Evaluation of forage production in maize-soybean and pearl millet-soybean intercroppings

In order to find an alternative to summer monoculture forage maize (Zea mays), intercropping systems of pearl millet (Pennisetum glaucum): soybean (Glycine max) (P:G) and maize: soybean (Z:G) and intercropping patterns, substitutive (XXG, XXGG and XGG) and additive (X%100G%25, X%100G%50 and X%83G%67) were evaluated as factorial in RCBD at research field of Agriculture and Natural Resources College of Tehran University in Karaj during 2013 and 2014 (G and X respectively: soybean and cereal including maize, Z, or pearl millet, P). Results showed that yields of cereal forage and mixed forage in Z:G were significantly higher than P:G. Cereals were dominant component in intercrop and the dominance of maize was higher than millet. Intercropping system or pattern did not affect total land equivalent ratio (LER).The highest LER was recorded 1.15 by P%100G%25 in 2013 and 1.07 by Z%83G%67 in 2014 without 2nd cut of pearl millet, and 1.10 by PGG in 2014 with sum of 2 cuts of pearl millet. In X%83G%67 despite the 83% cereal density of monoculture, partial LER was 0.95 for maize but 0.70 for pearl millet. It is concluded that additive patterns with a small ratios of soybean or with some decrease in ratios of cereal component, tend to have potential to achieve higher LERs. Thus intercropping, specially additive pattern can provide suitable alternatives to monoculture in production of forage with customized quality and higher diversity in ecosystem, in consistent with sustainability.