Italian Women on Philosophy of Nature

Combining corn N recommendation tools for an improved economical optimal nitrogen rate estimation

“…The tools' implantation cost varied based on the N fertilizer application timing and the labor and costs for obtaining the information required to produce an N recommendation (e.g., labor for collecting soil samples, cost of soil analyses, and equipment acquisition). These costs were based on the Iowa Farm Custom Rate Survey (Plastina et al, 2021) and the cost of soil analysis-calculated as the average of six Midwest soil testing laboratories (University of Minnesota, Midwest Laboratories, North Dakota State University, University of Missouri, University of Wisconsin-Madison, and Ward Laboratory). To determine if combining tools minimized forgone profits (i.e., a cost-effective approach), an analysis of variance (ANOVA) model was used to model forgone profits as a function of each tool and a combination of tools (across both single and split N application).…”

“…a The implementation cost was calculated as the sum of the cost for the N application and using the tool(s). The costs for the single ($13.70 ha −1 ) and split ($13.70 ha −1 + 29.15 ha −1 ) applications were based on the Iowa Farm Custom Rate Survey using the average cost of applying dry bulk fertilizer (at-planting) and sidedressing liquid fertilizer (split) (Plastina et al, 2021 Plastina et al, 2021) and the cost of analyzing one depth of soil (0-30 cm) for soil nitrate ($5.30/sample; based on the average costs reported from six Midwest soil testing laboratories) for an 8-ha area.…”

“…e The canopy reflectance sensing tool cost ($1.46 ha −1 ) was estimated as an additional cost to the application cost ($29.15 ha −1 ) using the reported average sidedress liquid fertilizer application rate from the Iowa Farm Rate Survey (Plastina et al, 2021). It was assumed that 50% of the sidedress application cost comes from machinery upkeep and acquisition, and 50% from labor and fuel (R. Massey, personal communication, 2017).…”