Soil chemical properties under a mahogany-based agroforestry system: Nutrient dynamics and crop interactions

Abstract

Globally, health of soil has been threatened for the past several decades and there has been a renewed interest in protecting and enhancing this most important resource for future generations. Agroforestry systems are known to improve the soil chemical and physical properties by addition of leaf litter. Trees act as nutrient pumps i.e., absorbing the nutrients from the deeper depths and during recycling make nutrients accessible to the shallow rooted crops. The interaction for nutrients between the trees and crops depends on the intensity and severity of planting geometry and density of each component. The present investigation was carried out at farmers field in Salgoan village of Mundgod taluk in Uttara Kannada district to assess the soil chemical properties under mahogany arecanut based agroforestry system. This system comprising of Swietenia macrophylla and arecanut. Mahogany was planted in the year 2018 at a spacing of 3 m x 3 m. The horticulture component arecanut was planted in quincunx planting pattern in the year 2019. Ginger varieties were sown during 2022 as intercrop. The design followed for the present experiment was Randomized Block Design with seven treatments and four replication. The soil samples were collected at two different depths (0-15 cm, 15-30 cm) in each treatment. The results revealed that among the systems highest soil pH and soil organic carbon was recorded under agroforestry system at both the depths. As depth increases soil organic carbon was decreased under agroforestry system. The maximum content of available Nitrogen (kg ha-1), Phosphorus (kg ha-1) and Potassium (kg ha-1) was recorded under sole cropping system compared to agroforestry system.