Oat genotypic requirement for intercropping with vetch under Mediterranean conditions

Abstract

AbstractOat (Avena spp. L.) intercropped with common vetch (Vicia sativa L.) has shown high forage yield and crude protein content (CP) in rainfed Mediterranean environments of Greece. The objective was to study the oat genotypic interactions for yield, quality and agronomic traits of four oat accessions (cv. Flega and lines B2, B3 and B4) grown as intercrops with a common vetch cultivar (Pegasus) and as monocrops without or with nitrogen (N) supplementation (100 kg N/ha). In all mixtures, the land equivalent ratio exceeded the unit indicating that there was a yield advantage. Intercrops produced, on average, 5.0% less dry matter (DM) and 38.9% more crude protein yield (CPY) compared to monocropped oats with N fertilization and 3.4% more DM and 75.5% more CPY compared to monocropped oats without N fertilization. The DM, CP and quality differences between the intercropped and monocropped oats were attributed to oats by vetch cultivar interactions. The oat B2 intercropped was the shortest, the latest flowering and the less vigorous early in the season, a trait that allowed common vetch to dominate in the intercrop (vetch participation 770 g/kg). The high vetch fragment in the intercrop contributed to high CP, CPY, acid detergent lignin, total digestible nutrients, relative feeding value, relative forage quality, net energy for lactation and to low neutral detergent fibre, acid detergent fibre and hemicellulose. The replacement value index indicated that the intercrop was 21% more economically viable in comparison to the fertilized monocrop.