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The aim of this study was to assess the influence of selected biostimulants (Tytanit, Rooter) and foliar fertilisers (Optysil, Metalosate Potassium, Bolero Bo, ADOB 2.0 Zn IDHA, ADOB B, ADOB 2.0 Mo) on the activity of dehydrogenases, acid and alkaline phosphatases and catalase, and their influence on the level of biological nitrogen fixation based on the nitrogenase activity in soybean cultivation. Between 2016 and 2018 a field experiment was conducted at the Gorzyń Experimental and Educational Station, Poznań University of Life Sciences in Poland. During the three years of the experiment the foliar fertilisers and biostimulants significantly stimulated the catalytic dehydrogenase activity (DHA) and alkaline phosphatase activity (PAL) in all the experimental variants, as compared to the control variant. The analysis of the results of acid phosphatase activity (PAC) during the entire soybean growing period showed that it decreased significantly compared to the control variant when Tytanit, Rooter and Bolero Mo preparations were applied. Additionally, the analysis of catalase activity (CAT) revealed that apart from Tytanit, all the preparations significantly stimulated this enzyme, as compared with the control variant. The field analyses of biological nitrogen fixation showed that the fertilisers and biostimulants significantly stimulated nitrogenase activity under the soybean plantation. [ABSTRACT FROM AUTHOR]

The study focused on the variability in properties and pedogenesis of soils located at post mining sites in the old industrial area in the Silesian-Krakow Upland, southern Poland. The investigated sites were comparable in terms of Zn–Pb mining history, soil texture and climate, but differed in duration of pedogenesis, which started after the waste materials were accumulated and covered 30, 70, 100 and about 400 years of self-restoration. A wide spectrum of soil parameters including: Zn, Pb and Cd contents, dehydrogenase activity, pores space and aggregate formation, organic matter decomposition were studied by chemical and micromorphological image analyses with the aim of tracing the evolution of soils and checking if the results of image analysis could be integrated with results obtained by chemical and biological determinations. Stepwise progressive regression equations were obtained to establish the parameters that varied over time. Zn, Pb and Cd contents exceeded several times permissible values in all soils studied. The evolution of these soils was significantly different from each other. During the process of self-restoration of the soil, the contents of organic carbon and total nitrogen, available potassium and phosphorus including dehydrogenase activity increased with increasing age of soils. Pedogenesis resulted also in the increasing amounts of aggregates of small sizes, which were set close to one another together with narrow pores, which was able to store water. A synchronisation between soil properties, obtained by chemical, biological and micromorphological analyses indicating their usefulness for the demonstration of temporal changes. [ABSTRACT FROM AUTHOR]

This paper analyzes the effects of soil reoxidation, expressed in terms of water potential (pF), air porosity (Eg) and oxygen availability (ODR), on soil dehydrogenase activity (DHA). Investigated soil samples were collected from the surface layer (0-20 cm) and subsoil (50-60 cm) of Rendzina Leptosols, Eutric Histosol and Eutric Fluvisol soils. All the examined factors varied widely in the tested material - DHA decreased whereas ODR and Eg increased with higher soil water tension. A close relationship, described by significant negative correlations between oxygenation indicators (pF, ODR, Eg) and DHA, was stated. To sum up the foregoing observations, we confirmed that dehydrogenases are sensitive enzymes, indirectly dependent on soil aeration status. [ABSTRACT FROM AUTHOR]

The aim of the study was to compare the effect of conventional, simplified, and organic farming systems on changes in the content of soil organic carbon, organic matter fractions, total nitrogen, and the enzymatic activity. The research was conducted from 2016–2018 on arable land in the south-eastern part of Poland. The selected soils were cultivated in conventional tillage (C_Ts), simplified tillage (S_Ts), and organic farming (O_Fs) systems. The analyses were performed in soil from the soil surface layers (up to 25 cm depth) of the experimental plots. The highest mean contents of soil organic carbon, total nitrogen, and organic matter fractions were determined in soils subjected to the simplified tillage system throughout the experimental period. During the study period, organic carbon concentration on surface soil layers under simplified tillage systems was 31 and 127% higher than the soil under conventional tillage systems and organic farming systems, respectively. Also, the total nitrogen concentration in those soils was more than 40% and 120% higher than conventional tillage systems and organic farming systems, respectively. Moreover, these soils were characterised by a progressive decline in SOC and Nt resources over the study years. There was no significant effect of the analysed tillage systems on the C:N ratio. The tillage systems induced significant differences in the activity of the analysed soil enzymes, i.e., dehydrogenase (DH) and catalase (CAT). The highest DH activity throughout the experiment was recorded in the O_Fs soils, and the mean value of this parameter was in the range of 6.01–6.11 μmol TPF·kg−1·h−1. There were no significant differences in the CAT values between the variants of the experiment. The results confirm that, regardless of other treatments, such as the use of organic fertilisers, tillage has a negative impact on the content of SOC and organic matter fractions in the O_Fs system. All simplifications in tillage reducing the interference with the soil surface layer and the use of organic fertilisers contribute to improvement of soil properties and enhancement of biological activity, which helps to maintain its productivity and fertility. [ABSTRACT FROM AUTHOR]

In many areas, organic crop production systems have been shown to contribute to maintaining good soil condition. The organic production system has been recommended as an alternative to conventional agriculture. However, in order to recommend this practice in new regions, it is necessary to obtain information about its effects and consequences in local environmental conditions. The research was completed during 2016–2018 in Osiny (Lublin region, Poland) on a field experiment established 26 years previously in a Haplic Luvisol soil. The research was aimed at comparing the effects of long-term use of tilled soil with organic (ORG) and conventional (CON) crop production systems with those in non-tilled soil under permanent grass (PRG) as a control. This comparison was done on the basis of changes in the values of soil properties as follows: Total porosity (TP), total organic matter (OM), particulate organic matter (POM), humic substances (HS), water-extractable carbon (WEC), microbial biomass carbon pool (MBC) and dehydrogenase activity (DH). Soil samples were collected from experimental fields (each treatment 1 ha) under winter wheat and permanent grass each year from 0–5, 5–10, 15–20 and 30–35 cm depths. Over the three year study period, it was found that permanent grass and the organic crop production system contributed to increased soil OM, POM, HS, WEC and MBC contents and DH activity compared to the CON system, especially in the top soil layer, 0–5 cm. To obtain a clearer picture of soil quality change our study examined for the first time the metabolic potential index (MPI) as a ratio of dehydrogenase activity to the soluble organic carbon content. The MPI values confirmed the increase of metabolism in ORG soil as a consequence of management practices compared with CON soil. The obtained correlations showed strong mutual relationships within properties of the heterogeneous soil complex. The results show the positive effects of the ORG management system causing soil condition improvement which is based on organic fertilization, enriching the soil with a large amount of plant residues in creating positive changes in the soil quality in contrast to the CON system. [ABSTRACT FROM AUTHOR]