Start Date: 2019
Principal Investigator: Jeffrey Vetsch
Co-Investigator: Dr. Daniel Kaiser
Organization: University of Minnesota
Previous research in the Midwest has shown mixed results for varying placement of P and K fertilizers (Randall and Hoeft, 1988; Mallarino et al., 1999; Borges and Mallarino, 2000; Rehm and Lamb, 2004; Wolkowski, 2007; and Boomsma et al., 2007). In a review paper, Boomsma et al. (2007) explained several factors and situations where band applications are likely to be superior to broadcast. These include: low P and K soil test levels, soils with high fixation capacity, reduced tillage systems (resulting in cooler soils with smaller root systems), low subsoil P and K levels (partly due to nutrient stratification in reduced tillage systems), cultivar differences, using strip tillage, not using P and K starter fertilizers, and when using automatic guidance for multiple field operations (including controlled wheel traffic). Band applications (deep and starter bands) have lost favor for some farmers due to increased farm size, equipment size, equipment cost, and time savings. Broadcast P and K applications are easier, faster and cheaper on a cost per acre of application. Recent challenging economic times in agriculture have farmers looking for ways to reduce input costs and increase efficiency and profitability of fertilizer inputs while maintaining or increasing yields. Banding P and K at reduced rates may be a viable option for many. Additionally, subsurface banding of P fertilizer can reduce the risk of P runoff compared to broadcast application (Lewandowski et al., 2006). These reasons warrant continued research on P and K placement methods.
To measure yield response, fertilizer use efficiency and nutrient removal in corn as affected by band and broadcast applications of P and K fertilizer
Correlate and calibrate crop yield response to STK using both dry (traditional ammonium acetate extractant) and moist (slurry) soil methods
To measure yield response and nutrient removal in soybean as affected by soil test P and K levels (only in year 1)
Soybean yields responded to changes in STK and K fertilizer treatments at both sites (Waseca and Rochester) in 2019; whereas, soybean yields only responded to changes in STP at Waseca.