Nutrient cycling in grassland dominated by Deschampsia flexuosa (L.) trin. and grazed by nursing cows

Abstract

A marginal agricultural area (soil pH = 4.0, sandy moraine) in Mols Bjerge, Jutland, Denmark, was grazed by a herd of nursing cows for five years. The amount of exchangeable Ca, Mg, K, Mn, Fe and P together with the pH, bulk density and organic material in the upper 10 centimetres of the soil as well as the amounts of the above elements in the above ground biomass were measured over the period.

Grazing did not cause any significant decline in the amounts of available nutrients in the soil even though no fertilizer was added, but the exchangeable amounts of Ca, Mg and to some extent Mn and P were increased as a result of grazing. No changes were detected in the pH of the soil, but the bulk density and the content of organic material in the upper soil layer were increased. Apart from P, the deposition of nutrients from precipitation was greater than the amounts removed from the area with the carcasses.