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Reducing pressure on agrolandscapes while maintaining indicators of economic efficiency is a promising and relevant task for researchers. The article presents the results of a four-year study on the formation of water, nutrient, and microbial regimes in the soil of mid-early ecological group hybrid sunflower crops PR64F66 F1 and Tunca F1 at different levels of biologization of zonal variety cultivation technologies in the conditions of the Southern Steppe of Ukraine: traditional intensive, extensive minimal, organic, and two levels of biologized. The dependence of the reduction in average daily soil moisture consumption on the application of biologization elements was established. The minimum value of the water consumption coefficient over the years of the study was found for organic cultivation technology - 407 (PR64F66 F1) and 423 (Tunca F1) m³/ton of dry matter, while the least economical consumption of active moisture for biomass formation was recorded for the extensive cultivation technology variant - 523 and 624 m³/ton respectively. Variants with the application of biologization elements in the mineral nutrition system were characterized by significantly higher efficiency and economy of nitrogen consumption from soil reserves. Throughout the vegetation period, under the conditions of intensive sunflower cultivation technology, both the overall population of the plowed soil layer and the number of microflora for individual key groups decreased significantly compared to variants where individual elements of biologization or their complex application (organic cultivation technology) were implemented, by 6.1-40.9%. [ABSTRACT FROM AUTHOR] more...

The influence of different agriculture systems and measures of basic tillage on nutrient regime, its relation to the number of microorganisms involved in transformation of organic matter in typical black soils was studied. Direction of the formation processes of some physiological indices in the field of wheat winter was investigated. It was found that the most favorable conditions of nutrition and soil microflora development, as well as indices of crop growth and development are created when using ecological system of agriculture. [ABSTRACT FROM AUTHOR] more...

Copyright of Plant & Soil Science is the property of National University of Life & Environmental Sciences of Ukraine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

Calcium cyanamide (CaCN2) is a nitrogen fertilizer which contains 19.8% nitrogen and 50% CaO. Nitrogen, which is in the cyanamide form, is gradually converted to plant-accessible amonum (NH4)2CO3 when decomposed in the soil. Dicyanamide ((H2N)2C = N - CN) which is a nitrification inhibitor is also formed. For this reason nitrogen remains for a longer time in the ammonium form and therefore in the root zone. The positive effect of calcium cyanamide (AD) on the maintenance of soil pH and on soil microflora is also known, while in the initial phase of hydrolysis in an improper use it can cause phytotoxicity. In the experiments, we wanted to determine the impact of AD on the growth and development of hop, determine its potential phytotoxicity, evaluate its impact on the yield and nitrate content in hop cones, and place this fertilizer in the hop fertilization program. Phytotoxicity was detected in the case of plants in the low trellis and in pots at rates of 800 and 1000 kg/ha AD. In the field experiment, 400 kg/ha AD was applied and this did not cause phytotoxicity in any combination. A positive impact of AD on soil pH maintenance was indicated, but no significant influence to soil microflora. As superior fertilization combinations in terms of hop yield AD at hop cutting in the spring + 2× KAN and AD hop cutting in the spring + 1 × urea + 1 × KAN were indicated. AD (400 kg/ha) is better to be applied in March during pruning compared to May application. Regarding the nitrate content in the cones, it is better to use KAN for the third top dressing and not UREE or AD. [ABSTRACT FROM AUTHOR] more...

Copyright of Plant & Soil Science is the property of National University of Life & Environmental Sciences of Ukraine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

Field management practices can alter the physical and chemical properties of the soil, also causing changes to the seed bank. Alterations can also occur to the soil microbial community, which in turn can increase or diminish the process of weed seed decay. In this research, the issue of seed degradation was studied in an undisturbed and a no-till soil, trying not only to uncover where seeds are more degraded, but also to investigate the microbial activities that could be involved in this process. Six different weed species, commonly found in northern Italy, were used: Abutilon theopharsti, Alopecurus myosuroides, Amaranthus retroflexus, Digitaria sanguinalis, Portulaca oleracea and Sorghum halepense. Seed decay was tested in two different sites, a no-till field and the adjacent buffer zone. Soil microbial activity was also measured using the Fertimetro, an approach based on the degradation of cotton and silk threads buried in the soil for one week. Degradation of the buried seeds was higher in the no-till field soil than in the buffer strip for all the studied species as was the microbial cellulolytic activity. Even though the buffer strip soil is an undisturbed habitat and resulted as having higher organic matter, the no-till soil conditions appeared more unfavourable to seed viability. Our findings suggest that no-till management can improve weed seed suppression in the soil. Moreover, cellulolytic microorganisms play an important role in seedbank longevity, so cellulolytic activity surveys could be used as an early monitoring bioindicator for weed seed suppression in soil. more...

The objective of this research has been to determine the impact of soil contamination with fluorine, including the concomitant application of substances neutralizing this pollution, on counts of actinomyces, fungi, and copiotrophic bacteria, and on the activity of acid phosphatase, alkaline phosphatase, grease, and dehydrogenase. The research was based on two pot experiments, both conducted in 2009 in a greenhouse at the University of Warmia and Mazury in Olsztyn, Poland. One experiment involved winter oilseed rape, while the other was performed on maize followed by yellow lupine. The following factors were included in both experiments: I) increasing doses of fluorine in the form of potassium fluoride (0, 100, 200, 300 mgF·kg-1 of soil) II) substances neutralizing soil pollution with fluorine: lime, in a dose corresponding to 1 Hh of soil, charcoal, and loam -- both in amounts equal to 3% of the soil mass per pot. The biological activity of soil was assayed after harvesting winter oilseed rape (BBCH 69) and yellow lupine (BBCH 69). It has been demonstrated that low doses of fluorine (from 100 to 200 mgF·kg-1 of soil) had a positive influence on counts of the analyzed microorganisms and on the activity of the examined soil enzymes. Under the influence of such low amounts of fluorine, the number of actinomyces and the activity of urease increased in soil tested after the harvest of winter rape and yellow lupine, the latter being a catch crop sown after maize. The neutralizing substances had a much better effect on counts of the analyzed microorganisms than on the activity of soil enzymes. The counts of actinomyces and copitrophic bacteria were positively affected by all the substances added to soil, as compared to the control treatments. With respect to fungi, these microorganisms responded positively only to the application of charcoal and loam to soil cropped with yellow lupine. In general, the tested substances had a beneficial influence on the activity of acid phosphatase and urease. As regards the activity of alkaline phosphatase, it was adversely affected by the neutralizing substances. The residual effect of fluorine on counts of the analyzed microorganisms and activity of the soil enzymes was milder in the soil sampled after the harvest of yellow lupine, which seems to indicate that fluorine loses its toxic properties with time. [ABSTRACT FROM AUTHOR] more...

Soil samples collected in South America, North America and West Siberia were measured by thermogravimetry to verify the connection between mass losses and soil respiration represented by the rate and amount of carbon dioxide measured under laboratory conditions. It was demonstrated that linear correlation between those parameters is a common feature for soils originating from different climatic and geographic regions. Significant coefficients of determination were observed in temperature areas corresponding to the moisture evaporation and degradation of soil organic matter (SOM). It was concluded that the correlations are the consequences of soil-forming processes mediated by microorganisms over a long time period. The comparison of experimental data with earlier results showed that disturbance of those processes causes the decrease in observed correlations. The subtraction of thermal mass losses of incubated and non-incubated soils revealed the change in water holding character in all samples, which was ascribed to the transformation of SOM and its water-holding properties during the incubation. In contrast, the changes in thermal mass losses above 200 °C showed that this area reflects the specificity of biological transformation of each soil sample. Further, applied approach and obtained results indicate the necessity of very gentle soil sample preparation and especially gentle air drying to get comparable results about intrinsic soils' features in different regions. [ABSTRACT FROM AUTHOR] more...

Respiration and ammonification tests were used for the determination of microbiological activity in soils which was complexly investigated within a project aiming in the development of precise farming. The tested sites were chosen according to their nutrient content and yield potential (low - medium high). Long-term respiration tests showed that there wee no significant differences between spring and autumn mineralization activity in vitro and among localities. The amendment of lucerne meal in this test resulted in significanlty higher mineralization activity. The increase in potential mineralization activity indicates a good biological activity of the tested soils. Basal and potential (with ammonium and glucose amendment) respiration in short term respiration test was significantly lower in soils from poor sites. The tendency to growing ammonification activity from poor sites to the best ones was determined. [ABSTRACT FROM AUTHOR] more...

The aim of the work is to evaluate the spatial distribution of Hg in the soil-plant system within an area where intense activity of Hg was dominant over a long period. An abandoned metallurgical plant from the 17th-18th centuries was chosen as the study area. It is situated in Almadenejos within the Almadén mining district (Spain) that constitutes the largest and most unusual concentration of mercury in the world and has provided a third of the entire world production of mercury (Hg). Nowadays, this study area is covered with cinnabar mine tailings and village habitants use it for livestock. The area has elevated Hg concentrations of natural origin and from human activities. Soil parameters are similar throughout the study area; however, data reveal high variability in total and available Hg concentrations in soils, making it difficult to establish a tendency. Marrubium vulgare L.has been studied due to its high presence in the field plot, and there is no evidence of phenological toxicity. Furthermore, in spite of elevated Hg concentrations, a good biological activity is tested in the soil samples. All these characteristics, spatial variation, high Hg concentration, good biological activity, enhance the peculiarity of the study area for studies involving Hg. more...

Dehydrogenase activity was studied in typical soils of the Northwest German Lower Plains in order to test some criticisms raised by nannipieri et al. (1990) about methodology. We found that in the same soils with the sampe crop, dehydrogenase activity varies significantly. In the field dehydrogenase activity was dependent on the soil type and not on the cropping system. There is no adequate explanation of these findings. Dehydrogenase activity is a parameter of soil microbiological activity and is influenced by many factors. Either purely accidental the results are or dehydrogenase activity is affected by unknown ecological interactions and by the composition of soil microflora. We conclude that without simultaneous investigations of other microbiological parameters (microbial biomass, ATP levels, enzyme activities, etc.) the measurement of dehydrogenase activity creates confusion and may impede valid ecological comparisons of soils. [ABSTRACT FROM AUTHOR] more...

The supply of commercial plant biostimulants (PB) for sustainable agriculture is currently very broad but also confusing, as there is little information on their use to mitigate the negative effects of water stress on plants growing in areas of water scarcity. The issue addressed in this article deals with the effects of Amalgerol®, a PB and soil conditioner mainly based on seaweed extracts (SWEs), on the water relations and the growth patterns of mandarin trees grown in pots and their response to a subsequent period of water stress compared with un-treated plants. When the SWE treatment accumulated 75 mL of product, plants exhibited an increase in vegetative growth and higher values of gas exchange rate, with 57% higher substrate microbiological activity than un-treated plants. After this, the irrigation was completely suppressed in all plants until a mean threshold value of −1.6 MPa of midday stem water potential was reached, and it was then reestablished after 7 consecutive days. The un-treated plants showed a higher level of water stress, around 0.4–0.7 MPa, compared to the treated ones, recovering at least three days after irrigation recovery. Furthermore, the presence of mycorrhized roots was 60% higher than un-treated plants, which resulted in greater resistance to water stress. The use of Amalgerol® resulted in a good complement for mineral plant fertilization in semi-arid agrosystems, where water resources are limited, allowing the hardening of citrus nursery plants, which can contribute to their more efficient field transplantation in water scarcity areas. [ABSTRACT FROM AUTHOR] more...

Field management practices can alter the physical and chemical properties of the soil, also causing changes to the seed bank. Alterations can also occur to the soil microbial community, which in turn can increase or diminish the process of weed seed decay. In this research, the issue of seed degradation was studied in an undisturbed and a no-till soil, trying not only to uncover where seeds are more degraded, but also to investigate the microbial activities that could be involved in this process. Six different weed species, commonly found in northern Italy, were used: Abutilon theopharsti, Alopecurus myosuroides, Amaranthus retroflexus, Digitaria sanguinalis, Portulaca oleracea and Sorghum halepense. Seed decay was tested in two different sites, a no-till field and the adjacent buffer zone. Soil microbial activity was also measured using the Fertimetro, an approach based on the degradation of cotton and silk threads buried in the soil for one week. Degradation of the buried seeds was higher in the no-till field soil than in the buffer strip for all the studied species as was the microbial cellulolytic activity. Even though the buffer strip soil is an undisturbed habitat and resulted as having higher organic matter, the no-till soil conditions appeared more unfavourable to seed viability. Our findings suggest that no-till management can improve weed seed suppression in the soil. Moreover, cellulolytic microorganisms play an important role in seedbank longevity, so cellulolytic activity surveys could be used as an early monitoring bioindicator for weed seed suppression in soil. [ABSTRACT FROM AUTHOR] more...