4R Farming

Corn Silage and Dairy Wisconsin

This 3,500-acre dairy farm in Wisconsin has a confined animal feeding operation permit. The farm rotates corn silage, corn grain, and alfalfa to produce dairy cow feed. Starting in 2017, liquid dairy manure was custom applied using a tool bar injector and dragline at a cost of $0.01 per gallon, including pit and manure handling, transport, and application. Any solid manure produced is spread with the farm’s equipment. Additionally, the farm recently purchased a high clearance applicator for in-season application of all fertilizer nutrients by the farm.


On average, the cost for corn silage increased per acre when more advanced 4R practices were implemented; however, the average cost by year for corn silage is influenced by crediting nitrogen from an alfalfa crop. For example, in the first-year corn silage rotation, immediately following alfalfa in the rotation, nitrogen rates are reduced. But in second- or third-year corn silage, the nitrogen rates are increased. Proper crediting like this for all nutrients in the rotation is critical to advancing management at a system level. Additionally, the cost of the custom application of the liquid manure with injection below the surface increased the cost of 4R practices after 2017, but the labor on the farm associated with pit and manure handling are not included in the 2016 costs. A major advantage of subsurface application of liquid dairy manure is the large decrease in the risk of phosphors loss to surface waters.

Basic to Advanced Practices Implemented

The first change to intermediate 4R practices was in 2017 with the change to custom application of dairy manure that included injection below the surface. This practice reduces the potential loss of phosphorus by surface runoff and decrease the volatilization on nitrogen as ammonia from the application of manure.

In 2018, the farm purchased their own high clearance application equipment. This changed nitrogen management to two in-season applications, the first sidedress of urea with an inhibitor product and the second as a liquid using y-drops and 28 percent urea ammonia nitrate.

The farm is crediting nitrogen from manure, crop, and fertilizer applications to fine tune applications throughout the year.

Cost and Environmental Data

Cost of 4R Practice Implementation for a Multi-Crop Rotation