Potato Yield Variability across the Landscape

Abstract

To reduce yield variability and optimize management that meets environmental objectives, it is essential to understand the relationship of the tri‐factor impact of plant health, soil physical, and chemical properties on potato (Solanum tuberosum L.) productivity. Potato producers emphasize management of soil chemical properties to achieve less variable and high yield, yet tuber yield heterogeneity persists. There has been limited integrated research on the tri‐factor impact on potato tuber yield. The objective of this study was to investigate how specific soil and plant variables (stable aggregates, nutrients, and plant spectral reflectance among others) affect yield across a landscape. Soil (0–100 mm depth) and plant properties were monitored in two Michigan commercial fields using georeferenced sampling points in Field A1 (108 grid points) in 2003, and Field A2 (100 grid points) in 2004 (0.05 ha grid−1). Near‐earth plant spectral remote sensing was conducted using a customized digital camera set‐up, and potato tuber yield was obtained through a GPS‐linked commercial harvester. Stepwise multiple linear regression showed a combination of soil physical and chemical properties, as well as plant spectral reflectance, accounted for more than 60% of the yield variability in both fields. Soil stable aggregates in particular, were sensitive predictors of field‐level variability for tuber yield in a commercial environment. Improvements in soil structure may take time and concerted management attention, but should not be overlooked as a supplement to monitoring and ameliorating soil chemical properties. Plant spectral reflectance analysis also provided insights into the role of plant health on potato yield.