Microbes benefit plants by increasing nutrient availability, producing plant growth hormones, and protecting against pathogens. However, it is largely unknown how plants change root microbial communities. In this study, we used a multi-cycle selection system and infection by the soilborne fungal pathogen Rhizoctonia solani AG8 (hereafter AG8) to examine how plants impact the rhizosphere bacterial community and recruit beneficial microorganisms to suppress soilborne fungal pathogens and promote plant growth. Successive plantings dramatically enhanced disease suppression on susceptible wheat cultivars to AG8 in the greenhouse. Accordingly, analysis of the rhizosphere soil microbial community using deep sequencing of 16S rRNA genes revealed distinct bacterial community profiles assembled over successive wheat plantings. Moreover, the cluster of bacterial communities formed from the AG8-infected rhizosphere was distinct from those without AG8 infection. Interestingly, the bacterial communities from the rhizosphere with the lowest wheat root disease gradually separated from those with the worst wheat root disease over planting cycles. Successive monocultures and application of AG8 increased the abundance of some bacterial genera which have potential antagonistic activities, such as Chitinophaga, Pseudomonas, Chryseobacterium, and Flavobacterium, and a group of plant growth-promoting (PGP) and nitrogen-fixing microbes, including Pedobacter, Variovorax, and Rhizobium. Furthermore, 47 bacteria isolates belong to 35 species were isolated. Among them, eleven and five exhibited antagonistic activities to AG8 and Rhizoctonia oryzae in vitro, respectively. Notably, Janthinobacterium displayed broad antagonism against the soilborne pathogens Pythium ultimum, AG8, and R. oryzae in vitro, and disease suppressive activity to AG8 in soil. Our results demonstrated that successive wheat plantings and pathogen infection can shape the rhizosphere microbial communities and specifically accumulate a group of beneficial microbes. Our findings suggest that soil community selection may offer the potential for addressing agronomic concerns associated with plant diseases and crop productivity.

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Rhizosphere community selection reveals bacteria associated with reduced root disease

The complexity of hydrological processes, spatial and temporal variation of all effective factors and lack of essential measured filed data convinced researchers to use empirical models in various scales. The IntErO model was used to predict maximum outflow (Qmax), soil erosion intensity (W year) and sediment yield (G year) in one of the internal sub-watersheds of Shirindarreh watershed, northeast of Iran. The results showed that the peak flow was 13.51 ms for a return period of 100 years. As an internal area, the peak flow of all upstream sub-watersheds should be also considered to be added to the predicted peak flow. The value of Z coefficient of 0.696 indicated that the river basin belongs to III destruction category and the strength of the erosion process was medium, and according to the erosion type, it was intrusive erosion. The predicted gross soil erosion in the study sub-watershed was 8.06 ton ha year. The coefficient of the deposit retention (Ru) or sediment delivery ratio (SDR) was 0.124 and therefore, the sediment yield was 1.00 ton ha year. According to Gavrilovic, the study sub-watershed is a region of very weak erosion.

Influence of abiotic and biotic factors on productivity of transgenic soybean and molecular properties of disease pathogen.

The current study analyzed heavy metal (HM) concentrations in the urban soil and tree leaves in the city of Novi Sad, Serbia, with the aim to identify specific tree species with good HM bioaccumulative abilities that can mitigate HM pollution in urban areas. Zinc (Zn), copper (Cu) and lead (Pb) were selected for the analysis of tree leaves and soil at 16 locations close to urban roads, main boulevards and high-traffic streets. Leaf material of four most common tree species: Platanus × acerifolia (Aiton) Willd., Celtis occidentalis L., Tilia argentea L. and Quercus robur L. and soil samples were analyzed with the aim to identify the potential hotspots and sources of pollution. Analysis of variance (ANOVA) and t test was applied to the available data sets to find differences between the HM concentrations in the analyzed trees and soil samples. Geographic information system (GIS) mapping was used for visualization of the concentration distributions and illustration of the HM contaminated hotspots. Bioconcentration factors (BCF) were calculated and they showed that the plants of the species Celtis occidentalis L. have the ability to retain Cu, the species Quercus robur L. retains mostly Zn, Tilia argentea L. accumulates Pb, while Platanus x acerifolia (Aiton) Willd. retains the smallest amount of the tested HMs.

Potential of urban trees for mitigating heavy metal pollution in the city of Novi Sad, Serbia.

Buckwheat (Fagopyrum esculentum Moench.) is a plant species which has been spreading in Bosnia and Herzegovina in the last decade. Because of its brief vegetation period, this crop species is especially interesting for hilly-mountainous regions. In 2015, the experiments were set in three localities (experimental field of the Faculty of Agriculture “Kula”, private economy “Sando” on the Nisici plateau and private economy “Jugovic” in Mokro), and two variants of fertilization (control variant – without the use of organic and mineral fertilizers and the use of N60P60K70). The Slovenian sort Darja was used for the experiments. The analysis of seed quality included the following analyses: humidity content (%), mineral matters content (%), protein content, starch content, carbohydrates content. In testing the qualitative characteristics for all localities and fertilizations we determined: 14.2% of humidity in seed, 1.47% of mineral matter in a peeled buckwheat grain, 11.88% of proteins in a peeled buckwheat grain, 51.9% of starch in a peeled buckwheat grain and 71.87% of carbohydrates.

https://doisrpska.nub.rs/index.php/AGR/article/download/2692/2577

The influence of locality and fertilization on buckwheat quality

This paper presents the use of Erosion Potential Method (EPM) for the prediction of runoff and soil loss in the Rakljanska Rijeka Watershed, Polimlje, Montenegro. Physical-Geographical, Climate, Geological, Pedological and Land Use inputs, which are the basis for the calculation of soil erosion intensity, we included in the EPM model. Information on runoff and sediment yield from the Rakljanska Rijeka Watershed, located in North-East Montenegro are described. The value of the Z coefficient was calculated on 0.457, what indicates that the river basin belongs to III destruction category. The strength of the erosion process is medium, and according to the erosion type, it is surface erosion. Our results suggest that the calculated peak discharge from the river basin was 78 ms for the incidence of 100 years. According to our analysis there is a possibility for large flood waves to appear in the studied river basin. The net soil loss was 2438 m3 per year, specific 210m3km per year. The Erosion Potential method we used in this study is highly recommended for soil erosion modelling in other river basins similar to the studied watershed, because of its simple and reliable identification of critical areas affected by the soil loss caused by soil erosion.

Calculation of runoff and soil erosion intensity in the Rakljanska Rijeka Watershed, Polimlje, Montenegro.

Use of models in the research of soil erosion processes is at the moment a standard practice and models are necessary tool for better understanding of sediment production and runoff, although their interpretation is limited by large uncertainties, including model parameter uncertainties. In this research we studied the main ecological factors and anthropogenic influences in sediment yield on the Provala basin of Montenegro analyzing the relationships between the physical-geographical, geological, soil, land use, climate characteristics and soil erosion intensity. Real soil losses, Gyr, were calculated on 7541 myr, specific on 597 mkmyr. The value of Z coefficient was calculated on 0.482 what indicates that the river basin belongs to the 3 destruction category; erosion process is medium. There is a possibility for large flood waves to appear in the studied basin. The results presented in this paper can provide decision support for watershed managers about where the best conservation measures can be implemented effectively and at low cost in the studied area. The methods we used in this study can also be of interest in sediment modeling for other basins in the Region.

Soil erosion in the river basin of Provala, Montenegro.

The aim of this study was to determine the microbiological activity in soil under beans in organic and conventional production. Organic production was conducted on the field in the village Pivnice (Serbia), while conventional production was conducted in the village Curug (Serbia) during 2014 on the chernosem type soil. Cultivars of beans Belko, Dvadesetica, Maksa, Slavonac, Sremac, Zlatko were used. Before sowing, the bean seeds were inoculated by biofertilizers NS-Nitragin. NS-Nitragin contains a mixture of selected strains of symbiotic bacteria Rhizobium leguminosarum bv. phaseoli. The total number of actinomycetes, ammonifiers, Azotobacter, bacteria and fungi were determined. At the end of vegetation period in conventional production the highest number of actinomycetes (5.83) and fungi (4.87) was recorded in cultivar Dvadesetica. In organic production the highest number of ammonifires was in cultivar Sremac (9.91). The highest number of bacteria was in cultivar Dvadesetica (9.08) and the highest number of fungi was in cultivar Zlatko (5.14).The results have shown that number of microorganisms was higher in organic production.

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Effect of Bean Cultivars on Soil Microorganisms

/pdf/effect-of-salinity-and-drought-stress-on-germination-and-4earbhncmt.pdf

Effect of salinity and drought stress on germination and early seedlings growth of bread wheat (Triticum aestivum L.)

Topography is a key factor that affects edaphic, climatic, and biotic factors directly or indirectly. Relationships between Compound Topographic Index (CTI) model and soil properties were investiga...

Determination of the relationship among compound Topographic Index (CTI), soil properties and land-use in karst ecosystems

Spatial assessment of soil erosion is an important indicator of ecological soil change and global environmental changes. This is especially true for countries with rich forest cover such as Bosnia and Herzegovina. In this study, the risk of soil erosion was assessed using the Revised Universal Soil Loss Equation (RUSLE) model and the impact of changes in the forest ecosystem, current conditions were compared with possible future forest management scenarios, and measures and solutions were proposed to reduce soil erodibility in vulnerable areas of the Pale Municipality in Bosnia and Herzegovina. The studied area is at increased risk of soil erosion due to natural conditions (mountain relief, climate change, and the frequency of extreme climatic events—drought and heavy rains, which occur more and more frequently in a short period of time) and due to anthropogenic factors, such as large-scale deforestation and conversion of mountain areas for tourism purposes, tracing and construction of ski slopes and ski resorts in general, and expansion of settlements. All this leads to threats to water conservation areas, landslides, floods, forest fires, and additional reduction of forest areas due to drying of forests and expansion of settlements. GIS as a tool provides us with a quick and accurate way to find possible solutions to problems resulting from the intensive use and inadequate monitoring. In this study, we have tried to offer possible solutions and show the benefits that can be obtained by varying the factors that affect soil erodibility and depend on vegetation cover, that is, land use (C-factor). This study presents the application of RUSLE methods in combination with GIS for the purpose of planning economic activities, such as winter tourism development in the community of Pale. An increase in soil loss due to inappropriate land use was found, with the average annual soil loss due to deforestation in the ski area increasing to 909.43 t ha−1 year−1.

/pdf/estimation-of-potential-soil-erosion-reduction-using-gis-1drqavp4.pdf

Estimation of potential soil erosion reduction using GIS-based RUSLE under different land cover management models: A case study of Pale Municipality, B&H

Vesna Tunguz

Papers

Soil erosion in the river basin of Provala, Montenegro.

Effect of Bean Cultivars on Soil Microorganisms

Effect of salinity and drought stress on germination and early seedlings growth of bread wheat (Triticum aestivum L.)

Determination of the relationship among compound Topographic Index (CTI), soil properties and land-use in karst ecosystems

Estimation of potential soil erosion reduction using GIS-based RUSLE under different land cover management models: A case study of Pale Municipality, B&H