Competition Effects and Productivity in Oat–Forage Legume Relay Intercropping Systems under Organic Farming Conditions

Cereal-legume intercropping is important in many low-input agricultural systems. Interactions between combinations of different plant species vary widely. Field experiments were conducted to determine yield formation regularities and competition effects oat (Avena sativa L.)–black medick (Medicago lupulina L.), oat–white clover (Trifolium repens oat–Egyptian (T. alexandrinum L.) under organic farming conditions. Oats forage legumes grown mono- intercrops. Aboveground dry matter (DM) measured at flowering, development fruit ripened grain, productivity indicators, grain nutrient content established. The results showed that oats dominated the Oat competitive performance (CPo), which characterized by aboveground mass reduction compared monocrops, 91.4–98.9. As ripened, its competitiveness tendency declined. In oat–forage legume systems, weeds was significantly lower monocrops. competed for P, but N K accumulation biomass not affected. We concluded that, relay intercrop, favourable conditions, easily adapted growth rhythm intensity does adverse effect on their yield.