The late, wet spring that occurred across Central Michigan forced many farmers to reprioritize their normal spring schedule and condense field activities into as few days as possible. Gratiot County farmers James and Bob Weburg were among those farmers who normally plan to start field work in mid-April but were forced to wait until late May before weather and field conditions allowed getting crops in the ground. In a normal year Weburg Farms hauls manure from the farm’s swine finishing facility prior to planting corn. To save time this year, the cousins decided to plant corn then sidedress with manure once the crop was up. Fortunately they had previously purchased and had some experience with a spreader and injectors capable of sidedressing in standing crops.
In mid-June, Weburgs started sidedressing corn with manure. The farm employee operating the equipment reported that the GPS and automatic guidance used on the farm simplified and improved the process. The driver was able to set the tractor to follow the line previously established during planting. The tractor and manure spreader combined create a long piece of equipment. Any slight direction corrections by the tractor pulling the spreader are magnified at the rear of the spreader and have the potential to either cover the corn or till it out. Because the planting tractor was equipped with automatic guidance, rows were planted such that the tractor pulling the manure tank didn’t need to respond to row variation and the manure spreader was held straight. The operator reported slightly adjusting the line of the sidedress tractor to center the manure injectors between the rows. The small corn plants were not disturbed by the operation.
The Weburgs are also cooperating on a field trial facilitated by the Michigan State University Extension Nitrogen in the Environment work group. This trial is currently designed to compare nitrogen (N) provided by sidedress manure to 28 percent liquid N applied with herbicides after the crop was planted and a combination of a reduced rate of liquid N plus sidedress manure. Using previous manure analysis, the manure application rate was adjusted to provide the crop with the equivalent amount of N as the normal farm application rate using the 28 percent liquid N. The trial was originally designed to include manure applied prior to planting, but weather prevented including that component in the plots. Evaluation factors include grain yield, nitrogen use efficiency and the impact of compaction caused by the manure spreader when sidedressing.