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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.

A field experiment was carried out in the years 2012-2018 in Poland in a split-plot design. The aim of the study was to determine the long-term effect of legumes as forecrops on the productivity of rotation with nitrogen fertilization. The rotation included: legumes + spring barley (SB), winter rape (WR), winter wheat (WW) and winter wheat. The study was conducted as a two-factorial field experiment with four replications. The present study showed that legumes as forecrops increased the yield of all after-harvest crops in rotation. Yielding of these crops also depended on nitrogen fertilization and position in the rotation. After comparison of the influence of nitrogen fertilization on yield of cereals, it was observed that the effect of this factor was greater for WW cultivated in the fourth year of rotation than for WW cultivated in the third year of rotation. In relation with control, each dose of nitrogen fertilization caused a significant increase of WR and cereals yield, but the dose of 180 kg N/ha did not increase yield significantly in comparison to the dose of 120 kg N/ha. There was also negative agronomic N-efficiency observed between doses of 120-180 kg N/ha, which means that it is not necessary to use 180 kg N/ha, especially if there are legumes in crop rotation.

In the present paper genetic relationships of twenty varieties of cashew are described on the basis of morphological characters and RAPD (Randomly Amplified Polymorphic DNA) markers. Results obtained for the phenotypic characters based on similarity coefficient were divided into four clusters with 70% similarity. By means of similarity coefficients (SG), cluster I was found to consist of twelve varieties. Cluster II consisted of a single variety, NRCC-1, cluster III consisted of six varieties and cluster IV had only one variety, Vridhachalam-2. The analysis started by using RAPD markers that allowed us to distinguish 20 varieties. A total of 80 distinct DNA fragments ranging from 0.2 to 3.0 kb were amplified by using 11 selected random 10-mer primers. Genetic similarity analysis was conducted for the presence or absence of bands in the RAPD profile. Cluster analysis clearly showed that 20 varieties of cashew grouped into two major clusters based on similarity indices. The first major cluster comprised one minor cluster. The other major cluster was divided into two sub-minor clusters, one sub-minor cluster having three varieties and the other sub-minor cluster was represented by 15 varieties. Among the 20 varieties, Ullal-3 and Dhana (H-1608) showed the highest similarity indices (87%). It was noted that Vengurla-2 and Vengurla-3 were not grouped into a single cluster but Vengurla-4 has 82% similarity to Vengurla-3. The variety Vengurla-2 has very close similarity (85%) with variety Vridhachalam-3 (M-26/2). The analysis of genetic relationships in cashew using morphological traits and RAPD banding data can be useful for plant improvement, descriptions of new varieties and also for assessment of variety purity in plant certification programmes.

Water stress is a frequent and critical limit to wheat (Triticum aestivum L.) production in North China. It has been shown that photosynthetic active radiation (PAR) is closely related to crop production. An experiment was conducted to investigate the effects of deficit irrigation and winter wheat varieties on the PAR capture ration, PAR utilization and grain yield. Field experiments involved Jimai 20 (J; high yield variety) and Lainong 0153 (L; dryland variety) with non-irrigation and irrigated at jointing stage. The results showed that whether irrigated at jointing stage or not, there was no significant difference between J and L with respect to the amount of PAR intercepted by the winter wheat canopies. However, significant differences were observed between the varieties with respect to the amount of PAR intercepted by plants that were 60-80 cm above the ground surface. This result was mainly caused by the changes in the vertical distributions of leaf area index (LAI). As a result, the effects of the varieties and deficit irrigation on the radiation use efficiency (RUE) and grain yield of winter wheat were due to the vertical distribution of PAR in the winter wheat canopies. During the late growing season of winter wheat, irrespective of the irrigation regime, the RUE and grain yield of J were significantly (LSD, P < 0.05) higher than those of L. These results suggest that a combination of deficit irrigation and a suitable winter wheat variety should be applied in North China.

This study is aimed at investigating the effect of different vineyard soil management systems on soil erosion and earthworm (Lumbricidae) population. Three soil management systems were investigated: permanent green cover (control), straw-cover and periodic soil tillage. Inter-row periodic soil tillage was applied in 2002 and 2003 (May and August), and straw-cover in May 2002. Periodic soil tillage resulted in increased erosion, i.e. 1746 kg/ha of soil/per year, on average. The greater portion of erosive events occurred after tillage in summer (August 2002), which was accompanied by heavy rainfall and slow renewal of grass cover (slower than in spring). The lowest average amount of soil erosion was observed in the treatment with straw-cover (56 kg/ha per year). This management system provided better environment for earthworm populations, most of which were found close to the soil surface, especially in the dry year 2003. In periodical soil tillage, the majority of earthworms were found in the soil horizon not disturbed by the tillage, i.e. at the depth of 10-20 cm. The lowest number of earthworms (only 2 per m²) was recorded in the herbicide intra-row strip.

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

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

This paper evaluates the response on the rate of photosynthesis (P_n), transpiration (E), stomatal conductance (g_s) and water use efficiency (WUE) in 15 genotypes of young hop plants (19 BBCH) grown in greenhouses in the conditions of water deficit for the period of 9 days. On the 9^th day, the relative content of water in the experimental plants fluctuated between 70.14-75.20%. The levels of P_n and g_s evidently dropped in the monitored species as a result of the water deficit. The decrease of P_n in the experimental plants compared with the control group was largest in the Saaz Os. cl. 72 (by 77.5%), Magnum (by 73.3%) and Columbus (by 62.3%). To the contrary, the lowest P_n decrease was noted in the case of genotypes Saaz Late (by 15.7%), Vital (by 23.9%) and Premiant (by 24.2%). All genotypes except for cv. H16 showed an evident decrease of E. Judging by the highest values of WUE, the most effective water management was shown by Premiant, Vital and Saaz Late genotypes. A significant stomatal limitation of photosynthesis due to water stress was identified in the most widely used Czech cultivar, Saaz Os. cl. 72, with low values of stomatal conductance, photosynthetic rate and transpiration.

The paper presents the results of a laboratory experiment aimed at the assessment of N₂O emissions, NO₃^-, NH₄⁺ and carbon (C) leaching from agricultural soils subjected to long-term mineral and organic fertilization. Our results show that long-term treatment impacts the N₂O emissions from loamy-sand Luvisols to a greater extent than the recent single application of mineral or organic fertilizers. The N₂O fluxes from soils with higher C_org content that results from long-term organic fertilization exceed those from soils with lower C_org content subsequent to long-term mineral fertilization. Our research confirms previous reports that the intensity of N₂O emission is related to soil moisture. The NO₃^- leaching depended on the recent application of fertilizers with a stronger influence of single application of NH₄NO₃ than farmyard manure. Long-term fertilization did not impact the NO₃^- leaching.

In four-year experiments, hop was treated with 7 biologically active substances in two terms during vegetation: Lignohumate max (a mixture of humic acids and fulvic acids), Lexin (a mixture of humic acids and fulvic acids enriched with auxins), Lexenzym (a mixture of humic acids and fulvic acids enriched with auxins, phytohormones and enzymes precursors), Ascophyllum nodosum seaweed extract, synthetic auxin, humic acids and fulvic acids alone. The chlorophyll content was monitored after the application both in the vine leaves and in the branch leaves. After harvesting of the hops from the individual treatments, the yield of dry hops was determined and the cones were analysed for the content of alpha bitter acids. The results show that the most effective hop treatment was the application of Lexin and Lexenzym. The Lexenzym treatment provided a yield of dry hops of 1.86 t/ha, i.e. 0.47 t/ha higher compared with untreated control. The Lexin treatment provided yield higher by 0.41 t/ha of dry hops compared with the untreated control, while the harvested cones contained the most alpha-bitter acids (4.57%).

The traditional management applied by the Native Community of Chambira (NCCh) is based on agroforestry plots with diverse species and areas with rotation of legumes, cassava and maize. The objective was to evaluate behaviour of the physicochemical indicators of soil quality with traditional crop management in the NCCh. A completely randomised design was applied, where the treatments were traditional mixed fruit management (MF), crop rotation (CR) and native forest (NF) as reference. Physical indicators of the surface layer did not show differences, the apparent density (AD) and the resistance to penetrability (RP) increased with depth; chemical indicators differed in the MF and CR had higher results compared to NF. The AD and RP had a significant negative correlation with soil organic carbon (SOC) and positive correlation between SOC, P, Ca, Mg, K available and cation exchange capacity. The MF and CR managements developed in the NCCh are techniques with great potential for soil conservation.

Vegetation restorations of degraded meadows have been widely implemented. The evaluation of soil nutrient changes as affected by degradation is vital for efficient restorations. However, while macronutrients (nitrogen, phosphorus and potassium) have been widely investigated, sulfur (S) as one important element correlated tightly with other nutrients has not been thoroughly studied. Two studies were conducted to determine changes of sulfur as affected by degradation and elevation gradients. The results showed that available S (AS) changed non-linearly with elevation and the first principal component based on other soil nutrient variables. Soil AS depended on degradation levels and contributed substantially to the separation of meadows with different degradation levels. Moreover, AS responded stronger to changes in elevation gradients and degradation levels compared with other major nutrients. Thereby, AS could be an important nutrient responding to meadow disturbance, which should be considered in future studies on meadow soil nutrients cycling and vegetation restorations. The findings have implications for ecological restoration of degraded meadows with respect to soil nutrient management and conservations.

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

The effect of organic, mineral and combined organic and mineral fertilization of soils on the winter wheat yields and nutrient contents in soils was evaluated in long-term field experiments. Two sites with different soil characteristics were evaluated - Lukavec u Pacova (cambisol) and Ivanovice na Hané (degraded chernozem). The type of fertilization influenced wheat yields. Nutrient uptake by winter wheat was higher under nitrogen (N) fertilization, which resulted in a negative balance of phosphorus (P) and potassium (K) and to a decrease of nutrient contents in the more fertile soils at Ivanovice na Hané. Two soil tests (Mehlich 3 method and NH₄-acetate method) were used to determine P and K availability. The mineral nitrogen fertilization negatively and significantly affected NH₄-acetate extractable concentrations of nutrients in the soils and these were lower in comparison with concentrations of P and K determined by Mehlich 3 method. Relative availability of P in alkaline soils from Ivanovice treated with mineral N increased while the soil pH decreased.

Soils harbour enormously diverse bacterial communities that interact specifically with plants generating beneficial interactions between them. This study was the first approach to assess bacterial communities before sowing with three cotton genotypes, including both transgenic and conventional ones. The structure of bacterial communities was identified using the next generation sequencing analysis, ion torrent PGM (Personal Genome Machine™) sequencer technology, based on the V2-V3 16S rRNA gene region. Quantitative insights into microbial ecology pipeline were used to identify the structure and diversity of bacterial communities in bulk soil samples collected in the northeast of Mexico. Bulk soil textures and chemical properties, including most nutrients, were homogeneous in these bulk soil samples. Relative abundance analysis showed similar bacterial community structures. Dominant taxonomic phyla were Proteobacteria, Firmicutes, Acidobacteria, Actinobacteria, Gemmatimonadetes and Bacteroidetes, whereas the main families were Bacillaceae, Chitinophagaceae and Rhodospirillaceae with an abundance average of BS1 (bulk soil sample), BS2 and BS3 (24.85, 19.74 and 19.71%, respectively). Alpha diversity analysis showed a high diversity (Shannon and Simpson index) and a large value of the observed species found in bulk soils samples. These results allowed establishing the previous bacterial structural community in an unused soil before sowing it with a transgenic crop for the first time.

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

The objective of this paper is to clarify the impacts of straw covering method on runoff and soil erosion in summer maize field on the Loess Plateau of China. A field experiment was conducted (2012-2014) in the artificial raining hall of the State Key Laboratory, with three soils and five straw covering methods. Three soils were Heilu soil (Calcisols), Huangmian soil (Fluvisols) and Lou soil (Anthrosols). Five straw covering methods were CK - no straw mulching and no stubble standing on the surface of the plot; T30 - 30 cm of winter wheat (WW) stubble standing above ground; M30 - 30 cm of WW stubble was harvest and mulched on the surface of the plot; M10T20 - 20 cm of WW stubble standing and 10 cm WW straw mulching on the surface of the plot; M20T10 - 10 cm of WW stubble standing and 20 cm of WW straw mulching on the surface of the plot. The results showed that (1) straw covering method not only impacted ITRP (initial time of runoff producing), but also affected runoff volume in summer maize field on the Loess Plateau of China. M10T20 was the best to postpone ITRP and to reduce runoff volume in summer maize field. (2) Different covering methods produced different sediment yield in summer maize field. M30 was the best to reduce soil erosion in summer maize field on the Loess Plateau of China. (3) When one covering method was used to reduce runoff or soil erosion, bulk density and soil mechanical composition (silt content, clay content and sand content) should be considered seriously.

In conjunction with soil type and climate, the use of nitrogen fertilizers is a major factor affecting nitrous oxide emissions. This study compares injection of pig slurry and pig slurry digestate at 15 or 20 cm depths with trailing-hose application followed by immediate incorporation. The work was based on a laboratory microcosm experiment with undisturbed soil cylinders (0-30 cm depth) from three arable soils (Histosol, Gleysol and Plaggic Anthrosol). Soil cylinders were fertilized with pig slurry and pig slurry digestate (150 kg N/ha) and emissions of N₂O, CH₄ and CO₂ were monitored. The comparison of application techniques over a 37-day period show that soil type and application technique, had a strong (P < 0.001) impact on N₂O emissions. Fertilization with pig slurry showed no significantly higher N₂O emissions than pig slurry digestate. Fertilizer injection significantly increased N₂O emissions compared to fertilization with a trailing-hose with incorporation.

The effects of lead on root, shoot and seedling length, leaf area, number of leaves, plant circumference, seedling dry weight, root/shoot and leaf area ratios of Thespesia populnea L. were determined in greenhouse under natural environmental conditions with and without phytotoxic metal ions at 5, 10, 15, 20, and 25 µmol/l. Lead treatments have a strong influence on the growth and development of T. populnea by reducing significantly (P < 0.05) all the above parameters. Lead treatment at 5-25 µmol/l produced significant (P < 0.05) effects on seedling and root length, plant circumference and seedling dry weight of T. populnea, while lead treatment at 10-25 µmol/l produced significant (P < 0.05) effects on shoot length, number of leaves and leaf area as compared to control. Tolerance in T. populnea seedling at 25 µmol/l of lead treatment was lowest as compared to all other treatments.

In arid and semiarid regions of northern China, there is an increasing interest in using water-saving superabsorbent polymer (SAP) for field crop production. Experiments were conducted during 2009 and 2010 to study the growth and yield characteristics of summer corn (Zea mays L.) under different (control, 0; low, 10; medium, 20; high, 30 and very high, 40 kg/ha) rates of SAP in a drought-affected field of northern China. Corn yield increased slightly following SAP application at low and medium rate, but significantly at high and very high rates by 22.4 and 27.8%. At the same time, plant height, stem diameter, leaf area, biomass accumulation, harvest index and relative water content as well as protein, sugar and starch contents in the grain increased significantly following SAP treatments. The optimum application of superabsorbent polymer for corn cultivation in the study area would be 30 kg/ha as it best increased the grain yield and quality and maintained higher levels of soil nutrients. Lower rates (10 and20 kg/ha) or higher (≥ 40 kg/ha) rates would neither be sufficient nor economical. We suggest that the application of SAP at 30 kg/ha could be an efficient and economic soil management practice for summer corn production in the drought affected regions of northern China or other areas with similar ecologies.

The purpose of the present studies was to determine the antagonistic effect of bacteria Bacillus spp. and Pseudomonas spp. towards selected fungi from the soil environment of carrot. Oats (Avena sativa L.), tansy phacelia (Phacelia tanacetifolia Bentham) and vetch (Vicia satica L.) were used as cover crops in the cultivation of this plant. In the traditional cultivation of carrot the population of bacteria was the smallest, while after the application of oats it was the largest. Laboratory tests showed that cover crops promoted the development of antagonistic Bacillus spp. and Pseudomonas spp. Irrespective of the experimental treatment, those bacteria were the most effective in limiting the growth and development of Fusarium oxysporum and Thanatephorus cucumeris (syn. Rhizoctonia solani), while being less effective towards Altenaria dauci and Alternaria radicina, and the least towards Sclerotinia sclerotiorum. The best total antagonistic effect of Pseudomonas spp. and Bacillus spp. towards the tested fungi was found after using oats and vetch, while the worst - in the traditional cultivation of carrot.

A 2-year field experiment was conducted under light enrichment and shading conditions to examine the responses of seed yield and yield components distribution across main axis in soybean. The results showed that the maximum increase in seed yield per plant by light enrichment occurred at 27 plants/m², while the most significant reduction in seed yield per plant by shading occurred at 54 plants/m². Light enrichment beginning at early flowering stage decreased seed size on average by 7% while shading increased seed size on average by 9% over densities and cultivars, resulting in a fewer extent compensation in seed yield decrement. Responses to light enrichment and shading occurred proportionately across the main axis node positions despite the differences in the time (15-20 days) of development of yield components between the high and low node positions. Variation intensity of seed size of three soybeans was dissimilar as a result of changes in the environment during the reproductive period. The small-seed cultivar had the greatest stability in single seed size across the main axis, followed by moderate-seed cultivar, while large-seed cultivar was the least stable. Although maximum seed size may be determined by genetic potential in soybean plants, our results suggested that seed size can still be modified by environmental conditions, and the impact can be expressed through some internal control moderating the final size of most seeds in main stem and in all pods. It indicates that, through redistributing the available resources across main stem to components, soybean plants showed the mechanism, in an attempt to maintain or improve yield in a constantly changing environment.

Selenium (Se) is a significant trace element for human and livestock animals because of its physiological functions. Se in plants, especially in the crop plants, is treated as a critical dietary source. The effects of foliar spray together with soil application of Se on Se uptake, distribution in common buckwheat (Fagopyrum esculentum M.) plants were discussed in this study. The results showed that both foliar spray and soil application of Se increased Se uptake in common buckwheat significantly (P < 0.05). The highest Se content was observed in leaves (113.37-690.75 μg/kg), followed by roots (28.98-283.78 μg/kg), grains (26.49-135.89 μg/kg) and stems (23.19-86.80 μg/kg). Se content in grains had the highest correlation coefficient (0.827 and 0.845) with soil Se application treatments. Grain yield of F1 (5 g Se/ha for foliar spray) was 3.65% and 10.25% higher than that of F0 (0 g Se/ha for foliar spray) in two study years, respectively. Under soil Se application conditions, mean grain yields fluctuated from 2890.5-3058.6 kg/ha, 2966.4-3352.8 kg/ha in 2012/2013, respectively. These results indicated a significant interaction effect of foliar spray Se and soil Se application on Se accumulation in common buckwheat. Appropriate Se application might improve common buckwheat grain yield.

Soil organic carbon (SOC) plays a critical role in rice production, but its feedback to the fate of fertilizer nitrogen (N) is not clear. In this study, a pot experiment was conducted to investigate the responses of rice yield and the fate of fertilizer N to different SOC levels using ¹⁵N-labelled urea. The results showed that rice biomass, yield and the total N uptake increased significantly with increasing SOC content. Both rice N uptake from soil and urea increased significantly with increasing SOC content. The recovery rate and residual rate of fertilizer N improved significantly with increasing SOC content, leading to a reduced rate of not-specified fertilizer N. Therefore, it was concluded that high SOC could not only improve rice yield and fertilizer N recovery, but also could increase the retention of fertilizer N and decrease the not-specified N in the paddy soil.

The present study investigated the impact of transgenic Bacillus thuringiensis (Bt) cotton on several aspects of arbuscular mycorrhizal (AM) fungus Funneliformis mosseae. The results showed that Bt cotton significantly inhibited spore germination and pre-symbiotic hyphal growth. The appressorium density, arbuscule frequency and colonization intensity in Bt roots were also decreased. The statistical analysis demonstrated that the transformation event resulted in the inhibition of hyphal development and colonization. The reduced interaction between AM fungi and plants could affect nutrient uptake and transportation in plant-fungus symbiosis. The mechanism might involve the direct toxicity of Bt toxins or the interference of signal perception between AM fungus and Bt cotton.

A micro-plot field experiment with reduced urea ¹⁵N application was conducted to study the effects of urease inhibitor NBPT (N-(n-butyl) thiophosphoric triamide) and nitrification inhibitor DMPP(3,4-dimethyl-1H-pyrazolium dihydrogen) on the fate of applied urea ¹⁵N; it aimed to find an efficient way to reduce the urea N application rate while improving the agronomic and environmental benefits. Five treatments were installed, i.e., 180 kg N/ha (N₁, conventional application rate), 126 kg N/ha (N₂, reduced to 70% conventional application rate), N₂ + NBPT, N₂ + DMPP, and N₂ + NBPT + DMPP. Compared with treatment N₁, all the other treatments had a significantly higher total ¹⁵N recovery by both soil and plant (P < 0.05 48.20, 41.39, 37.69, 38.85 and 34.83% soil recovery for N₂ + NBPT + DMPP, N₂ + DMPP, N₂ + NBPT, N₂ and N₁treatment, respectively; and 42.68, 40.86, 40.25, 37.18 and 36.30% plant recovery for N₂ + NBPT + DMPP, N₂ + DMPP, N₂ + NBPT, N₂, and N₁ treatment, respectively). In the plant ¹⁵N recovery, the ¹⁵N absorbed in grain/stem was highest in treatment N₂ + NBPT + DMPP. The maize biomass and the maize yield had a slight increase in treatment N₂ + NBPT + DMPP, compared with those in treatment N₁. In sum, for the maize production in study area, N₂ + NBPT + DMPP application method would be a feasible way to ensure the normal maize yield while improving yield quality, saving urea fertilizer, and protecting the environment.

An ideal strain for crude oil degradation in saline soils would be one with high salt-tolerance. A novel bacterial strain, Serratia sp. BF40, was isolated from crude oil contaminated saline soils. Its salt-tolerance, surface activity and ability to degrade crude oil in saline soils were evaluated. It can grow in liquid culture with NaCl concentration less than 6.0%. Its surface activity characterized as an efficient surface tension reduction, was significantly affected by salinity above 2.0%. BF40 inoculation could decrease surface tension of soil solutions and facilitate crude oil removal in soils with 0.22-1.20% salinity, but the efficiency was both significantly lower than its biosurfactant addition. The BF40 strain has a high potential for biodegradation of crude oil contaminated saline soils in view of its high surface activity and salt-tolerance, which is the first report of biosurfactant producing by the genus Serratia for petroleum degrading. We suggest that biosurfactant addition is an efficient strategy. Simultaneously, the growing status of the strain and how to boost its surface activity in saline soils should deserve further studies in order to achieve a continuous biosurfactant supply.

The effect of mineral fertilizer (F) and mineral combined with organic fertilizer (MF) on N₂O flux in grassland and cornfield was investigated for one year in Southern Hokkaido, Japan. Annual N₂O flux was higher in grassland than in cornfield, and it was higher in MF plot (14.9 kg N/ha/period) than in F plot (11.1 kg N/ha/period) in grassland. However, in cornfield, the annual N₂O flux was equal between both plots (5.6 kg N/ha/period). These results clarified that high nitrogen application was not always responsible for the high soil N₂O flux. N₂O flux was significantly correlated with air, soil temperature and water-filled pore space. More than 80% of the annual N₂O flux occurred before freezing and less than 4% during melting period. Denitrification was the main process of N₂O flux during study, it was evidenced by the distribution of N₂O and NO ratio which is from 1 to 1000. The denitrification activity (DEA) potentially increased in grassland soil in the beginning and the end of winter season when NO₃-N was abundant; on the other hand the abundance of carbon potentially increased DEA in cornfield soil.

One of the most serious threats facing agricultural productivity in the world is unfavourable soil conditions. Several studies have shown that almost half of the world's land-mass is affected by either natural or human-induced pollution. This, therefore, poses a threat to agricultural improvement needed to tackle the problem of a continuous increase in the world population. The emergence of soil extremophiles with plant growth-promoting trait has proven to be a reliable means to quell the threat posed by some factors limiting soil potency. Adopting these organisms as bio-inoculants will easily proffer a solution to both biotic and abiotic soil stress. As such, the natural bio-fertilisers will help to improve the quality of the soil by making it healthy enough to sustain sufficient plant growth. This review gives an overview of the multifarious importance of extremophiles on plants grown under harsh soil conditions, with the multifaceted application of omics as a means to unveil these organisms and their benefits for environmentally sustainable agricultural systems and food safety.

Transpiration efficiency (TE) is an important physiological trait associated with drought tolerance of plants. Currently, little is known about the grain sorghum TE and its dynamics with the age of plants. To compare the sorghum TE at different growth stages, four studies (two in the greenhouse and two in the growth chamber) were conducted under controlled environmental conditions. Plants were grown in lid-covered boxes and harvested at six-leaf, flag leaf, grain filling and maturity stages. The mean shoot TE values were 4.47 and 4.10 kg/m³ for two greenhouse studies, and 4.85 and 4.30 kg/m³ for two growth chamber studies, respectively. The shoot TE was not different among four growth stages within each study, suggesting that sorghum plants used the same amount of water per unit of biomass production for different growing periods. Because crops grown under dryland environments often run out of water during reproductive periods, result supports the ideas that soil water availability at later growth stages is crucial to achieve the yield potential of dryland sorghum.