The potential of biomass grown for bioenergy production in temporarily fallowed fields was evaluated in the present study. The fields were sown with fodder galega, smooth brome, or left to natural vegetation. The aim of the study was to determine the dry matter yield (DMY) and fresh matter yield (FMY), higher heating value (HHV), and lower heating value (LHV) of fallow biomass. Energy inputs, energy gain, and the energy efficiency ratio (EER) of different types of fallow biomass were estimated during a 12-year experiment. The energy inputs associated with the production of biomass pellets in a conventional stationary pellet line and the innovative Krone Premos 5000 mobile pelleting press were calculated. The smooth brome monoculture was characterized by the highest energy output (138.5 MJ/ha) in the third year of the study. The EER differed across fallow management strategies, and it ranged from 4.87 to 8.91 for pellets produced in the conventional pellet line and from 8.91 to 13.07 for pellets produced with the Krone Premos 5000 mobile pelleting press. The energy inputs associated with pellet production reached 896-942 MJ/Mg in the mobile pelleting press and 1649-1693 MJ/Mg in the conventional stationary pellet production line.

The aim of this incubation experiment was to evaluate the effect of Tenebrio molitor L. frass on selected chemical and microbiological properties of acid peat. The optimal rate of mealworm frass in the substrate for growing ornamental trees and shrubs was determined. Acid peat was fertilized with frass or urea at five nitrogen (N) rates: 0, 50, 100, 200, and 400 mg dm−3. Mineral N content and electrical conductivity increased, and calcium content decreased in peat with increasing N rates. Similarly to urea, frass increased the ammonification rate at the beginning of incubation and the nitrification rate from the second week of incubation. Higher frass rates increased the abundance of plant-available nutrients (N, P, Mg, K, and Na) in acid peat. Frass undesirably decreased the counts of bacteria with antagonistic activity against soil-borne plant pathogens. Regarding the abundance of functional genes, the optimal N rate was 100 mg dm−3, which promoted the growth of N-fixing and chitinolytic bacteria. Higher N rates promoted the development of aerobic spore-forming bacteria, which produce antibiotics that can be used as biocontrol agents. Moderate fertilizer rates contributed to N accumulation in bacterial biomass. These preliminary findings, which indicate that insect frass can partially replace mineral fertilizers, are promising and can be used in pot and field experiments testing various plant species.

Smooth brome (Bromus inermis L.) is a species of perennial grass with growing economic importance. Initially, this species had attracted interest as a source of animal feed. Over the years, the interest in smooth brome increased significantly due to the growing knowledge about its advantages. The aim of this study was to explore the contemporary significance of smooth brome. This plant is characterized by a high tolerance to many negative environmental factors, such as periodic droughts, low temperatures and salinity, which contributes to its constant presence in the landscape of many countries. The moderate soil requirements of smooth brome, combined with the effective use of soil resources and rational nutrient utilization, contribute to high biomass yields that can reach 13 t/ha DM. The usefulness of this grass species in various management systems has been recognized in numerous research studies. Smooth brome can generate benefits in many branches of the economy. This efficient energy plant is used in paper production, and it is also recommended for the protection of fallow land or the reclamation of degraded land. Smooth brome prevents erosion, enhances biodiversity, and provides shelter for many animal species. This species fits well into the current assumptions of agricultural policy and increasingly demanding environmental standards. According to the latest guidelines, modern agriculture should pursue economic and environmental goals simultaneously. In this context, smooth brome constitutes a valuable link in sustainable development. Due to its numerous advantages, smooth brome not only provides high-quality feed and biomass but also effectively sequesters CO2, improves soil fertility and enhances biodiversity, which makes it an important element of agriculture and environmental protection.

The efficacy of Festulolium in lamb nutrition remains insufficiently investigated, and the nutritional value of different hybrids has not yet been compared. This study evaluated the feed value of three Festulolium cultivars (Becva, Felopa, and Paulita) in fattening Berrichon du Cher ram lambs compared to hybrid ryegrass cv. Bakus. Herbage of the grass cultivars was harvested and ensiled, and fed to 24 lambs divided into four groups depending on the type of silage in the ration. The dry matter (DM) content of experimental silages was similar and exceeded 40%. Fibre fractions were found to be lowest in silage produced from Festulolium cv. Felopa, and highest in hybrid ryegrass cv. Bakus. Lambs fed cv. Felopa exhibited a tendency towards increased DM intake (1046.9 g/day), and were characterised by the highest daily weight gain. They also had the highest intramuscular fat content (4.49%) in the longissimus lumborum muscle. The feed value of hybrid ryegrass cv. Bakus and Festulolium was comparable. Felopa was superior to other cultivars in terms of nutrient intake, nutrient digestibility, dry organic matter digestibility, and its effect on lamb growth performance.

The proper fallowing of soil maintains or even improves its yield potential. The aim of this research was to compare five methods of soil protection with high production potential on the yield and quality of strategic plants. The tested methods consisted of five variants: bare fallow—BF; natural fallow—NF; fodder galega (Galega orientalis Lam.)—FG; a mixture of fodder galega (Galega orientalis Lam.) with smooth brome (Bromus inermis)—FG+SB; and smooth brome (Bromus inermis)—SB. The soil had been set aside for 9 years, after which time the fallows were terminated and the fields were cropped with winter oilseed rape, winter wheat, and spring wheat in three consecutive years. After the end of fallowing, the content of Nog. and Ctot., pH, and forms of available macro- and microelements in the soil were determined. The influence of each type of fallow on the yield of seeds/grain, straw, total protein, crude fat, and the content of macronutrients in the seeds/grain and straw of the grown crops was determined. Regarding the yields of the crops, the best solution was long-term soil protection via sowing fodder galega or a mixture of fodder galega and smooth brome. A field previously maintained as a fallow with these plants (singly or in combination) could produce over twice-as-high yields of wheat and oilseed rape as those harvested from a field established on bare fallow. The yields of the cereals and oilseed rape obtained in this study prove that food security and environmental protection issues can be reconciled. The methods for protecting farmland temporarily excluded from agricultural production presented in this paper correspond perfectly to the framework of the Green Deal for Europe. Arable land excluded from cultivation can be used to overcome new challenges facing modern agriculture.

Insect farming is growing in popularity, and in addition to insect meal, it generates waste products such as exuviae and frass, which can be recycled in agriculture. The aim of this incubation experiment was to evaluate the effect of Tenebrio molitor L. frass on selected chemical and biological properties of deacidified peat, which is widely used in horticulture. The optimal rate of frass fertilizer in peat for growing vegetables and ornamental plants was determined, with special emphasis on mineral nitrogen levels. Peat was fertilized with five nitrogen rates, 0, 50, 100, 200, and 400 mg dm−3, and supplied with frass or urea. The study demonstrated that frass can be used as organic fertilizer. An increase in the nitrogen rate significantly increased mineral nitrogen content and electrical conductivity and decreased Ca content in peat. Both frass and urea increased the ammonification rate at the beginning of incubation and the nitrification rate from the second week of the experiment. Higher frass rates (5 and 10 g dm−3) increased the content of plant-available nutrients (nitrogen, phosphorus, magnesium, potassium, and sodium) in peat as well as the abundance of microorganisms supporting organic matter mineralization. Unlike frass, urea increased the counts of nitrogen-fixing bacteria in peat.

Soil-dwelling microorganisms play an important role in the environment by decomposing organic matter, degrading toxic compounds and participating in the nutrient cycle. The microbiological properties of soil are determined mainly by the soil pH, granulometric composition, temperature and organic carbon content. In agricultural soils, these parameters are modified by agronomic operations, in particular fertilization. Soil enzymes participate in nutrient cycling and they are regarded as sensitive indicators of microbial activity and changes in the soil environment. The aim of the present study was to determine whether PAH content in soil is associated with the microbial activity and biochemical properties of soil during the growing season of spring barley treated with manure and mineral fertilizers. Soil samples for analysis were collected on four dates in 2015 from a long-term field experiment established in 1986 in Bałcyny near Ostróda (Poland). The total content of PAHs was lowest in August (194.8 µg kg-1) and highest in May (484.6 µg kg-1), whereas the concentrations of heavier weight PAHs was highest in September (158.3 µg kg-1). The study demonstrated that weather conditions and microbial activity induced considerable seasonal variations in PAHs content. Manure increased the content of organic carbon and total nitrogen, the abundance of organotrophic, ammonifying and nitrogen-fixing bacteria, actinobacteria and fungi and enhanced the activity of soil enzymes, including dehydrogenases, catalase, urease, acid phosphatase and alkaline phosphatase.

Abandonment of crop production on agricultural lands for several or more years is a widespread practice not only in Europe but also around the world. Economic and political considerations lead to the abandonment of crop production on the poorest lands, although sometimes agriculturally valuable lands are also excluded from farming. Fallow land can be afforested, designated as a dedicated protection area, exposed to natural succession, or used to grow biomass for energy purposes. However, the most important role of agricultural land should be to ensure food safety. The set-aside land with high production potential should be treated in a special way. While lying fallow, the soil can have its fertility sustained or even improved considerably. To this aim, uncultivated land should be properly protected by growing a permanent cover of plant species which will have a positive influence on the soil's physical, chemical, and biological characteristics. Depending on the geographical location, different plant species will have a beneficial effect on set-aside soil. Given economic and environmental considerations, the best solution is to sow a mixture of grasses and legumes, which can improve substantially the biodiversity on fallow fields, raise the soil's fertility, ensure high CO2 sequestration ratios, and influence beneficially the soil's nutritional status and nutrient management. Soil protection can be provided for many years with little effort. The most recent reports implicate that it is possible to achieve several economic and environmental aims simultaneously in the course of the management of land excluded from agricultural production. These aims include the improvement of biodiversity, control of greenhouse gas emissions, generation of energy, and readiness to resume production of commodity plants. Proper management of fallows corresponds well with the challenges defined in the Green Deal for Europe or the US Green New Deal.

The study aimed to develop a cost-effective and rapid approach for monitoring eleven crucial parameters that describe the health of cultivated Haplic Luvisol soils. To achieve this, the diffuse reflectance spectra in the NIR spectral region, between 1100 and 2500 nm, were registered, and partial least-squares (PLS) models to predict the concentrations of the critical parameters, including organic carbon, total nitrogen, the available soil nutrients (phosphorus, potassium and magnesium), the exchangeable cations (calcium, magnesium and potassium), the pH levels (determined in deionized water or KCl solution and hydrolytic acidity), were built. The validation results, which are expressed as RMSE and R2val that were obtained for validation the samples, demonstrate that the proposed approach is a reliable and efficient way to monitor the health of Haplic Luvisol soils. Specifically, excellent predictions were obtained for the total nitrogen, organic carbon and pH, which was determined in KCl solution with R2val values equal to 0.9696, 0.9573 and 0.9176, respectively. Additionally, very good PLS models were constructed to estimate the pH levels determined in deionized water, exchangeable magnesium, and po-tassium, which achieved R2val values of 0.8650, 0.8383, and 0.8329, respectively. For the remaining parameters, the corresponding R2val values were above 0.7294.

Polycyclic aromatic hydrocarbons (PAHs) are mainly accumulated in soil. Plants secrete enzymes that transform or biodegrade PAHs in soil. Some plant species are more effective in stimulating the biodegradation of these pollutants than other species. This study was undertaken to evaluate the influence of crop rotation on PAH concentrations in soil. Four crops were grown in rotation: sugar beets, spring barley, maize, and spring wheat. Soil samples for the study were obtained from a long-term field experiment established in 1986 in Bałcyny, Poland. The concentrations of PAHs were analyzed in soil samples gathered over a period of 12 years (1998–2009). An attempt was made to evaluate the effect of crop rotation (sugar beets, spring barley, maize, and spring wheat) on PAH concentrations in soil. The content of PAHs in soil samples was measured by gas chromatography with flame ionization detection. Data were processed statistically by repeated measures ANOVA. The concentrations of ∑16 PAHs were lowest in soil after sugar beet cultivation, and highest in soil after maize cultivation. It can be concluded that maize was the plant with the greatest adverse effect on the content of heavy PAH in the soil, a completely different effect can be attributed to spring wheat, which has always been shown to reduce the content of heavy PAH in the soil. Weather conditions affected PAHs levels in soil, and PAH content was highest in soil samples collected in a year with the driest growing season. This arrangement suggests a greater influence of weather conditions than of the cultivated plant.

The aim of this study was to assess the effect of long-term fertilization with manure and mineral fertilizers on the content and distribution of selected polycyclic aromatic hydrocarbons (PAHs)—the content of a sum of 16 polycyclic aromatic hydrocarbons, light and heavy PAHs in two soil layers (0–30 cm and 30–60 cm). The material for the study was composed of soil samples collected from the sixth rotation in a long-term, controlled field experiment, conducted in Bałcyny since 1986. The content of 16 polycyclic aromatic hydrocarbons was determined on a gas chromatographer coupled with an FID detector. In order to evaluate the significance of differences between the mean effects on the tested characteristics, a non-parametric Mann–Whitney U test for two independent samples was applied. A higher content of the sum (16) of PAHs was found in the 0–30 cm than in the 30–60 cm soil layer. The research results also demonstrated a higher content of the sum of light PAHs in the 30–60 cm than in the 0–30 cm soil layer. The content of heavy PAHs, in turn, was significantly higher in the upper than in the deeper soil layer. This dependence appeared in both the soil fertilized with manure and soil nourished only with mineral fertilizers.

This study illustrates the successful application of near-infrared reflectance spectroscopy extended with chemometric modeling to profile Cd, Cu, Pb, Ni, Cr, Zn, Mn, and Fe in cultivated and fertilized Haplic Luvisol soils. The partial least-squares regression (PLSR) models were built to predict the elements present in the soil samples at very low contents. A total of 234 soil samples were investigated, and their reflectance spectra were recorded in the spectral range of 1100-2500 nm. The optimal spectral preprocessing was selected among 56 different scenarios considering the root mean squared error of prediction (RMSEP). The partial robust M-regression method (PRM) was used to handle the outlying samples. The most promising models were obtained for estimating the amount of Cu (using PRM) and Pb (using the classic PLS), leading to RMSEP expressed as a percentage of the response range, equal to 9.63% and 11.5%, respectively. The respective coefficients of determination for validation samples were equal to 0.86 and 0.58, respectively. Assuming similar variability of model residuals for the model and test set samples, coefficients of determination for validation samples were 0.94 and 0.89, respectively. Moreover, the favorable PLS models were also built for Zn, Mn, and Fe with coefficients of determinations equal to 0.87, 0.87, and 0.79.

This article presents results of a three-year field experiment laid out on medium textured soil, in north-eastern Poland. Winter oilseed rape was sprayed with foliar fertilisers AgravitaActive 48 (AA48) - NPK 8:8.7:16.6 and AgravitaActive70 (AA70) - NPK 10:22.7:6.6 at different phases of the crop’s vegetative growth (BBCH 14, BBCH 35). The impact of the fertilisers on the yield of seeds, straw, total protein, crude fat, and on the content of macro- and micronutrients in aerial parts (BBCH 20 and 89) and roots (BBCH 20) of oilseed rape was evaluated. Foliar nutrition of oilseed rape plants with AA48 and AA70 significantly increased the seed yield of oilseed rape. The best yield-stimulating effect was achieved after the application of AA48 in autumn. Fertilisation of oilseed rape in that season of the year caused an increase in seed yield by 430 kg ha-1. Each fertiliser contributed to a rise in the yield of protein and yield of crude fat but had no effect on the content of magnesium, copper, and zinc in seeds.

Fodder galega is a perennial, wintering plant, which in recent years has been gaining popularity, mainly because of its useful characteristics. Many researchers have noted its large yield potential and exceptional adaptability to various environmental conditions. The purpose of this study was to collect the most up-to-date knowledge about this valuable plant, a member of the Fabaceae family. Green fodder, especially that made from young plants, possesses very good biochemical parameters which allow it to be used in the nutrition of animals including poultry. Plantations of fodder galega can be set up on highly diverse soils, and in all systems of management. The yielding potential of this plant is appreciated on all farms: organic, extensive and conventional ones. Many scientific studies have demonstrated the usefulness of fodder galega for the protection of farmland that is periodically excluded from farming. In recent years, reports have been published suggesting the high potential of this plant for the acquisition of inexpensive energy from its biomass. Moreover, many scholars have emphasised the medicinal applications of fodder galega. The advantages of the cultivation of fodder galega are (1) its low nutritional requirements; (2) a lack of threats from the specialised pests; and (3) its positive effect on soil fertility. It is recommended that areas having undergone several years of fodder galega cultivation act as very good forecrop for plants with high nutritional requirements.

The study assessed changes in the total 16 PAH (polycyclic aromatic hydrocarbon) content of soil which occurred in 1998–2009, during a multi-annual, manure-mineral and mineral fertilisation experiment, carried out in Bałcyny near Ostróda (Poland), according to a design unchanged since 1986 The study focused on the impact of multi-annual, diversified mineral fertilisation (N, P, K, Mg and Ca) compared to manure applied every two years at a dose of 40 t/ha. The four plants used in the crop rotation included sugar beet, spring barley, maize and spring wheat. The content of the total 16 polycyclic aromatic hydrocarbons was significantly higher in the manure-fertilised soil than in the soil fertilised with mineral fertilisers only. Under the regular manure fertilisation conditions, liming of the soil significantly increased the total 16 PAH content, and the lowest dose of nitrogen significantly decreased its PAH content. The lowest nitrogen dose had an opposite effect in the soil fertilised with mineral fertilisers only, where it caused a significant increase in the content of the PAHs. However, the increased doses of nitrogen also resulted in an increase in the PAH content in the soil fertilised with manure and without this fertiliser.

The aim of this study has been to evaluate the effect of sewage sludge and composted sewage sludge and municipal waste on the content of various forms of P in soil. The experiment scheme: C, control; NPK; FYM; DGSS, dried and granulated sewage sludge; CSS, composed sewage sludge; CSSS, composted sewage sludge and straw; CMMW, composted mixed municipal waste; CMGW, composted municipal green waste. The content of bound P was determined in the fractions: F1, easily soluble; F2, exchangeable; F3, organic; F4, carbonate; F5, stable organic-mineral and mineral bonds; and F6, residual. The NPK fertilisation as well as the soil fertilisation with organic substances raised the P-total content and of P bound in the fractions: F3, F4, F5 and F6. The highest amount of phosphorus in the studied soil was in fraction F3 (phosphorus in organic compounds) and the lowest in fraction F1 (phosphorus in the ionic form as H2PO4− and HPO42−). Composted sludge and straw introduced into the soil increased the content of readily soluble P (F1), while the NPK effect was reversed. NPK fertilisation and enhancement of soil organic matter (except CSSS, CMGW) led to a reduction of the P content in F2 fraction. The content of available P determined by the Egner-Riehm method depended on the content of C-organic, P-total and CEC soil. Among the determined phosphorus fractions, the content of available P was most strongly correlated with the content of P bound in the carbonate fraction (F4) and residual fraction (F6) and, less strongly, with the organic phosphorus fraction.

The purpose of this study was to evaluate the effect of ash from combustion of plant biomass of energy willow and Pennsylvania fanpetals on yields of willow grown as an energy crop and on soil properties. A three-year pot experiment was carried out on substrates with a loamy sand texture. Ash application rates were based on the potassium fertilisation demand. An incubation experiment was carried out to determine the effect of biomass-based ash on soil properties. Three soils with textural categories were incubated for 3 months with the ashes, the doses of which were determined on the basis of the hydrolytic acidity of soils (¼; ½ and 1.0 Hh). It was found that ashes generated from burning willow or Pennsylvania fanpetals can be applied instead of phosphorus, potassium and magnesium fertilisers in the cultivation of energy willow. The plant uptake of P, K and Mg from the ashes did not diverge from their absorption by plants when supplied with mineral salts. The application of these alkaline ashes will increase the soil content of phytoavailable forms of phosphorus, potassium and magnesium. The examined ashes enriched the soil with micronutrients.

A study was conducted to explore the effects of fertilisation with farmyard manure (FYM) and mineral fertilisers on the content of PAHs in soil. The analyses were made on soil samples (collected in 1998–2009) from a long-term field experiment set up in 1986 in Bałcyny near Ostróda. The content of light and heavy polycyclic aromatic hydrocarbons was determined on a gas chromatograph coupled with an FID detector. The analytical data were processed statistically according to an analysis of variance with repeated measurements. The content of light and heavy polycyclic aromatic hydrocarbons was significantly higher in soil fertilised with FYM than in soil nourished only with mineral fertilisers. The effect of increasing doses of potassium on total light PAHs in soil depended on a fertilisation system – there was either a distinct decrease in soil fertilised with mineral substances alone or a slight increase in soil fertilised with manure. Regular soil liming significantly raised the ∑ of heavy PAHs in soil treated with manure but significantly decreased it in soil supplied only mineral fertilisers.

Chromium (Cr) is a micronutrient that occurs in the natural environment in different oxidation states. Natural compounds contain chromium in the +3 oxidation state, whereas chromic(VI) acid derivatives are industrial products with strong toxicity. Hexavalent chromium compounds can adversely affect the respiratory system and the gastrointestinal tract, cause skin changes, and exert carcinogenic, mutagenic, embryotoxic as well as teratogenic effects. Research indicates that both organic and inorganic trivalent chromium compounds improve carbohydrate, lipid, and protein metabolism. These compounds are found in many enzymes, and they influence antioxidant processes, regulation of immune responses, and the secretion of hormones and selected vitamins in the body. In animals, Cr has been found to increase fat-free body mass, improve reproductive parameters, enhance growth, increase feed conversion efficiency, boost immunity, and decrease mortality. It has been suggested that Cr supplements can intensify the effects of insulin, decrease the plasma levels of non-esterified fatty acids (NEFAs), decrease triglyceride concentrations in the liver, and improve glucose tolerance, thus improving the performance and productivity of cattle in the perinatal period. Symptoms of chromium deficiency, including decreased feed intake, lower weight gains, reproductive disorders, and higher lipid levels, are observed in cattle fed diets that are low in this nutrient, and in animals that are exposed to considerable and prolonged stress. In ruminants, chromium supplementation is recommended during thermal stress, in the perinatal period, and during infections.

Soil temporarily excluded from agricultural production is exposed to several factors which deteriorate its chemical, physical and biological properties. To preserve the productive potential of uncropped soil, it is recommended that the soil surface be turfed. In the spring of 1996, a field experiment was set up in Knopin (municipality Dobre Miasto, the Province of Warmia and Mazury), where the effect of the type of a plant cover or its lack (bare fallow) on the physical and chemical characteristics of soil was investigated. One of the goals of the study reported below, which was conducted between 2000 and 2007, was to determine how the way uncropped farmland was maintained affected the content of nitrogen in soil. The experiment comprised five treatments: bare fallow, traditional fallow, a fallow field cropped with eastern galega (Galega orientalis Lam), or a mixture of eastern galega (Galega orientalis Lam.) and smooth brome (Bromus inermis), and finally a fallow field seeded with smooth brome (Bromus inermis). The set-aside land was only sampled for soil, while the biomass which grew on it every year was left in the field. Soil for analyses of physical and chemical characteristics was sampled from the 0-25 cm topmost layer, four times a year (April, July, September and November). During the research, there was only one agritechnical treatment performed, such as the mechanical weeding of the bare fallow field. The best way to maintain land excluded from agricultural production for many years proved to be by seeding it with eastern galega or its mixture with smooth brome. A far less beneficial solution was to grow smooth brome alone. When there was no grass on a field to synthetise free nitrogen, the content of nitrogen mineral forms in soil decreased. However, the depeletion of nitrogen from turfed soil was distinctly lower than from the soil kept as a bare fallow. Consistent eradication of weeds most probably ensured much better conditions for organic matter mineralisation. Hence, the concentration of nitrates in soil under a bare fallow field was the highest. The absence of a plant cover, as many authors maintain, exclude the possibility of the uptake of mineral nitrogen forms, which is conducive to their leaching into the deeper layers of a soil profile, a consequence which mostly affects nitrates. The study reported underneath supports this opinion. In the light of our results we can conclude that farmers should be discouraged from keeping set-aside land as a bare fallow.