Dual intercropping of common vetch and wheat or oats, effects on yields and interspecific competition
¹Institute of Agricultural and Environmental Sciences, Estonian University of Life
Sciences, Kreutzwaldi St. 1, EE51014 Tartu, Estonia; e-mail: ruth.lauk@emu.ee. 2
²Institute of Agricultural and Environmental Sciences, Estonian University of Life
Sciences, Kreutzwaldi St. 1, EE51014 Tartu, Estonia; e-mail: ervi.lauk@emu.ee.
Abstract:
A three-year field experiment was conducted in Estonia to determine a) which combinations of vetch (Vicia sativa L.) intercropped with either wheat (Triticum aestivum L.) or oats (Avena sativa L.) were most suitable for mixed cultivation and b) the effect of vetch on the yield potential of cereals in different weather conditions as compared to the respective sole crops of cereals. The vetch-wheat intercrops did not produce any greater yield than wheat sole crops but the yield of vetch-oats intercrops was higher as compared to oat sole crops and vetchwheat intercrops. The grain yield of vetch when intercropped was strongly correlated with seed density. In the years of normal precipitation and at higher vetch seed densities (over 60 seeds m- 2 ) the grain yield of intercrops was lower than that of the respective cereal sole crops. The yield of the cereal component was higher in sole crops and when increasing vetch seed density cereal grain yield decreased. The inter-specific competitiveness of wheat towards vetch increased when doubling the wheat seed density. Likewise the relatively dry growth period favored the growth of wheat as compared to vetch. Vetch-cereal intercrops produced considerably higher protein yields on the soil without any N-fertiliser than cereal sole crops and are regarded as highly suitable for organic farming.
Key words:
cereals, intercrops, seed density, seed weight, Vicia sativa