Row Spacing and Direction Effects on Yield, Water Use, Tillering and Light Interception of One-Irrigation Barley

Abstract

The one-irrigation barley variety Solum is adapted to wide row spacing, and sometimes yields higher in wide compared to narrow spacing. This study was initiated to determine the effect of row spacing and direction on Solum water use and yield components. Solum barley was planted at the Marana Agricultural Center at 6, 12, 18, and 24 inch row spacings in north-south and east -west rows in late November and late -February or early March over 2 growing seasons. Row spacing and direction had little effect on yield and yield components, water use, tillering, and light interception. Nevertheless, in some instances narrow row spacing resulted in more heads that were smaller and had lighter kernels than wide row spacing. We measured greater soil water depletion for the narrow row spacings at the late planting date one year due to greater stem density. The narrow rows intercepted more light than wide rows and the wide rows intercepted more light at solar noon in east-west compared to north -south rows. We were not able to confirm the theory that soil water is conserved in wide rows for use at more critical stages later in the season.