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This study was aimed to determine the impact of risk element content on the prevalence of the selected microbial groups in industrial soils of one of the steelworks in Poland. The concentration of heavy metals: Cd, Cr, Cu, Hg, Fe, Ni, Pb and Zn along with soil pH and the number of mesophilic bacteria, fungi, actinomycetes and Azotobacter was assessed in 20 soil samples. The limit concentrations of Cd, Pb and Zn were exceeded in five sites. However, even in these strongly contaminates sites, the studied microorganisms were abundant. The correlation between the concentration of heavy metals and microbial numbers was very weak and statistically insignificant. High numbers of fungi were observed in the contaminated sites, which was particularly interesting in one of the sites, strongly contaminated with Cd, Pb and Zn.

Ozone, as a strong oxidative agent, is used to eradicate microbial, but this treatment affects also the quality of grain. The objective of this study was to evaluate the effect of ozonation of winter wheat grain harvested in different cropping and tillage systems on the number and composition of fungi colonizing grain surface and on the contents of total-phosphorus (P), phytate-P and phenolic acids. Wheat was sown in a two-factor experiment established with the method of randomized sub-blocks. The first order factor included cropping systems: (a) crop rotation and (b) monoculture, whereas the second order factor included tillage systems: (1) conventional (CT); (2) reduced (RT); and (3) herbicide. Ozonation significantly reduced the count of fungi on the surface of grain, especially on the grain harvested from wheat monoculture. In addition, it increased the content of phytate-P but decreased the content of total-P. A higher total-P content was determined in the grain harvested from monoculture than from crop rotation, whereas phytate-P content in the grain from crop rotation was higher than from monoculture. The ozonated grain harvested from CT plots was characterized by a higher content of phytate-P and a lower content of total-P, compared to the non-ozonated grain. Ozonation also increased the content of phenolic acids in the grain, especially in that harvested from the RT system.

Pot experiment was conducted under glasshouse conditions to investigate the effects of the inoculation of N₂ fixing Stenotrophomonas maltophilia strain Sb16 and application of three herbicides (paraquat, pretilachlor and 2,4-D) at 0, 1/2X, X and 2X their recommended field application rates (X) on endophytic bacterial populations and physio-morphological parameters of aerobic rice. The physio-morphological traits such as plant height, leaf area, chlorophyll content, nitrogen (N) content, root dry mass, root length, root volume and root average diameter were assessed at 60^th day after the treatment. Data on endophytic bacterial counts were collected at 15, 30, 45 and 60 days after the treatment. Results obtained from the study revealed that the number of endophytic bacteria and physio-morphological characters of aerobic rice significantly decreased with increasing herbicides dose. Sb16 inoculation significantly (P ≤ 0.0001) increased all the parameters measured. N contents were the highest (2.53 %) in the inoculated samples treated with half dose of 2, 4-D; but the lowest contents (1.89 %) were obtained in the non-inoculated samples treated with double dose of paraquat. The results suggest that Sb16 strain can improve productivity of aerobic rice under herbicide-stressed soil.

The yield forming response of maize cultivar to zinc (Zn) application depends on its timing. This hypothesis was validated in 2007, 2008, 2009 and 2010 growing seasons. The zinc treatments as the first factor were: NPK; NPK + Zn applied before sowing; NPK + Zn applied to maize at the stage of 4^th leaf. The second factor was the maize type: stay-green (modern cultivars) - Paroli, Veritis, Anamur; classical (old cultivars) - Inagua, Kirola. The grain yield of modern cultivars responded the best to zinc applied before sowing, whereas the old ones, when applied to foliage. The yield of the stay-green maize depended upon the number of kernels per row, whereas the classical one on all yield structural components. The zinc management in the modern cultivars should be oriented towards maximization of the number of kernels per row, whereas in the old one on its optimization with the simultaneous kernel weight increase. The positive impact of zinc application before sowing on dry matter translocation from vegetative tissues to growing kernels underlines its practical usefulness, especially in areas with frequent water shortage during maize growth.

Stalk lodging is a major constraint to limit grain yield under increased planting density in modern maize (Zea mays L.) production. A 3-year field experiment was imposed to study the effects of plant density and nitrogen (N) rate on stalk lodging and lodging-related stalk traits of two maize hybrids of contrasting susceptibility to lodging. The results indicated that the stem diameter, rind penetration strength (RPS), bending strength (BS), rind thickness, vascular bundle sheath's thickness (Vbs) and number of vascular bundle (Vb) of both hybrids all significantly decreased at the high density, while ear height and ear ratio clearly increased in Ludan981 (LD981; lodging-susceptible cultivar) with plant density increase. The lower plant height and ear height, stronger RPS and BS, and more Vb at high plant density might be reasons for Zhengdan958 (ZD958, lodging-resistant cultivar) had lower rate of stalk lodging. Meanwhile, N supply can significantly improve the stalk quality and decrease the risk of stalk lodging, however, little effects were observed in cv. LD981. Therefore, using lodging-resistant cultivar, planting at 82 500 plant/ha and supplying 180 kg N/ha can obtain high grain yield and low stalk lodging.

Two wheat cultivars (Gaocheng8901 and Yumai50) grown were used to investigate the effect of sulphur fertilizer on the glutenin macropolymer (GMP) size distribution and the contents of glutenin subunits in wheat. The results showed that the contents of GMP, high molecular weight glutenin subunit (HMW-GS) and low molecular weight glutenin subunit (LMW-GS) were improved by sulphur fertilizer under lower nitrogen (N) condition in both cultivars. Under normal N (240 kg N/ha) conditions, sulphur application improved the contents of HMW-GS, LMW-GS and GMP within sulphur rates from 30-60 kg/ha, while decreased when sulphur rate of 90 kg/ha. The volume percentage of GMP particles < 60 μm decreased within sulphur rates from 30-90 kg/ha under lower N treatments. Under normal N condition, the volume percentage of GMP particles > 60 μm increased within the sulphur rates from 30-60 kg/ha, while decreased when excessive sulphur of 90 kg/ha was applied. It is suggested that appropriate sulphur fertilizer was favourable for the formation of large GMP particles, but too much of it was unfavourable under normal nitrogen condition. Sulphur fertilizer did not significantly affect the number distribution of GMP particles in both cultivars. The volume percentage of GMP particles > 60 µm was positively correlated with H/LMW-GS (the ratio of HMW-GS and LMW-GS) and GMP content. It indicated that larger GMP particles had more the ratio of HMW-GS and LMW-GS. And the higher the proportion of larger particles, the higher the content of GMP in wheat grain.

The aim of this study was to compare the incidence of pathogens and pesticide residues in rapeseed samples depending on integrated and organic cultivation systems and cultivars. No pesticide residue was detected in seeds coming from the organic production system. However, trace amounts of pesticide residues admissible in rapeseed protection were detected for samples from integrated pest management. Seeds from both cultivation systems were most frequently infested by fungi Alternaria brassicicola and A. alternata. The greatest number of Leptosphaeria spp. cultures was obtained from seeds from organic cultivation.

A greenhouse experiment was conducted to investigate the effects of salt stress and ozone on yield and yield components of cucumber. The treatments were defined by a two-factorial design of three irrigation water salinity levels (2, 4 and 6 dS/m) and three ozone concentrations (0, 0.5 and 1 ppm). After germination, cucumber seeds were grown in pots containing soil, coco peat and perlite and fed with Hoagland's solution and were imposed with salt and ozone treatments. The results showed that salinity of irrigation water significantly reduced fruit yield of cucumber owing to a decrease both in fruit number and fruit weight. Also, statistical testing showed significant reductions in vitamin C, fresh and dry weight of shoot and root with increasing water salinity. Ozonated water improved fruit yield by increasing fruit number, but had no significant effect on fruit weight. Application of ozone caused significant increases in fresh and dry weight of shoot and leaf area but caused a significant decrease in the vitamin C. Generally, using ozonated water irrigation can induce positive effect on cucumber under salt stress. In conclusion, the saline water in combination with ozone could be recommended in strategic management to grow cucumber (without impaired effects on crop quantity).

The aim of the conducted study was to assess the effect of two types of stubble catch crops (a mixture of legumes and white mustard) as well as varied nitrogen fertilization on weed infestation of a spring wheat stand depending on the adopted tillage system. Weed infestation assessed at the tillering phase of spring wheat showed the lowest number of weeds in direct sowing after the mixed legume catch crop. The next assessment of weed infestation performed at the flowering phase of spring wheat showed that the lowest number of weeds was found in direct sowing immediately after the catch crop of a mixture of legumes and white mustard for the complete nitrogen fertilization rate. The lowest weed dry weight was recorded in conventional tillage after a mixture of legumes for the complete nitrogen fertilization rate and after white mustard for a reduced nitrogen fertilization rate.

Influence of plant growth regulators chlormequat chloride, chlormequat chloride + ethephon, ethephon, and mepiquat chloride + prohexadione-Ca + pyraclostrobin + ammonium sulphate (BAS67800F + BAS00800D) on decreasing sunflower height was evaluated. It was determined that sunflower height can be reduced by as much as 30 cm. In the case of BAS67800F + ammonium sulphate, there was a slight difference between application at BBCH 31-33 and BBCH 50-51, whereas for ethephon better application time was at BBCH 50-51. For chlormequat chloride, application at BBCH 31-33 was better, but height reduction did not endure until harvest. Flower head diameter shortly before harvest was not affected at any tested regulator. Flowering was delayed primarily at applications at BBCH 50-51.

In a two-year pot experiment, the effect of five growing media on the growth, flowering, decorative value of Pelargonium peltatum cv. Maxime as well as on their uptake of the nutrients and heavy metals were studied. The media were prepared from four composts (made from: sewage sludge 70% or 35%, potato pulp 35%, straw 30% or sawdust 30%) and peat in 1:1, V:V ratio. In the 1^st year of research 7-month-old composts and in the 2^nd year 18-month-old composts were used. Plants cultivated in 7-month-old composts showed better growth-related parameters, created more inflorescences and were more decorative than those cultivated in 18-month-old ones. The medium with compost consisting of 70% sewage sludge and 30% straw gave the best results. Composts application increased nutrients and heavy metals content in pelargonium leaves. Heavy metals content was definitely lower than the value considered toxic to plants.

Biosolids are organic fertilisers derived from treated and stabilised sewage sludge that increase soil fertility and supply nitrogen to crops over a long period, but can also increase the risk of nitrogen (N) leaching. In this work, spring barley was grown in lysimeters filled with soil amended with biosolids, and with and without mineral N fertilisation. Biomass and the N concentration and content of shoots and roots were determined at flowering and maturity, and the N remobilization was calculated during grain filling. Drainage water was collected and analysed for N leaching. Biosolids increased soil porosity and soil nitrate, and positively affected the growth and N uptake of barley. Compared to mineral fertilisers, biosolids produced 18% higher vegetative biomass and 40% higher grain yield. During grain filling, both N uptake and N remobilization were higher with biosolids, which increased the grain N content by 32%. Nitrogen loss in leachates was 1.2% of plant uptake with mineral fertilisers and 1.7% with biosolids. Thus, soil fertilisation with biosolids greatly benefits spring barley, only slightly increasing N leaching.

Recycling of phosphorus (P) from municipal waste for the use as a fertiliser can be an alternative to the non-renewable resources of this element as well as a method in the management of civilisation by-products that are a burden to the environment. An innovative phosphorus suspension fertiliser, produced on the basis of ash from incineration of sewage sludge and phosphorus solubilising bacteria Bacillus megaterium was compared in field trials with spring wheat conducted in 2014 and 2015 with superphosphate and phosphorite. The new fertiliser was not inferior to the commercial fertilisers in terms of the effect on wheat yield volumes, the uptake of P by wheat and the sanitary condition of the wheat field, especially when grown protected from weeds, pathogens and pests. It is expected that such a fertiliser can be an alternative to fertilisers produced from non-renewable resources, provided it does not deteriorate the quality of agricultural production and will be safe for the environment.

Soils of forest ecosystems can release or consume methane (CH₄) depending on their specific hydrological regime. Our study reported the consumption of CH₄ by soil in a lowland broadleaf mixed temperate forest in the Czech Republic (Central Europe). The motivation of our study was to determine the importance of CH₄ fluxes in context of carbon dioxide (CO₂) fluxes of a broadleaf mixed forest. CH₄ and CO₂ emissions from the soil were measured during the 2016 vegetation season on a long transect applying the chamber technique. The average daily consumption of atmospheric CH₄ by the forest soil ranged from 0.83 to 1.15 mg CH₄-C/m²/day. This consumption of CH₄ during summer and autumn periods was not significantly affected by soil temperature and soil moisture. However, during spring period the consumption of CH₄ was positively significantly affected by soil temperature and moisture. Estimated amount of carbon (CH₄-C) consumed by the forest soil makes up a very small part of carbon (CO₂-C) participated in the ecosystem carbon cycle.

The aim of this study was to test different soil phosphorus (P) extraction methods in relation to plant P uptake. A greenhouse pot experiment was conducted with spring wheat. The soils were extracted with the following methods/extractants: H₂O, CaCl₂, LiCl, iron oxide impregnated filter papers (Fe-oxide P_i), Olsen, calcium-acetate-lactate (CAL), cation and anion exchange membranes (CAEM), Mehlich 3, Bray and Kurtz II (Bray II), citrate-bicarbonate-dithionite, organic P, HCl, acid ammonium oxalate, total P. Plant P uptake was in the range of the P extracted by neutral salt solutions (CaCl₂, LiCl). P extracted with H₂O, CaCl₂ and CAEM correlated best with plant P uptake over one growing season, while several established soil P test methods, including CAL, Mehlich 3 and Bray II, did not show significant correlations. When grouping the soils according to pH, the weaker extraction methods (H₂O, CaCl₂, LiCl) showed significant correlations with plant P uptake only for the low and intermediate pH groups (pH in 1 mol/L KCl ≤ 6.6), while some of the stronger extraction methods (CAL, Mehlich 3, Bray II, dithionite, oxalate, total P) showed significant correlations only for the high pH group (> 6.6) comprised of calcareous soils. It was concluded that weaker P extraction methods, especially neutral salt solutions best predict plant-available P in the short term. However, they do not perform well for calcareous (and clayey) soils and do not account for P that may become available beyond one growing season.

The studies determined the effect of bacteria Bacillus spp. and Pseudomonas spp. isolated from the soil after carrot cultivation on pathogenic fungi Altenaria dauci, A. radicina, Fusarium oxysporum, F. solani, Rhizoctonia solani and Sclerotinia sclerotiorum. A field experiment on carrot cultivation considered different intercrop plants (rye, buckwheat, white mustard, sunflower). Rye and buckwheat were the most conducive to the growth of Bacillus spp. and Pseudomonas spp. Those bacteria were the most effective in inhibiting the growth of F. solani, F. oxysporum and R. solani. The antagonistic effect of soil-borne Bacillus spp. and Pseudomonas spp. towards the tested fungi was the largest after the application of rye and white mustard as intercrop plants in the cultivation of carrot. Buckwheat and sunflower showed a slightly smaller influence on the antagonistic activity of the studied bacteria. Bacillus ssp. had a significantly lesser antagonistic effect than Pseudomonas ssp.

Soil bacteria are critical to maintain soil fertility. In this study, soil chemical properties, enzyme activities and soil bacterial community from a long-term fertilizer experiment (37 years) were analysed to elaborate the effects of long-term mineral fertilizer application on soil enzyme activities and bacterial community composition. Compared with control treatment, bacterial community richness was reduced in low nitrogen (N) fertilizer and high N fertilizer treatments and increased in high N fertilizer and phosphorus (P), high N fertilizer and potassium (K) (N2K), and high N fertilizer, P and K (N2PK) treatments. The distribution of each phylum and genera was obviously changed and the range of the dominant phyla was not affected in all fertilization treatments. Principal component analysis showed that soil bacterial community in the N2K treatment was clearly different than in the N2PK treatment. The N2PK treatment had much higher available P, total organic carbon, invertase, urease and phosphatase activities than the N2K treatment, which might change soil bacterial community composition. In conclusion, fertilization with combined application of P, K and N in appropriate proportions is an optimum approach for improving soil quality and soil bacterial community abundance in non-calcareous fluro-aquic soils in the North China Plain.

The aim of this research is to estimate the influence of a bioeffector (BE) application on dry matter yield and nutrient content (P, K, Ca, Mg, S) in maize (Zea mays L.). Between 2014 and 2016, a field experiment with silage maize as a testing plant was realized on sandy loam Cambisol. The application of Pseudomonas sp. in combination with phosphorus (rock phosphate (RP) or triple superphosphate (TSP)) and nitrogen fertilizers (ammonium nitrate with urea, ammonium nitrate with limestone, calcium nitrate or ammonium sulfate with a nitrification inhibitor) and with different application strategies was studied. The effects of a bioeffector application on the increase of dry matter yields were not confirmed. An important influence on the BE application and its activity was probably those of soil and site conditions and competition of the researched microorganisms with other present microorganisms. Higher yields of dry matter were shown in treatments where P fertilizers were applied. There was almost no difference between the application of RP and TSP. This could be caused by the fact that the soil had a slightly acidic pH value. In this case, the RP showed similar results to the TSP. The application of bioeffector significantly increased Mg, K and S contents in maize above-ground biomass. An increase of the Ca content was almost significant and a tendency towards a higher average content of phosphorus was also recorded.

Mehlich 3 is an extractant used worldwide for extracting bioavailable nutrients in soils; however, its extraction abilities for sulfur (S) are still not well described. The aim of this preliminary study was to compare the results of Mehlich 3 determined soil S fraction (S_M3) with the results of sulfur fractionation, mainly focusing on bioavailable S (S_av - sum of water-extractable (S_w) and adsorbed (S_ads) sulfur). Air dried soil samples from commonly used agricultural soils were chosen for the analyses. The following S fractions were determined: (i) S_w; (ii) S_ads; (iii) S_av; (iv) 1 mol/L HCl extractable (S_HCl); (v) estersulfate (S_es); (vi) organic (S_org) and (vii) total (S_tot). The median value of S_M3 (18.3 mg/kg) was similar to S_av (17.9 mg/kg). From the correlation and regression analysis it is clear that S_M3 results are in close relationship with S_av form. On the other hand, the relationships between S_M3 and organic S (including S_HCl) were very weak. Based on the obtained results it can be concluded that Mehlich 3 method has a good potential to determine bioavailable sulfur in commonly used agricultural soils. However, especially the plant response should be further studied to confirm this theory.

Spectral data contain information on soil organic and mineral composition, which can be useful for soil quality monitoring. The objective of research was to evaluate hyperspectral visible and near infrared reflectance (VNIR) spectroscopy for field-scale prediction of soil properties and assessment of factors affecting soil spectra. Two hundred soil samples taken from the experiment field (soil depth: 30 cm; sampling grid: 15 × 15 m) were scanned using portable spectroradiometer (350-1050 nm) to identify spectral differences of soil treated with ten different rates of mineral nitrogen (N) fertilizer (0-300 kg N/ha). Principal component analysis revealed distinction between higher- and lower-N level treatments conditioned by differences in soil pH, texture and soil organic matter (SOM) composition. Partial least square regression resulted in very strong correlation and low root mean square error (RMSE) between predicted and measured values for the calibration (C) and validation (V) dataset, respectively (SOM, %: R_C² = 0.75 and R_V² = 0.74; RMSE_C = 0.334 and RMSE_V = 0.346; soil pH: R_C² = 0.78 and R_V² = 0.62; RMSE_C = 0.448 and RMSE_V = 0.591). Results indicated that hyperspectral VNIR spectroscopy is an efficient method for measurement of soil functional attributes within precision farming framework.

Four clones of short rotation coppice (SRCs) were investigated for phytoextraction of soil contaminated by risk elements (REs), especially Cd, Pb and Zn. As a main experimental factor, the influence of rotation length on the removal of REs was assessed. The field experiment with two Salix clones (S1 - (Salix schwerinii × Salix viminalis) ×S. viminalis; S2 - S. × smithiana) and two Populus clones (P1 - Populus maximowiczii × Populus nigra; P2 - P. nigra) was established in April 2008 on moderately contaminated soil. For the first time, all clones were harvested in February 2012 (2012_4y) after 4 years. Subsequently each plot was equally split into halves. The first half of the SRC clones was harvested in February 2014 after 2 years (2014_2y) and again it was harvested in February 2016 after further 2 years (2016_2y). The second half was harvested in February 2016 after 4 years (2016_4y). The results showed that the biomass production for the second 4-year harvest period was significantly higher for all clones but the metal concentration was lower in the mentioned period. 4-year rotation seems to be more advantageous for the phytoextraction than two 2-year rotations. The highest metal removal presented by remediation factors (RFs) per 4 years for Cd (6.39%) and for Zn (2.55%) were found for S2 in the harvest 2016_4y treatment. Removal of Pb was the highest by P1 clone with very low RF per 4 years (0.04%). Longer rotation is also economically superior.

The present studies aim at determining the antagonistic effect of selected fungi species occurring in the soil under carrot cultivation towards Altenaria dauci (J.G. Kühn) J.W. Groves & Skolko, Alternaria radicina Meier, Drechsler & E.D. Eddy, Fusarium oxysporum E.F. Sm & Swingle, Rhizoctonia solani J.G. Kühn and Sclerotinia sclerotiorum (Lib.) de Bary. The field experiment considered cover crops (oats, tansy phacelia and vetch). The control consisted of traditional carrot cultivation (without cover crops). Statistically, the smallest population of fungi was found in 1 g of soil dry weight after the application of oats, and a slightly bigger - after tansy phacelia and vetch. The largest population of fungi was obtained in the traditional cultivation of carrot. Cover crops contributed to the increase of the population of antagonistic Clonostachys spp., Myrothecium spp., Penicillium spp. and Trichoderma spp. in the soil. Regardless of the experimental treatment, those antagonistic fungi were the most effective in limiting the growth of S. sclerotiorum, A. dauci and A. radicina. The effect of those fungi was a little smaller towards F. oxysporum and R. solani. Oats as a cover crop had the best effect on the antagonistic activity of the studied fungi occurring in the soil environment of carrot.

Excessive nitrogen (N) and water input, which are threatening the sustainability of conventional agriculture in the North China Plain (NCP), can lead to serious leaching of nitrate-N (NO₃^--N). This study evaluates grain yield, N and water consumption, NO₃^--N accumulation and leaching in conventional and two optimized winter wheat-summer maize double-cropping systems and an organic alfalfa-winter wheat cropping system. The results showed that compared to the conventional cropping system, the optimized systems could reduce N, water consumption and NO₃^--N leaching by 33, 35 and 67-74%, respectively, while producing nearly identical grain yields. In optimized systems, soil NO₃^--N accumulation within the root zone was about 80 kg N/ha most of the time. In the organic system, N input, water consumption and NO₃^--N leaching was reduced even more (by 71, 43 and 92%, respectively, compared to the conventional system). However, grain yield also declined by 46%. In the organic system, NO₃^--N accumulation within the root zone was generally less than 30 kg N/ha. The optimized systems showed a considerable potential to reduce N and water consumption and NO₃^--N leaching while maintaining high grain yields, and thus should be considered for sustainable agricultural development in the NCP.

Monitoring of grassland dry matter yield (DMY) is important for the economy and ecosystem management, but it is a time-consuming process. Calculating the correlation between compressed height (CH) and DMY is a faster way to estimate DMY. The aim of our study was to use CH in order to predict DMY for a meadow with different fertilization management and plant species composition. Four fertilization treatments and one unfertilized control were established in a mesophilic meadow in the Czech Republic. Using a rising plate meter (RPM), CH was measured before the first and second cuts. In addition, the cover of individual vascular plant species was estimated. Significant correlations between CH and DMY were ranging from 0.41 to 0.79 for treatments without nitrogen fertilization in the first and second cuts; for treatments with nitrogen fertilization there was a significant correlation only in the second cut. According to our results, the RPM method seems to be suitable for a rough DMY estimate for meadows with coverage of about 60% grasses, 10% legumes and 30% forbs. However, considerable changes in the cover of tall forbs (e.g. Urtica dioica L.) or tall grasses (e.g. Dactylis glomerata L.) could be the main sources of DMY estimation inaccuracy.

Soil erosion by water has become an issue in the cultivation of maize (Zea mays L.) on sloping lands in recent years. The following three technologies of tillage have been assessed: disc cultivator, strip-till and no-till (raw land). Seeding machine Kinze 3500 was used for sowing maize cultivar Silvinio FAO 210. The experiments were conducted within the years 2013, 2014 and 2016. Erosion was evaluated under simulated rain in three stages of maize growth. The following parameters of each tested tillage treatment were measured: water infiltration (mm), soil loss (converted to t/ha), dry matter yield of the aboveground biomass and grain yield. The results confirmed that no-till technology reduced water erosion to the value of 0.40 t/ha. This technology along with the row spacing of 0.75 m tended to bring higher yields of aboveground biomass (13.40 t/ha). Tillage and phacelia as a catch crop increased water infiltration in the soil.

A field experiment was conducted on rendzina soil in the years 2010-2012. The seeds of two linseed cultivars (Szafir and Oliwin) were sown at row spacing of 15 cm and 25 cm. Three agrotechnical levels in different nitrogen doses and with or without application of herbicides were used. The objective of the study was to evaluate the effect of row spacing on yield, seed protein and oil content of two linseed cultivars grown under different conditions of mineral fertilization and chemical weed control. Results showed that cv. Szafir was characterized by significantly higher seed yield (on average by 20.2%) and protein content (by 2.6%) while cv. Oliwin had higher content of oil (by 4.9%). Intensive technology of cultivation (80 kg N/ha, Linurex 50 WP, Fusilade Forte 150 EC, Glean 75 WP), compared to the economical technology (40 kg N/ha, without herbicides), significantly increased the seed yield of both linseed cultivars (on average by 80-102%). This was due to higher plant density, higher number of branches, and higher number of capsules per plant. The intensive technology of cultivation had a beneficial effect on the content of α-linolenic acid in linseed seed.

Potato (Solanum tuberosum L.) crop is the world's number one non-grain food commodity and the fourth main food crop in the world after maize, rice and wheat. It is a typical plant mainly of temperate climate. Chlorophyll a fluorescence kinetics is an informative tool for studying the effects of different environmental stresses on photosynthesis. The aim of this work was to study the response of selected potato cultivars to meteorological conditions during the growing season and physiological age of plants using chlorophyll a fluorescence parameters. The pot experiment was carried out over the course of 2 years with six early cultivars. Chlorophyll a fluorescence measurements were performed on the plants with a Pocket plant efficiency analyzer determined parameters were: F_v/F_m (the ratio of variable to maximal chlorophyll fluorescence) and PI (the performance index of photosystem II). In total 2040 measurements of each parameter were made. Final harvest was performed after full maturity of plants. The results of the experiments were analysed with ANOVA. Changes of chlorophyll a fluorescence parameters in terms of physiological age were analysed using polynomial regression model. A significant negative correlation between the maximum air temperature and PI parameter was found as well as a significant negative correlation between physiological age of potato plants and both chlorophyll a fluorescence parameters.

The aim of study was to compare the effect of farming methods on soil microbial communities and dehydrogenase activity (DHA). During 2008-2013, in the five-field crop rotation the following treatments were carried out: ORG - organic; ORGFYM - organic with cattle manure; CONFYM - conventional (cattle manure, mineral fertilizers and pesticides were used). From the treatments soil samples in three replicates were taken for microbiological tests in September yearly. Total bacteria and cellulose decomposing bacteria were determined as a number of colony forming units per g of dry soil. Soil DHA was determined in accordance with Tabatabai (1982). Solid cattle manure applied in the ORGFYM rotation increased significantly (P < 0.05) the number of total bacteria and cellulose decomposing bacteria (by 19.4% and 45.3%, respectively), and DHA by 22.7%. There appeared no clear and significant differences in effects between ORGFYM and CONFYM treatments, as an average of experiment period. In some cases, the use of certain pesticides in CONFYM treatment significantly affected the microbe numbers and soil DHA.

The paper presents the results of studies concerning the phytotoxicity of biodiesel and its diesel oil blends with a germination and root elongation test. The paper also analyses the effect of fuel on the number and activity of soil microorganisms and the reaction of plants used in the research. Fuel was introduced into the soil at a concentration of 10 and 50 g/kg dry mass soil. Based on the test results, it was found that from among 19 plants species representing 5 families taxonomically, only 4 species showed resistance to the presence of the fuel in soil, regardless of their type and dose (Glycine max (L.) Merill, Helianthus annuus L., Lupinus luteus L., cv. Lord and Pisum sativum L., cv. Eureka). Fuel generally reduced the number of heterotrophic microorganisms, and stimulated the growth of decomposing microorganisms and content of biomass. Significant differences in the number and activity of microorganisms were associated with the presence of biodiesel in the soil. The fuel had a negative influence on the biometric and physiological parameters of plants. A shorter length of shoots and roots was noted, especially in objects with biodiesel, reduced water content, and general content of assimilation pigments.

The objective of this study was to analyze the effect of tillage systems and nitrogen fertilization on the grain yield and quality of spring wheat and on selected chemical and biological properties of soil. The first order factor was the tillage system: (1) conventional (CT) - shallow ploughing and harrowing after harvest of the previous crop, and pre-winter ploughing; (2) reduced (RT) - only a cultivator after harvest of the previous crop, and (3) no-tillage (NT) - only Roundup 360 SL herbicide (a.s. glyphosate) after harvest of the previous crop. The second order factor was nitrogen dose: (1) 90 kg N/ha and (2) 150 kg N/ha. Higher yields were demonstrated for spring wheat sown in CT and RT systems, compared to the NT system. In addition, grain yield was increased by a nitrogen dose of 150 kg/ha, compared to 90 kg/ha. Contents of protein and wet gluten in the grain were also increased by the higher nitrogen dose. The RT and NT systems were observed to increase the content of organic C, total N and available phosphorus in the soil, compared to the CT system. They also increased the number and mass of earthworms in the soil, compared to the CT system.