The effect of four calcium‐based amendments on soil aggregate stability of two sandy topsoils

Abstract

The structural stability of soil is a physical characteristic that affects soil degradation processes. Calcium‐based amendments, such as calcium carbonate, calcium sulfate, and calcium oxide/hydroxide, have been shown to improve the stability of soil aggregates. This study seeks to determine which calcium‐based soil amendments, and at what concentration, are the most efficient in improving aggregate stability of sandy topsoils derived from granitic and metamorphic parent materials, and to analyze the mechanisms involved. In the pot experiment, soils amended with CaCO3, CaCl2, and CaSO4 did not present significant differences in aggregate stability compared to the control or among each other. In contrast, Ca(OH)2 soil amendment brought the greatest stability to the soil aggregates. A dose of 1% Ca(OH)2 significantly increased the stability of soil aggregates. This effect is due to the reaction of Ca(OH)2 with atmospheric CO2 which leads to the formation of CaCO3, a delayed reaction not showed by the other soil amendments tested. Likewise, the greater solubility of Ca(OH)2 compared to CaCO3 exerts a greater aggregation effect on soil. Thus, the mechanism of action of Ca(OH)2 is related to cementation, rather than flocculation. Future studies should be carried out to demonstrate the effectiveness of Ca(OH)2 under field conditions.

Soil characteristics and tillage can predict the effect of ‘structure lime’ on soil aggregate stability

“…Bivalent Ca 2+ ions in the soil solution minimise the diffuse double layer (Vargas et al 2019). The attraction between clay particles then increases, leading to flocculation, which is a prerequisite for aggregation (Payne 1988).…”

The Effects of Manure Application and Herbivore Excreta on Plant and Soil Properties of Temperate Grasslands—A Review

“…Ca is an important element for the stability of soil aggregates, particularly by binding clay particles together [148]. Mg is the central element of green plant pigment and helps to regulate water balance [149].…”

A Systems-Based Approach to Ecosystem Services Valuation of Various Atmospheric Calcium Deposition Flows

“…Atmospheric calcium deposition flows (dry, wet, composite) are significant and valuable sources of Ca 2+ , which is an essential nutrient [15]. The significance of Ca 2+ in the environment and agriculture (especially as a soil amendment) is well documented by Vargas et al (2018) [16], and the following examples are directly linked to the selected SDGs [1]:…”

“…2. End hunger, achieve food security and improve nutrition and promote sustainable agriculture; Atmospheric calcium deposition has many beneficial impacts on soils, including: increase in soil alkalinity [17], availability of nutrients and biota, and improved soil structure [16], which can promote sustainable agriculture and food security. Calcium from atmospheric deposition enriches the nutrient cycling which contributes to increased yield of grain and biomass necessary for food security [18].…”