Anthropogenic activities have resulted in land desertification in various regions of the world, leading to the degradation of critical soil characteristics such as organic matter (OM) content, nutrient stock, and prevailing biodiversity. Restoring such degraded soils through organic matter amendments and diversified crop rotations is thus an intrinsic part of organic farming. This review discusses a wide range of organic farming impacts on soil health and crop productivity by focusing on organic fertilizers and crop diversification. Conventional fertilizers were considered vital for agricultural production to harvest high crop yields. Nevertheless, they are now deemed as environmentally hazardous and an obstacle to sustainable agroecosystems due to intensive chemical inputs that damage the soil over time and have long-lasting impacts. Conventional fertilization results in nutrient depletion, loss of microbial diversity, organic matter reduction, and deterioration of physical characteristics of the soil. Conversely, organic fertilization makes use of naturally existing resources to improve soil health. Organic amendments such as biochar, manure, and fermented grass improve soil’s physical, chemical, and biological properties and promote the growth and diversity of beneficial soil microorganisms—important in nutrient cycling and soil stability. They facilitate the uptake of nutrients, hinder crop pathogen growth, mitigate heavy metals, and decompose xenobiotic organic substances. Moreover, growing cover crops is also a major strategy to improve soil health. Diversified crop rotation with combinatorial use of organic fertilizers may improve soil health and agricultural yields without any detrimental impacts on the environment and soil, ensuring sustainable food production, safety, and security. This integrated approach contributes to minimizing the use of chemical fertilizers and their effects on environmental health. It also contributes to reducing agricultural inputs along with enhancing OM, soil microbial diversity and biomass, nitrogen fixation, and carbon sequestration. Therefore, cover crops and organic fertilization may offer sustainable agroecosystems and climate change mitigation.

One of the main goals of the 21st century’s developing society is to produce the necessary amount of food while protecting the environment. Globally, particularly in Lithuania and other northern regions with similar climatic and soil conditions, there is a lack of data on the long-term effects of crop rotation under the current conditions of intensive farming and climate change. It has long been recognized that monocultures cause soil degradation compared to crop rotation. Research hypothesis: the long-term implementation of crop rotation makes a positive influence on the soil environment. The aim of our investigation was to compare the effects of a 50-year-long application of different crop rotations and monocultures on soil CO₂ emissions, earthworms, and productivity of winter rye. Long-term stationary field experiments were established in 1966 at Vytautas Magnus University Experimental Station (54°53′ N, 23°50′ E). The study was conducted using intensive field rotation with row crops, green manure crop rotations, three-course rotation, and rye monoculture. Pre-crop had the largest impact on soil CO₂ emissions, and more intensive soil CO₂ emissions occurred at the beginning of winter rye growing season. Rye appeared not to be demanding in terms of pre-crops. However, its productivity decreased when grown in monoculture, and the optimal mineral fertilization remained lower than with crop rotation, but productivity remained stable.

Equally effective way to achieve sustainable farming and the challenge set by the European Commission on 20 May 2020: proper crop rotation and thus reduction of the quantity of on-farm chemicals. Long-term stationary field experiments were established in 1966 at Vytautas Magnus University Experimental Station (54°53′ N, 23°50′ E). The study was conducted with intensive, three-course, field rotation with row crops, for green manure crop rotations, and rye monoculture as well during the last 5-year period of a 50-year investigation to determine the effect of crop rotation combinations and rye monoculture on weed density and seed bank and grain yield. In cereal crops, weed counting was performed twice: weed density was determined before the application of herbicides, and weed counting was done before the harvest. Weed seedlings were counted, their botanical species were determined, annual and perennial weed number was estimated. Weed seed bank was established before primary tillage in soil. The results obtained confirmed the hypothesis that with climate change and intensive farming, long-term crop rotations are likely to increase crop productivity, reduce weeds and weed seed banks in the soil, and thus contribute to maintaining agroecosystem sustainability. The winter rye 1000 grain weight and yield decreases as weed mass increases showing strong negative correlations: y = 475.56 − 11.93x, r = −0.91, p ≤ 0.05; y = 82.97 −14.82x, r = −0.97, p ≤ 0.01. Reseeding of rye crops leads to a growing prevalence of weeds such as Equisetum arvense L. and Mentha arvensis. Crop structures these days are dominated by cereals, which inevitably increase the spread of weeds, and therefore, the importance of crop rotations increases in the context of intensive farming.

Sowing time, as an element, is important to improving the adaptation of cultivars to environmental conditions and to achieving high seed yields. The field experiment was conducted from 2018–2019 at the Experimental Station of Vytautas Magnus University Agriculture Academy. The experimental design included treatments with different sowing dates: eight sowing dates in 2018 and 10 sowing dates in 2019. The first sowing of spring rapeseed was carried out when the soil reached its physical maturity, i.e., it did not stick to agricultural implements and it crumbled well. The other sowing dates were every seven subsequent days. From 2018–2019, the rapeseed emerged as best in early May (3 and 4 May), and later sowing reduced the emergence of rapeseed. In 2018, most pods were formed on one plant when the rapeseed was sown (on 1 June), compared to other sowings, on average 2.8 times more. In 2019, most pods were formed by the latest-sown rapeseed (7 June), from 1.4 to 2.7 times more compared to previously sown crops. In 2018, the sowing time of spring rapeseed did not have a significant effect on the number of seeds in one pod. In 2019, it was found that the rapeseed formed most of the seeds in the pod at a similar time as in 2018: the sowings of 19 April and 7 June. The average number of seeds in the pod was significantly reduced by early sowing (5 April). In 2019, the highest 1000-seed weight was found at the earliest-sown crop (5 April), which was on average 18.0% higher compared to the later sowings. The 1000-seed weight of the last-sown rapeseed (7 June) was the lowest. In 2018, the yields of early-sown (20 April) spring rapeseed were the highest. Later sowing significantly reduced the yields by 20.7 to 48.2%. In 2019, the highest seed yield was obtained after sowing spring rapeseed in late April (26 April); it was significant, on average, 1.9 times higher than the yields of spring rapeseed sown from 3 May to 7 June. Meteorological conditions had a stronger effect on the field emergence and yield components of spring rapeseed than the sowing date.

A peat substrate is made from peat from drained peatlands, which is a limited resource. A realistic estimate is that 50% of the world’s wetlands have been lost. Peat is used in horticulture, especially for the cultivation of vegetables in greenhouses. The consequences of peatland exploitation are an increase in the greenhouse effect and a decrease in carbon stocks. Wood fiber can be used as an alternative to peat. The chemical properties of growing media interact and change continuously due to the small volume of growing media, which is limited by the growing container. This study aims to gain new knowledge on the impact of nutrient changes in the microbial degradation of carbon compounds in wood fiber and mixtures with a peat substrate on the content and uptake of nutrients required by plants. The cucumber (Cucumis sativus L.) variety ‘Dirigent H’ developed in the Netherlands was cultivated in growing media of a peat substrate and wood fiber: (1) peat substrate (PS); (2) wood fiber (WF); (3) wood fiber and peat substrate 50/50 v/v (WF/PS 50/50); (4) wood fiber and peat substrate 25/75 v/v (WF/PS 25/75). The rates of fertilization were the following: (1) conventional fertilization (CF); (2) 13 g N per plant (N₁₃); (3) 23 g N per plant (N₂₃); (4) 30 g N per plant (N₃₀). The experiment was carried out with three replications. As the amount of wood fiber increased, the humidity and pH of the growing media increased. The fertilization of the cucumbers with different quantities of nitrogen influenced the nutrient uptake. The plants grown in the 50/50 and 25/75 growing media had the best Cu uptake when fertilized with N₂₃. When the plants grown in the wood fiber media and the 50/50 media were fertilized with N₁₃, N_23, and N₃₀, the Mn content in the growing media at the end of the growing season was significantly lower than the Mn content in the media with conventional fertilization. Thus, nitrogen improved the uptake of Mn by the plants grown not only in the wood fiber, but also in the combinations with a peat substrate. Growing plants in wood fiber and fertilizing them with N₁₃ can result in the optimum uptake of micronutrients. The number and biomass of cucumber fruits per plant were influenced by the amount of wood fiber in the growing media and the application of nitrogen fertilizer. The highest number of fruits and biomass of fruits per plant obtained were significantly higher when the cucumbers were grown in WF/PS 50/50 growing media with additional N₁₃ fertilization.

The composition of weed communities in agricultural crops is dependent on soil properties and the applied agronomic practices. The current study determined the effect of different tillage systems and crop residue on the soil weed community composition. The research programme encompassed 2013–2015 in a long-term field experiment located in the Experimental Station of Vytautas Magnus University in Lithuania. The soil type in the experimental field was qualified as Endocalcaric Stagnosol (Aric, Drainic, Ruptic, Amphisiltic). Weeds were categorised into communities according to soil pH, nitrogen and moisture indicators. The results of investigations were grouped using cluster analysis. Agricultural crops were dominated by different weed species depending on the soil pH and moisture. Weed species were relatively more frequent indicating nitrogen-rich and very nitrogen-rich soils. In the reduced tillage and no-tillage systems, an increase in the abundance of weed species indicating moderate acidity and low acidity, moderately wet and wet, nitrogen-rich and very nitrogen-rich soils was observed. The application of plant residues decreased the weed species abundance. In the reduced tillage and no-tillage systems, the quantitative distribution of weed was often uneven. By evaluating the association of weed communities with groups of different tillage systems with or without plant residues, their control can be optimised.