Bio-Organic Amendments Enhanced Faba Bean (Vicia faba L.) Productivity and Nutrient Uptake in Acidic Soils

Abstract

Faba bean (Vicia faba L.) production and productivity in the highlands of Ethiopia are very low due to acidic soil conditions. Enhancing soil fertility and nutrient availability through proper agricultural practices is essential for increasing productivity. Hence, this study was conducted under controlled conditions in a lath house to examine the effects of coffee husk biochar and Rhizobium inoculation on the growth, nodulation, and nutrient uptake of various faba bean varieties. Four varieties (Local, Dosho, Gebelcho, and Numan), four inoculation treatments (uninoculated, inoculated with strains FB-WAR-15, TAL-1035, and EAL-110), and three rates of biochar (0, 5, and 10 t ha⁻¹) were tested on acidic soils collected from the Goriche and Hagere Selam districts. The treatments were arranged in a factorial completely randomized design with three replicates. The results revealed that the varieties, inoculation, and biochar had a significant (p < 0.05) effect on most parameters. Furthermore, the three-way interaction among these treatments markedly influenced nodule dry weight. Notably, the Gebelch variety combined with strain EAL-110 and 10 t ha^-1 of biochar led to a 22.3% increase in nodule dry weight compared to the Local variety that did not receive inoculation or biochar. The use of variety Dosha, strain EAL-110, along with a biochar application rate of 10 t ha^-1, hugely improved the growth, nodulation, and nutrient uptake of faba beans in acidic soil. Therefore, it is critical to evaluate these agronomic practices in real field conditions in Ethiopia to enhance the productivity of faba beans in these areas.