Intercropping annual medic (Medicago scutellata L.) with barley (Hordeum vulgare L.) may improve total forage and crude protein yield in semi-arid environment

Abstract

Abstract In arid and semi-arid conditions, production of high-yielding quality forage is still a challenge. Intercropping of cereals with annual forage legumes may improve forage yield and increase on-farm protein production. A two-year field experiment was conducted during the growing seasons of 2009 and 2010 at the experimental farm of University of Tehran, Iran to determine whether intercropping of barley (Hordeum vulgare L.) and annual medic (Medicago scutellata L.) could produce sufficient amount of forage with higher protein content. A four-replicated randomized complete block design with eight cropping patterns [1B:1M (one row of barley: one row of annual medic), 2B:2M, 4B:4M, 6B:6M, 6B:2M, 4B:2M, 2B:4M, and 2B:6M] along with pure stands of barley and annual medic was implemented. Land equivalent ratio (LER) was the highest (1.19) when barley was intercropped with annual medic in 1B:1M arrangement indicating that 19% more land area would be required by a sole cropping system to produce similar yield in intercropping system. Calculated partial LER, aggresivity (A) and competitive ratio (CR) indicated that barley was the dominant species in most of the barley-annual medic cropping patterns. Based on results from LER, system productivity index (SPI) and monetary advantage index (MAI), it was concluded that 1B:1M cropping pattern was superior to either barley or annual medic monocropping. The results of this study revealed that the total protein yield of barley and annual medic forage in the selected intercropping patterns specifically 1B:1M could be enhanced while the total harvested dry matter remained unchanged