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Yields of winter wheat, winter rape and oats were evaluated in the field; the field was divided into the site-specific zones and treated with variable doses of nitrogen fertilizer in years 2004-2006. Measurements of the yields were carried out with a yield monitor placed in a combine harvester. The measured data were processed into the yield maps by means of ArcGIS 9.2 software. Variable application of fertilizer should balance yield potential of the field. Generally, total yield variability on the field after the application of various doses of experimental fertilizer was similar in the years 2004 (11.3%), 2005 (14.7%) and 2006 (11.7%) in comparison with the year 2003 (25.02%). Variable application of nitrogen in the site-specific zones, created on the basis of the yield levels, decreased the yield variability in comparison with the uniform dose. Different doses of nitrogen fertilizer also enabled to increase utilization of production potential of the experimental field.

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.

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.

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.

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.

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.

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.

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.

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.

This study evaluated how organic manures and mineral fertilizers affect winter wheat grain and straw yields and grain quality properties. The analysed period of the long-term fertilizer experiment was established in Čáslav, Czech Republic, in 1955 and covers the seasons 2011-2014. The fertilizer treatments were: control; farmyard manure (FYM); FYM + P; FYM + K; FYM + PK; FYM + N₁; FYM + N₂; FYM + N₁PK; FYM + N₂PK and FYM + N₃PK. The highest grain yields were recorded in the FYM + P and FYM + N₃PK treatments (8.9 t/ha). The highest straw yields were recorded in the FYM + N₃PK treatment (6.52 t/ha). The lowest yields were provided in the unfertilized control and FYM treatments. Qualitative parameters were evaluated in the control, FYM and FYM + N₃PK treatments between the years 2011 and 2013. The best quality of wheat grain was provided by the FYM + N₃PK treatment. Combination of the farmyard manure with NPK is the best way to achieve high grain yields with good quality and leads to sustainable food production.

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.

A five-year (2010-2015) field experiment was conducted to investigate warming impacts on organic carbon (OC), total nitrogen (TN) and total phosphorus (TP) contents and their ratios in bulk soil and soil water-stable aggregates in an alpine meadow of the Tibetan Plateau. Compared with unwarmed control, warming had no significant effects on OC, TN and TP contents and their ratios in bulk soil. The contents of OC, TN and TP associated with macroaggregates and microaggregates decreased, whereas those associated with silt + clay fractions significantly increased. The C:N and C:P ratios in macro- and microaggregates and silt + clay fractions decreased, with significant differences for C:P ratio in microaggregates and C:N and C:P ratios in silt + clay fractions. The results indicated that C, N and P were protected chemically in silt- and clay-size fractions under warming, which offset the loss of C, N and P protected physically by macro- and microaggregates. Both physically and chemically protected C decomposition proceeded relatively more rapidly or accumulated relatively more slowly than did N and P. Our results suggest that C, N and P distributions within soil aggregate size fractions influence their net changes in bulk soil under future climate change scenarios.

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.

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.

Potato yield is affected by an interaction between nitrogen (N) and potassium (K) supply. This hypothesis was verified in a series of field experiments conducted during 2010-2013 in Albania (AL), Czech Republic (CZ) and Poland (PL). The two-factorial experiment was founded on relative scales of K (0, 50, 100, and 150%), and N application rates (75% and 100%) of the recommended doses, which were country-specific. The average tuber yield was doubled for AL, increased by 50% for PL, and by 15% for the CZ in response to K and N interaction. These differences are caused by an increase in the apparent nitrogen efficiency (ANE), which rose significantly by the progressive Krates. Maximum average ANE of 90 kg tubers/kg N was recorded in AL; it was 2-fold lower in CZ. Top average apparent potassium efficiency (AKE) of 65 kg tubers/kg K was recorded in PL; it was 4-times lower in CZ. The relationships between AKE and ANE clearly demonstrate the tight interaction between the N and K, and its effects on potato yield. However, a sound K application management should be adjusted to the local edaphic and climatic conditions.

The complex interaction process of the abiotic factors (sunlight, air temperature and soil water) in regulating maize (Zea mays L.) photosynthesis has not been fully understood. Our field experiment explored the changed sensitivity (or role) of the abiotic factors in regulating maize photosynthesis under a drought development process. The experiment established a scenario with a long-term drought and an instantaneous cloud cover. The results revealed that long-term drought stress causes the sensitivity (or role) of sunlight and temperature exchanged in regulating maize photosynthesis. The maize photosynthesis was more sensitive to instantaneous sunlight rather than temperature in the absence of drought. However, a diminishing photosynthetic sensitivity to sunlight but an increasing photosynthetic sensitivity to temperature was observed with drought development process. The variable photosynthetic sensitivity indicated that the roles of temperature and sunlight in regulating maize photosynthesis were exchanged, so it is expected that higher photosynthetic rate could be achieved by adjusting temperature rather than sunlight after severe drought. Nevertheless, further studies are needed to provide more evidence and mechanism explanations.

For the purposes of assessment of long-term changes, two sets of Chernozems soil samples were analysed and compared in parallel: 'old' file samples obtained during the Soil Survey 1960-1970 in the former Czechoslovakia and a 'present' (2013) set of samples from exactly the same sites as the archive samples. The recently collected samples revealed worse qualitative parameters (lower humic acid to fulvic acid (HA/FA) ratios and higher colour quotient Q4/6 values) than the file samples, for all the localities. On the other side, the quantitative soil organic matter (SOM) parameters (oxidizable carbon (C_ox) and all its determined components) showed contrary results. The amount of total SOM at the same sites is higher now than it was about 50 years ago. It can be concluded that the current decline in SOM quality in Chernozems is partly compensated for by higher accumulation of SOM in the soils. All the analysed Chernozem samples were found to have much worse qualitative SOM parameters than the values mentioned for this soil type in the older literature. However, a comparison of the current data and the file data of Chernozem SOM quality can still be considered an open issue and require more complex research.

Biochar has been studied extensively in terms of its influence on soil hydrophysical properties, but only small part of results was obtained from the field experiments. In this study, the soil water content was measured in 5-10 cm depth at experimental plots which received 20 t/ha and 0 t/ha (control) of biochar amendment at the Malanta area (Slovakia). The experimental area was cultivated with maize in 2015 and spring wheat in 2016. Our field measurements show that the positive effect of biochar amendment (20 t/ha) on soil water content is strongly related to the type of the crop grown and not straightforward. Unexpectedly, during the monitoring campaign in 2015 the soil water content of the biochar-amended soil was lower than control. In 2016, negligible differences were observed in soil water contents at both experimental plots, especially during the dry spells. However, higher soil water content was measured at the plot with biochar amendment after the series of precipitation events during the physiological maturity of the spring wheat. Moreover, the biochar amendment did not increase the biomass production and yields of maize in 2015, but it significantly increased the biomass production and yields of spring wheat in 2016.

In Hawaii, past use of arsenical pesticides has left elevated levels of arsenic (As) in some soils. Sorption isotherms of an Andosol and an Acrisol showed that the former required 1100 mg/kg, and the latter 300 mg/kg of added As to maintain 0.20 mg As/L in solution, the maximum allowable As level in streams/rivers in Hawaii. Greenhouse experiments were conducted on an Andosol (315 mg/kg total As), which was amended with 0, 5 g/kg compost, 5 g Fe/kg as amorphous Fe(OH)₃, or 250 mg P/kg as Ca(H₂PO₄)₂, and on a low-As (15 mg/kg) Acrisol, which was spiked with 0, 150 or 300 mg As/kg as Na₂HAsO₄.7 H₂O. Brake fern (Pteris vittata L.) was used as the test plant. Arsenic concentration in the fern fronds averaged 355 mg/kg in the Andosol, and 2610 and 1270 mg/kg (from consecutive plantings, 2 and 12 months after As addition, respectively) in the Acrisol spiked with 300 mg/kg of As. Chemical reactions, as suggested by sequential extractions, likely controlled the availability and uptake of soil As. Mehlich-3 extraction could be used to identify As-contaminated soils and potential phytoremediation as it correlated well with bioaccessible As and with As in fern fronds.

Three moss (Pleurosium spp., Polytrichum spp., Rhytidiadelphus spp.) and two lichen taxa (Hypogymnia physodes L., Pseudevernia furfuracea L.), were exposed for four weeks in six petrol stations, two consecutive years (2015-2016), in urban area of the Prešov city (Slovakia), to assess accumulation of selected airborne elements Cd, Co, Cu, Fe, Hg, Mn, Ni, Pb and Zn. Significantly highest (P < 0.01) ability to accumulate Zn, Ni, Co and Fe was found in Pleurosium spp.; Pseudevernia furfuracea was determined the best accumulator of Hg, whereas Rhytidiadelphus spp. was found as the least suitable for this purpose. No significant differences in heavy metal accumulation between moss and lichen taxonomic group were found. Samples of conifer (used as a moss/lichen bag holder) showed significantly lower content of heavy metals compared to mosses and lichens. Major content of heavy metals trapped in the air around petrol stations, did not originate from the petrol combustion, but predominantly from the car body, which is mechanically disrupted during fuelling.

Poplars grown in short rotation coppice on agricultural land are a promising bioenergy crop. This study aimed to evaluate the soil organic matter (SOM) quality and viable microbial consortium under six-years-old poplar (Populus maximowiczii) and under wheat (Triticum aestivum) at a test site in central Germany. The SOM molecular composition and stability was determined by pyrolysis-field ionization mass spectrometry (Py-FIMS). The microbial consortium was assessed in terms of microbial phospholipid fatty acid (PLFA) profiles. Py-FIMS and the PLFAs agreed in showing crop-specific differences in the SOM quality and in the associated microbial communities. Higher proportions of carbohydrates, long-chained fatty acids, sterols and suberins at the expense of N-containing compounds under poplar than under wheat were associated with lower concentrations of microbial PLFAs in the organic matter. A higher ratio of total fungal to bacterial (f/b) PLFAs, a lower ratio of Gram-positive to Gram-negative bacterial PLFAs and lower biomass of arbuscular mycorrhizal fungi in the organic matter were revealed under poplar than under wheat. Lower N- and increased C-availability in the SOM promoted fungal vs. bacterial colonization, increased the SOM stability by a lower decomposability and caused SOM accumulation under poplar.

N-fertilization type affected differently tomato growth. In the field experiment, hydroponic cultures were conducted using NO₃-N (5 mmol); mixture of KNO₃-N (3 mmol) and (NH₄)₂SO₄-N (2 mmol); NH₄⁺-N (5 mmol) or urea (5 mmol) as nitrogen source. Compared to nitrate, ammonium and urea had negative effects on morphology and dry matter production. Effects of the different nitrogen forms were investigated by measuring several photosynthesis parameters and chl a fluorescence. Two different significant types of reaction were found. When nitrogen was added as ammonium or urea, dry weight, chlorophyll tenor, transpiration rate, stomatal conductance and photosynthetic activity were inhibited. Supply of ammonium or urea, reduced the ratio (F_v/F_m), photochemical quenching and enhanced the non photochemical quenching. These data suggest that the adverse decrease in tomato growth under ammonium or urea supply may be related principally to inhibition of net photosynthesis activity. The high non photochemical quenching shown in tomato fed with ammonium or urea indicated that PS II was the inhibitory site of NH₄⁺-N which was directly uptaken by roots, or librated via urea hydrolysis cycle.

The aim of this study was to evaluate nitrogen (N) efficiency from different organic and mineral fertilizers applied to the spring barley. Dry matter yield, N content and N uptake of spring barley from 16 years of experiments at two sites in the Czech Republic with different soil and climatic conditions were analyzed. For assessing of nitrogen efficiency nitrogen utilization efficiency (NUtE, kg/kg), recovery efficiency of applied N (%), agronomic efficiency of applied N (kg/kg) and summary N balances (ΣΔN, kg/ha) were observed. Six fertilization treatments were utilized: no fertilization (control); sewage sludge; farmyard manure (FYM); N in mineral fertilizers (N); NPK in mineral fertilizers (NPK) and N in mineral fertilizers + straw (N + ST). Yields were about 68% higher at NPK (S1 site) and 55% at N + ST (S2 site) in comparison with control. The highest NUtE was recorded at both locations after application of FYM. Higher NUtE from mineral fertilizers was obtained at low productive S1 site. At both sites a trend of decreasing ΣΔN over time was observed. At both sites a trend of decreasing negative N balance was observed. At lower productive site the decline of N balance was minimized for mineral fertilizers treatments in last experimental years. At higher productive site the differences between treatments with mineral nitrogen and control were lower and the decline of N balance continued over all 16 years of experiment duration.

Two-way field experiment was carried out in a split-plot design in 4 growing seasons at the Experimental Station of the Bydgoszcz University of Science and Technology in Mochełek (Poland). The forecrops for winter triticale cv. Tulus were lupins: yellow, blue and white, field pea and spring barley. Nitrogen (N) fertilization in triticale after harvesting forecrops was: 0-60-120-180 kg N per ha. Average long-term yields of grain and protein in triticale after leguminous forecrops were statistically similar, by 0.84 t/ha and 86 kg/ha higher than after spring barley. On plots without mineral N fertilization, by over 1.5 t/ha more grain was obtained after leguminous forecrops, and by 142 kg/ha more protein than on the plot after spring barley. However, the rate of 180 kg N/ha guaranteed obtaining a significantly highest mean protein yield in triticale. The applied mineral N fertilization at rates from 60 to 180 kg N/ha did not significantly vary the average yield of winter triticale. Mineral nitrogen (N_min) content in the layer 0-60 cm after harvesting the leguminous forecrop without mineral N fertilization was by 25.5% higher than after harvesting spring barley fertilized with a rate of 60 kg N per ha.

The surface carbon dioxide (CO₂) fluxes together with the soil microbial biomass and activity in undisturbed soil columns were studied in three growing seasons. Soil columns had six treatments: (1) control without plants; (2) mineral fertilized without plants; (3) no fertilizer and maize plants; (4) mineral fertilized and maize plants; (5) manure and maize plants; (6) mineral fertilized plus manure and maize plants. Soil microbial biomass was measured by substrate-induced respiration (SIR) and microbial activity as fluorescein-diacetate hydrolysing activity (FDA). Treatments had a significant effect (P < 0.001) on CO₂ fluxes, SIR and FDA. The presence of maize increased CO₂ efflux, SIR and FDA compared to unplanted column. Fertilizer + manure treatment resulted in the greatest plant biomass and the greatest CO₂ efflux. Significant correlation (r = 0.680; r = 0.586 in two consecutive years) between SIR and FDA was found.

The study evaluates how sixty years of application of organic manures and mineral fertilizers (ten fertilizer treatments altogether), planting of cultivars with different length of stem (long- and short-stem cultivars) and preceding crops (potatoes and alfalfa) affected grain and straw yields of winter wheat in the Prague-Ruzyně long-term fertilizer experiment (RFE). Fertilizer treatments did not affect grain yield during the first ten years of the RFE experiment (1959-1968), but influenced straw yield. The grain yield ranged from 5.08 (control) to 5.43 (farmyard manure) t/ha, straw yield varied from 6.02 t/ha (control) to 8.31 t/ha (poultry slurry (PS) + N₄P₂K₂). In the last ten years of the RFE experiment (2004-2013) grain yield ranged from 7.01 t/ha (control) to 8.88 t/ha (stale + N₄P₂K₂), while straw yield decreased and varied from 3.12 (control) to 6.21 t/ha (PS + N₄P₂K₂). Comparing the potatoes and alfalfa as preceding crops, the grain yield was 0.5 t/ha higher after alfalfa, but straw yield was 1.3 t/ha higher after potatoes. Introduction of short-stem cultivars increased average grain yield about 2 t/ha and decreased average straw yield about 0.85 t/ha.

Stable isotope ¹⁵N tracer technique was used in combination with artificial rainfall simulation to study the influence of interflow and surface-flow on nitrogen (N) migration loss of soil-plant systems on typical red soil sloping uplands. This study also investigated the utilization efficiency of fertilizer N during different peanut plant growth stages. The results indicated that soil N loss was predominantly via interflow and erosive sediment. Fertilizer N loss during the initial growth stage was mainly through surface runoff, while that occurred as interflow increased from less than 5% to around 16% during the middle and late growth stages. The loss of fertilizer N through surface runoff, erosive sediment and interflow accounted for over 18% of the total N application. The utilization rate of fertilizer N by peanut plants was around 45% through its life cycle, and that 70% of N absorbed by this plant derived from the soil. This highlighted the importance of adopting effective methods to reduce nutrient loss through interflow and surface-flow, the need to increase the utilization rate of fertilizers, and the importance to maintain soil fertility at a relatively high level.

Carbon dioxide (CO₂) fluxes from agricultural soils have been considered as one of the important environmental impact issue, due to their role in global warming and also its mitigation by carbon (C) sequestration in soils. Substantial scope of C sequestration with the application of inorganic fertilizers and manures has been reported, but the long-term effects of continuous application need to be critically examined. To study the effect of continuous differential application of NPK fertilizers and farmyard manure (FYM) in maize-wheat cropping system, CO₂ fluxes were measured via closed chambers and gas chromatography in a long-term experiment in progress for the past 42 years. The average daily CO₂ fluxes differed significantly amongst various treatments and were 55, 26 and 92% higher in NPK, N and NPK + FYM treatments over the control in the maize crop season and 43, 8 and 83% in the wheat crop season. Highly significant correlation of CO₂ emissions was found with soil organic carbon and total nitrogen in the maize and the wheat crop seasons. Although, CO₂ emissions were higher from long-term inorganic fertilizers and FYM treatments, still they are environmentally sustainable management practices, as they increased soil fertility and crop yields which consequently resulted in higher atmospheric CO₂ capture by plants and carbon sequestration in soils.

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.

Soybean yields can be considerably improved by inoculation with selected Bradyrhizobium japonicum strains and foliar fertilization. An exact field experiment was carried out in 2012-2014 at the Experimental Station of Cultivar Assessment in Przecław, Poland. The test plant was soybean cv. Aldana. The experimental factors were: bacterial inoculant Nitragina (Bradyrhizobium japonicum); foliar fertilization with Mikrokomplex; combined applications Nitragina + Mikrokomplex and the control treatment. Significant effect of Nitragina on an increase in the number of plants prior to harvest, plant height and the number of pods per plant was indicated. Fertilization with Mikrokomplex caused an increase in the number of pods per plant and thousand seed weight. Nitragina + Mikrokomplex increased the number of plants prior to harvest, plant height, the number of pods per plant and thousand seed weight. Seed yield was significantly higher in all the treatments compared to the control (2.31 t/ha). Higher soil plant analysis development values were found after the application of Nitragina + Mikrokomplex, and in the stage of pod development, also after foliar fertilization with Mikrokomplex. Application of Nitragina and Nitragina + Mikrokomplex resulted in an increase in leaf area index and mean tip angle and total protein in seeds. Fe content in seeds was the lowest in the control (69.2 mg/kg) and significantly higher in the other treatments (Nitragina, Nitragina + Mikrokomplex), and Mg content significantly increased after the application of Mikrokomplex and Nitragina + Mikrokomplex.