Evergreen fruit crops improve carbon pools, enzymes and nutrient availability in soil over deciduous ones under subtropical conditions

Abstract

ABSTRACT Soil is an important natural resource, a medium for plant growth, and its quality is decisive for sustainable crop productivity. Soil biological properties in evergreen and deciduous fruit crops were estimated under subtropical region of north-west India; wherein, samples were taken from 0–20 to 0–40 cm soil layers. In the present study, total soil organic carbon (TSOC) and carbon (C) pools, viz., very labile (CVL), labile (CL), less labile (CLL), non-labile (CNL) and biological properties were determined in fruit crops. The results revealed that TSOC, C pools and soil enzymes activities were significantly higher in fruit crops as compared to control (uncultivated). The uncultivated soils (1.96 g kg−1) had the lowest TSOC content, which was lower (p < 0.05) than evergreen (3.19–4.69 g kg−1) and deciduous (2.99–5.68 g kg−1) fruit crops. Soil biological properties (microbial biomass carbon, basal soil respiration and quotients) were significantly higher in the fruit crops than the uncultivated, which has increased the C mineralization in soil. Principal component analysis identified CL in PC1 (explaining 52.2% of total variability), microbial quotients in PC2 (25.7% variability) and soil pH in PC3 (10.3% variability) as the most dominant and reliable indicators for the assessment of soil quality in fruit crops. In general, evergreen crops showed higher soil biological activities than deciduous fruit crops. The result signifies that the evergreen fruit crops substantially influenced C sequestration than deciduous fruit crops, which consequential mitigate the negative impacts of climate change.