Forage Yield and Quality of Annual Medic Intercropped with Barley.

It is generally understood that for forage production, combinations of legumes with cereals would benefit farmers in resource-limited conditions specifically in arid and semi-arid environments. Intercropping of two or more crop species not only improves yield on a given piece of land by making more efficient use of the available growth resources, but also improves the forage quality due to the high protein content of legumes. A 3-yr field study was conducted at the experimental farm of University of Tehran, Iran in 2007, 2009, and 2010 to investigate the compatibility of annual medic-barley intercrops and to determine if the forage production and quality of these crops would increase under different intercropping patterns.  Intercropping arrangement consisted of 1B:1M (one row barley: one row annual medic), 2B:2M, 4B:4M, 6B:6M, 6B:2M, 4B:2M, 2B:4M and 2B:6M along with sole culture of both crops were statistically compared based on a Randomized Complete Block Design with four replications. Forage yield and quality were determined in this experiment.  Land equivalent ratio (LER) was calculated to determine the superior cropping pattern. Generally, the higher the ratio of each crop the higher the forage production. Sole culture of each crop produced the highest forage production yield.  The highest barley forage yield (3182 kg ha^-1) was obtained in 2007 from its sole culture however; the highest forage dry matter of annual medic (1773 kg ha^-1) was observed in 2010. Among cropping patterns, 2B:2M in 2007, and 1B:1M in 2009 and 2010 were found the most beneficial treatments with the LER of 1.10, 1.19, and 1.23, respectively.   Dry matter digestivity of barley (765.5 g kg^-1) in 2010 was highest and the highest crude protein was observed in annual medic sole culture (310.3 g kg^-1).  Overall, considering both forage yield and quality, 1B:1M found to be the most suitable cropping pattern to suggest to farmers.