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The aim of this study was to assess the leaf area index (LAI) of tomato and cucumber using an AccuPAR-LP-80-ceptometer to find the influence of irrigation. LAI was also determined by destructive sampling for comparison. The research was conducted at the Liaoning Water Conservancy Institute, North China in 2016. A randomized block design was used to test the influence of four treatments corresponding to field water capacity. Full irrigation (W_1.0), 15% (W_0.85), 25% (W_0.75) and 35% (W_0.65) water deficit were applied using the drip system. Regression model was developed to estimate LAI in response to irrigation. The results show that there is no difference between the two methods. The highest LAI obtained for tomato and cucumber was 5.21 and 3.21 m²/m², respectively, with W_0.85 at 70-days after transplanting, which corresponds with destructive results. This result was found 11% higher and equal compared with W_1.0 for tomato (4.62) and cucumber (3.21), respectively. For both crops, LAI was found significantly influenced at 50-days after transplanting. It also indicated that LAI significantly influenced (by 15%) deficit irrigation for both crops and methods that achieved the highest yield. The predicted LAI was obtained best-fitting with the observed values, which indicated that the AccuPAR-ceptometer is suitable to be used.

Slow-release nitrogen fertiliser can potentially increase crop production and improve fertiliser nitrogen use efficiency. However, it is unclear that are suitable for different regions and crops in the northeast of China. Therefore, according to different soil and climate characteristics, we investigated the synchronised relationships between nitrogen slow release fertiliser and nitrogen maize requirements. Experiments were conducted at Shenyang Agricultural University, Liaoning province, Northeast China, from 2016 to 2017. Stabilised fertiliser treatments increased grain yield, nitrogen use efficiency and nitrogen accumulation at each maize growth stage. Grain yield increased by 2.32% and 11.33% (2016), and 1.55% and 7.87% (2017), respectively, when compared with the urea CK1 (233 kg N/ha) and CK2 (210 kg N/ha) treatments. Additionally, during the growth period of the stabilised fertiliser treatment, the stability of the synchronisation relationship between nitrogen absorption and absorption of spring maize was significantly higher than other treatments, and the effect was the best. Therefore, we conclude that the stabilised fertiliser is the most suitable option for promotion and application in spring maize in Northeast China.

Recently, plant-available sulphur (S) in the soil is decreasing due to the limited use of S containing fertilisers and the reduction of atmospheric S deposition. The aim of this work was to evaluate the S status in a long-term fertilisation experiment on a Chernozem in Hungary, with control and 2 NPK rate treatments, considering that after 27 years of superphosphate (SP) use, SP was replaced by monoammonium phosphate in 2010. Plant and soil sampling were performed in 2017 at three different development stages of winter wheat. To assess the S status, the S balance was estimated (for 34 years), KCl soluble soil sulphate, S as well as nitrogen (N) concentration and some amino acids in wheat grain were measured. N/S ratios, S and N uptake of wheat were calculated. The residual effect of SP could be measured only in terms of KCl soluble SO₄^2--S in soil. According to the wheat grain S concentration (0.08-0.10%) and N/S ratio (14.9-22.0), wheat was S deficient, despite the positive S balance in the fertilised plots. In this experiment, where S fertiliser was applied with 84 kg S/ha dose in 1983-2010, followed by a 7-year period without S fertilisation, S supply is necessary for achieving adequate wheat quality.

The tillage depth plays a critical role in solving soil compaction - a global problem of soil degradation. However, to date, there are few research reported about tillage depth, and the standard of optimum tillage depth is lacking. Therefore, we conducted a meta-analysis to quantify the effect of tillage depths on crop yield across a global scale, and then to analysis their influence factors such as local climate, soil properties, and managements. Moreover, a global distribution of the optimal tillage depths was estimated by using a random-forest model. Overall, our result demonstrated that crop yield first increased within tillage depths from 25 to 35 cm, and then reduced under higher depth of deep tillage compared to conventional tillage, according to 1109 wheat, maize and soybean (WMS) yield observations from 202 studies and 109 publications. Visibly, 35 cm hence became the optimum tillage depth of WMS across the world, while it varies with different regions. Furthermore, higher crop yields observed in areas with a humid climate, high clay contents, and large bulk density under the optimal depth 40, 35 and 45 cm, respectively. In contrast, a lower yield was observed in areas with arid climates, silty and sandy soils, and lower bulk density within optimal depth of 25 cm, 30 cm, and 25 to 35 cm. Human management efforts, including fertilizer addition, irrigation, straw returning, and changing of cropping system or crop species mostly increased the crop yield under deep tillage. Particularly, our meta-analysis indicated that straw returning needs a greater depth. Finally, we predicted the distributions of optimum depths, which showed that 30 and 35 cm were the optimum tillage depths in the temperate and tropical regions, and the total crop yields of global WMS increased by 2689 million tons per year under the optimal tillage depth, compared with the conventional tillage.

Development of methods for bioremediation of soils contaminated with petroleum products is one of the most urgent tasks of our time. This task is more difficult to perform in high-mountainous landscapes, at an altitude of more than 4 000 m a.s.l. Moreover, these high-mountain ecosystems are the most vulnerable to various kinds of anthropogenic impacts, and therefore the relevance of bioremediation is obvious. The research was conducted in the high-altitude ecosystems of the Kyrgyz Republic at the Kumtor mine. In this study was carried out on the bioremediation of oil contaminated soil using biostimulation, bioaugmentation and biostimulation + bioaugmentation remediation techniques for 90 days in the climatic conditions of high mountain region. The biostimulation treatment showed the highest total petroleum hydrocarbons (TPH) biodegradation percentage 62.78% compared to the bioaugmentation 50.63% and biostimulation + bioaugmentation 49.11%. Thus, the method of biostimulation proved to be the most effective method for bioremediation of soils contaminated with petroleum products. The application of this method could be one of the successful methods of recycling contaminated soils. This study demonstrated the possibility of restoring TPH-polluted soils using biological methods of soil treatment in climatic cold conditions of high mountains.

The aim of this study was to determine the heavy metals concentrations in soil, inflorescences of Brassica napus and rapeseed honey sampled from some regions of north-eastern Bulgaria. Thirteen locations were selected for experimental studies. The soils, plants and honeys samples were taken from conventional beekeeping areas away from major industrial pollutants. The median amounts of elements in the soil samples (mg/kg DW) are 1.1246 for Fe(s), 0.7048 for Al(s), 0.5636 for Pb(s), 0.1658 for Cu(s) and 0.0148 for Zn(s). The median amounts of heavy metals measured in the inflorescences of Brassica napus (mg/ kg DW) are 5.5430 for Fe(p), 2.9095 for Zn(p), 1.3225 for Pb(p), 0.2593 for Cu(p) and 0.2105 for Al(p). The median heavy metals concentrations in  tested honey (mg/kg DW) are 1.0026 for Fe(h), 0.1849 for Al(h), 0.1832 for Pb(h), 0.1250 for Zn(h), 0.0702 for. Cu(h). The relationship between the heavy metal in soil, plants and honey was investigated using the Spearman’s rank correlation coefficient. Significant differences in the concentrations of Fe(s), Al(s) and Pb(s) in soils, Fe(p) and Zn(p) in the plant samples, Fe(h) in honey samples from the different locations were found. The heavy metal content tested in honey did not pose a risk to human health.

Use of microorganisms as heavy metal remediators is an effective approach for chromium reduction in plants. Chromium carcinogenicity (Cr⁶⁺) beyond the permissible levels elicits environmental and health problems. To reduce chromium toxicity along with the plant growth improvement, a cost-effective and eco-friendly remediation approach is necessary. In the current study, chromium-resistant bacterial species were evaluated for growth improvement of sunflower. Three auxin-producing bacteria able to tolerate hexavalent chromium, i.e., Sporosarcina saromensis (EI) and two species of Bacillus cereus (AR and 3a) were selected for the proposed study. Growth studies along with auxin synthesis potential of bacterial isolates with and without chromium were conducted. Results revealed a 188% enhancement in plant height under laboratory-grown plants with B. cereus (AR) under 500 mg/L chromium stress (Cr⁶⁺). B. cereus (3a) also showed an 81% increase in leaf number with 400 mg/L chromium stress in laboratory-grown plants. Similarly, 73% increment in the amount of auxin was reported in the case of inoculation with S. saromensis isolate (EI) over respective control treatment. These improvements provide an excellent means of reducing chromium (Cr⁶⁺) in the contaminated soils naturally by stimulating plant growth along with bioremediation potential.

The study aimed to evaluate the effect of the straw mulch and compost application on the soil losses in potatoes cultivation. The three-year (2016-2018) exact field plot trials with the potato cv. Dicolora was carried out at the experimental station in Prague-Uhříněves. Wheat straw mulch in two doses 2.5 t/ha (SM1) and 4.5 t/ha (SM2) was applied on the soil surface; the compost in a dose of 20 t/ha (CM) was shuffled to the surface soil layer. Both straw mulch and compost application contributed to the significant reduction of the soil losses compared to control untreated (C). In the average of 2016-2018, the lowest soil loss 17.54 g/m² (amount of the soil sediment caught) was found for the variant with the straw mulch treatment (SM2); it means the decrease of soil losses by 71.9% compared to C. Variant SM1 (lower rate of straw mulch in dose 2.5 t/ha) showed the soil loss 18.6 g/m² (the decrease by 70.2% compared to C). The similar results for both variants indicate that for effective soil protection, it is not necessary to use the high doses of the straw mulch. Regarding the distribution of precipitation during the vegetation season, intensive precipitation during the short time, especially when they came after the longer period of drought led to higher soil losses compared to the precipitation distributed regularly.

In sustainable agriculture crop residues management should consider the interactions between soil and residue properties, which can affect the decomposition and global greenhouse gases (GHGs) emission. Through a laboratory experiment, we investigated the effect of the management (incorporation and surface placement) of wheat and faba bean residues on their decomposition and CO₂, CH₄ and N₂O emissions from two soils, a Chromic Vertisol and an Eutric Cambisol. In the Vertisol, wheat residues increased the CO₂ emission more than faba bean when left on the surface whereas no differences among residues were observed when incorporated. In the Cambisol, faba bean emitted more than wheat when left in the surface and less when incorporated. Total CH₄ emissions were higher in faba bean in Cambisol for both management and only when applied in the surface in Vertisol. Total N₂O emission in the Vertisol was higher when faba bean was incorporated, and wheat was left on the surface. In the Cambisol, wheat addition increased total N₂O emissions by 20% compared to faba bean, with no differences between managements. Our study confirmed that contrasting properties among tested soils resulted in significant interactions with residues own degradability and their placement affecting residue decomposition, soil C and N dynamics, and GHGs emission.

The experiment aimed to obtain a quadratic regression mathematical model of the comprehensive evaluation score of yield, quality, and four macroelements (N, K, P and Ca). The suitable nutrient solution was chosen and verified via computer simulation of the model and the highest comprehensive score in all treatments. Results showed that P, K and Ca had a positive effect on the comprehensive evaluation value of tomato, whereas N showed a negative effect. The optimal formula calculated using the regression equation could promote high-yield and high-quality tomato. The single-plant yield, soluble protein, vitamin C, total sugar, lycopene, and elemental utilisation of K and Ca in the tomato were 13.93, 78.95, 3.29, 20.98, 51.91, 16.69 and 24.14% higher than those in the special formula treatment of Japanese Yamazaki tomato, respectively. In summary, the optimal nutrient solution formula of tomato cultivation was obtained, in which the N, P, K and Ca levels were 24.83, 4.50, 9.49 and 5.73 mmol/L, respectively.

A field campaign was conducted using six treatments under the summer rice-winter wheat cultivation system to evaluate the response of soil greenhouse gas (GHG) emissions to long-term differentiated fertilisation regimes. The treatments included control, phosphorus plus potassium, nitrogen only, nitrogen plus phosphorus (NP), nitrogen plus potassium, and NP plus potassium (NPK). Compared to the control, mineral fertilisation increased CH₄ emissions during the rice season by 69% to 175%. Phosphorus amendment also enhanced seasonal CO₂ emissions by 21% to 34% when compared with the treatments without receiving P, while combined use of P and potassium suppressed seasonal N₂O emission to the same level of control. Net CO₂ and N₂O emissions from the dried fallow and wheat seasons and CH₄ emissions from the flooding rice season dominated annual budgets of individual GHGs. All of the soils under different treatments were net sources of global warming and the overall net global warming potential ranged from 9 799 to 14 178 kg CO₂ eq/ha/year with CO₂ emission contributing 52% to 76%, CH₄ contributing 20% to 40% and N₂O occupying the rest. The annual maximum grain yields and minimum GHG intensity was observed at the NPK treatment, suggesting it to be the environmental-friendly optimum fertilisation regime.

In the present study, free amino acid (AA) regulation in the arsenic (As) hyperaccumulating ferns was evaluated in a pot experiment to determine the relationship between As stress and the characteristic change in metabolism of AAs. The ferns Pteris cretica cv. Albo-lineata (Pc-Al) and cv. Parkerii (Pc-Pa) were exposed to As treatments at 0, 20, 100, and 250 mg As/kg for 90 days. Greater As content, as well as higher biomass production, were identified in Pc-Al compared with Pc-Pa. Ferns showed changes in the stress metabolism of free AA homeostasis. These results indicate a disturbance in nitrogen metabolism and depletion of pool assimilated carbon metabolism. In the fronds and roots, Pc-Pa accumulated higher amounts of free AAs than Pc-Al. The total free AA content, as well as the ratio of the main AA family pathway (glutamate family), were increased by the accumulation of toxic As in the ferns. Results suggest that Pc-Al tolerates higher As doses better due to changes in AA biosynthesis; however, at higher As doses, Pc-Pa upregulated AA biosynthesis due to As toxicity. The most abundant free AAs of ferns was glutamine, which was enhanced by As. Furthermore, the ratios of selected individual free AAs revealed a characteristic phenotype difference between ferns.

The effect of the application of compost and cow manure on nectarine (Prunus persica L.) root growth and survivorship was investigated in a commercial orchard during the growing seasons 2003, 2004 and 2005. Our main objective was to determine whether compost affects root dynamics differently than cow manure. The experiment was a complete randomized block design with four replicates of two treatments: cow manure and compost applied at planting in 2001 at 10 t dry weight (DW)/ha and from 2004 at the rate of 5 t DW/ha. The compost fertilization represented a yearly rate of 120 kg N/ha, while cow manure was approximately 80 kg N/ha/year. Both root growth and survival were evaluated at 20-day intervals during the growing season by the minirhizotron technique. Cow manure increased the production of new roots compared with compost (P ≤ 0.001). Roots were mainly produced at a depth of 21-40 cm for compost and 61-80 cm for cow manure. The root lifespan was longer in compost than in cow manure treated trees (P ≤ 0.05) and was strongly affected by depth. No differences were observed in root length and diameter.

This study quantifies the effects of weather conditions, irrigation, and plant age on yield and alpha-acids content of Czech hop cultivars Saaz, Sládek, Premiant and Agnus in a 25-year long period, i.e., from 1993 to 2018. The yields of Czech hop cultivars were increasing for the first three years of plant age until they stabilized and then started to decline slightly for 15 to 20 years until they reached the optimal time for replanting. The highest alpha-acids content in hop cones was achieved in the first year of cultivation, followed by a logarithmic decline in the upcoming years. Rainfall was the most significant factor that positively influenced the yield of Saaz hops with correlations of r = 0.59 and 0.61 (P < 0.01) for total seasonal rainfall (April-August), 0.65 (P < 0.001) and 0.60 (P < 0.01) for daily rainfall above 3 mm, 0.37 (P < 0.05) and 0.58 (P < 0.01) for rainfall in May and 0.50 (P < 0.01) and 0.32 (P < 0.05) in July in the Saaz region and the Stekník farm, respectively. The yield of cultivars Sládek, Premiant and Agnus was not statistically influenced by the amount of precipitation, but there was a positive effect of irrigation level on yield increase with correlations 0.58 (P < 0.01), 0.55 and 0.49 (P < 0.05), respectively. High air temperatures during summer were the most significant factor that negatively influenced the alpha-acids content with the correlations ranging from -0.56 to -0.83. However, cv. Agnus showed a stable weather-independent alpha-acids content.

We studied the dynamics of soil organic carbon (SOC)-pool mineralisation in agricultural soil. A laboratory incubation experiment was conducted using the soil from a long-term experiment involving the following fertilisation regimes: no fertilisation (CK); mineral (NPK); organic (M), and combined organic-inorganic fertilisers (MNPK). SOC mineralisation rate decreased as follows: MNPK > M > NPK > CK. Cumulative SOC mineralisation (C_m) ranged between 730.15 and 3 022.09 mg/kg in CK and MNPK, respectively; 8.81% (CK) to 20.45% (MNPK) of initial SOC was mineralised after a 360-day incubation. Soil C_m values were significantly higher under NPK, M, and MNPK compared to those under the CK treatment. Dynamic variation in C_m with incubation time fitted a double exponential model. Active carbon pools accounted for 2.06-6.51% of total SOC and the average mean resistant time (MRT₁) was 28.76 days, whereas slow carbon pools accounted for 93.49-97.94% of SOC, with an average MRT₂ of 8.53 years. The active carbon pool in fertilised soils was larger than in CK; furthermore, it was larger in M- and MNPK- than under NPK-treated plots. SOC decomposed more easily in long-term fertilised plots than in non-fertilised plots.

Cytoplasmic male sterility (CMS) allows efficient biological confinement of transgenes if pollen-mediated gene flow has to be reduced or eliminated. For introduction of CMS maize in agricultural practice, sufficient yields comparable with conventional systems should be achieved. The plus-cultivar-system in maize offers a possibility for biological confinement together with high and stable yields whereas pollinator amount and distribution within the CMS crop is crucial. The aim of this EU-funded study was to identify the best proportion (10, 15, and 20%) and spatial arrangement (inserted rows, mixed seeds) of the pollinator within the CMS maize cultivar under field conditions in the Czech Republic, in Germany and in Spain. In Germany and in the Czech Republic, a pollinator proportion of 10% produced significantly lower yield than the treatments with a pollinator proportion of 15% and 20%. Differences in yield between row and mix arrangements were not detected. No differences between the tested arrangements occurred in Spain. With respect to practical conditions, a pollinator proportion of 15% can be recommended for achieving a satisfactory yield. CMS maize cultivar released no or merely a small amount of pollen and self-pollinated plants developed no or only a small number of kernels indicating that currently recommended isolation distances between genetically modified (GM) and non-GM fields can be substantially shortened if the CMS confinement tool is used.

Phenolic compounds (PCs) - with special reference to secondary plant metabolites - were characterised in two Mediterranean olive groves (Olea europaea L.). Representative pedological profiles were dug to identify and characterise the pedotype. Qualitative and quantitative analyses were carried out on soil core samples gathered at fixed depths (0-20 cm and 20-40 cm) and olive leaf methanol extracts by high-performance liquid chromatography with ultraviolet detection. The total PCs content reflected the soil organic carbon distribution, especially carbon of humic and fulvic acids, corroborating their crucial role in humification pathways. Among the analysed plant secondary metabolites, luteolin-4'-O-glucoside and verbascoside were the most abundant in leaves and soils, respectively. Most of the easily hydrolysed/metabolised phenols were not found in soils. Rutin and verbascoside, despite containing glucose, strongly persisted in the soil environment, probably due to their allelopathic effect. Oleuropein was not found in soils because it is highly soluble and mobile in the soil environment. Furthermore, the presence of clay in soil seemed to determine the accumulation of specific PCs. Our data suggest that PCs persistence in soil seems to be mainly determined by a balance between physicochemical and biochemical instability and allelopathic stability rather than their abundance in the plant.

The study presents results of the one-factor field experiment carried out in years 2005-2011 located on a slope with an inclination of 9%, in the mountain region (southern Poland, 545 m a.s.l.). Soil-protection effectiveness of potato, spring barley and meadow was studied on the basis of vegetation cover forming during whole plant vegetation period, expressed as LAI (leaf area index). The mass of surface runoff from the plots was measured after precipitation and snowmelts causing surface wash-out. The plots were arranged in a randomized block design, in four repetitions. Surface wash-outs were caught in the Słupik's catchers. The soil-protection effectiveness of potato starts when plants cover 80% of the soil surface, in spring barley it was 60%, and for meadow 10%. Reduction of the intensity of surface wash as a result of an increase in the surface of the plants aerial-parts is described in the following simple regression equations: y = -1480.7x + 4094.2 (r = 0.63, n = 216) for potato; y = -59.2x + 157.4 (r = 0.69, n = 200) for spring barley, and y = -1.5097x + 11.6 (r = 0.37, n = 236) for meadow. Meadow protects soil against water erosion 6.8-times more effectively than spring barley and 324-times better than potato. The results enabled verification of the nomograms determining the carbon indicator value in the USLE equation for tested plants under similar conditions.

In this experiment, the response of winter oilseed rape cv. SY Alister F1 to diverse foliar fertilization was evaluated. Foliar fertilization with the preparation Insol 5 was applied at the following dates: control (without a foliar fertilizer); autumn; autumn + spring; autumn + twice spring; spring and twice spring. Each variant in which autumn foliar fertilization was carried out contributed to a significant increase in plant density before harvest. In turn, each variant with spring foliar fertilization significantly increased the number of pods per plant compared to the control. Variants with autumn + spring, autumn + twice-spring, and twice-spring foliar fertilization influenced the increase in the soil-plant analysis development index (SPAD), thousand seed weight and protein and fat yield. The leaf area index was the highest after foliar fertilization applied in autumn + in spring or autumn + twice in spring. Foliar fertilization affected a significant increase in seed yield compared to the control. The content of protein and magnesium in seeds was the highest after the fertilizer application in autumn + twice in spring or twice in spring.

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.

Aeroponics would appear to have a number of potential attributes to make potato production more efficient. In a 3-year experiment, from 2019 to 2021, potatoes were grown in aeroponic units using two nutrient solutions as well as in a conventional polycarbonate greenhouse in a substrate. Potato cultivars Adéla, Zuza and Ornella were used in all experiment years. No statistically significant effect of nutrient solution or potato cultivar on the number and weight of tubers was found in the trial. However, the advantages of aeroponics over conventional technology were statistically proven. The number of tubers per plant in aeroponic units ranged from 2.4 (2019, cv. Adéla) to 41.0 (2021, cv. Zuza), while in the greenhouse, they ranged from 3.9 (2019, cv. Adéla) up to 12.6 (2021, cv. Adéla). The average weight of tubers in aeroponic units ranged between 2.0 g and 9.9 g per plant (2 to 10 successive harvests), and in the greenhouse, 22.7 g to 41.9 g per plant (single harvest). The influence of cultivar on the average weight of tubers within individual cultivation technology variants was statistically proven only for polycarbonate greenhouse: only one harvest after the end vegetation.

Knowledge about the spatio-temporal variability of soil chemical and biological properties is crucial in evaluating their structure-function relationship and their impact on ecosystem functions. A study was conducted in order to evaluate the spatial variability of nitrogen (N) forms and N-cycle enzymes of a Phaeozem located in the Northwestern Poland. Fifty soil samples were collected every 10 m from the area of 90 × 40 m that was selected from an 80 ha agricultural field after the harvest of winter wheat. The samples were analysed for total nitrogen (N_tot); mineral nitrogen (NO₃^--N, NH₄⁺-N) and the activities of the N cycle enzymes - urease (UR), nitrate reductase (NR) and arginine deaminase (ADA). The coefficients of variation were low for N_tot content and UR activity, while a moderate variability was noted for mineral N and ADA activity and a high one was noted for NR activity. Most of the properties revealed a contribution of random variance (nugget effect) in total variability (sill), while only N_tot and ADA activity were determined by the structural variance. The effective ranges were from 11.9 m for NO₃^--N to more than 50.3 m for NH₄⁺-N. Kriged maps showed that every property revealed a different distribution on the study area. The significant variability of the studied properties should be taken into account in soil management practices. Additionally, this knowledge would contribute to a better understanding of the nitrogen transformation in soil and functioning of the ecosystem.

To assess the response of promising safflower genotypes to late-season drought stress in delayed planting conditions, an experiment was conducted in two years (2016-2017 and 2017-2018) in Iran. The irrigation regime was specified in two levels, including normal irrigation and irrigation cut off in the seed filling stage in main plots, and five safflower genotypes, including Soffe, Goldasht, Golmehr, Padideh, and Parnian were categorized in subplots. Applied drought stress significantly reduced the seed yield and yield components of all genotypes, which accompanied with a substantial decrease in oil content and oil yield of all genotypes. However, the highest seed and oil yield in drought stress conditions obtained in the Parnian genotype by value 2338 and 561 kg/ha, respectively. Moreover, a significant drought-induced increase in palmitic, stearic, and oleic acids, as well as a decrease in linoleic acid content, was observed in all genotypes. Parnian genotype with high unsaturated fatty acids content (90.9%) and the minimum amount of saturated fatty acids (8.7%) might be a promising genotype to starting a formal crop improvement program to achieve more drought-tolerant safflower genotype.

The competitiveness of Bradyrhizobium japonicum inoculation strain against indigenous rhizobia was examined in a soil pot experiment. The effect of inoculation strain was evaluated under different soil conditions: with or without previously grown soybean and applied commercial inoculant. Molecular identification of inoculation strain and investigated rhizobial isolates, obtained from nodules representing inoculated treatments, was performed based on 16S rDNA and enterobacterial repetitive intergenic consensus (ERIC) sequencing. Inoculation strain showed a significant effect on the investigated parameters in both soils. Higher nodule occupancy (45% vs. 18%), nodule number (111% vs. 5%), nodule dry weight (49% vs. 9%), shoot length (15% vs. 7%), root length (31% vs. 13%), shoot dry weight (34% vs. 11%), shoot nitrogen content (27% vs. 2%), and nodule nitrogen content (9% vs. 5%) was detected in soil without previously grown soybean and applied commercial inoculant. Soil had a significant effect on the shoot, root and nodule nitrogen content, while interaction of experimental factors significantly altered dry weight and nitrogen content of shoots, roots and nodules, as well as number of nodules. Nodulation parameters were significantly related with shoot dry weight, shoot and nodule nitrogen content. Symbiotic performance of inoculation strains in the field could be improved through co-selection for their competitiveness and effectiveness.

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.

Soil erosion is one of the major environmental problems in open-cut mines in tropical regions. It causes negative impacts including the removal of nutrient-rich topsoil, destroys aquatic habitat, dam and pond siltation, clogs river by deposition of sediment, and causes water pollution in the rehabilitation process. Soil texture is an important factor to affect soil erosion. In this study, artificial rainfall experiment in the laboratory scale was conducted to clarify the mechanism of soil erosion under the different soil composition and to discuss the methods for minimizing soil erosion. The obtained results showed that the soil seal generated due to the presence of fine particle under high rainfall intensity is the main contributor to accelerate the soil erosion. Additionally, the surface coverage by the cover crops is the most effective measure to reduce soil erosion because both the coarse and fine contents runoff can be minimized while arranging of the slope angle is effective for reducing the runoff of coarse contents and the soil compaction is effective to reduce that of fine contents. Soil erosion can be minimized by selecting prevention method considering the type of soil because the prevention effect on soil erosion is different depending on the type of soil.

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.

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.

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.

The aim of this study carried out in 2017-2018 was to determine the effect of white cabbage (Brassica oleracea L.), which is known to have an allelopathic effect on the germination of some weed and cultural crops seeds. In addition to weeds, Amaranthus retroflexus L., Chenopodium album L. and Solanum nigrum L., cultural plants such as Zea mays L., Beta vulgaris L., were used in this study. It has been shown that the seed germination rate was decreased by the increased concentration of white cabbage post-harvest leaves extractions, which were made with different concentrations of aqueous and methanol extracts (30, 40, and 50%). The methanol extract was found to be more effective in germination. According to these results, S. nigrum and Z. mays seeds were less affected than A. retroflexus, C. album and B. vulgaris seeds. In the light of these data, it is observed that extracts obtained from white cabbage can be effective on some weeds; however, it was concluded that in order to reach more definite conclusions, studies on the subject should be increased, and similar studies should be continued under greenhouse or field conditions.