Some effects of soil waterlogging on the cobalt and copper status of pasture plants grown in pots

Abstract

Glass-house experiments were made to measure the effect of soil waterlogging on the cobalt and copper status of subterranean clover and ryegrass. The cobalt content of the plants was much increased by soil waterlogging. Very high plant cobalt contents were obtained when soil was waterlogged for 2 months at room temperature, or for shorter periods at higher temperatures, before planting; or when it was waterlogged while the plants were growing rapidly. The effect of waterlogging on the cobalt content persisted when soils were stored air-dry. Soil waterlogging raised the copper content of the plants much less than it did the cobalt. The copper content was significantly increased only when plants had been severely stunted by waterlogging. Waterlogging raised the plant cobalt content more than it reduced the yield. Thus the total uptake of cobalt, but not of copper, from the soil was increased by waterlogging.

Pedogenic factors and measurements of the plant uptake of cobalt

“…Given the poor relationships often observed between plant Co uptake and soil pH or total soil Co concentrations, a number of other soil properties have also been investigated (Adams and Honeysett 1964;Adams et al 1969;Berrow et al 1983;Hill et al 1953;Iu et al 1982;Kubota et al 1963;Li et al 2004;McLaren et al 1987;Wright and Lawton 1954). For example, a positive and significant correlation between soil organic carbon and Co uptake by ryegrass has been reported by McLaren et al (1987) for a range of 20 acidic to neutral Scottish soils.…”

“…Whilst total soil Co extractions were all by acid digestion, minor variations in foliar Co extractions are acknowledged. As Co fertilisation is normally applied to pastures as a topdressing, studies reporting foliar Co concentrations after fertilisation have not been included due to the potential of foliar Co contamination (Adams and Honeysett 1964;Adams et al 1969;Li et al 2004;McLaren et al 1987;Nicolls and Honeysett 1964;Price et al 1955;Wright and Lawton 1954) a similar negative curvilinear response between soil pH and Co uptake by two Alyssum species has also been noted for a polluted soil containing 47.5 mg Co/kg (Kukier et al 2004). Due to the high concentration of other metals in this soil, however, it is unclear if this response would be due to sorption site coverage or simply pH-controlled precipitation/ dissolution reactions.…”

“…Given the general low and narrow range of Co concentrations found in most soils, the first two groups are probably indistinguishable in field conditions. In fact, plant Co concentrations are typically <10 mg/kg and, more often than not, <1 mg/kg (Adams and Honeysett 1964;Adams et al 1969;Gille and Graham 1971;Gupta 1993;Klessa et al 1989;Li et al 2004;McLaren et al 1987;McLaren and Williams 1981;Nicolls and Honeysett 1964;Paterson et al 1991;Price et al 1955;Rosbrook et al 1992;Sherrell et al 1990). For comparative purposes, the threshold deficiency concentration of Co in pastures for sheep and cattle grazing has been identified as 0.05-0.1 mg/kg (Gupta 1993;Klessa et al 1989;Sherrell 1990b;Sherrell et al 1990).…”

“…Indeed, since a requirement of Co was demonstrated for symbiotic N 2 -fixing Rhizobium species in the 1960s (Reisenauer 1960), the positive effects of Co on legume (many of which are also used for pastures) growth (including N fertilisation) have been widely studied with the majority of work being conducted in Australia, New Zealand and Scotland (Adams and Honeysett 1964;Bolland 1985;Chatel et al 1981;Nicolls and Honeysett 1964;Paterson et al 1991;Reisenauer 1960;Dilworth 1982, 1985a;Riley and Dilworth 1985b;Riley and Dilworth 1985c;Robson et al 1979;Robson and Mead 1980;Robson and Snowball 1987;Rosbrook et al 1992;Sherrell 1990a, b;Sherrell et al 1990). Although the role of Co in legume nutrition is now well known, its importance to other plant species is relatively ambiguous.…”

Lamb/hogget weight response trials to cobalt on the West Coast sand country of the North Island

“…Mitchell (1972) also found that extractable cobalt from adjoining soil profiles developed on similar parent materials was much greater for poorly drained soils than for freely drained soils. Adams & Honeysett (1964) working in Australia, found that cobalt in subterranean clover (Trifolium subterraneum) and ryegrass (Lolium species) was greatly increased by soil waterlogging.…”