Soil aggregate stability is a key indicator of soil health and is fundamental to soil processes such as water infiltration, nutrient cycling, carbon sequestration, erosion control, and ecosystem functionality. However, research concerning the impact of natural and anthropogenic factors on SAS across different climates, soil types, and management practices is lacking. This review synthesizes current understanding of physical, chemical, and biological mechanisms that govern the aggregate formation and stability and brings to light how the natural and anthropogenic drivers influence these processes. It highlights how clay mineralogy, root systems, microbial diversity, soil organic matter, and management practices shape the structure and turnover of aggregates essential for agricultural productivity. Key drivers of aggregate formation, categorized into natural (such as texture, clay mineral interaction, biota, and climate) and anthropogenic (such as tillage, land use changes, organic amendments) factors, have been critically evaluated. This review provides an insightful framework for soil management that may help enhance soil aggregation and promote sustainable agriculture and food security, especially under climate change.

Biochar is a promising tool to immobilize heavy metals (HMs) in the soil. Biochar’s effect on HMs immobilization into acidic soil (pH < 5) and the interaction of plants have been investigated. Three types of feedstocks were used for biochar development via pyrolysis at two temperatures and then applied as soil amendments. A vegetative experiment has been carried out with buckwheat and white mustard to determine the effect of biochar as an HMs immobilizing agent in the presence of sewage sludge. The results show promising biochar properties to immobilize heavy metals and reduce their availability for plants. Biochar incorporation increased soil pH and reduced heavy metal forms available to plants. A sequential extraction procedure was applied to investigate five different forms of six heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) and evaluate their distribution after plants’ cultivation. The proportion of the residual fraction (RES) of HMs varied widely and differed from metal to metal and from plant species. RES in the soil after treatment with biochar and buckwheat harvest varied between 68.14 and 96.40% for Zn, 42.39 and 59.48% (Cu), 75.89 and 93.11% (Cr), 81.85 and 92.83% (Ni), and 98.94 and 99.20% (Pb). In comparison, a slightly opposite trend was found in the soil after white mustard cultivation. The proportion of RES was: 0.82–53.44% for Zn, 0.99–52.93% (Cu), 48.87–76.41% (Cr), 10.22–72.63% (Ni), and 98.31–99.32% (Pb). HMs immobilization efficiency in the soil after biochar treatment followed the order Ni > Cr > Pb > Cu > Zn and Ni > Pb > Zn > Cr > Cu after buckwheat and white mustard cultivation, respectively.

Soil pH influences the composition and activities of microbial communities, which are driving the transformations of soil organic carbon (SOC). However, the effect of liming on SOC sequestration remains controversial. Evaluation of the effect of liming on SOC and humified carbon fractions was one of the most important tasks of this work. Studies were carried out in the long-term field experiment using slaked-lime rates of 0.5 or 2.0, depending on the soil hydrolytic acidity. It was determined that liming did not increase SOC content, but led to redistribution of SOC. The amount of mobile humic acids in the soil decreased while the intensity of liming increased. When liming at the 2.0 rate, the lowest HA1 level (0.251 g kg⁻¹ C) and highest amount of HA2 (0.21 g kg⁻¹ C) were found. It could be stated that soil liming, as a measure, allows the stabilization of HA and FA by the cation bridging mechanism. Liming resulted in slower mineralization of SOC and at the same time it also resulted in carbon sequestration in the form of valuable humic acids. An important consistent pattern of carbon transformation was identified in this study and can be applied in selecting of the most suitable combination of agricultural practices, promoting carbon sequestration and soil fertility.

Environmental pollution caused by increasing levels of heavy metals (HM) is a pressing problem throughout the world. Phytoremediation is considered a prospective remediation approach for HM-contaminated soil, but more research is required to enhance remediation efficiency. Biochar is a promising bio-residue material that can be used for the sustainable remediation of heavy metal-contaminated soil. In this study, a pot experiment was conducted to investigate the effects of biochar from different bio-substrates (digestate, waste of biodiesel production from rapeseed, corn stalk) on HM (Cr, Cd, Cu, Ni, Pb, and Zn) accumulation in buckwheat and white mustard cultivated in sewage sludge-contaminated soil. The total amount of HM in soil, plant above- and below-ground biomass, leachate, and bioconcentration and translocation factors were studied to explore the mechanism of how the different bio-substrates’ biochar affects HM accumulation in selected plants. It was observed that rapeseed biochar showed the greatest significant effect in reducing the HM content in soil, plant biomass, and lysimetric water. Meanwhile, the incorporation of digestate biochar significantly increased the HM content in all the soil-plant systems and affected the HM leaching from the soil. The concentration of HM in the leachate decreased from 2.5 to 10 times. It was determined that phytostabilization is the core process of HM accumulation in buckwheat, in contrast to mustard, where the mechanism is phytoextraction. This study confirmed that biochar addition enhances the phytoremediation efficiency in soil, which can potentially improve the development of ecofriendly in-situ bioremediation technology for HM-contaminated sites.

This paper presents water erosion data of three stationary series of field experiments (each analysing 10 land plots) on various steepness slopes with different soil texture of the hilly topography of Western Lithuania (Zemaiciai Upland). Six different erosion-preventive crop rotations (four field crop rotations and two perennial grasses for sward formation) were investigated. It was demonstrated that extent of water erosion depends on erosion-preventative capabilities of different crop rotations, slope gradient, soil texture and the amount of precipitations. According to the results of long-term experiments, the mean annual erosion rate under the grass–grain rotation decreased by 95.0% compared with crop rotation with black fallow. The annual soil loss (SL) due to water erosion in the crop rotation with bare fallow was estimated to be between 0.01 and 18.56 t ha⁻¹ yr⁻¹. Usage of long-term grass sward completely prevented soil erosion. Perennial grasses and grass⁻grain crop rotations also prevented soil erosion on slopes during rainstorm (41–65 mm of precipitation during the day). However, even grain–grass rotations could not completely prevent the water erosion on the 9°–11° slopes with light textured soils. SL rate in 5-year rotation was 1.64 and 1.41 t ha⁻¹ yr⁻¹, respectively. Soil water erosion and nutrient losses are effectively inhibited by long-lived perennial grasses. Covering slopes with erosion-preventive sward forming perennial grasses in many cases prevented available potassium (K) and phosphorus (P) loss from inside the soil, however, the K and P losses resulting from runoff were 0.005–1.0 and 0.001–0.071 kg ha⁻¹, respectively.

Phytoremediation is a green technique being increasingly used worldwide for various purposes, including sewage sludge contaminated by heavy metals. Most plants proposed for this technique have high nutrient demands, and fertilization is often required to maintain soil fertility and nutrient balance. In this context, sewage sludge could be a valuable source of nutrients (especially N and P) and water for plant growth. The main aim of this study was to assess the phytoremediation potential of selected energy plants, aspects of its increase, as well as contamination risks. Three treatments were used: unfertilized soil and the application of 45 and 90 t ha⁻¹ of sewage sludge. The experiment was performed in common osier and cup plant growing sites. Cr, Ni, Pb, Cu, and Zn contents in the soil tended to rise steadily when the amount of sewage sludge increased from 45 to 90 t ha⁻¹. Heavy metal concentrations in the soil were ranked as follows: Zn > Cr > Ni > Pb > Cu. Cr and Pb concentrations increased by 22.5% and 37.4% in 2020, respectively, compared to those in 2017, whereas Cu concentrations declined by 44.4%. Cu and Ni were significantly reduced by common osier while Pb and Zn were reduced by cup plant. A moderate potential ecological risk due to Cr, Ni, Cu, Pb, and Zn was observed in soils. The data can be used to estimate the suitability of the soil treated by sewage sludge for added value development in line with circular economy principles.