Soil ecological index as an approach to assess soil health across diverse land use types

Land degradation is a global challenge driven by increasing demands for food, fodder, and fiber. It is often associated with rapid urbanization and poor land resource utilization, including overlooked areas such as urban marginal lands (UML). However, these lands can address degradation if monitored and restored sustainably. Therefore, the present study developed and validated a Soil Ecological Index (SEI) focusing on UML types. The SEI was developed through soil physicochemical and biological properties across bareland (Sites 2,4,5), grassland (Sites 1,3), scrubland (Site 6), and forest area (control) of UML using principal component analysis (PCA). Results depicted that the physicochemical properties for available nitrogen, total nitrogen, available phosphorus (AP), total phosphorus, and soil organic carbon (SOC) ranged from 123 to 531 kg ha^-1, 151-656 kg ha^-1, 35-48 kg ha^-1, 44-51 kg ha^-1, and 1.53-1.78 %, respectively. Moreover, biological parameters such as microbial biomass carbon (MBC) ranged from 57.47 to 117.88 μg g^-1. PCA trends suggested that MBC, AP, and SOC were the most prominent variables for SEI across all seasons. A vegetation survey was also done to gather baseline data, highlighting leguminous trees, such as Leucaena and Albizia, which could enhance soil quality. Based on the SEI profile, bareland had poorer soil quality than other land-use types. Therefore, this study emphasizes the significance of building a comprehensive SEI, suggesting apposite trees across UML types to enhance soil quality, and providing directions for multipurpose benefits in achieving the Land Degradation Neutrality and UN-SDG targets.