Nitrogen uptake, use and utilization efficiency by oat–pea intercrops

Abstract

Cereal–legume intercropping in sustainable arable farming systems in temperate regions is of increasing interest for increasing productivity. This study assessed the influence of sowing ratio and N fertilization on nitrogen uptake, use and utilization efficiency of oat (Avena sativa L.) and pea (Pisum sativum L.) in intercrops. A two-year field study was carried out in eastern Austria with oat and pea sown in three substitutive sowing ratios and at different nitrogen levels.Oat was the dominant partner in the mixtures strongly outcompeting pea. Total grain yields were generally lower in intercrops than in pure stands. Consequently, nitrogen use and the partial factor nitrogen use efficiency for grain production were lower in intercrops. Nitrogen utilization efficiency was highest in pure oat stands and decreased with higher pea shares.Grain N concentration of oat and pea increased with N fertilization. In intercrops, grain N concentrations of oat increased with lower oat share whereas those of pea were not affected by cropping system. Due to higher grain N concentrations of oat in intercrops, intercrops could attain a higher grain N yield in unfertilized treatments. Thus, growing oat–pea intercrops can be reasonable for producing grain feed at low N input level.