The dissimilarity between multiple management practices drives the impact on soil properties and functions

Abstract

- Higher dissimilarity between restoration factors boosted soil microbial activities when multiple factors jointly applied.

- More diverse management practices enhanced soil aggregate stability and improved soil pH.

- Increasing restoration factors up to 8 factors only influenced soil properties (water stable aggregates and soil pH) but not soil microbial activities.

A range of land management practices are available to achieve better soil quality, but their combined effects remain understudied. We hypothesize that more diverse management practices, meaning higher dissimilarity, lead to stronger effects on soil functions and properties. Eight practices (biochar, compost, clay, amorphous silica, basalt, microbial inoculum, reduced physical disturbance and organic matter diversity) were selected with 20 replicates for treatments involving 2, 4, or 6 factors and 10 replicates for 8 factor treatments. We investigated the impact of individual factors, factor number, factor dissimilarity and factor composition on soil respiration, soil enzymatic activities (β-glucosidase, β-D-cellobiosidase, β-N-acetylglucosaminidase and phosphatase), soil pH, water stable aggregates and permanganate oxidizable carbon fraction. By including dissimilarity in addition to factor number, variance explained for soil respiration and enzymatic activities increased up to 54.21%. For soil pH and water-stable aggregates, explained variability increased to 65.57% and 57.38%, respectively. More diverse management practices boosted soil microbial activities, enhanced soil aggregate stability, improved soil pH while reducing labile carbon, whereas factor number only influenced water stable aggregates and soil pH. Our study highlights the importance of management practices diversity in soil functions and properties and calls for further research on synergistic combinations of diverse interventions.