Soil contamination and sample washing effects on major nutrient and soluble sugar concentration of pasture

摘要

Abstract Pasture harvested and dried to provide estimates of either standing dry matter (DM) or growth rate usually contains some soil contamination. Pasture samples are therefore usually washed in order to provide a reliable estimate of total DM. Although the effect of washing on soluble plant components has been studied for several species, there have been few measurements on pasture. Mixed-pasture samples were subjected to one of three levels of contamination by soil and each divided into three subsamples for random allocation to one of three washing treatments. Each pasture sample was subsequently dissected into ryegrass (Lolium perenne) and white clover (Trifolium repens) components before N, P, S, K, Na, Ca, and Mg analysis. Uncontaminated samples only were analysed for soluble sugar content. The percentage contamination of plant material by soil was determined by reference to the titanium (Ti) content of the soil used to contaminate the samples. Unwashed samples directly from the field contained mi...