Nutrient fertilization, copper toxicity and growth in three grassland species in the Netherlands.
The response to Cu of Lolium perenne, Trifolium repens and Agrostis capillaris, originating from 2 areas where Cu-enriched pig slurry had been applied on a large scale and one area where it had not, was examined in relation to the nutritional level of the soil. No indication of Cu tolerance was found in plants from slurry treatments. The uptake of Cu per unit wt root by L. perenne and A. capillaris increased with the nutrient level. It was concluded that excessive application of piggery wastes to grasslands is likely to increase Cu toxicity to a problem level for plants and sheep but not for cattle.