Effect of Tree Canopy Cover on Soil Moisture Dynamics in Different Agroforestry Systems under Semi-arid Condition

Abstract

The experiment was conducted in an Agroforestry plot under the maintenance of AICRP on Agroforestry located in GKVK, Bengaluru, Karnataka, India. This study measures the soil moisture dynamics in different agroforestry systems under semiarid conditions, focusing on the influence of tree canopy cover on surface soil moisture. Seven agroforestry systems were analyzed, featuring tree species such as Tectona grandis, Melia dubia, Pongamia pinnata, Swietenia mahagoni, Anacardium occidentale, Mangifera indica and Syzygium cumini paired with intercrops. Soil moisture was measured monthly using the gravimetric method, with samples collected inside and outside the tree canopy. The results indicate that soil moisture levels are generally higher inside the canopy due to reduced evaporation, improved microclimate, and enhanced soil structure from leaf litter accumulation. Species with dense canopies, like S. cumini and M. indica, demonstrated higher soil moisture retention, while deep-rooted species like S. mahagoni and A. occidentale maintained moisture during dry periods by accessing deeper soil layers. It highlights the significant role of canopy cover in soil moisture conservation within agroforestry systems. It underscores the importance of selecting appropriate tree species and managing canopy density to optimize soil moisture levels, particularly in semiarid regions.