Faidherbia albida -based agroforestry systems are increasingly playing an important role in sustaining agricultural productivity by mitigating climate variability, land degradation, and increasing food demand in the global south. However, tree canopy and silvicultural management practices influence crop yield and soil properties under the tree canopy. This study examined how Faidherbia albida tree sizes and pollarding frequencies impact wheat yield, yield components, soil characteristics, and economic return in the drylands of Tigray, north Ethiopia. The experiment involving two tree sizes (medium and large) and five pollarding frequencies (none; 1-5, 6-10, 11-15, and >15 times) was conducted from 2018 to 2020. Crop yield and soil properties were measured across three canopy distances (full canopy, edge canopy, and open canopy). Forty trees were sampled, each having nine plots, totaling 360 plots in a nested plot design. Data were analyzed using a linear mixed effects model with tree sizes, pollarding frequencies, and canopy distances as fixed effects, and tree and cropping season as random effects. Wheat plant height, panicle length, grain yield, straw yield, and key soil properties were significantly influenced by canopy distances and pollarding frequencies. Mean grain yields were the highest under full canopy (2638.8 kg ha -1 ) and canopy edge (1852.6 kg ha -1 ), with increases of 60% and 43%, respectively, over open canopy plots (1060.9 kg ha -1 ). Yield improvements near canopies were linked to higher soil organic matter input and nutrient availability compared to open canopy plots. Total nitrogen, available phosphorus, organic carbon, electrical conductivity, cation exchange capacity, and pH were all significantly higher (p < 0.05) under full canopy. Faidherbia albida -based agroforestry systems produced the highest return on investment (4.91) and benefit-cost ratio (1.75), compared to the open canopy wheat cultivation (1.18 and 0.68, respectively). This demonstrates its potential to enhance crop yield, while maintaining soil health and profitability when managed effectively. These findings underscore the importance of integrating Faidherbia albida -based agroforestry systems to enhance crop productivity, soil fertility, and farm profitability in dryland agroecosystems.
Darcha et al. (Mon,) studied this question.