Legumes have a wide range of positive effects on soil properties, including nitrogen and carbon storage, soil structure and the phytosanitary condition of crops. From an agronomic point of view, legumes are most valued for their ability to take up atmospheric nitrogen in symbiosis with nitrogen-fixing bacteria. The aim of this research was to determine the effect of legume residues (peas, fodder beans, narrow-leaved lupins) on the N (N_total) and organic carbon (C_org) accumulation in soil and N leaching under temperate climate conditions. The experiment was carried out in lysimetric equipment in 2016–2023. The effect of legumes on C_org and N_total accumulation in soil and N leaching were studied in a Fabaceae–Cereals sequence. Three species of legumes—peas, fodder beans and narrow-leaved lupines—were tested; spring barley (Hordeum vulgare L.) was grown as a control treatment. The lysimeter surface area was 1.75 m² and the experimental soil layer was 0.60 m (sand loam Haplic Luvisol). It was found that after harvesting, more residues were incorporated into the soil with lupines (p < 0.05), which, compared to pea and bean residues, increased N_total and C_org concentrations in the soil. There was a strong correlation (r = 0.95) between the N_total concentration in the soil and the N amount incorporated with residues. Mineral N released during residue decomposition was leached from the humic horizon under conditions of excess moisture in the autumn–winter period and increased the nitrate concentration in the lysimeter water. The increase in concentration was recorded within 5 to 6 months after the application of the residues. As a result, the N leaching losses increased on average by 24.7–33.2% (p < 0.05) during the year of legume cultivation. In the following year, after legume residue incorporation, the effect of residues on nitrate concentration and N leaching decreased and did not differ significantly from that of barley residues.

This study aims to determine the differences in the organic carbon, humic acid (HA), and fulvic acid (FA) concentrations in the A and AB horizons, depending on land use, in order to determine the influence of the land use on the soil organic carbon (SOC) sequestration rate in the A horizon, and to assess the impact of the land use on the quality of the humic substances (HS) (the humification rate (HR) and the HA/FA ratio). On the basis of the data of 1995–2018, it would be expedient to convert cropland (CL) areas to fertilized managed grassland (MGfert) in order to increase the SOC accumulation (28%) in the Arenosol. In the unfertilized managed grassland (MGunfer) areas, the SOC accumulation in the A horizon was similar to that in the MGfert (p > 0.05); however, significantly less (−45.0%) HAs were formed, the HR decreased 2.8%, and the HA/FA ratio was 1.12%. This means that less stable humic substances were formed in the MGunfer soil. In the Arenosol, the fastest SOC sequestration took place in the AL and PP areas, the annual SOC stocks increased by 393 and 504 kg ha⁻¹ year⁻¹, respectively, and the HR increased to 19.1–21.3% (CLfert: 11.9%). However, these types of land use produce more FAs (14.5 and 32.5% more, respectively, compared to the MGfert, and 36.3 and 57.7% more, respectively, compared to the CLfert), which can lead to soil acidification and can accelerate eluvial processes. Because of the faster leaching of the FAs from the upper layers of the A horizon to the AB horizon, the humus type changes from humate–fulvate in the A horizon, to fulvate–humate in the AB horizon.

The application of organic fertilizers and biological inputs to soil inevitably affects its quality, agrochemical indicators, and microbiota. Sustainable agriculture is based on continuously learning about how to properly manage available soil, water, and biological resources. The aim of the study was to determine changes in microorganism communities and carbon stocks in infertile soils for fertilization using different organic fertilizers and their combinations with bio-inputs. Genetic analysis of microorganism populations was performed using the NGS approach. Our study showed that the application of organic fertilizers affects the soil microbiota and the taxonomic structure of its communities. Specific groups of bacteria, such as Bacillota, were promoted by organic fertilization, meanwhile the abundance of Pseudomonadota and Ascomycota decreased in most treatments after the application of poultry manure. Metagenomic analysis confirmed that the use of bio-inputs increased the relative abundance of Trichoderma spp. fungi; meanwhile, a significant change was not found in the representatives of Azotobacter compared to the treatments where the bio-inputs were not used. The positive influence of fertilization appeared on all the studied agrochemical indicators. Higher concentrations of C_org and N_min accumulated in the soil when we used granulated poultry manure, and pH_KCl when we used cattle manure.

Ex-arable land-use change is a global issue with significant implications for climate change and impact for phytocenosis productivity and soil quality. In temperate humid grassland, we examined the impact of climate variability and changes of soil properties on 23 years of grass productivity after conversion of ex-arable soil to abandoned land (AL), unfertilized, and fertilized managed grassland (MG_unfert and MG_fert, respectively). This study aimed to investigate the changes between phytocenosis dry matter (DM) yield and rainfall amount in May–June and changes of organic carbon (C_org) stocks in soil. It was found that from 1995 to 2019, rainfall in May–June tended to decrease. The more resistant to rainfall variation were plants recovered in AL. The average DM yield of MG_fert was 3.0 times higher compared to that in the AL. The DM yields of AL and MG were also influenced by the long-term change of soil properties. Our results showed that C_org sequestration in AL was faster (0.455 Mg ha⁻¹ year⁻¹) than that in MG_fert (0.321 Mg ha⁻¹ year⁻¹). These studies will be important in Arenosol for selecting the method for transforming low-productivity arable land into MG.

This study provides the first long-term, cross-border evaluation of Lithuanian potato (Solanum tuberosum L.) cultivars, integrating agronomic performance, tuber quality, and resistance to major pathogens across diverse environments. Field and controlled trials conducted in Lithuania and Ukraine from 2014 to 2024 revealed substantial genetic variability among 14 national cultivars, enabling their classification into five distinct maturity groups. Maincrop cultivars outperformed others in yield and starch accumulation, with ‘VB Meda’, ‘Goda’, and ‘VB Aista’ exhibiting a superior balance of productivity (up to 49 t ha⁻¹), starch content (>19%), and moderate-to-high resistance to Phytophthora infestans. A broader genetic screening of 287 accessions—including varieties, breeding lines, and hybrids—demonstrated wide diversity in phenological development, disease resistance, and reproductive traits. Notably, Ro₁ pathotype resistance was identified in 85 genotypes, predominantly with yellow-skinned tubers, while genotypic sterility in flowering and berry set was associated with both parental lineage and elevated temperatures. Although no complete immunity to P. infestans was detected, several genotypes displayed stable polygenic field resistance, suggesting the presence of horizontally inherited defense mechanisms effective under variable agroclimatic conditions. These results underscore the strategic breeding potential of Lithuanian potato germplasm for developing high-performing cultivars with enhanced resilience to late blight and nematodes and offer valuable insights for climate-adapted potato breeding in Northern and Eastern Europe.

The research was carried out at Vokė Branch of the Institute of Agriculture of Lithuanian Research Centre for Agriculture and Forestry in 2018–2019. The objective of this study was to determine the influence of the relative proportion of stems, leaves and flowers on biomass formation and grain yield in organic and conventional farming systems. The study found that buckwheat produced one-third more biomass in the conventional farming system than in the organic farming system. Differences between buckwheat cultivars were more distinct due to biomass formation than grain yield. The research determined that the productivity (biomass and grain yields) of buckwheat was dependent on the proportion of morphological elements in plants and the process of biomass formation and grain yield in organic and conventional agricultural systems. Biomass yields depended on the relative number of stems in both farming systems. Grain yield depended on the ratio of flowers in the morphostructure; however, statistically significant correlations were found only in the organic farming system.