Long-term effects of slurry and fertilizer applications on soil extractable potassium and the soil potassium balance for a temperate grassland

Abstract

The potassium (K) balance is a key indicator of the suitability and sustainability of grassland nutrient management practices. K inputs can impact soil fertility, biomass yield and herbage quality. This study evaluated data from a long-term grassland experiment established in 1970 in Northern Ireland with eight treatments: control, mineral fertilizer (NPK), cow and pig slurry at three application rates (50, 100 and 200 m3/ha). The objectives were to investigate the nutrient treatment effects on: (i) soil extractable K (SEK) (using a ammonium acetate solution), (ii) herbage K concentration and K offtake and (iii) the long-term K balance. Cow slurry provided significantly greater K inputs than..