Effect of cobalt application on the cobalt status of pastures 1. Pastures with history of regular cobalt application

Abstract

Pasture and soil cobalt (Co) concentrations weremonitored for 8-9 yearson six properties that had been developed in pasture for periods ranging from 15 to 24 years on yellowbrown pumice soils in the Rotorua-Taupo area, NewZealand Allsiteshadbeentopdressedannually withCo beforethe survey beganin 1979, but from then the amount and frequency of Co applied was reducedconsiderably.Despitethisreduction, pasture Co concentration remained adequate for grazing livestock and soil Co extracted with EDTA was maintained at satisfactory values throughout the survey period. Serum vitamin B 12 inlambs grazed on the sampled pastures confirmed that they all had adequate Cointake. Ina fieldtrialnearTaupo, small plotsofwhiteclover, perennialryegrass, andlucerne wereestablished on a site previously in permanent pasturewhich had received 16applications of Co. Ryegrass had thehighest Co concentration, lucerne the lowest, and white clover intermediate but the outstandingresultwasthatCoconcentrationremainedhighinryegrass andwhitecloverandtherewasno decrease for 12yearsevenwherenofurther Co was applied. Conclusions are that pastures on yellowbrown pumice soils, where soil Co reserves have been increased by repeated annualCo application, A89085Received 30 November 1989; accepted 23 March 1990 canbemaintained as Co-sufficient for livestock by much lowerrates than the traditional 350 g/ha per yearofcobaltsulphate. Thisworkindicates that175 g/ha applied every third year or 100 g/ha annually are satisfactory and that the accumulated soil Co reserves can last for 10 years or more.

Pedogenic factors and measurements of the plant uptake of cobalt

“…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). Despite the fact that higher plants may control, to a large degree, Co uptake, soil parameters are also likely to be involved in the seven orders of magnitude difference in plant Co concentrations.…”

“…Despite this knowledge, Co deficiency was still a common nutritional disorder of ruminants in the UK in the 1980s and, at that time, constituted 15-20% of all recorded trace element deficiencies in farm animals (Klessa et al 1989). In severe cases, Co deficiency in ruminants can be fatal (Klessa et al 1989) and, in the scientific literature, has been reported to occur in Scotland (Klessa et al 1989), Australia (Nicolls and Honeysett 1964) and New Zealand (Sherrell et al 1990). Typically, pasture top dressing with Co salts or the oral administration of Co have been used to alleviate Co deficiency in ruminants (Smith 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.…”

A comparison of soil and environmental quality under organic and conventional farming systems in New Zealand

“…A 10-year study by Sherrell et al (1990) found that lucerne grown on pumice soil had a long-term average Co content only half that of white clover. However, there is evidence that other deep-rooting plants have higher levels of trace elements than ryegrass and white clover {Trifolium repens).…”

Slow‐release cobalt fertilisers: What release rate is required?

“…After several year's application, pasture Co concentrations can be maintained at adequate levels for grazing animals (Sherrell 1990a). However, initial applications of CoSO4 to a deficient site result in immediate elevation of herbage Co concentration followed by a rapid decline within a few months (Sherrell 1990b).…”