ارزیابی عملکرد علوفه و برخی شاخص‌های سودمندی در کشت مخلوط ذرت با چند لگوم در کشت دوگانه

In order to study the effects of intercropping maize with legume on forage quantity, field experiments were carried out at the Agricultural Research Station, Faculty of Agriculture, University of Tabriz, Iran, in 2006 and 2007 growing seasons. Two maize (Zea mays L.) hybrids (SC704, SC301), vetch (Vicia villosa), bitter vetch (Vicia ervilia), berseem clover (Trifolium alexandrinum L.) and common bean (Phaseolus vulgaris) sole crops as well as intercrops of maize hybrids with each of the legumes were used. The experiment was carried out as randomized complete block design with three replications. Results of analysis of variance showed that dry matter (DM) yield of corn in intercropping with vetch and bitter vetch decreased. The corn dry matter yield loss in intercrop treatments in comparison with the sole crop of maize was 15.80 percentages. Also legumes dry matter yield decreased as compared to the legumes monoculture. In general total forage yield of intercrops of corn hybrids with legumes was increased. On the average of two years, the largest DM yield was obtained from maize hybrids -vetch mixture, which indicates the larger effect of vetch in increasing forage yield. On the other hand the lowest dry matter yields were achieved from maize monocultures and maize hybrids -bitter vetch mixture. In all intercropping treatments, land equivalent ratios (LER) were well above one, indicating usefulness of intercropping systems. The highest LER was obtained from maize hybrid SC301– vetch mixture (1.45) and maize hybrid SC704- vetch (1.36). Also maximum of RVT (1.098) was obtained from maize hybrid 301 – vetch mixture