If you hook up to an older spreader at a fertilizer dealership (where maintenance isn't job one) and go spread fertilizer, experts say you may not get the proper spread pattern. The same applies if you use a spreader to apply lime, gypsum or waste products. Spreaders must be in good working order and adjusted properly to give you an even spread.
You also need to know your product and its characteristics, equipment experts say. For example, if you're spreading gypsum, which is somewhat similar to lime but lighter, you need to have the spreader adjusted properly.
Ron Chamberlain, head of Gypsoil, a firm that sells gypsum, says you need a machine with a belt at least 30 inches wide to spread the product. You're typically spreading from half a ton to two tons per acre, so you need a spreader that is accurate at various rates.
You also need to be able to move the double spinners in or out depending upon the rate and flow of the product. Where the product hits the spinners can determine how far it is thrown, and whether you end up with a uniform pattern, or too much product directly behind the spreader. Most typical spreaders cover a width of 60 feet accurately—30 feet on either side of the center of the spreader.
Older spreaders that have rusted chains can still be retrofitted and brought back into usable condition, equipment dealers say. The secret is to prevent the rust from forming in the first place. Some new models have automatic oilers that allow the spreader to oil itself while it's empty. This keeps rust from forming. If rusting gets too severe, the adjustments may not work properly, and it may need reworking until they do.
You can check spread pattern by using pans placed at equal intervals across the spread pattern, and then either weighing the material or dumping it into volumetric tubes to make sure that you're getting the same amount of product at different distances from the spreader.