Yield and water use of broadleaf crops in a semiarid climate

The predominate crops grown in the northern Great Plains of the United States are cereal grains, which are well adapted to the region’s semiarid climate and short growing season. However, rotations are changing because minimum- and no-till production systems improve precipitation-use-efficiency. Therefore, producers are seeking diversity in crop choices to improve the design of their rotations. Our objective with this study was to examine water relations and agronomic performance of seven broadleaf crops that may be suitable for a semiarid climate. Dry pea (Pisum sativum L.), dry bean (Phaseolus vulgaris L.), and sunflower (Helianthus annuus L.) were the most favorable for this region considering crop yield and water-use-efficiency (WUE). Soybean (Glycine max L.), crambe (Crambe abyssinica Hochst), canola (Brassica rapa L.), and safflower (Carthamus tinctorius L.) were less successful. Water use for grain production ranged from 23 to 37 cm among crops whereas water-use-efficiency varied three-fold. Soil water extraction patterns differed between sunflower and dry pea, with sunflower extracting more water as well as accessing water deeper in the soil profile. Integrating oilseed and legume crops with cereal grains in a cycle-of-four rotation will aid producers in managing diseases and weeds, as well as improve grain yield due to the rotation effect.