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A reliable tuber yield prognosis requires a complex statistical analysis of potato nutritional status in the fully developed 4^th leaf at the onset of tuberisation. This hypothesis was validated in the series of field experiments conducted in 2006-2008 in Poland. The experimental design was composed of two nitrogen (N) rates (60, 120 kg/ha), two N fertilisers (Urea and Agrotain), two rates of sulfur (0, 50 kg/ha). The marketable tuber yield of cv. Zeus ranged from 31.3 to 59.3 t/ha in 2008 and 2006, respectively. Despite annual variability, the potato presented a good nutritional status. In 2008, the contents of N, Mg, Cu and Zn were about 33% lower as compared to 2006. The stepwise and path analyses indicated N, Mg and Cu as the key yield-limiting nutrients. The diagnosis and recommendation integrated system (DRIS) showed that a slight imbalance of N and Mg did not disturb tuber yield, provided a positive balance of K was maintained. The Mg index, as a result of the DRIS procedure, emerged as the best single predictor of potato yield.

Members of Brassicaceae have been frequently cited as allelopathic crop. The toxic effect of Brassica spp. may be caused by hydrolysis products of glucosinolates that occur in substantial amounts in the vegetative parts of Brassica spp. This study investigated the allelopathic potential of Brassica napus, B. rapa and B. juncea on the sunflower seed germination and seedling growth. Aqueous extracts of three species from two stages (full flowering and straw) of sampling were separately made with 0 (distilled water), 10, 20, 30 and 40% concentrations. This experiment was conducted in 2 × 3 × 5 factorial arrangement based on completely randomized design with five replications. There was a highly significant difference among different concentrations of extracts and also between two stages of extraction. All aqueous extracts significantly affected sunflower germination, germination rate, seedling root and hypocotyl length, fresh and dry matter weight when compared with distilled water control. The greatest concentration showed a stronger inhibitory effect. Root length was more sensitive to extracts than hypocotyl length.

To estimate the long-term performance and the optimal ratio of feldspathic sandstone with sandy soil, experiments with different ratios of feldspathic sandstone to sandy soil (0:1, 1:1, 1:2 and 1:5 v/v) was conducted. The physical properties as soil texture, water-stable aggregate (WR0.25) content, and the organic carbon content of the composited soil for 6 years, and corn yield for 9 years were determined. Our results showed that after the addition of feldspathic sandstone: (1) soil texture was notably improved, changing from sand loamy soil (1:2 and 1:5) to sand loam soil (1:1) and silt sand soil (1:1) over planting time; (2) content of water-stable aggregate (WR0.25) significantly increased: WR0.25 of treatments 1:1, 1:2 and 1:5 all increased (by 29.26, 31.47 and 11.56%, respectively) compared with that of treatment 0:1; (3) the organic carbon content of the composited soils increased with time in all treatments. After six years of planting, average organic carbon content in treatments 1:1, 1:2 and 1:5 were 1.64, 1.51 and 1.77 g/kg, respectively, which were higher than that of 0:1 treatment; and (4) among the three ratios, treatment 1:2 (12 984 kg/ha) had the highest corn yield, followed by treatment 1:1 (12 040 kg/ha) and 1:5 (11 301 kg/ha). In conclusion, with a good performance, 1:2 was the best ratio of feldspathic sandstone to sand in improving the sandy soil structure of the Mu Us Desert, China.

The paper presents the impact of a historical system of terraces constructed centuries ago to mitigate the effect of a steep slope on overland flow. Systems of this type were constructed in past centuries by land owners, who then ploughed the land and grew crops on it. They used stones collected from the local agricultural fields as their terracing material. The influence of terraces on overland flow was simulated using the KINFIL. The overland flow is therefore reduced by greater infiltration of extreme rainfall excess flows on the terraces, and the KINFIL model shows to what extent the system of terraces can mitigate the resultant flood and soil erosion. The Knínice locality in North-Western Bohemia, with seven terraces and six field belts between them, was selected as the experimental catchment area. The results compare hydrographs with N-year recurrence of rainfall-runoff time, where N = 10, 20, 50, and 100 years, and the hydraulic variables, e.g. overland flow discharges of a design rainfall, hydraulic depths, flowing water velocity, and shear stress. The comparison provides hydraulic results with terraces and without terraces. The contrast between the results with and without terraces shows the positive role of the system of terraces in protecting the field belts.

This study was based on a long-term field experiment established in 1967 in which winter wheat is grown in two rotations consisting of: potato-winter wheat-fodder crops-winter wheat (rotation A) and oat-winter wheat-winter rye-winter wheat (rotation B). In the years 2010-2013 selected soil properties and winter wheat yields as influenced by these rotations were analysed. The soils under winter wheat grown in crop rotations A and B contained similar amounts of total organic carbon (C) (0.76% and 0.80%, respectively) and did not differ significantly with respect to biological characteristics (contents of microbial biomass C and nitrogen (N), dehydrogenase and acid phosphatase activities). Averaged for 3 years, the highest grain yields were obtained for winter wheat grown after potato in rotation A (7.94 t/ha) and the lowest (6.0 t/ha) for wheat following winter rye in rotation B. The highest take-all index and the lowest numbers of ears/m² were the main factors influencing poor performance of winter wheat following rye.

The objective of the present work was to determine changes in total sugars, reducing sugars and sucrose content in potato tubers under conditions involving an application of biostimulants and herbicides. Research material included table potato tubers obtained in a three-year field experiment. The experiment was a split-plot design with three replicates. The factors were as follows: factor I - three table potato cultivars (Bartek, Gawin and Honorata), factor II - five methods of biostimulant and herbicide application (1. control - without biostimulants or herbicides; 2. Harrier 295 ZC (linuron + chlomazon); 3. Harrier 295 ZC (linuron + chlomazon) and growth regulator Kelpak^®SL; 4. Sencor 70 WG (metribuzin); 5. Sencor 70 WG (metribuzin) and growth regulator Asahi^®SL. Variance analysis demonstrated that total sugars, reducing sugars and sucrose content were affected by the biostimulants and herbicides applied as well as cultivars and weather conditions. Compared with control, a significant increase in total sugars followed an application of Sencor 70 WG as well as Sencor 70 WG and the growth regulator Asahi^®SL whereas reducing sugars and sucrose content significantly increased after Sencor 70 WG and the growth regulator Asahi^®SL were applied.

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.

The objective of the study was to examine a possibility of predicting phosphorus leaching from the top layer of agricultural soils by rainfall simulations by means of three multi-nutrient soil tests: Mehlich 3, NH₄-acetate extraction and water extraction (1:5, w/v). Another objective was to determine parameters of maximum phosphorus losses after an extreme load of rainfall on the top layer. Forty soils from different localities of the Czech Republic were used for the experiment. A leaching experiment was conducted in pedological cylinders with a soil layer of about 1 cm and with the bottom from a glass microfibre filter with pores 1.2 μm in size. Within 15 days the soils were flooded ten times with 25 mm of simulated rainfall in a minimum interval of 1 day. The closest regression between the soil test and phosphorus leaching was computed for NH₄-acetate soil test (R² = 0.8831) and Mehlich 3 test (R² = 0.8572) after the first application of 25 mm of rainfall. In water extraction it was for the mean of 10 simulated rainfalls (R² = 0.8674). As leaching proceeded, the closeness of regression diminished due to fluctuations of P concentration in leachates (increases and decreases), mainly in soils with higher P-test. The increase in P concentration could be caused by the activation of phosphorus from Fe-phosphates under anaerobic conditions in wet soils. The steepest decrease in P concentration in leachates was observed in light soils with low CEC value and higher initial P-test.

An incubation study was carried out to investigate the influence of nitrogen rates to determine optimum C/N ratio under various moisture levels for straw decomposition and sequester carbon (C) in the soil. The aim was to observe straw carbon mineralization through measuring the amount of CO₂ evolution. A clay loam topsoil mixed with maize straw was supplied with four nitrogen rates (0.04, 0.08, 0.16, 0.32 g N/kg) using (NH₄)₂SO₄ to adjust C/N ratios at 82, 42, 20, and 10. Soil moisture was maintained at 55%, 70%, 85%, and 100% of field capacity incubated at 25°C for 53 days. The experiment was set up with 16 treatments arranged in complete randomized design. Results showed that mixing of straw with soil increased 50% cumulative CO₂-C compared to controls. Averagely, about 44% of added maize straw C was mineralized to CO₂-C. Straw addition along with nitrogen and moisture had significant relationships (P < 0.05) to cumulative CO₂-C, soil organic C and microbial biomass C. There was a highly significant relationship (R² = 0.99) between CO₂-C emission and incubation time.

Relatively little is known about potassium leaching losses following harvest of silage maize. While direct negative impacts on the environment are unlikely, losses of K with leaching need to be known for accurate balancing, especially on coarse textured soils, where K can be a critical element. In a four-year field experiment the effects of fertilizer forms (inorganic, cattle slurry and pig slurry) and four levels of N input (0, 80, 160, 240 kg N/ha) with corresponding amounts of K on the nutrient balances and leaching of K from silage maize grown on a sandy soil were investigated using suction cups. After four years, surplus of K from cattle slurry led to higher lactate-soluble K in the topsoil. Potassium leaching differed between years with different amounts of rainfall during winter. Annual leaching losses of K increased with N and K input and amounted to 38 kg K/ha, while fertilizer form had no significant effect. Losses of K increased with increasing N leaching (R² = 0.69). We conclude that in maize production on coarse textured soils and under conditions of high N leaching (86-152 kg N/ha), K leaching can be large (6-84 kg K/ha) and constitutes a relevant part of K balances (-84 to +127 kg K/ha).

Bromus species are annual winter weeds from the Poaceae family which have become troublesome weeds of winter cereals. The herbicides propoxycarbazone and pyroxsulam are widely used for control of B. sterilis. The objective of this study was to determine the effect of different types of adjuvants and carriers on the efficacy of pyroxsulam and propoxycarbazone on B. sterilis. Small plot field trials were carried out in North Bohemia, Central Europe during 2011-2013. The tested carriers and adjuvants affected the efficacy of both herbicides and the seed production of B. sterilis. Urea ammonium nitrate was a less effective carrier than water (differences 5-30%). The most effective adjuvant was methylated seed oil (MSO), whose addition into the application water solution increased the herbicide efficacy of propoxycarbazone by 5-35%. Efficacy of the herbicide pyroxsulam was increased by adjuvant MSO by 10-30%. Nonionic surfactant increased herbicide efficacy only in 2013 (by 17%). Effect of organosilicone surfactant on the herbicide efficacy was negative (lower efficacy). Seed production of B. sterilis on untreated plots ranged between 20 000 and 50 000 seeds/m² in experimental years. Seed production was the lowest on plots treated by the herbicide plus MSO (1300-4500 seed/m²).

Temporal changes in the concentrations of plant-available phosphorus (P) in soil (Olsen-P), total soil-P and P activation coefficient (the ratio of Olsen-P to residual-P (i.e. an approximation to total-P)) were measured in plots that received consistent inorganic nitrogen, phosphorus and potassium plus organic fertilizers annually. Maize and winter wheat crops were grown in rotation for 24 years. Olsen-P and P activation coefficient declined significantly in the earlier years (< 12 years) for treatments that did not include any P fertilizer, and increased over the same period for the P-fertilized treatments. The rates of change in the Olsen-P and P activation coefficient values were positively related to P balance. In the later years, the Olsen-P and P activation coefficient plateau values were positively related to the P balance.

To determine the best phosphorus (P) fertilizer management strategy in chernozem soil in the semi-arid region of Northeast China, a field experiment under film mulched drip irrigation was conducted for two consecutive years. Five P application methods were tested, including no P fertilizer applied (P0); P fertilizer one-time basal application (P1); one fertigation one time (P2); fertigation twice (P3) and fertigation four times (P4). The shoot dry matter weight, phosphorus accumulation, yield and POlsen in soil were measured regularly during the maize growing season. The results demonstrated that P fertilizer application methods imposed significant effects on dry shoot matter, the apparent P loss, P fertilizer use efficiency and yield of maize (P < 0.05). The yield, P agrinomic efficiency and P recovery efficiency of P4 treatment were significantly higher than P1 treatment by 4.2, 39.7, and 66.4% across two year. In addition, P4 treatment significantly enhanced the shoot dry matter weight after V12 stage, post-silking P uptake and reduced the apparent P loss. In conclusion, P fertigation and a rational frequency (e.g., fertigation four times) enable to keep the maximum grain yield, the shoot dry matter, and recovery efficiency of P fertilizer (66.4%) though changing agronomic methods for efficient acquisition of P toward a sustainable and productive agricultural fertigation system.

This study mainly estimates the effect of grazing on plant diversity and soil storages on the northern Loess Plateau of China. Four grazing intensities of ungrazed (UG), light (LG), moderate (MG), and heavy (HG) grassland were selected according to the vegetation utilization across the study area, in which plant diversity, heights, above- and belowground biomass, and soil carbon (C) stock were investigated. The results showed that overgrazing negatively affected plant growth and soil C stock. Plant cover, height, litter, above- and belowground productivity, as well as soil C stock significantly decreased with the increasing grazing intensity. Meanwhile, the UG and LG had higher grasses biomass together with lower forbs (P < 0.01) compared with MG and HG. The abundance of dominating grasses species, such as Stipa bungeana and S. grandis were decreased through long-term grazing as grasses species are palatable for herbivores, and the dominating forbs species, such as Artemisia capillaries and Thymus mongolicus were significantly increased with increasing grazing intensities. The results indicated that grazing exclusion or light grazing had positive effects on the sustainable development of grassland ecosystems. Therefore, a balanced use and a long-term efficient management of grasslands were better measures to counteract their local degradations.

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.

The aim of the study was to evaluate total and individual glucosinolates concentration, root weight and diameters of horseradish accessions (Cor and Mon) grown by adding nitrogen (N) and sulphur (S) and harvested at the beginning (late autumn) and towards the end (early spring) of the harvest period. The concentration of the 9 glucosinolates (GLS) quantified in roots varied greatly between accessions (6-fold higher in Cor) and with fertilization (N alone led to an increase of 64% of GLS with an additional enhancement of 65% when S was added to N). Root GLS concentration was significantly higher in early spring compared to the previous harvest in late autumn (12.5 vs 8.9 µmol/g DW (dry weight)); a drastic decline of GLS (2.7 µmol/g DW) occurred in root harvested in the following autumn from plants left ad hoc in the field. The aliphatic sinigrin was the most abundant (80% of total GLS), followed by the aromatic gluconasturtiin and the indolic glucobrassicin (5.8% and 4.7%, respectively). Root diameter and weight increased in plants treated with fertilizers (19% and 61%, respectively) and throughout the harvests with Cor showing values double with respect to Mon (925 vs 476 g/plant). Relationships between GLS concentration and root weight (R² = 0.61) and diameter (R² = 0.69) were improved by excluding the roots harvested from plants left ad hoc in the field that showed the worst performances.

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.

In field experiments over three vegetation periods (2010-2012) we studied impact of the CULTAN (controlled uptake long term ammonium nutrition) method on yield and yield parameters of kernel maize. The field experiments were conducted at three sites with different soil-climatic conditions. CULTAN treatments were fertilized once with the total amount of nitrogen using an injection machine (at the canopy height of 20 cm) and compared to conventional fertilization with calcium ammonium nitrate application at pre-sowing preparations. In all treatments the amount of nitrogen was the same, 140 kg N/ha. In 2010 at Humpolec site, CULTAN urea ammonium nitrate + inhibitor of nitrification treatment gave by 20.5% higher number of ears compared to CULTAN urea ammonium nitrate treatment. In 2011 at Ivanovice all CULTAN treatments reached statistically significantly higher number of kernels per ear. The higher 1000 kernel weight at CULTAN treatments was observed in 2012 at the Ivanovice site; a statistically significant difference between conventional and CULTAN urea ammonium nitrate + inhibitor of nitrification treatment was observed. Fertilization of maize with nitrogen using the CULTAN method under the conditions of the Czech Republic provides the same yield certainty as the conventional surface application and the CULTAN method of fertilization increases the yield certainty at delayed sowing. Harvest index was statistically significantly influenced by year, fertilization treatment and site.

The aim of the study was to evaluate the effect of nitrogen (N) and sulphur (S) fertilizer on grain yield of spring wheat and its technological quality. A field experiment (2009-2011) was conducted in south-eastern Poland on Cambisols. The experiment included 2 factors: N fertilization (0, 40, 80, 120 kg/ha) and S fertilization (0, 50 kg/ha). The experiment showed that spring wheat cv. Tybalt exhibited a positive reaction of N and S fertilization on grain yield, which was the highest at the application of 80 kg N/ha (5.40 t/ha), increasing by 1.30 t/ha (13.1%) with respect to the control. S fertilization increased grain yield by 3.58%. S application increased significantly the content of gluten by 3.2%, cysteine by 6.0% and methionine by 16.5%. The most beneficial effect on the content of N, S, total protein, gluten, cysteine and methionine was observed for N application a rate of 80 kg/ha and for S at a rate of 50 kg/ha. Positive correlation was found between the content of S in grain and grain yield (r = 0.73). Significant correlations were found also between grain yield and all other quality characteristics except for N and starch content.

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.

Application of composted pig manure (PM) is a traditional practice to improve soil fertility, whereas generally leads to some environmental questions. The effects of PM application on Cd, Cu and Zn accumulation in soil and maize were investigated based on a long-term field trial in Northeast China, including control (CK), PM_L, PM_M, and PM_H, receiving 0, 100, 250 and 500 kg total N/ha/year from 2002 to 2008 and 0, 10, 25 and 50 t fresh weight/ha/year from 2009 to 2018, respectively. Results showed that long-term soil application of PM increased maize grain yield, soil organic carbon (SOC) contents, coupled with significant accumulation and availability of Cd, Cu, and Zn in soil (0-15 cm). Compared with CK, the soil total Cd, Cu and Zn concentrations significantly increased by 105, 287 and 108% at high PM rate, respectively. Notably, the increments enhanced these heavy metals storage in maize roots rather than in grains. Moreover, the application of PM confirmed vertical transport of heavy metals in the tested soil, particularly for Cd and Cu in PM_H treatment. Overall, the repeated application of PM can cause the accumulation and leaching of Cd, Cu and Zn in soil.

The study focused on the effects of gap size on natural regeneration of European beech (Fagus sylvatica L.) and Norway spruce (Picea abies L.) and micro-environmental soil conditions in gaps of different sizes under temperate mixed forest in the Czech Republic. Six gaps comprising two for small (≥ 200 m²), medium (≥ 500 m²) and big (≥ 900 m²) each were selected. Ten circular 1 m² subsampling plots were established at 2 m intervals along individual North-South-East-West transects, including one at the gap centre. Regeneration was monitored in 2014 and repeatedly in 2019. Soil conditions were only measured in 2019. Gap size was found to be a significant parameter for European beech natural regeneration in 2014. Besides, the quick occupation of European beech in gaps at natural beech zone provoked its prolific regeneration compared to Norway spruce in 2014. However, in 2019 the recent threat of weather variabilities was responsible for the general abysmal growth performance of natural regeneration. Division of gap microsites into different within-gap positions based on prevailing light or shade conditions was helpful in assessing the significant variations of soil conditions within-gap positions and among gap sizes. Soil temperature and moisture significantly influenced the regeneration of European beech and Norway spruce, respectively.

In five consecutive growth seasons from 2003 to 2007 a response of maize variety Eurostar (var. FAO 240) to supply of NPK fertilizer supplemented with magnesium or zinc was investigated. The aim of the study was to evaluate the role of zinc (NPK + Zn) or magnesium (NPK + Mg) in controlling nitrogen management by maize crop fertilized with 80 and 140 kg N/ha. In the course of the study, total grain nitrogen content did not show any response to both experimental factors and weather variability, as well. However, the obtained results indicate, that magnesium and zinc have significantly increased SPAD (chlorophyll index) indices of maize cob leaf at anthesis. A significant effect of both factors interaction on nitrogen accumulation in grain and cob covering leaves was noted, but limited to the 80 kg N/ha treatment. The physiological role of Mg and Zn in nitrogen management was most manifested throughout its greater recovery from nitrogen fertilizer applied at the rate 80 kg N/ha, amounting to 92 and 94% respectively; for the NPK, it was only 78%.

Influence of the nitrogen injection fertilization 'controlled uptake long term ammonium nutrition' (CULTAN) on winter rape yield and seed composition was studied in 2009 and 2010 at two sites with different soil-climatic conditions in the Czech Republic. Two conventional treatments consisted of fertilization using the system of divided doses applied on soil surface. Two CULTAN treatments used injection fertilization with the whole dose of nitrogen applied once in the vegetation period, in early spring at the BBCH 26 stage (6 side shoots detectable). The trial compared conventional and CULTAN treatments. The overall dose of nitrogen was 200 kg N/ha in each treatment. The seed yield in a two-year average was 4.83 t/ha at conventional and 4.80 t/ha at the CULTAN treatment. This difference was not statistically significant. The higher nitrogen content in seed was recorded mainly at CULTAN treatments at the Hněvčeves site in 2009. An inconclusively higher phosphorus content was recorded in winter rape seed fertilized with the CULTAN method at both sites in 2010. Content of K, Ca, Mg and S did not show statistically significant differences between the two treatments during both experimental years. In oiliness no differences between conventional and CULTAN methods were observed.

The stem and bulb nematode (Ditylenchus dipsaci) is a serious quarantine pest of vegetables spreading worldwide via seed and planting material. Currently, a hot water technique is used as the pre-seed treatment, which is difficult to execute and the risk of seed damage is high. The objectives of this study were to evaluate the (a) penetration of gaseous hydrogen cyanide (HCN) into garlic tissue; (b) HCN phytotoxicity, and (c) nematicide potential of HCN against D. dipsaci. Penetration of HCN into the core of the garlic clove was approximately 30% of the concentration inside the fumigation chamber after 30 h of exposure. Decreased emergency was observed only in the exposure treatment lasting 16 and more hours. Garlic cloves naturally infested by D. dipsaci were treated with HCN at a concentration of 20 g/m³ for 12, 18 and 24 h in a fumigation chamber, and 99% mortality was achieved in all three exposure times.

Changes of soil organic matter (SOM) parameters were investigated in a haplic Luvisol with medium-heavy texture. Soil samples were taken from several layers at minimum (MT) and conventional (CT) tillage plots of a field experiment in Sitzenhof (Germany). All cultural practices except for tillage (crop rotation, fertilizing, protection measures, etc.) were identical over the whole time of the experiment. The concentrations of oxidizable carbon C_ox and its constituents (humic acids (HA), fulvic acids (FA), and hot-water soluble carbon) are comparable in layers 15-20 cm in both variants. In 0-15 cm and 30-55 cm layers, these concentrations were higher in the MT variant. A similar trend was observed in the colour quotient values of humic substances Q4/6, which indicates increasing condensation of humus substances (HS) at deeper layers in both variants, and it is also confirmed by a humic to fulvic acids ratio HA:FA. Concentrations of SOM fractions were higher (except 15-20 cm layers) in the MT than CT treatment throughout the profile, especially below the 30 cm depth. The SOM did not accumulate markedly in the surface layer of long-term MT treatment.

Isotopic carbon discrimination (Δ¹³C) of winter wheat grain grown under different water and nitrogen supplies was determined. In two field experiments during years 2004-2007 (A) and 2008-2013 (B), a water shortage was induced from the flowering stage on with a mobile shelter (S), while an optimal water supply was ensured with drip irrigation (I), and a rain-fed crop served as the control treatment (R). Water supply had a statistically significant effect on grain Δ¹³C values in both experiments (P < 0.01). The average values of grain Δ¹³C in treatments I, R and S were 19.43, 18.68 and 17.70‰ (A); and 20.36, 19.60 and 18.13‰ (B). Grain Δ¹³C was in a significant linear relationship (P < 0.01) with the amount of water supplied by precipitation or irrigation. The regressions suggested that grain Δ¹³C increased by 1.14‰ and 1.16‰ (A), and 0.98‰ or 0.96‰ (B) for every 100 mm of water from January and March, respectively, until the early dough stage (r = 0.79-0.74, P < 0.05). Pooled data for the whole period 2004-2013 showed increases of 1.06‰ and 1.08‰ (r = 0.91 and 0.82, P < 0.05) for 100 mm of water, respectively. The results of the experiment confirmed the stable and predictable effect of water supply on wheat grain Δ¹³C.

Physicochemical properties of the tuber as a commercial product differ according to environmental conditions of the area and the growing season. The knowledge about how weather affects these characteristics, allows estimating the correct selection of the cultivars in order to obtain the highest yields or desired physicochemical qualities. In this sense, the effect of the main meteorological factors on the physicochemical characteristics (size, texture, dry matter, soluble solids, phenols, flavonoids, carotenoids and inhibitor concentration (IC₅₀)) of 8 potato cultivars growing in A Limia (North-West Spain) was analysed. The study was conducted during three consecutive years (2014-2016) and the results presented significant differences in the analyzed parameters between years (P < 0.05). Spearman's correlations and principal component analysis showed that the tubers of 2014 (with colder weather conditions) had the highest phenol content and the lowest flavonoids and carotenoids content. Therefore, the temperature positively favoured the flavonoid content and carotenoid content (samples from 2016), although the size of potato tubers was considerably smaller.

The aim of this work was to compare herbicide efficacy and reduction of weed reproduction after the application of three frequently used soil residual herbicides during pre-emergent (PRE) and early post-emergent (EPOST) application in maize. Plot field trials were carried out in Central Bohemia during two growing seasons (2010 and 2011). Good efficacy (88%, resp. 83%) was found in isoxaflutole + thiencarbazone (ISF + THC) and terbuthylazin + S-metolachlor (TBA + SMC) on Echinochloa crus-galli, especially in PRE application use. Efficacy on Amaranthus retroflexus was 91% at both tested application periods and there were no significant differences between experimental years. Significant differences in A. retroflexus control were recorded among all tested herbicides (ISF + THC > TBA + SMC > pendimethalin (PEM) + dimethenamid (DMA)). No significant differences between PRE and EPOST were recorded in efficacy on Chenopodium album. Significant differences in efficacy on C. album were recorded among all tested herbicides (ISF + THC > TBA + SMC > PEM + DMA). Mercurialis annua was the most tolerant tested weed, which was significantly better controlled at EPOST herbicide application (73%) compared to PRE application (32%). TBA + SMC showed a significantly higher efficacy on M. annua compared with other tested herbicides. Seed production of all tested weeds was strongly effected by weather conditions, which were significant during 2011, when there was higher than average precipitation during May and June. The most seeds were produced by A. retroflexus > C. album > E. crus-galli > M. annua. ISF + THC best reduced seed production of E. crus-galli, A. retroflexus and C. album, especially when applied at PRE. TBA + SMC best reduced seed production of M. annua. Weed competition on untreated control plots caused yield loss by 90%and 47% in 2011 and 2012, respectively, compared to treatments with the highest yield (ISF + THC).

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.