Hordeum vulgare Lolium multiflorum Research & information: general Zea mays L. barley biodiversity border effect brachiaria cereal-legume mixture cereal-livestock production cereals common vetch competition indices conventional farming cultivar differentiations of cereal mixture grain yield growth herbivores intercropping land equivalent ratio leaf area index leaf greenness index legume maize metabolic energy yield mixed crop natural enemy neighbor effect non-legume