Importance of Dalbergia sissoo for restoration of degraded land: A case study of Indian dry tropical vindhyan regions

Abstract

To achieve the UN Sustainable Development Goals and preserve biodiversity and ecosystem services, degraded land must be restored. The focus of the current study was to evaluate the impact of Dalbergia sissoo Roxb (D. sissoo), a multipurpose native Indian tree in restoring degraded land. The significance of this species in restoring the fertility of agricultural soil in the dry tropical region of India was also examined in this study. This study showed an improvement in the soil quality (physical, chemical, biological, and enzymatic properties) of rhizosphere zone of D. sissoo (DL) throughout three seasons (rainy, winter and summer) in comparison to D. sissoo based agricultural soil (AL) and degraded (barren) land soil (BL). Soil moisture and water holding capacity (WHC) was significantly higher in DL in all three seasons compared to AL and BL, whereas, lower soil temperature and bulk density were noted in the rhizospheric soil of DL. The amount of soil organic carbon (SOC) was 75–94% higher in DL rhizospheric soil and 12–20% in the AL compared to BL soil in all three seasons. Total nitrogen (TN) and total phosphorus (TP) in the rhizospheric soil of DL were significantly higher (TN, 0.15–0.17% and TP, 16.1–21%) than those in AL (TN, 0.05–0.06%; TP, 11.4–14.2%) and BL ((TN, 0.03–0.04%; TP, 11.6–10.5%) soils, while C: N ratio was higher in BL (13.2–14.8) than AL (10.8–12.1) and lower in DL (6.5–8.2) soil in all three seasons. The rhizosphere soil of DL had considerably greater levels of microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and soil dehydrogenase activity (SDA) than the AL and BL. Pearson's correlation showed a significant strong positive correlation of SOC with WHC, TN, TP, MBC, MBN and soil dehydrogenase activity (SDA) (p < 0.01). Additionally, the principal component analysis (PCA) showed large and positive loading of PC1 for TN, WHC, MBN, MBC, SOC and SDA, suggesting that the restoration efforts should focus on increasing the TN, MBC, MBN, SOC and SDA. Increased SOC, TN, TP, microbial biomass and SDA in the rhizosphere soil of D. sissoo indicate healthy soil conditions in the Vindhyan dry tropical region of India. Therefore, this study advises to use D. sissoo tree extensively in land restoration initiatives for the benefit of both nat ure and people and also to achieve the goal of the United Nations Decade on Ecosystem Restoration (2021−2030).