Intercropping wheat ( Triticum aestivum ) with faba bean ( Vicia faba ) combined with vermicompost and NPS fertilizer application increases crop yields and agronomic efficiency in the humid mid-highlands of Ethiopia

A field study was conducted in Dire and Legedadi watersheds in the humid mid-highlands of Ethiopia to determine the effect of intercropping and application of vermicompost (VC) on crop yield. Eight treatments (two treatments included 100% recommended NPS and urea fertilizer treatment versus 100% recommended VC application. The four other treatments are combinations of 50% of recommended NPS and urea and the 50% of VC rate of applications) were studied on farmers' fields using a randomized complete block design (RCBD) with three replications. The assessment of these treatments relied on a range of intercropping and agronomic performance metrics, including the land equivalent ratio (LER), crowding coefficient (K), marginal rate of return (MRR). Results revealed that the highest total wheat yield of 4000 kg ha−1 in Dire and 4151.7 in Legedadi site, achieved from the application of 100% recommended NPS + urea fertilizers. Wheat–faba bean intercropped with 50% NPS + Urea and 50% VC added treatment resulted in higher agronomic and recovery efficiency (RE) of N (41.0% and 41.9%) and (124.8% and 126.7%), K (2.91 and 2.38), LER (1.89 and 1.49), system productivity index (5672.02 and 4423.80) and net benefits (US$ 5598.1 ha−1, 5690.8 ha−1) values in Dire and Legedadi sites, respectively. Wheat–faba bean intercropped with half dose NPS + urea and VC added treatment was cost-effective and had the biggest yield advantage in both research locations.