Spatio-Temporal Variability of Soil Beta-glucosidase Activity at the Arable Field Scale

Knowledge about the spatio-temporal variability of soil enzymatic properties is crucial in evaluating their structure-function relationship and their impact on ecosystem functions. The aim of this study was to assess the spatio-temporal variability of soil β-glucosidase (BG) activity against selected physico-chemical properties at the arable fild scale. A grid soil sampling (10×10 m) was used to measure the spatial variation of soil properties across a 0.4-ha fild. The BG activity was analyzed in soil samples that were collected from the upper 20 cm of Luvisols at 50 locations in April and August 2007 and 2008. Additionally, total organic carbon (CORG), total nitrogen (NTOT) concentrations, soil pHKCl as well as texture and water content were determined. The dataset was analyzed using classical statistical and geostatistical methods. Based on the analysis of variance, it was found that the BG activity, CORG, and water content showed signifiant differences between the four sampling dates. The BG activity showed a high contribution of nugget effect in sill (over 50%) and revealed a moderate spatial structure. The range of spatial autocorrelation calculated for the BG activity was between 15.0 and 61.0 m. Less intensive sampling grid should be recommended for soil BG activity in further studies concerning spatial variability in arable fild scale. In turn, more frequent sampling must be included in the sampling strategy in order to better understand whether the BG activity always shows permanent spatial patterns in soil or whether it is more randomized

Phytoplankton production in relation to simulated hydro- and thermodynamics during a hydrological wet year – Goczałkowice reservoir (Poland) case study

Phytoplankton is one of the crucial components of water body ecosystems. Its presence and development depend on biological, physical and chemical factors and in consequence it is an important indicator of ecosystem condition. Monitoring of phytoplankton production, measured as chlorophyll a concentration, is a useful tool for assessing the status of dam reservoirs. Modeled chlorophyll a concentrations are used as water quality indicators in locations not included in monitoring systems, in situations when the temporal resolution of the monitoring is not enough, and in assessments of the impacts of future activities. Therefore, the aim of this study was to find correlations between hydro- and thermodynamics and the chlorophyll a concentration for possible application in reservoir monitoring and management, using an ELCOM-CAEDYM model. The analysis included summer and fall which are most prone to algal blooms, and four phytoplankton groups identified as dominant in the reservoir based on periodic observations. Comparisons of simulated water temperature and both observed and simulated chlorophyll a concentrations confirmed that these variables are significantly correlated (correlation of hourly chlorophyll a and water temperature was 0.70, ranging from 0.55 to 0.81 in the bottom and surface water layers, respectively, while for daily outputs it was 0.74, ranging from 0.60 to 0.83). This relation was stronger than that of chlorophyll a to nutrient (N, P and Si) concentrations. What is more, the method used allowed the assessment of a much more detailed spatial and temporal distribution of phytoplankton groups compared with conventional monitoring techniques. The study indicated that the phytoplankton community was dominated by Chlorophytes and Diatoms with a larger share of Chlorophytes in shallow parts of the reservoir. This domination was weaker after short water mixing events in summer and especially after the fall turnover. The increase in phytoplankton diversity was estimated to occur mainly near the surface and in shallow parts of the reservoir. Most of the observed concentrations of individual phytoplankton groups differed from simulation results by less than 25% and the model reflected accurately 74% of observed trends in concentrations. Calculated chlorophyll a concentration was well matched to hourly monitoring data (mean squared error = 5.6, Nash–Sutcliffe model efficiency coefficient = 0.51, Pearson correlation coefficient = 0.72 and p-value = 0.0007). High compatibility of the model to the values measured in the reservoir make it a promising tool for the prediction and planning of actions aimed at maintaining good functioning of the reservoir

Different Response of Carbon and P-Related Soil Properties toward Microbial Fertilizer Application

While some studies regarding the effect of biofertilizers on plants, including their yield and quality, less is known about how they affect the soil properties, especially the microbial and enzymatic properties. Biofertilizers are promising for enhancing the nutrient availability in agricultural soils and reducing the reliance on inorganic fertilizers. The aim of this four-year-long field experiment was to assess the influence of the use of UGmax biofertilizer, which contains bacterial strains enhancing the soil phosphorus availability, e.g., the Pseudomonas spp. strains from Azotobacter and Penicillium genera, on the soil P forms and acid and alkaline phosphatase activity (AcP, AlP) in the surface soil horizon (Ap). Winter wheat was cultivated in 2005, 2006, and 2008, while winter rapeseed was cultivated in 2007 in a research area (2 hectare) that was selected for the investigation. These plants were selected because they are the main agricultural crops in Poland. UGmax was applied in three successive years after the plants had been harvested. One dose of the biofertilizer (0.7 L per hectare) was applied after the harvesting of wheat had been harvested (2005–2007), while the second dose (0.3 L per hectare) was applied as a top dressing in the spring, when the plants were beginning to grow (2006–2008). Forty soil samples were taken in 2005 (the control year without the application of UGmax). In the following years (2006–2008), 20 soil samples were taken from the area after the UGmax had been applied in the previous year, as well as 20 soil samples from the control area. A grid soil sampling technique (40 m × 25 m) was used to assess the changes in the soil properties across both of the studied areas. The soil samples were taken from the surface (Ap) horizon. Only at the end of the experiment (2008) did the application of UGmax remarkably increase the organic carbon (Corg) and total nitrogen (Nt) content, while the microbial biomass carbon (MBC) content was notably higher in the field with UGmax than in the control. The available P content (Pavail) was significantly higher in the field with UGmax compared to these without the biofertilizer in 2006 and 2008, while no considerable relation was noted for the total phosphorus (Ptot) and water soluble P (Pwater) content in any of the study years. Over the entire period of the experiment, the AcP and AlP were notably lower in the soil samples that were collected from the UGmax field compared to that of the control soil. It was concluded that the application of UGmax exhibited a phosphate-solubilizing activity that could be an encouraging attitude for increasing P bioavailability in arable fields and that further studies ought to be carried out under different soil and climatic conditions in order to confirm such a phenomenon

Depth-Related Changes in Soil P-Acquiring Enzyme Activities and Microbial Biomass—The Effect of Agricultural Land Use/Plant Cover and Pedogenic Processes

Although the phosphatase enzymes regulate phosphorus (P) turnover throughout the soil profile, at present, they are rarely studied and are less well understood in the deeper soil layers than in the surface horizons. Hence the changes in P-associated soil properties were assessed throughout five Phaeozem profiles for different agricultural land uses including alfalfa, winter wheat, grapevine, apple trees and hops. The acid phosphatase (AcP), alkaline phosphatase (AlP) and phosphodiesterase (PDE) activity was assayed, as were the microbial biomass carbon (MBC) and phosphorus (MBP) contents and also other properties (e.g., available phosphorus, total organic carbon, total nitrogen). We have also determined the mass, length and surface area of the plant roots. In general, the activities of the studied enzymes were highest in the topsoil in four out of the five profiles studied, which corresponded to the highest level of root mass. The older the plant, the greater the root mass and increased enzymatic activity in the deeper horizons of apple trees and hop profiles in comparison to the surface layers. The greatest enzymatic activity, MBC and MBP contents were found in the horizons with a TOC content >0.5% and decreased down the soil profiles similarly to the changes in TOC and TN contents. While the studied properties were determined to varying degrees by means of the organic C content and availability in all of the genetic horizons, the influence of the prevailing conditions and the factors related to soil depth and pedogenic processes were less pronounced. The clay content was related to a significant extent to all of the studied enzyme activities, but only in horizons with a TOC content <0.5%. Significantly higher phosphatase activity under aerobic as opposed to anaerobic conditions were determined in this study, while the opposite trend was found for the content of MBC and MBP as well as the ratio of MBC/MBP. Overall, we pointed out the complex effect of the soil depth, soil forming-processes and cultivated plants on soil P-associated enzyme activities and other properties throughout the soil profiles. This knowledge will allow better understanding of the state of enzymes and their contribution to the biogeochemical cycle of soil P, especially in subsoils, where the enzyme activities follow different patterns than those in the surface horizons

Enzymatic Activity and Physicochemical Properties of Soil Profiles of Luvisols

Most studies on soil enzymes are focused on the upper horizons of the soil profile, even though they transform the soil organic matter at every depth of the soil profile. The aim of this work was to investigate the distribution of β-glucosidase (GLU), nitrate reductase (NR), urease (UR), phosphatase (PHA), dehydrogenase (DHA) and catalase (CAT) activity through 14 trunked soil profiles of the Luvisols formed from a glacial till. The content of microbial biomass carbon (MBC) as well as physicochemical properties such as organic carbon (CORG), total nitrogen (NTOT), available P, K and Mg, soil density and porosity, pH in KCl and fractional composition were also studied. In general, enzymatic activity was highest in the top 30 cm layer of the profiles and decreased progressively towards the deeper horizons. The exceptions were the NR activity, which was active only in the Ap horizon and whose activity decreased sharply to nearly zero in the Bt horizon and parent rock, and the PHA activity, which was highly active even in the parent rock depth. The decreased availability of carbon and nutrients was the main driver of decreases in microbial abundance and enzymatic activity with depth. The enzymatic activity, when expressed on a CORG and MBC basis, behaves differently compared to the activity expressed on a soil mass basis. The activity decreased (NR), increased (PHA, UR), showed no clear pattern (GLU) or the changes were not significant (DHA, CAT). The content of CORG, NTOT, K and PAVAIL generally decreased with depth, while for Mg, there was no clear direction in the profile distribution. Future studies to characterize the substrate distribution within the soil profile and enzyme stability will provide further insight into the controls on nutrient cycling and related enzymes throughout the soil profiles

Application of Multi-Component Conditioner with Clinoptilolite and Ascophyllum nodosum Extract for Improving Soil Properties and Zea mays L. Growth and Yield

The application of various conditioners in agriculture is one of the management practices used to improve soil quality and plant growth and development. The aim of this study was to assess the effect of a multi-component conditioner on the selected soil properties and maize (Zea mays L.) growth and yield. The effect of a conditioner on a set of soil properties and maize growth and yield was studied in one-year experiments carried out at three study sites, which were under a conventional tillage system. All of the study sites were located on farms in three geographic mezoregions in the Kuyavian-Pomeranian Region (Midwestern Poland). The studied soils were Haplic Luvisol (Janocin and Kobylnica) and Albic Luvisols (Krukówko) that were composed of sandy loam. A one-way analysis of variance (ANOVA) was used to determine the effect of a conditioner Solactiv on the soil and plant properties. The conditioner significantly affected the soil enzyme activities such as dehydrogenase (DHA), fluorescein sodium salt hydrolysis level (FDAH) and carboxymethylcellulose cellulase (CMC—cellulase); wherein the last one increased by about 16–20%. The application of Solactiv also increased the available K content (about 11%) but not the content of the microbial biomass C and N. Total porosity (TP), which was significantly higher in the soil treated with conditioner than in the control soils, increased the available water capacity (AWC) (about 2.2%). The higher AWC in the treated soil indicated the greater contribution of the mesopores in the TP (about 4%). A significantly higher readily available water capacity (RAWC) and small pores available water capacity (SAWC) was determined in the treated soils compared to the controls. Of the plant properties, only plant height, fresh cob biomass (BBCH 87–89) and fresh plant biomass (BBCH 84–85) were significantly increased by the conditioner. The application of Solactiv is considered to be a promising approach for developing sustainable agriculture by improving the soil’s biological activity and water-related properties

Responses of N-Cycling Enzyme Activities and Functional Diversity of Soil Microorganisms to Soil Depth, Pedogenic Processes and Cultivated Plants

The rates of N cycling and soil enzyme activities involved in the transformation of soil N-related nutrients are rarely measured in soils below a 30 cm depth, even though substantial amounts of nitrogen are also stored in deep soils. The aim of this study was to determine how soil microbial and enzymatic properties changed as a function of depth across soil profiles that were developed on the same parent material but differed in terms of soil-forming processes. Two soil profiles were excavated in fields with lucerne and two under winter wheat. We assessed the N-cycling enzymes, the microbial utilization of the N-substrates, the microbial biomass carbon and nitrogen (MBC, MBN) content, and the related physicochemical properties. The most beneficial enzymatic (on a soil mass) and microbial properties, as well as nitrogen substrate utilization, were found in the Ap horizons and decreased with depth to varying degrees. The specific enzymatic activity (per unit of soil TOC and MBC), was more variable in response to the depth of the profile, but did not exhibit clear trends. The potential enzyme activities in the subsurface layers were also affected by factors that are associated with the pedogenic processes (e.g., the lessivage process, clay content). Only nitrate reductase activity was significantly higher in the horizons with potential reducing conditions compared to oxidative horizons, while the opposite trend was found for N-acetyl-β-D-glucosaminidase (NAG) activity. The cultivated plants had a significant impact on the degree of enzymatic activity and N-substrate utilization. The lessivage process significantly reduced microbial biomass and enzymatic activity (except for NAG activity). In general, nitrogen substrate utilization decreased with increasing soil depth and was greater in lucerne than the winter wheat profiles. Mollic Stagnic Gleysols (MSG) and Cambic Stagnic Phaeozems (CSP) horizons also have higher nitrogen substrate utilization than Luvisol profiles

Depth-Related Changes in Soil P-Acquiring Enzyme Activities and Microbial Biomass—The Effect of Agricultural Land Use/Plant Cover and Pedogenic Processes

Although the phosphatase enzymes regulate phosphorus (P) turnover throughout the soil profile, at present, they are rarely studied and are less well understood in the deeper soil layers than in the surface horizons. Hence the changes in P-associated soil properties were assessed throughout five Phaeozem profiles for different agricultural land uses including alfalfa, winter wheat, grapevine, apple trees and hops. The acid phosphatase (AcP), alkaline phosphatase (AlP) and phosphodiesterase (PDE) activity was assayed, as were the microbial biomass carbon (MBC) and phosphorus (MBP) contents and also other properties (e.g., available phosphorus, total organic carbon, total nitrogen). We have also determined the mass, length and surface area of the plant roots. In general, the activities of the studied enzymes were highest in the topsoil in four out of the five profiles studied, which corresponded to the highest level of root mass. The older the plant, the greater the root mass and increased enzymatic activity in the deeper horizons of apple trees and hop profiles in comparison to the surface layers. The greatest enzymatic activity, MBC and MBP contents were found in the horizons with a TOC content >0.5% and decreased down the soil profiles similarly to the changes in TOC and TN contents. While the studied properties were determined to varying degrees by means of the organic C content and availability in all of the genetic horizons, the influence of the prevailing conditions and the factors related to soil depth and pedogenic processes were less pronounced. The clay content was related to a significant extent to all of the studied enzyme activities, but only in horizons with a TOC content <0.5%. Significantly higher phosphatase activity under aerobic as opposed to anaerobic conditions were determined in this study, while the opposite trend was found for the content of MBC and MBP as well as the ratio of MBC/MBP. Overall, we pointed out the complex effect of the soil depth, soil forming-processes and cultivated plants on soil P-associated enzyme activities and other properties throughout the soil profiles. This knowledge will allow better understanding of the state of enzymes and their contribution to the biogeochemical cycle of soil P, especially in subsoils, where the enzyme activities follow different patterns than those in the surface horizons

Mineral matter composition of drained floodplain soils in north-eastern Poland

Soils in two river valleys (Rozoga and Omulew) in north-eastern Poland were investigated. The valleys are located on a sandy outwash plain formed during the Vistulian (Weichelian) Glaciation. The soils are drained, used as meadows and classified as Fluvic Umbric Gleysol, Fluvic Mollic Gleysol, and Eutric Fluvic Histic Gleysol (IUSS Working Group WRB 2015). The aim of the study was to identify the composition of mineral matter and to determine the types of clay minerals and intermediate stages of clay minerals by means of the X-ray diffraction (XRD). The studied floodplain soils are rich in organic matter and contain considerable mineral alluvial admixtures. The content of clay fraction (< 2.0 μm) is low (0.02–5.61% of total mineral matter). Higher content of clay fraction was noted in soils with elevated content of organic matter, which can be evidence of simultaneous accumulation of both components. In deeper depressions occurring in river valleys (oxbow lakes), a specific deposit termed silty telmatic mud (16–24% TOC, 50–75% silt, 3.1–5.6% clay fraction content) was accumulated. On the other hand, in shallow depressions, a muddy deposit was accumulated (5.7–7.7% TOC, sandy texture). The main identified clay minerals were smectite, vermiculite, illite and kaolinite as well as variety of mixed-layer clays. Alluvial clay admixture in studied soil formations showed mineralogical similarity to typical floodplain mineral soils (Fluvisols). Mineral fraction of studied soils is mostly of allochthonous origin