Forage yield and competition indices of Berseem clover intercropped with Barley
Berseem clover (Trifolium alexandrinum L.) should be intercropped with cereals for forage quality improvement, livestock bloat avoidance, and fertilizer requirements reduction. A 2-yr field study was conducted using a cultivar of berseem clover and two barley (Hordeum vulgare L.) cultivars as sole crops compared to six berseem clover–barley intercrops planted at three seeding rates (250–338, 500–225, or 750–113 seeds m–2). The objective of the study was to compare forage and protein yield productivity for sole crops with crop mixtures. Land equivalent ratio (LER), relative crowding coefficient (RCC), aggressivity (A) which indicates the relative yield increase of legume in comparison with that of cereal in an intercropping system, and competition ratio (CR) were also assessed. Barley was cut once, while berseem clover was cut four times. Total dry matter (DM) yield produced by most intercrops was similar with that of berseem clover sole crop averaged 24.9 Mg ha–1, but greater than that of barley sole crops averaged 12.7 Mg ha–1. Berseem clover sole crop and its intercrop with barley at 750–113 seeds m–2 provided the greatest total protein yield. Total LER or RCC did not exceed unity for the intercrop, which indicated that there was no advantage of the intercrops over sole cropping systems. The results of this study indicated that intercropping of berseem clover with barley at the seeding rate of 750–113 seeds m–2 could be used as alternative practice of berseem clover sole crop for high forage and protein production.