Root characteristics of some temperate legume species and varieties on deep, free-draining entisols

Abstract

We report experiments comparing several legumes with the aim of distinguishing genotypic from environmental differences in those root parameters which influence water use and nutrition. Temperate crop and pasture legumes were grown on three xeric psamment soils at latitude 29�S. in Western Australia to evaluate the relative root characteristics of different species. Sites had 428, 298 and 155 mm rainfall in the (winter) growing season. Maximum root depth was significantly different (P < 0.001) between genotypes, but non-significant between sites. Genetic control for maximum root depth is thus implied. This has significance for water use and plant production of these low water-storage sandy soils. Lupinus spp. extended their roots to an average 190 cm, Pisum sativum L. to only 65 cm, Triticum aestivum L. to 113 cm. The pasture species ranged from Vicia benghalensis L. (75 cm) and Trifolium spp. (69 cm) to Medicago spp. which averaged 92 cm. Lupins and wheat had less than 50% of their total root length (cm-1) in the top 20 cm, whereas other species all had over 70% of roots in that layer. Pasture legumes with high root density in that layer tend to dry sandy topsoils frequently, reducing nutrient availability and hence vegetative growth. Root density averaged only 0.045 for lupins, compared with 1.0 cm-2 for clovers. All total root lengths were low at maturity, compared with more favorable environments. Nevertheless, they were calculated to be adequate for water and mobile nutrient extraction from these sandy soils.

Simulating lupin development, growth, and yield in a Mediterranean environment

“…The potential elongation rate for the lupin of 44 mm/day was taken as 10% higher than in the APSIM-Wheat model. This was supported by the findings by Hamblin and Hamblin (1985), Hamblin and Tennant (1987) and Anderson et al (1998b) who measured slightly deeper roots in lupin than in wheat in a range of soil types. However, and Gregory (1998) measured similar or lower values of root depth in lupin compared with wheat in a duplex soil.…”

Root systems and root:mass ratio-carbon allocation under current and projected atmospheric conditions in arable crops

“…There are few studies of roots of different species grown under comparable conditions and even fewer in which a species has been grown on the same site over several seasons. Hamblin and Hamblin (1985) compared the root growth of several species on deep Entisols at two locations in Western Australia and found that the ranking of total root length was pasture legumes (clovers and medics) > wheat > lupins and peas. Other comparisons of crop species also confirm the impression that temperate cereals have greater root lengths than temperate legumes when grown on the same site.…”

Global synthesis of drought effects on cereal, legume, tuber and root crops production: A review

“…5A). Cereals such as wheat could extend their roots to an average 113 cm and had less than 50% of their total root length in the top 20 cm, while legume (i.e., field pea) to only 65 cm with more than 70% of the root system in the top 20 cm (Hamblin and Hamblin, 1985). This rapid development of deep rooting system in cereals enabled them to absorb water from deep soil horizon and contributed to the drought avoidance strategy within the crop group (Yue et al, 2006).…”