb N, and if interest rates are at 6% to 8% (assume 7% or 3.5% for a half year) and if you assume a 6 month difference between fall and spring purchase, the break even spring price would be $0.60+$.60*.035 = $0.62/lb of N.

Also compare application costs and always buy from supplier who can get you the product when want it and need it, they conclude.

Source: SDSU