Above- and below-ground net primary production of four barley (Hordeum vulgare L.) cultivars in western Canada

Abstract

Information on above- and below-ground primary production for a wide range of agro-ecosystems is needed. The objective of this study was to quantify the shoot and root mass, shoot mass/root mass ratios, and root lengths of four barley (Hordeum vulgare L.) cultivars (Abee, Bonanza, Harrington and Samson) grown in a Black Chernozem in north-central Alberta. The cultivars were grown using a randomized complete block design with three replicates and were sampled at the tillering, stem-extension, heading, and ripening stages. Root mass and root lengths from soil cores were measured. The results showed that (1) shoot mass and root mass of Harrington and Bonanza were not different from those of Abee and Samson, but those of Abee were significantly greater than those of Samson, indicating that the below-ground input of organic matter could be a function of specific cultivar; (2) root mass increased rapidly until the heading stage, and shoot mass increased at a higher rate than roots between the heading and ripening stages, producing a widening of shoot/root ratios with time; and (3) decomposition of very small roots may have contributed to a more rapid decrease in root length than in root mass after the heading stage.Key words: Barley (Hordeum vulgare L.) cultivars, Typic Cryoboroll, root mass, root lengths, shoot/root ratio, soil organic matter