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Fertilization of crops with pig manure is a common practice throughout the world. Nevertheless, due to the relatively high copper (Cu) and zinc (Zn) contents in pig manure, continuous application of pig manure could have negative effects on soil and plant. The study aimed at the impacts of long-term applying different pig manure rates (equivalently 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 2011, respectively) on Cu and Zn accumulation in soil and plant. During the 10 years of the experiment, a total of 2.04 to 10.20 kg/ha/year for Cu, 3.15 to 15.73 kg/ha/year for Zn were applied to the soil. Results from this study showed that long-term pig manure application resulted in serious accumulation of Cu and Zn in soil, total Cu and Zn concentrations increased by 204% and 107% at high application rates, respectively. Although topsoil Cu and Zn concentrations were below concentrations considered phytotoxic to crops, according to current Chinese legislation, it would take only less time than 16 and 27 years of high application rates to reach the allowable limits. Our result also suggested that Cu and Zn leaching occurred in the tested soil. The Cu and Zn concentrations in stalks and grains were not affected by the application of pig manure, and these values were lower than the threshold values for animal and human ingestion.

Agronomic zinc (Zn) biofortification of crops could help to alleviate dietary Zn deficiency, which is likely to affect more than one billion people worldwide. To evaluate the efficiency of agronomic Zn biofortification of broccoli, four application treatments were tested: no Zn application (control); soil application of 5 mg/kg ZnSO₄.7 H₂O (soil); two sprays (15 mL/pot each) of 0.25% (w/v) ZnSO₄.7 H₂O (foliar); and soil + foliar combination. Soil Zn application increased Zn-DTPA (diethylenetriamine pentaacetic acid) concentration by 3.7-times but did not affect plant growth or plant Zn concentration. Foliar Zn application increased stem + leaves and floret Zn concentration by 78 and 23 mg Zn/kg, respectively, with good bioavailability based on phytic acid concentration. Boiling decreased mineral concentration by 19%, but increased bioavailability by decreasing the phytic acid concentration. The entire broccoli could constitute a good nutritional source for animals and humans. An intake of 100 g boiled florets treated with the foliar treatment will cover about 36% of recommended dietary intake (RDI) of Zn, together with 30% of Ca, 94% of K, 32% of Mg, 6% of Na, 55% of P, 60% of S, 10% of Cu, 22% of Fe, 43% of Mn, and 35% of Se RDIs.

To investigate the effect of microbial inoculum on soil heavy metal immobilisation, pot experiments were conducted with paddy soils contaminated by cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg), respectively. The results showed that the inoculation of Rhodopseudomonas palustris was more effective in the immobilisation of Pb and Cd in soils than the composite of R. palustris and Bacillus subtilis. Interestingly, a lower dosage of inoculum immobilised significantly more heavy metals than the higher dosage, potentially due to the competition of bacteria with limited nutrients. The heavy metal contents in rice grains also supported this finding, as less Pb and Cd were accumulated under the lower dosage. However, there were limited effects of microbial inoculations on the immobilisation of Hg and As. In general, our study indicated the effectiveness of R. palustris in immobilising Pb and Cd in soils and highlighted the importance of determining the optimal dosage of inoculum in bioremediation.

Insect pollination is one of the most important ecosystem services. Pollinator communities are rarely studied across years and crops in the same location. The aim of this study was to investigate the pollinator community structure on five different fruit crops, as well as the activity of different pollinator groups during the day and their temperature preferences. Pollinator activity was observed across two years on apple trees and blueberry, strawberry, blackcurrant and raspberry bushes. Pollinator community structure varied by plant and year. Honeybees were the most numerous pollinators on all plants except blueberry bushes (39-95% of visits). Bumblebee numbers were high on blackcurrant (up to 28%) and blueberry bushes (up to 61%). Solitary bees visited all plants except blueberries. Honeybees, solitary bees, and hoverflies were most active in the middle of the day, while bumblebees became active earlier in the morning and remained active later in the evening. Pollinators also differed greatly in their temperature preferences. This knowledge gained is necessary for less harmful pesticide application management and the development of more sustainable agriculture to maintain pollinator diversity and thus reliable pollination in extreme weather conditions.

The dissipation patterns of thiamethoxam insecticide at two different rates (12.5 and 25 µg/g) in both silty clay loam and loam soils were studied. The half lives of thiamethoxam were in the range of 15.0 to 18.8 days in silty clay loam and 20.1 to 21.5 days in loam soil. The residues of thiamethoxam in potato tubers and soil at harvest time (90 days after planting) could not be detected either in soil or in tubers at any of the applied rates (25 and 50 g a.i./ha). Thus, thiamethoxam does not appear to pose any health hazard to consumers or harm to the environment.

This study was carried out to present an innovative solution for interpreting large data sets in agri-statistics with the invocation of programmed visualisation. Moreover, the following polyfactorial long-term experiment embodies a comprehensive study of 18 wheat quality parameters. The effect of increasing dosages of fertiliser (control, N₉₀PK, N₁₅₀PK) was examined on 3 winter wheat cultivars (KG Kunhalom, GK Csillag, Hybiza) in two consecutive growing seasons (2018-2019). The ecological conditions of 2018 gave a significantly higher yield, meanwhile 2019 significantly augmented gluten spread, alveographic tenacity, alveographic deformation work, valorigraphic stability and quality group and loaf volume. N₉₀PK dosage was enough to realise yield and quality potential as well. Fertilising significantly improved 13 indices, namely yield, crude protein, Zeleny index, wet gluten content, alveographic extensibility, alveographic deformation work, valorigraphic water absorption, quality number and group, dough development time, stability, softening and loaf volume. Considering yield, cv. Hybiza performed better, while cvs. KG Kunhalom and GK Csillag possessed significantly better protein-linked postharvest attributes. One of the most important findings is that waffle chart, joint plot, correlation matrix and complexradar of Python provide a very powerful tool in agri-statistics. Also, the results can potentially improve the knowledge about cultivar-specific agronomy practice, wheat quality and the connections between these parameters.

The oil content and fatty acid composition were determined in the seed of 19 poppy genotypes (both landraces and modern cultivars) grown in three-year field trials. The total oil content ranged from 34.56-44.76%. The oil content in white-seeded genotypes (40.73-44.76%) exceeded the oil content in blue-seeded genotypes (34.56-40.34%) and ocher-seeded genotypes (38.36-42.69%). Linoleic acid (71.41-74.02%), oleic acid (12.35-15.51%) and palmitic acid (8.95-10.29%) were the most abundant fatty acids in the evaluated seeds of poppy genotypes. A significant negative correlation (-0.7574**) was found between linoleic and oleic fatty acids. The sum of polyunsaturated (PUFA), monounsaturated (MUFA) and saturated (SFA) fatty acids ranged from 72.43-74.91%, 12.90-16.14% and 10.99-12.46% of the total fatty acids, respectively. Both the total oil content and the content of individual fatty acids were mainly affected by the crop year (weather conditions); however, the effect of genotype and year × genotype interaction was also significant. Due to the favourable composition of fatty acids, the evaluated poppy genotypes can be a good source of nutritionally valuable oil.

Plant growth regulators play crucial roles in modulating plant response to environmental stresses. In this experiment, the effect of different doses of paclobutrazol (PBZ) and putrescine (Put), i.e., 0, 50, 100 and 150 mg/L on mung bean in two conditions of water deficit (WD) and well-watered (WW) was investigated. The seed yield decreased due to water deficit stress, while the PBZ and Put application alleviated the damage of drought stress through increasing proline and leaf chlorophyll content and improving membrane stability, and thus increased plant yield compared to untreated control plants. According to regression equations, the high PBZ levels (150 mg/L or more) and moderate levels of Put (about 90 mg/L) were determined as the optimal concentrations to maximise mung bean yield in WD conditions. In WW conditions, the mung bean responses to PBZ were inconsistent, whereas Put application positively affected some physiological traits and seed yield. In conclusion, the physiological attributes and, subsequently, the seed yield of drought-stressed mung bean plants could be improved by foliar application of PBZ and Put.

The efficacy of using maize (Zea mays L.) as a suitable substitute for other crops with high arsenic (As) accumulation in As-contaminated farmlands remains debated. Here, the As uptake capacity and the stability of accumulated As of different maize cultivars were studied using pot and field experiments, outdoor investigations and literature data analysis. When the total and available soil As levels were 238.8 and 8.1 mg/kg, respectively, grain As ranged from 0.03 to 0.07 mg/kg, significantly lower than the acceptable As limit (0.5 mg/kg) for maize in China. The results of field investigations and literature data analysis also supported this observation. Maize is a crop with low grain As, thus, making it suitable for substitution planting in As-contaminated farmlands. Further, grain As concentration varied among different maize cultivars. The planting of normal and waxy maize is prioritized over the sweet maize as the first one has lower available bio-concentration factor (aBCF) of 0.007 for grain and higher accumulated As stability among its cultivars (CV < 10%) than those for sweet maize (aBCF = 0.01 and CV = 35.5%). Arsenic compartmentalization in the roots and low As upward migration into the grain were responsible for the low grain As of maize.

Air-drying of soil samples is a common practice for all-purpose soil testing. However, it may cause the cessation of microbial activity changing the biochemical attributes. For this reason, field-moist samples are commonly used in the assessment of the enzyme activity in soils. This practice may, therefore, discourage the use of enzymes in soil quality evaluations. This study evaluated the effects of air-drying on cellulase, arylsulfatase and acid phosphatase activities in soil; the hypothesis was that the activities of these enzymes determined in air-dried soil samples are similar to those obtained at field-moist samples. Soil samples were collected (0-10 cm) in a long-term experiment that received two rates (10 and 20 t/ha) of sewage sludge and mineral fertilizer and was cropped with maize. Collected soil samples were split into two groups. In the first one, the enzymes were determined at field-moist samples, while in the second one, the samples were air-dried before enzymatic analyses. Acid phosphatase was significantly affected by air-drying while the arylsulfatase activity hardly changed. The results showed that the enzymes determined in air-dried soil samples hold the capacity to identify different organic management and can, potentially, be used as soil quality indicators.

Dung deposited by grazing animals is a key driver affecting sward structure and nutrient cycling in pastures. We tested herbage and soil properties in three types of tall sward-height patches (> 10 cm): (i) patches with dung under intensive grazing; (ii) patches with dung under extensive grazing; and (iii) patches with no dung under extensive grazing. These patches were compared with grazed swards under intensive and extensive grazing. Analyses indicated no significant effect of different types of patches on plant available nutrients. Herbage nutrient concentrations from the different types of patches differed significantly. The highest concentrations of nitrogen (30.65 g/kg), phosphorus (4.51 g/kg) and potassium (22.06 g/kg) in the herbage dry matter were in the tall patches with dung presence under intensive grazing regime because of nutrients from dung utilized for sward regrowth. Regardless of dung presence, similar herbage nutrient concentrations were revealed in non-grazed tall sward-height patches in extensive grazing regime. The presence of dung did not have any effect on the plant available nutrients in any type of patches, therefore we suppose that non-utilized nutrients were probably leached, volatilised or transformed into unavailable forms and thus soil nutrient enrichment was low.

The effect of agrotechnical elements (crop rotation, fertilisation, irrigation) on maize yield and various chemical characteristics of the soil (pHH2O, pHKCl, hydrolytic acidity (y1)) were examined in a long-term experiment (established in 1983) on calcareous Chernozem in the Hajdúság region of Hungary. The yield obtained in 2019 showed the favourable water supply of the crop year and outstanding nutrient utilisation of maize. In the control (non-fertilised) treatments, maize yield was 8 t/ha in monoculture, 11 t/ha in biculture and 12 t/ha in triculture, while the highest yield obtained with the optimum fertiliser treatment increased to 13, 13.5 and 14 t/ha, respectively. In the long-term experiment established 35 years ago, the pH values of the soil greatly decreased in comparison to the initial value. The following ranges were observed in monoculture: 5.57-6.49 (pHH2O), 4.69-5.34 (pHKCl), in biculture: 5.22-6.62 (pHH2O) and 4.36-5.68 (pHKCl), and in triculture: 5.46-6.29 (pHH2O), and 4.56-5.24 (pHKCl). Hydrolytic acidity values (mono y1 = 7.75-14.75, bi y1 = 11.50-23.00, tri y1 = 10.13-18.38) showed strong soil acidity. In the long-term experiment, a moderate (0.512xx, LSD0.01=xx) correlation between fertilisation and yield and a moderate (0.397xx) correlation between crop rotation and yield could be established on Chernozem. A moderately negative (pHH2O = -0.594xx, pHKCl = -0.543xx) correlation was found between the yield and pH values, while a moderately positive (y1 = 0.409xx) correlation was found between the hydrolytic acidity and yield.

Recent concerns over the environmental impact of peat harvesting have led to restrictions on the production of peat based potting substrates. Therefore the objective of our study was to evaluate the use of compost and biogas residues without and each with 20% additives (Perlite, Styromull, Hygromull, Lecaton, Peat, Cocofiber) as a substitute for peat. Ryegrass (Lolium perenne L.), chosen as an experimental plant, was cut four times. The results reveal that compost and biogas residues are suitable potting substrates. The incorporation of additives mixed into the basic materials partly resulted in higher yield and nutrient uptake. However, the difference among additives was mainly insignificant. Incorporation of Hygromull, especially into biogas residues favored plant growth and increased the uptake of nutrients, which is attributed to the fact that Hygromull stores nutrients and delivers them even later in the growing season. Furthermore Hygromull reduces the salt concentration of the medium, resulting in favored plant growth of younger plants.

A long-term experiment was used to evaluate the effects of different nutrient management practices on the distribution of soil organic N fractions and their contribution to N nutrition of a rice-wheat system. Continuous rice-wheat cultivation for 13 years without any fertilization was unable to maintain total soil nitrogen level to its original level and resulted in a decrease at 8.3 mg N/kg/year. Likewise, amino acid N, amino sugar N, ammonia N, hydrolysable unknown N, total hydrolysable N and non-hydrolysable N decreased by 37.2, 29.6, 33.7, 10.4, 26.6 and 20.4%, respectively over their initial status. However, application of inorganic fertilizers alone or in combination with organic manures led to a marked increase in total N and its fractions. The increase in total N with the application of farmyard manure, press mud and green manure along with inorganic fertilizer over treatment with inorganic fertilizer alone was 23.1, 34.4 and 7.0%, respectively. These results imply that integrated use of inorganic fertilizers with organic manures represent a sound practice for sustaining N reserves in soil. On average, amino acid-N, amino sugar-N, ammonia-N and hydrolysable unknown-N constituted about 27.9, 10.7, 28.7 and 32.7% of the total hydrolysable-N, respectively.

Fencing is the common management practice to restore degraded grasslands. However, long-term fencing decreases grassland productivity and species diversity. The study was therefore conducted as a three-year (2011-2013) experiment with a randomized complete block in a grassland fenced for 20 years in the Loess Plateau of China, and the effects of fertilization, burning and grazing on aboveground biomass, species and functional group composition, species and some functional group diversity were analysed. Our results showed that the functional group of perennial bunchgrasses dominated the grassland regardless of management practices. However, burning altered species composition (i.e. the unpalatable species, Artemisia sacrorum) more significantly than fertilization or grazing, and surprisingly, nearly quadrupled the functional group of shrubs and semi-shrubs. Fertilization had a positive effect on the aboveground biomass (44.0%), while clearly reducing species diversity (21.9%). Grazing decreased aboveground biomass, but increased species diversity by 15.9%. This study indicated that fertilization influenced plant community through its impact on aboveground biomass, while burning changed plant community by altering dominant species. Thus, it was concluded that fertilizer could further improve community biomass while burning reduced the edibility of grass. Grazing could be carried out to enhance the biodiversity in the long-term fenced grasslands.

Barren brome (Bromus sterilis L.) is a troublesome weed of winter cereals in western and central Europe and its control requires an exact estimation of emergence time. The study focused on the germination response of populations from the Czech Republic to water availability at different temperatures and under different light regimes. Seeds were able to germinate even at very low water potential (Ψ) close to the wilting point, but decreasing temperatures below 25°C and exposure to light decreased the germination percentage (GP) and prolonged the time to reach 50% germination (T₅₀). At higher temperatures of 15, 20, and 25°C, seeds germinated up to a Ψ value of-1.5 MPa; however, the GP differed between light (0-3%) and darkness (50-75%). At the highest temperature of 25°C and germination in water, T₅₀ was less than 1 day, but a decrease in Ψ to -1.5 MPa prolonged the T₅₀ to 5 days; however, this occurred without any significant effect of light regime. With decreasing temperature and Ψ, seeds were more sensitive to the light regime and the disproportion between T₅₀ in light and darkness increased. At a Ψ of less than -1.0 MPa, seeds needed twice as long for germination in light than in darkness when germinating at 20°C or 15°C. The results may be of value for the development of predictive models and for identifying times when weed control may be the most effective.

The aim of the study was to evaluate the amount of nitrogen taken up from air, mineral fertilizers and soil by yellow lupine (Lupinus luteus L.) and spring triticale (Triticosecale Wittm. ex A. Camus) in their intercropping cultivation. The factor examined in the experiment was percentage of yellow lupine seeds and spring triticale grain in sown mixtures: 100/0, 75/25, 50/50, 25/75 and 0/100, respectively. Yellow lupine yield was reduced by spring triticale when intercropped. In the yield of both plants the percentage share of spring triticale grain was larger and that of yellow lupine seed was smaller than in the sown mixture. Land equivalent ratio informs that yield advantage under intercropping of lupine and triticale was minor. The total protein yield was the highest in lupine cultivation when sown pure, and decreased with increasing share of triticale in their intercropping. The mean percentage nitrogen share from N₂ fixation, fertilizer and soil reserves in yellow lupine mass was: 65.2, 8.8 and 26.0%, respectively, while in the mass of spring triticale it was 10.1, 23.5 and 68.8%, respectively.

This study attempted to evaluate the efficiency of zeolite and pyrophyllite ore materials in reducing the mobility of heavy metals in soil near the lignite mining dumps, and consequently in their availability for plants. Extraction of pseudo-total and available forms of heavy metals from soil samples was performed by using aqua regia and ethylenediaminetetraacetic acid, respectively. Concentrations of heavy metals in soil and plant samples were determined by atomic absorption spectrophotometry. The results of this study illustrate that application of zeolite and pyrophyllite could be a suitable technique to reduce heavy metals availability in soils. Zeolite treatments have been shown to be significantly effective in reducing cadmium (Cd) mobility, as well as pyrophyllite treatments in reducing lead (Pb) mobility in the studied soil, regardless of applied rates. The accumulation of heavy metals in leaves of maize grown on soil plots treated by zeolite and pyrophyllite, was found to be lower compared to the untreated plots. This finding was to be expected, considering the effects of these treatments on heavy metals mobility in the studied soil.

Little information is available on how fertilizer application affects concentration of many elements in peeled potato (Solanum tuberosum) tubers and peels. We analyzed how long-term application of cattle slurry and mineral N, P and K fertilizers affects the yield of tubers, their dry matter content and concentrations of elements. In 2009, potatoes tubers were collected in control, cattle slurry (CS), mineral N₄P₂K₂ and combined CSN₄P₂K₂ treatment of the Ruzyně Fertilizer and Crop Rotation Experiment established on Illimerized Luvisol in Prague (Czech Republic) in 1955. Amount of N, P and K supplied by CS was 138, 30 and 172 kg/ha and the amount supplied by N₄P₂K₂ was 110, 31 and 186 kg/ha. Yield of fresh potatoes ranged from 20.6 in the control up to 31.2 t/ha in CSN₄P₂K₂ treatment. Dry matter content of unpeeled tubers, peeled tubers and potato peels was not significantly affected by fertilizer treatments probably because of not excessive N application. Normal cropping practices with application of CS and mineral N, P and K fertilizers did not significantly increase concentrations of trace elements in peeled tubers or potato peels on neutral soil with low trace elements availability. Concentrations of many elements (N, P, K, Ca, Mg, Cd, Cr, Cu, Mn, Ni, and Zn) were higher in potato peels than in peeled tubers, but the differences in the case of trace elements were relatively small.

Based on a long-term fertilization experiment on sandy soil, research concerning the effect of variable fertilization on the soil content of silicon extracted by CaCl₂ solution was performed. The content of plant available silicon was evidenced to depend on the applied fertilization and soil properties. Plant silicon supply coefficient varied depending on the fertiliser combination. In the case of potatoes this coefficient was smaller then 1 but for oat was usually higher then one. It suggesting that the amount of available silicon in soil is sufficient to cover the nutritional needs of potatoes but not sufficient for oat.

Pyrolysis is a promising technology for sewage sludge (SS) treatment providing several improvements of SS properties for soil application. However, information on the influence of pyrolytic temperature on the availability of nutrients in resulting biochar (BC) is limited. In this study, anaerobically stabilised SS was pyrolysed in a laboratory fixed-bed reactor at 220, 320, 420, 520, and 620 °C for 30 min in the N₂ atmosphere. Pyrolysis resulted in a higher total content of all studied nutrients in BCs. Aromaticity and hydrophobicity of BCs increased with increasing temperatures while solubility decreased. Relative availability (% from total content) of nutrients in BCs was in order: Ca > Mg ~ K > S > P. Pyrolysis at 220 °C produced acidic BC with a higher content of acetic acid-extractable nutrients compared to non-pyrolysed control. An increment in pH and a significant drop in the content of available Ca, Mg, K and S were found at temperature 320 °C. Pyrolysis at 320 °C increased the content of available P by 28 % compared to non-pyrolysed SS. At the temperature of 420 °C and higher, available contents of all studied nutrients were lower than in non-pyrolysed SS.

Conservation tillage harmonizes soil protection with demands of the crop, soil and climate. The continuous conservation tillage improves soil properties and modifies impact of weather extremes. The aim of the paper was to investigate the changes in four soil physical states affected by soil conservation tillage and to evaluate soil water content in a critical period. The study was carried out on Chernozems applying six tillage treatments, that are loosening, ploughing, tine tillage (a deeper, and a shallower), disk tillage and direct drilling. The investigation suggested that soil conservation was the major solution resulting in the balanced water content (SWC) and penetration resistance values in both treatments under peculiar weather conditions. However, the crumb ratio and the crusted area resulted in significant differences between the treatments, presumably due to the level of surface preservation. Soil water content differed significantly between months, with higher contents in spring and lower values in the end of summer. The higher SWC expected at the beginning of the growing season was reliably fulfilled, but the SWC level for workabilty differed from the optimum.

The effect of soil selenate application to two different soils (Phaeozem and Cambisol) on biomass yield and selenium (Se) uptake by spring wheat (Triticum aestivum L.) was investigated in a pot experiment. Additionally, organic amendment (fugate, i.e. liquid by-product from the biogas plant) was applied to assess (i) the effect of organic matter on the bioavailability of Se and (ii) the fugate (containing 2.3 mg/kg of Se) as a potential source of Se for plants. Selenium was applied at two levels: 6.4 µg/kg (Se1) and 32 µg/kg (Se2) of soil. The efficiency of biofortification and the distribution of selenium within individual plant compartments were assessed in this case. The highest Se contents in the grain were achieved in the treatments receiving NPK fertiliser together with selenate, 455 µg/kg (Se1) and 2 721 µg/kg (Se2) when wheat was planted in Phaeozem. Fugate in co-application with selenate significantly reduced Se content in wheat plants as compared to treatments enriched solely with selenate. The lower Se contents in the wheat plants growing in Phaeozem were due to the biodilution effect, whereas in Cambisol, the decrease in wheat Se uptake was not clearly driven by a particular factor.

The aim of the study was to determine the interaction of herbicides and herbicides with biostimulants on the accumulation of dry matter and starch in potato tubers. In a three-year field experiment based on the method of randomised sub-blocks, two factors were taken into account. The first factor were potato cultivars: Bartek, Gawin, Honorata. The second factor were five methods of herbicides and biostimulants application: (1) the control object without chemical protection (CO); (2) herbicide linuron + clomazone (Harrier 295 ZC) (H); (3) herbicide linuron + clomazone (Harrier 295 ZC) and biostimulant Ecklonia maxima (Kelpak SL) - (H + K); (4) herbicide metribuzin (Sencor 70 WG) - (S); (5) herbicide metribuzin (Sencor 70 WG) and biostimulant sodium para-nitrophenol, sodium ortho-nitrophenol, sodium 5-nitroguaiacol (Asahi SL) - (S + A). The cultivars and weather conditions significantly affected the content and yields of dry matter and starch. The herbicides and biostimulants used determined the starch accumulation as well as dry matter and starch yields. Most starch in tubers (more by 3.7 g/kg) and the highest dry matter and starch yields (more by 2.87 and 1.79 t/ha, respectively), compared to the control object, were obtained after the application of the herbicide Sencor 70 WG and biostimulant Asahi SL.

Optimal soil nitrogen management is vital to crop production and environment protection. Little knowledge is available on crop yield, nitrogen uptake, use efficiency and balance in paddy rice-upland wheat cropping system of China. A thirty-five-year long-term field experiment was designed with nine treatments, including an unfertilized treatment (control), nitrogen (N), phosphorus (P), potassium (K) fertilizer, manure (M), and manure combined with mineral fertilizer treatments. Crop yield, N uptake, use efficiency, and N surplus or deficit amount were determined. The results indicated that rice, wheat yield and N uptake amount in the manure combined with mineral fertilizer treatments were higher than that in the manure alone or mineral fertilizer alone treatments. N use efficiency was the highest in the treatment with manure alone. Soil N input indicated a surplus in the mineral fertilizer in combination with manure treatment, but soil N input indicated a deficit in the control, NPK and M treatments. Considering crop yields, N use efficiency and N balance, recommended N application amount is almost 220 kg N/ha/year in the paddy rice-upland wheat cropping system. Taking into account labour and fertilizer sources, half mineral N and half organic N applications were recommended.

Pot experiments were carried out to study the effects of a novel stabilizer of 2,4,6-trimercaptotriazine, trisodium salt, nonahydrate (TMT) on the bioavailability of heavy metals (Cu, Zn, As, Cd and Pb) in soils and heavy metals accumulation in tobacco. The results showed the optimal TMT dosage 200 mL/kg could effectively reduce the bioavailability of heavy metals in soils, and the bioavailability of Cu, Zn, As, Cd and Pb in soils was reduced simultaneously by up to 73.1, 63.2, 48.0, 68.9 and 57.2%, respectively. Application of TMT could significantly decrease Cu, Zn, As, Cd and Pb contents of all parts of tobacco. Furthermore, the contents of available Cu, Zn, As, Cd and Pb in soils were significantly positively correlated with Cu, Zn, As, Cd and Pb contents in upper, middle and lower leaves and stems of tobacco. There were no significant differences among plant height, number of leaves, stem girth, length and width of maximum leaves of tobacco under TMT treatments and that under control (P < 0.05), which showed that the TMT did not promote and inhibit the growth of tobacco.

Hydrocarbon contaminants have become a global concern due to their long-term adverse effects on soil ecosystems and human health. Successful implementation of phytoremediation to clean up hydrocarbon contaminants requires the identification of the most effective remediation plant species. Twelve native plant species of the Sudd Wetland in South Sudan were evaluated for their potential application as phytoremediators. The treatments included six total petroleum hydrocarbon (TPH) concentrations of 0, 25, 50, 75, 100 and 125 g/kg soil. The twelve native plant species tested were: Sorghum arundinaceum Desv., Oryza longistaminata A. Chev. & Roehrich, Hyparrhenia rufa Nees, Abelmoschus ficulneus L., Gossypium barbadense L., Nicotiana tabacum L., Sorghum bicolour L. Moench, Eleusine coracana Gaertn., Capsicum frutescens L., Zea mays L., Tithonia diversifolia Hemsl. and Medicago sativa L. Significant differences in phytoremediation rates were observed amongst the treatments with exception of the 125 g/kg soil concentration of hydrocarbon that was lethal to all the plant species. Over 50% TPH reduction in the 75 g/kg soil concentration was observed in contaminated soil phytoremediation in H. rufa, G. barbadense, O. longistaminata, T. diversifolia and S. arundinaceum, making them potential phytoremediators of hydrocarbon-contaminated soil in the Sudd-Wetland of South-Sudan.

A three-year pot experiment carried out in the vegetation hall in 2014-2016 included studying the enzymatic activity of soil, into which various amounts of copper: (100, 200 and 300 mg Cu/kg soil) and organic materials (cattle manure, chicken manure, post-mushroom substrate) were introduced, used separately, at a soil-introduction dose of 2 g C_org/kg. Copper and organic materials were used once, only in the first year of the study, before sowing test plant orchard grass. In soil collected after the last (fourth) swath of grass in each year of the study, the activity of urease, dehydrogenases, acid, and alkaline phosphatase was determined. Applications of copper to the soil, regardless of its dose, resulted in a decrease in urease, dehydrogenases and alkaline phosphatase and an increase in acid phosphatase activity. The inactivating effect of this metal on the activity of urease, dehydrogenases and alkaline phosphatase increased with the increase of its dose. Organic fertilisation generally increased the enzymatic activity of the analysed soil. In subsequent years of the study, urease and alkaline phosphatase activity decreased, while acid phosphatase activity increased. Dehydrogenase activity did not change significantly in subsequent years of the study.

Soil arsenic (As) levels are particularly high in parts of China, where wheat and rape are widely grown. Understanding the effects of As concentration on the growth of these two major crops is of significance for food production and security in China. A pot experiment was carried out to study the uptake of As and phosphorus (P), and the soil As bioavailability at different growth stages of wheat and rape. The results indicated that winter wheat was much more sensitive to As stress than rape. Wheat yields were elevated at low rates of As addition (< 60 mg/kg) but reduced at high rates of As concentrations (80-100 mg/kg); while the growth of rape hadn't showed significant responses to As addition. Phosphorus concentrations in wheat at jointing and ear sprouting stages increased with increasing soil As concentrations, and these increases were assumed to contribute a lot to enhanced growth of wheat at low As treatments. Arsenic did not significantly affect P concentrations in rape either. The highest As concentrations in wheat shoot and rape leaf were 8.31 and 3.63 mg/kg, respectively. Arsenic concentrations in wheat and rape grains did not exceed the maximum permissible limit for food stuffs of 1.0 mg/kg. When soil As concentration was less than 60 mg/kg, both wheat and rape could grow satisfactorily without adverse effects; when soil As concentration was 80-100 mg/kg, rape was more suitable to be planted than wheat.

The aim of the study was to determine the glycoproteins content (total glomalin (TG), easily extractable glomalin (EEG) and soil proteins related to glomalin (GRSP)) in soil under long-term monoculture of maize. Soil microbiological and biochemical properties, including microbial biomass and enzymatic activity were also assessed. The presence of total, easily-extractable glomalin and soil proteins related to glomalin was dependent on both the growth phase of the plant and tillage system. The highest content of glomalin was detected in the soils under maize in direct sowing and reduced tillage. The glomalin content was correlated with soil biological activity. The linear regression was observed between TG and GRSP content, but no linear relationship was found between GRSP and C_org. The principal component analysis showed the strong correlations between the parameters of soil quality and biodiversity indicators. Selected indicators of soil microbial parameters explained 52.27% biological variability in soils.