In 1993, two cooperators continued manure trials begun in previous years (Table 2). Vic and Cindy Madsen, Audubon, want to demonstrate that livestock manure is an asset to the farm operation, not a liability. Their manured field strips averaged 21.4 bushels per acre more corn than strips with no fertilizer input, easily justifying the cost of proper application.
Dick and Mary Jane Svoboda, Aurora, compared manure to 28-percent nitrogen solution. The corn sidedressed with manure yielded just as well as the corn receiving 28-percent N. Economically, it was cheaper to use purchased N – until the other manure nutrients are also taken into account. Those other nutrients are needed on the farm, too. In dry years, for example, some of the Svobodas’ corn fields have shown potassium deficiency symptoms. And economics for manure N-P-K don’t reflect benefits like tilth improvement, micronutrients, and food for soil biota like earthworms.