The advantage of intercropping is beneficial biological interactions between crops and their different use of growth resources. Our experiment aimed at investigating the effects of pea intercropping with cereals on the improvement of cereal supply with nitrogen and protein content in grain on a loamy soil in organic farming conditions. It was carried out during 2007-2009 at the Lithuanian Institute of Agriculture in Dotnuva. Pea ( Pisum sativum L.) and spring wheat ( Triticum aestivum L.), spring barley ( Hordeum vulgare L.), oats ( Arena sativa L.), and triticale (* Triticosecale Wittm.) were sown as intercrops 50:50 or as a sole crop. The results obtained during the experimental years showed that the productivity and quality of spring cereal sole crops or intercrops depended on the species of cereals and varied between different year's cultivation conditions. Grain productivity in some cases was estimated to be higher in the intercrops, however it was not stable in three experimental years. The protein content and yield in the grain of cereals grown in intercrops was positively affected by pea intercrops.
