Leaching of Phosphorus, Calcium, Magnesium and Potassium in Barley, Grass and Fallow Lysimeters

Abstract

Abstract Leaching of total and dissolved phosphorus, calcium, magnesium and potassium from fallow, unfertilized and fertilized barley and grass ley was studied in a four-year experiment carried out in lysimeters filled with clay, silt, coarse sand and Carex peat. Half of the lysimeters were irrigated with 290–480 mm of water annually. Irrigation increased the nutrient leaching. Phosphorus losses were anyway small (tot. P 0.02–0.26 kg ha−1 a−1 from the fallowed soils) owing to omission of surface runoff. Leaching of cations was more comparable with field observations. The annual average varied in the bare soils from 50 to 120 and from 30 to 70 kg ha−1 a−1 for Ca and Mg, respectively. The average leaching of K was small (4–24 kg ha−1 a−1) in other than sand soil (56–94 kg ha−1 a−1). Cropping of soil generally decreased the leaching of dissolved and total phosphorus and cations compared with the fallow treatment. Fertilization did not have any consistent effect.