The effect of dolomite amendment on soil organic carbon mineralization is determined by the dolomite size

Hongtao Wu,Jinli Hu,Muhammad Shaaban,Peng Xu,Jinsong Zhao,Ronggui Hu

doi:10.1186/s13717-020-00278-x

Abstract

BackgroundThe size of lime material is vital for the efficiency of ameliorating soil acidity, thereby influencing soil biochemical processes. However, the effects of different sized lime material application on soil organic carbon (SOC) mineralization are yet to be elucidated. Therefore, a 35-day incubation experiment was conducted to determine the effects of three particle size fractions (0.5 to 0.25, 0.25 to 0.15, and < 0.15 mm) of dolomite on SOC mineralization of two acidic paddy soils.ResultsCO2 emission was increased by 3–7%, 11–21%, and 32–49% for coarse-, medium-, and fine-sized dolomite treatments, respectively, compared to the control in both soils. They also well conformed to a first-order model in all treatments, and the estimated decomposition rate constant was significantly higher in the fine-sized treatment than that of other treatments (P < 0.05), indicating that SOC turnover rate was dependent on the dolomite size. The finer particle sizes were characterized with higher efficiencies of modifying soil pH, consequently resulting in higher dissolved organic carbon contents and microbial biomass carbon, eventually leading to higher CO2 emissions.ConclusionsThe results demonstrate that the size of dolomite is a key factor in regulating SOC mineralization in acidic paddy soils when dolomite is applied to manipulate soil pH.

Highlights

The size of lime material is vital for the efficiency of ameliorating soil acidity, thereby influencing soil biochemical processes
The particle size of a lime material is one of the major factors that influences its efficiency of neutralizing soil acidity, because the reaction rate between lime material and H+ in the soil is dependent on the specific surface area (Huang et al 2007)
The application of dolomite significantly changed the pH for both soils (P < 0.001), and the dolomite with fine-size was more effective in neutralizing soil acidity than those with course- or medium-size (Fig. 1)

Summary

Introduction

The size of lime material is vital for the efficiency of ameliorating soil acidity, thereby influencing soil biochemical processes. The effects of different sized lime material application on soil organic carbon (SOC) mineralization are yet to be elucidated. A 35-day incubation experiment was conducted to determine the effects of three particle size fractions (0.5 to 0.25, 0.25 to 0.15, and < 0.15 mm) of dolomite on SOC mineralization of two acidic paddy soils. The particle size of a lime material is one of the major factors that influences its efficiency of neutralizing soil acidity, because the reaction rate between lime material and H+ in the soil is dependent on the specific surface area (Huang et al 2007). For a given lime material, the finer the particle size, the more rapid rate of dissolution in soil is, and the more effective it is in modifying soil pH (Coleman et al 1959)

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