Soil quality and health under different tree species in an urban university campus: A multidimensional study

Abstract

Soil is vital to food security and ecosystem nutrient recycling. Rapid infrastructure development projects requiring mineral resource extraction have led to an overall decrease in soil quality. Due to a higher environmental footprint, cities' soil quality has declined quickly, which requires continuous monitoring and evaluation. Educational institutions are traditionally not taken into account for such monitoring. Thus, the present study investigated the soil health status under 10 different plantations in Maharshi Dayanand University located in Rohtak city. Using different digital and volumetric methods, 20 physicochemical parameters and nutrients viz. sand, silt, clay, pH, electrical conductivity (EC), organic matter (OM), macronutrients and micronutrients. Sampling was performed at four depths (0-10, 10.1-20, 20.1-30 and 30.1-40 cm) to collect 40 samples. Repeated measures of one-way analysis of variance (ANOVA) and pairwise comparison were used to detect significant differences. Different tree plantations affected soil parameters significantly (p<0.05). The soil nutrient index value (SNIV) classified sand (3), pH (2.62), Ca²⁺ (2.82), Cu (2.60) and Fe (2.65) in the high fertility class. Network analysis demonstrated an effect of physicochemical parameters on OM and nutrients. The structural stability index (SSI) appropriated 50 % of the samples as thoroughly degraded (SSI<5 %). Principal component analysis (PCA) produced five significant components and designated N, P, Cu and OM as the most critical soil chemistry variables. Hierarchical cluster analysis (HCA) produced 3 clusters for tree species with similar soil properties. Overall, the campus's soil is alkaline, non-saline and nutrient deficient, and surface layers are more fertile. The soil under F. virens is the most productive. The results obtained and customized solutions provided in this article may help to improve soil health on the campus ans aid in sustainable soil use, conservation and management. This may also motivate other campuses around the globe to assess their soil health status.