Sustainable Soil Amendment: Effect of Reusing Saturated Dolomitic Calcareous Amendment (DCAS) on Chemical Properties of Two Types of Agricultural Soils

Replacing the linear process based on production, consumption, and disposal gives rise to the circular economy, in which materials are reincorporated into a new production process to create new amendments, following the model of sustainable agriculture. Through the circular economy approach, the aim is to add value to the waste generated during the adsorption process by recovering and reusing it as sustainable soil amendments. The present study analyzes the effects of saturated dolomitic calcareous amendment (DCAS) on the chemical properties of sandy-textured and clayey-textured agricultural soils. For this purpose, the dolomitic calcareous amendment, saturated with nutrients from hydroponic effluent through an adsorption process, was reused, and its effects on the chemical properties of agricultural soils were evaluated during incubation periods of 30, 60, and 90 days and compared with other amendments. A completely randomized experimental design was used, applying 4 treatments with 5 replications, totaling 20 experimental units for each soil type (sandy and clayey): T1 (control), T2 (dolomitic calcareous amendment in natura—DCAN), T3 (saturated dolomitic calcareous amendment—DCAS), and T4 (granulated dolomitic calcareous amendment—DCAG). The chemical properties evaluated were: pH in water, exchangeable aluminum, exchangeable calcium and magnesium, and available phosphorus. An interaction test between treatments and incubation periods was performed for each soil type and analyzed through analysis of variance, with means compared using Tukey’s test (p < 0.05) in InfoStat software, version 2020I. Through statistical analysis, it was confirmed that there was both interaction and a time effect for the variables pH, exchangeable aluminum, and available phosphorus in both sandy and clayey soils. Furthermore, the results showed that the saturated dolomitic calcareous amendment—DCAS (T3)—had good compatibility with both soil types, highlighting its ability to improve soil chemical properties by increasing pH, and available phosphorus levels, as well as completely reducing exchangeable aluminum concentration. This indicates that the saturated dolomitic calcareous amendment (DCAS) derived from the adsorption of nutrients from hydroponic effluent, can be effectively used to amend soil chemical properties, thereby promoting more efficient and environmentally sustainable agriculture.