Заснивање и производно-квалитетне особине еспарзете (Onobrychis viciifolia Scop.) у условима здружене сетве / Establishment and productive and quality characteristics of sainfoin (Onobrychis viciifolia Scop.) in intercropping

The establishment of perennial legumes in the spring is often followed by intensive weeds infestation and reduced yield. This is also the case when growing sainfoin (Onobrychis viciifolia Scop.) which is considered a potential substitute for alfalfa (Medicago sativa L.). Intercropping or growing two or more species in the same field during a certain period can be used for establishing this perennial legume. A field pea (Pisum sativum L.) has a potential to be used as companion crop due to a short growing season and reduced competing impact. The aim of this research was to determine the suitability of field pea as a companion crop for sainfoin establishment and to determine the appropriate cultivar and pea density that provides the best yield and impact on undersown crop. A two-factorial trial was set up in the experimental field of the Institute of Field and Vegetable Crops, Novi Sad, during 2010-2014. The experiment included two morphologically different pea cultivars (Jezero-afila leaf type and Javorreduced leaflet) and three pea densities. The sainfoin pure stand and a mixture with oat were used as control treatments. The trial included four sowing years and the analysis was performed in the establishment years and in the first cut in the full harvest year. The weather conditions significantly influenced obtained yield. Field pea as a companion crop had a better impact on sainfoin development in the establishment year, while in subsequent year companion crops had minimal impact on sainfoin yield. Concerning pea cultivars, a higher dry matter yield was obtained with cultivar Jezero. It was concluded, there were no significant differences between obtained yield with 60 and 90 pea plants per m2 which have importance from the economic aspect. The results showed that the highest annual yield had a mixture of sainfoin and oat, due to a significant share of the first yield. The weed proportion was lower in intercropping compared to the sainfoin pure stand. The cultivar Jezero and a density of 60 pea plants per m2 were more competitive to weeds. Morphologically different pea cultivars did not significantly affect leaf area index of sainfoin. However, its value decreased with the increase of pea density in the stand. Intercropping and weather conditions had a significant impact on pigment content in sainfoin leaves. The examined soil biological activity was higher in intercropping treatments. The number of nitrogen fixation bacteria increased with a decreased number of pea plants, while the number of total bacteria and fungi increased with increasing pea density. The intercropping of the legumes influenced the higher content of mineral nitrogen in the soil, but also the more intensify use of soil moisture. The positive effect of intercropping of two legumes was demonstrated by the obtained higher content of crude protein with a lower proportion of digestibility parameters - NDF and ADF compared to both control treatments. The obtained results show that sainfoin can be successfully established with field pea in intercropping, which ensures the stable and high-quality yield of the first cut, without negative effect on sainfoin re-growth and yield in subsequent cuts. Thus, intercropping can be considered as a reliable and ecological practice for sainfoin establishment, which provides the possibility for increasing production of this species.