US EPA

4843604 

Technical Report 

Seasonal changes in the concentrations of copper, molybdenum and sulfur in pasture plants 

Reddy, GD; Alston, AM; Tiller, KG 

1981 

21 

112 

498-505 

HEEP COPYRIGHT: BIOL ABS. Seasonal changes in the concentrations of Cu, Mo and S in subterranean clover (Trifolium subterraneum), silver grass (Vulpia sp.), Wimmera ryegrass (Lolium rigidum) and capeweed (Arctotheca calendula) growing on lateritic podzolic soils were measured in glasshouse and field studies. The effects of varying soil temperature and water content on the concentrations of Cu, Mo and S in subterranean clover on a lateritic podzolic soil and a calcareous sand were also investigated. similar seasonal patterns in plant composition were observed in the glasshouse and the field. The concentration of Mo remained constant throughout the season but that of Cu and S declined from autumn to spring; the decline was more rapid in the grasses than in subterranean clover and capeweed. Subterranean clover had higher concentrations of Cu and S but lower Mo than silver grass or Wimmera ryegrass. Capeweed contained more Cu and Mo but less S than subterranean clover. The concentrations of Mo and S were similar in capeweed and the grasses. Increasing soil temperature from 12 to 22? C increased the dry matter production and the concentrations of Cu and Mo (but not S) in subterranean clover on both soils. Increasing soil water content slightly increased dry matter production and the concentration of Mo but had no effect on the concentration of Cu and S in subterranean clover. Results were discussed in relation to the health of grazing animals.