Assessment of Organo-Mineral Post-sorbents for Improving Acidic, Organic-Matter Deficient Soil: Implications for Crop Physiology and Soil Microbial Activity

Soil nutrient deficiencies and fertility loss due to the organic matter depletion are major constraints in meeting the growing food demand. In this context, the recovery of humic substances (HSs) and nutrients from the reject water can be an economically promising approach for the reduction of anthropogenic pressure on soil organic matter and sustainable use of resources. The present study investigates the potential of the organo-mineral preparations formulated during the adsorption of HSs and nutrients from reject water on opoka (OP) and autoclaved aerated concrete (AAC) as conditioners of the organic matter-poor acidic soils. Given the environmental concerns associated with the soil application of reject water-derived compounds, the effect of post-sorption OP (PSOP) and AAC (PSACC), and the raw materials used for their preparation were assessed based on the physiological traits of planted crops and the functional potential of soil microbial communities. The results indicate that Trifolum pratense (TP), Brassica napus (BN), and Sorghum saccharatum (SS) responded differently to soil amendment with the tested preparations. All amendments had a positive effect on the development of TP and SS in particular. As observed, the community-level physiological profiles were altered in soils derived from the cultivation of these crops, especially those enriched with post-sorbents.