Trends in the variability of potato tuber yield under selected land and soil characteristics

The objective of this study was to evaluate variations in potato tuber yield with the selected land and soil characteristics including (i) topography (elevation and slope); (ii) geometry (horizontal coplanar geometry (HCP) and perpendicular coplanar geometry (PRP)); (iii) hydrology (volumetric moisture content; theta v), and (iv) chemistry (phosphate, potash, organic carbon; organic carbon and pH). Analyses of the data collected across four potato fields, two each in Prince Edward Island and New Brunswick (NB), showed that the tuber yield negatively correlated with the field slope and positively correlated with most of the soil characteristics studied. Field elevation affected yield only under certain conditions such as higher range of elevation (>= 7 m) (Field 2 in NB). Among soil characteristics, only HCP and PRP correlated with field elevation. The slope and elevation explained 22% to 36% variability of yield. Investigations of yield and topography by zonal analysis showed that yield was lower in zones of higher slope or elevation and lower theta v, as the mean theta v decreased in zones with a higher slope.