Abstract

Soil and water conservation measures, widely promoted to control soil erosion in erosive orchards, can alter soil aggregates, thereby influencing the soil quality index (SQI). However, it's still unclear how these measures affect soil aggregate nutrients, stoichiometry, and their association with SQI at a long-term timescale. This study focused on a 22-year homogeneous orchard in subtropical hilly region. Five soil and water conservation measures, namely clean tillage (CT), engineering measures (EM), tillage measures (TM), non-leguminous biological measures (NLBM), and leguminous biological measures (LBM), were implemented. Sampling depths were 0–20 cm, 20–40 cm, and 40–60 cm. The results revealed that LBM significantly enhanced SQI across the soil profile, increased the proportion of macroaggregates, and improved aggregate stability, soil organic carbon, and total nitrogen. Additionally, LBM demonstrated the highest capacity for carbon and nitrogen preservation. Soil stoichiometry revealed carbon and nitrogen limitations in the orchard soils, and leguminous cover proved effective in alleviating these limitations and maintaining the stoichiometric balance of soil aggregates. Under a long-term timescale, these measures mitigated or even surpassed the impact of soil depth on soil aggregates and SQI. The improvement of orchard SQI through the measures was primarily achieved by enhancing aggregate stability. There was no significant correlation between soil organic carbon and SQI in relation to fruit yield, ascribed to the intense competition for water and nutrients between cover plants and citrus trees. In conclusion, LBM emerges as the most beneficial soil and water conservation measure for enhancing orchard SQI, preserving nutrients, and maintaining aggregate stoichiometric balance. It holds the potential to improve orchard yield and contribute to sustainable development.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.