Undersowing Italian ryegrass diminishes nitrogen leaching from spring barley

Authors

• R. LEMOLA
• E. TURTOLA
• C. ERIKSSON

DOI: https://doi.org/10.23986/afsci.5661

Abstract

Nitrogen (N) leaching from spring barley with and without undersown Italian ryegrass was studied in Jokioinen, south-western Finland during five years (summer 1993spring 1998) in 1.7 m deep lysimeters (Ø0.9 m) filled to 1.1 m with clay, silt, sand and peat soil. Tillage was performed in mid- October or in May, before sowing of the barley and ryegrass for the next season. In the second, third and fourth years of the experiment, total N leaching from barley without undersown ryegrass was 15, 7.9,32 and 38 kg ha-1 y-1 in clay, silt, sand and peat soil, respectively. Undersowing reduced N leaching by 52,31,68 and 27%. The reduction in N leaching from clay and sand when barley was undersown with ryegrass was nearly the same as the increased total uptake of N (barley +ryegrass).In sand soil, ryegrass was able to diminish the NO 3-N concentration of the drainage water well below the limit for acceptable drinking water. Spring tillage reduced N leaching only on peat soil (16%). Slight competition between the main and the undersown crop was indicated by lower N contents of the barley yield.;