Biochar effects are strongly dependent on its properties. Biochar improves physical soil properties by decreasing bulk density and increasing medium and large aggregates, leading to faster and deeper water infiltration and root growth. Improvement of the chemical properties of soil is connected with pH neutralization of acidic soils, increase of cation exchange capacity and base saturation, providing a larger surface for sorption of toxicants and exchange of cations. Biochar increases the stocks of macro- and micronutrients in soil and remains sufficient for decades. Biochar effects on (micro)biological properties are mainly indirect, based on the improvements of habitat conditions for organisms, deeper root growth providing available C for larger soil volume, higher crop yield leading to more residues on and in the topsoil, better and deeper soil moisture, supply of all nutrients, and better aeration. Along with positive, negative effects of biochar while used as a soil conditioner are discussed in the review: presence of PAH, excessive amounts of K, Ca and Mg, declination of soil pH. In conclusion, despite the removal of C from the biological cycle by feedstock pyrolysis, the subsequent application of biochar into soil increases fertility and improves physical and chemical properties for root and microbial growth is a good amendment for low fertility soils. Proper use of biochar leads not only to an increase in crop yield but also to effective sequestration of carbon in the soil, which is important to consider when economically assessing its production. Further research should be aimed at assessing and developing methods for increasing the sequestration potential of biochar as fertilizer.

Ethylenediaminetetraacetic acid (EDTA), when used as a main chelator for complex plant microfertilizers, causes many negative environmental effects; therefore, new compounds or new use of the known compounds to replace EDTA have been widely studied. In the present study, biodegradation rate, plant (Raphanus sativus) growth stimulation and ecotoxicity towards Daphnia magna and Chlorella vulgaris of iminodisuccinic acid (IDS), considered as an alternative for EDTA in agriculture, has been investigated. It was demonstrated that IDS’ biodegradation rate over 28 days was 28.1%, which is 4.5 times higher than that of EDTA. Similar to EDTA, complexation with metals led to an increase in the degradation rate by 1.8-fold. The majority of compounds were degraded within first 7 days. The GI values for IDS implemented at concentrations of 100 mg/L (both in pure form and in combination with microelements) were 2.4–2.6 times higher than those of EDTA. The ecotoxicity index EC10 of IDS was estimated to be 2.0 g/L and 5.8 g/L towards D. magna and Ch. vulgaris which are 4.1- and 10-fold higher than those for EDTA, respectively. It can be concluded that IDS is a promising agent to chelate microelements used in plant nutrition.

Around the globe, only 30–50% of the amount of oil estimated to be in reservoirs (“original oil in place”) can be obtained using primary and secondary oil recovery methods. Enhanced oil recovery methods are required in the oil processing industry, and the use of microbially produced amphiphilic molecules (biosurfactants) is considered a promising efficient and environmentally friendly method. In the present study, biosurfactants produced by the Pseudomonas putida PP021 isolate were extracted and characterized, and their potential to enhance oil recovery was demonstrated. It was found that the cell-free biosurfactant-containing supernatant decreased the air–water interface tension from 74 to 28 mN m⁻¹. Using TLC and FTIR methods, the biosurfactants produced by the isolate were classified as mono- and di-rhamnolipid mixtures. In the isolates’ genome, the genes rhlB and rhlC, encoding enzymes involved in the synthesis of mono- and di-rhamnolipids, respectively, were revealed. Both genes were expressed when the strain was cultivated on glycerol nitrate medium. As follows from the sand-packed column and core flooding simulations, biosurfactants produced by P. putida PP021 significantly enhance the degree of recovery, resulting in additional 27% and 21%, respectively.