Mulberry based agroforestry system and canopy management practices to combat soil erosion and enhancing carbon sequestration in degraded lands of Himalayan foothills

Abstract

One of the main issues influencing the quality of the soil and agricultural productivity is land degradation. In degraded lands, crop cultivation is not sustainable without adopting resource conservation practices. Agroforestry systems that incorporate canopy management practices have the potential to significantly contribute to the restoration of degraded land by preserving natural resources. We hypothesized that restoring degraded land through a combination of tree planting, shade-loving crop cultivation, canopy management, and land management practice could result in significant improvements in soil fertility, productivity, and carbon sequestration. To test this hypothesis, an experiment was conducted involving a combination of Mulberry (Morus alba L.) and Turmeric (Curcuma longa) in conjunction with canopy management practices including coppicing pollarding and lopping. This experiment, designed as a randomized block design (RBD) with eight treatments, evaluated the impacts on soil erosion, soil health, and carbon sequestration over four years. The results revealed that mulberry under coppicing combined with turmeric treatment reduced the runoff by 45.3% and 28.7% compared to cultivated fallow and sole turmeric, respectively. Sole mulberry under coppicing treatment showed even greater efficacy, reducing soil loss by 73.3% and 57.8% over cultivated fallow and sole turmeric, respectively. Additionally, the mulberry under coppicing combined with turmeric treatment decreased the losses of N, P, and K by 31.8%, 63%, and 22.5%, respectively, compared to sole turmeric. Moreover, the mulberry under pollarding combined with turmeric enhanced SOC stock and SOC sequestration rates by 23.3% and 107.4%, respectively, over fallow and sole turmeric. This treatment also increased soil moisture and turmeric yield by 25% and 17.6%, respectively, over sole turmeric. Furthermore, sole mulberry under lopping treatment produced the highest above-ground biomass (AGB), carbon stock (CS), and carbon sequestration (CSe), followed by lopping combined with turmeric and pollarding combined with turmeric. Hence, the adoption of a mulberry-based agroforestry system with canopy management practices system could be a sustainable technique for restoring the degraded land. Therefore, this system could be recommended for improving soil fertility, reducing soil degradation, and improving productivity, particularly in the Western Himalayan region of India or similar agro-climatic regions worldwide.