Effect of vermicompost and selected plant preparations on the development of arbuscular mycorrhizal symbiosis in lettuce (Lactuca sativa)

The aim of the pot experiment was to evaluate effect of vermicompost and promoting plant preparations application (Symbivit and Plantaktiv) on the development of arbuscular mycorrhizal symbiosis in lettuce, amount of extraradical mycelium of mycorrhizal fungi in soil and plant biomass production. Symbivit contains six species of mycorrhizal fungi and Plantaktiv contains magnesium sulfate activated by oxygen promoting activity of aerobic microorganisms in the soil. The application of vermicompost and promoting plant preparations did not have a statistically significant effect on lettuce root colonization by mycorrhizal fungi. The greatest length of extraradical mycelium was observed in variant with vermicompost application, in variant with addition of vermicompost and Symbivit, and in variant with vermicompost applied with both plant preparations. There was detected statistically significant difference when compared to control variant. Dry matter weight of aboveground biomass and root of the lettuce were statistically significantly increased in all variants, where vermicompost was applied, either alone or in combination with plant preparations. Separate application of Symbivit or Plantaktiv did not have a statistically significant effect either on the length of extraradical mycelium or dry matter weight of the lettuce.O

Effects of Biochar Application on Winter Wheat (Triticum aestivum L.) Roots Under Long-Term Drought Conditions

The main objective of this paper was to evaluate the effect of applying biochar and activated carbon on winter wheat affected by drought in model laboratory conditions. Cultivation tests of the soil-microorganisms-plant (winter wheat) system were focused on understanding the interactions between microbial soil communities and experimental plants in response to specific cultivation measures, in combination with the modelled effect of drought. The containers were formed as a split-root rhizotron. In this container experiment, the root system of one and the same plant was divided into two separate compartments where into one half, biochar or activated carbon has been added. The other half without additives was a control. Plants favoured the formation of the root system in the treated part of the container under both drought and irrigation modes. In drought mode there was lower production of CO2, lower overall length and surface of the roots of winter wheat compared to variants in irrigation mode. The application of biochar and activated carbon, therefore, supported the colonization of roots by mycorrhiza in general. The Scientific merit of this paper was to investigate the possibility of mitigating the effects of a long-term drought on winter wheat through the application of biochar or the application of activated carbon.O

Biochar Alone Did Not Increase Microbial Activity in Soils from a Temperate Climate That Had Long-Term Acidity Stress

Biochar can increase the microbial activity of a soil and the seed yield of oilseed rape. We performed a field experiment to determine the effect of different doses of biochar and the impact of nutrient additions on microbial activity in soils with low pH (4.69). Different doses of biochar were applied to plots in 2016 (0 t/ha (control), 15 t/ha (B15), 30 t/ha (B30), or 45 t/ha (B45)), and fertilization was applied during 2019 (90 kg P/ha) and 2020 (50 kg N/ha, 80 kg P/ha, and 50 kg K/ha). Maize was grown in 2016, barley in 2017, maize in 2018, wheat in 2019, and winter oilseed rape in 2020. All analyses were carried out in 2020. Higher biochar doses led to reduced seed yield of oilseed rape and inhibition of microbial activity (cumulative soil respiration, dehydrogenase activity (DHA), and leaching of mineral forms of nitrogen). Notably, dehydrogenase activity was more than 60% lower in plots with the highest biochar dose. All doses of biochar increased the soil pH compared to the control (control: 4.51 +- 0.04, B15: 4.69 +- 0.04, B30: 5.06 +- 0.05, B45: 5.05 +- 0.04) but did not increase microbial activity or the seed yield of oilseed rape. Thus, application of biochar alone did not increase the seed yield of oilseed rape or soil microbial activities, although it did increase soil pH.O

Modifying effect of biochar by mixing it with digestate

Biochar is a carbonized organic matter formed by the pyrolysis process. This material contains a high percentage of carbon from the original biomass which provides an idea to design “a tool to reduce the impact of climate change“. The positive effect of biochar on the physical and chemical properties of soil has been demonstrated in many papers. However, the issue of the influence of carbonized matter on biological processes in soil is still unclear, and scientific results is often inconsistent. In our work, we wanted to modify the effect of biochar by adition of another organic fertilizer. Please click on the file below for full content of the abstract

Effects of Drought on Microbial Activity in Rhizosphere, Soil Hydrophobicity and Leaching of Mineral Nitrogen from Arable Soil Depending on Method of Fertilization

This work presents the first results from the long-term laboratory experiment dealing with impact of drought on soil properties. Three groups of the treatment (A, B and C) with different regime of irrigation were prepared. The soil water content was maintained at 70 % of soil water holding capacity in group A, at 40 % in group B. In group C, soil water regime was maintained in the range of wilting point. Each group of the experiment was divided into three variants (A1 = B1, C1; A2 = B2, C2 etc.) with three repetitions: Variants A1 (B1, C1) were controls without addition of another fertilizer. Variants A2 (B2, C2) were fertilized with mineral nitrogen fertilizer DAM 390 (0.140 Mg of N per ha) and variants A3 (B3, C3) contained 45 g of Cp per a pot. The significant differences (ANOVA, P<0.05) in the leaching of mineral nitrogen and values of saturated hydraulic conductivity (Ksat) were found. The highest values of Ksat were found in variants (within each group) with addition of compost (A3, B3, C3). Conversely, the lowest values of Ksat were found in variants with addition of mineral nitrogen. Low values of Ksat indicate an increased level of hydrophobicity in individual groups of the experiment. Moreover, all variants with compost addition showed lower amount of mineral nitrogen leaching and high level of microbial activity than variants without. This decrease of mineral nitrogen leaching was about 200 % in comparison with the control variant and about 300 % with variant, where mineral nitrogen was added. Based on these results, we can conclude that changes of soil water content directly have impact on microbial activity, soil hydrophobicity and loss of mineral nitrogen from the soil

El efecto de los polímeros absorbentes en la actividad microbiologica del suelo bajo condiciones mediterráneas

Objectives. The aim of this study was to evaluate the effect of the hydropolymer TerraCottem on soil microbial activity by measuring soil respiration and leaching of mineral nitrogen. Materials and methods. The incubation experiment contained control variants with natural soil of Nerja area (South Spain, inside the Sierra Tejeda, Almijara and Alhama Natural Park, 36.7985173° N 3.8511693° W; WCGS84), variants with the addition of easy available nitrogen compounds (kg N ha-1), easy accessible carbon compounds (1% glucose solution) and a combinations of both. Within each variant, the recommended amount of control hydropolymers (1.5 kg/m3) and a double dose of 3.0 kg/m3 were compared. Results. Showed that respiration activity of the soil in this Mediterranean area was not eliminated by the lack of ready available nitrogen or carbon substrates. Furthermore, differences in CO2 production between the variants containing different amounts of hydropolymers were not significant. A statistically significant difference in the CO2 production was found in the first week compared to longer time periods. Conclusions. The mineral nitrogen leaching measurement showed that the biological activity of the studied is not affected by nitrogen dynamics which is balanced regardless of the amount of applied hydropolymer. On the other hand, leaching processes occurred when soil was doped only with nitrogen compounds or only carbonaceous, a problem that can appear after fertilizers applicatio Objetivo. El objetivo de este estudio pasa por evaluar el efecto del-Terracottem- en la actividad microbiana del suelo mediante la medida de la respiración edáfica y la pérdida de nitrógeno mineral por lixiviación. El ensayo se ha realizado en condiciones de laboratorio controladas y con suelos naturales. Materiales y metodos. Para el experimento, se han diseñado varios tratamientos: i) suelos naturales a los que se les ha adicionado compuestos nitrogenados de libre disponibilidad (Kg N ha-1); ii) suelos naturales a los que se les ha adicionado carbohidratos de libre disponibilidad (1% de solución de glucosa); iii) suelos naturales a los que se les ha adicionado una mezcla de compuestos nitrogenados de libre disponibilidad (Kg N ha-1) con carbohidratos (1% de solución de glucosa). En cada variante se han testeado diferentes dosis del polímero. Resultados. Los resultados han demostrado que la actividad respiratoria del suelo es independiente de la disponibilidad de compuestos como el nitrógeno o carbono. Tampoco se han observado diferencias significativas entre las diferentes dosis del polímero. Por el contrario, si se observaron diferencias en la producción de CO2. Conclusiones. La lixiviación únicamente se producía cuando los suelos era enmendado con compuestos únicamente nitrogenados o únicamente sólo carbonosos

Nomogrammes adjoints aux nomogrammes a lignes concourantes et aux nomogrammes a contact tangentiel ayant au moins un système d'isoplèthes courbes

summary:L'article traite une transformation non-corrélative, qui adjoint au nomogramme à lignes concourantes (au nomogramme à contact tangentiel) ayant $r$ systèmes d'isoplèthes courbes $r$ nomogrammes à contact tangentiel ($r$ nomogrammes à lignes concourantes)

Nomogrames a trois feuilles comme regles a calcul

summary:L'article décrit une règle à calcul dont les parties glissables sont déplacées plusieurs fois. La règle à calcul résout une forme canonique à $6n$ variables