There is a lack of research on the practice of intercropping sugar beet and the impact of such agrocenoses on soil and crop fertility, especially under organic farming conditions. For this reason, a three-year stationary field experiment was performed at Vytautas Magnus University, Agriculture Academy, Lithuania. Sugar beet was grown continuously with intercropped Persian clover (Trifolium resupinatum L., MC), white mustard (Sinapis alba L., MM) and spring barley (Hordeum vulgare L., MB) as a living mulch. Inter-row loosening (CT) and mulching with ambient weeds (MW) were used as comparative treatments. The results showed that, under minimal fertilization, CT and intercropping increased the average content of nitrogen, phosphorus and potassium in the soil. However, the average content of magnesium was reduced in single cases (MW, MB), and the average content of sulphur was reduced in all cases. Intercropping significantly decreased the yields of sugar beet root-crop, but was mainly neutral in quality terms. The meteorological conditions during experimentation had a weak impact on root-crop quantity and quality. Generally, the practice of sugar beet intercropping requires more detailed research on how to minimize the competition between the sugar beet, living mulch and weeds, and how to balance the nutrition conditions.

Differently tilled faba bean cultivations, in particular, require a comprehensive study of weed diversity, abundance, and seedbank due to the lack of experimental data. Therefore, in 2016–2018, field trials were conducted at Vytautas Magnus University on the basis of a long-term tillage experiment. Conventional deep and shallow plowing, deep chiseling, shallow disking, and no-tillage systems were investigated. According to the results of the investigations, the air temperature and amount of precipitation during the vegetative season had a greater influence on the total number of weeds (r = 0.538 and 0.833 p > 0.05) than the types of tillage systems investigated. However, on average, a reduction in tillage intensity did not change the weed number, especially in disked and not tilled plots. On average, the biomass of weeds varied little between the treatments (from 105.9 to 125.7 g m⁻²) and mainly depended on the volume of forecrop residues (r_annual = −0.982 p ≤ 0.01 and r_perennial = 0.890 p ≤ 0.05). Higher total weed seedbanks were found in the disked (+43.0%) and not tilled (+21.6%) soils compared to deeply plowed ones. The weed seedbank was almost similarly distributed between the treatments, irrespective of the tillage depth and method used.

At present, the consumption of medical plants and functional foods is growing across the whole world. Fireweed (Chamerion angustifolium (L.) Holub), an important medicinal plant that has various pharmacological effects (antioxidant, anti-inflammatory, anticancer and others), can improve the state of health and well-being and reduce the risk of various diseases. The aim of this work was to investigate polyphenols (flavonoids, phenolic acids and tannins) and antioxidant activity in fireweed leaves fermented for 24, 48 and 72 h in solid-phase fermentation under aerobic and anaerobic conditions. High-performance liquid chromatography (HPLC) for polyphenols and the spectrophotometric method based on quenching of stable colored radical (ABTS^•+) for antioxidant activity determinations were used. The results showed that the highest amounts of total polyphenols, total flavonoids and tannin oenothein B in the dried matter were found after 72 h and the highest total phenolic acids after 48 h of anaerobic solid-phase fermentation. The highest antioxidant activity was found after 72 h of solid-phase fermentation under aerobic conditions.