Effect of Mycotoxins in Silage on Biogas Production.

Mycotoxins can pose a threat to biogas production as they can contaminate the feedstock used in biogas production, such as agricultural crops and other organic materials. This research study evaluated the contents of deoxynivalenol (DON), zearalenone (ZEA), fumonisin (FUM), and aflatoxin (AFL) mycotoxins in maize silage prior to it being processed in a biogas plant and in digestate produced at the end of the anaerobic digestion (AD) process. In the experiment, three samples of silage were collected from one silage warehouse: Variant 1 = low contamination, Variant 2 = medium contamination, and Variant 3 = heavy contamination, which were subjected to investigation. A significantly reduced biogas production was recorded that was proportional to the increasing contamination with molds, which was primarily due to the AD of silage caused by technologically erroneous silage treatment. The AD was connected with changes in silage composition expressed by the values of VS content, sugar content, lactic acid content, acetic acid content, and the ratio of lactic acid content to acetic acid content. The production of biogas and methane decreased with the increasing contents of NDF, ADF, CF, and lignin. The only exception was Variant 2, in which the content of ADF, CF, and lignin was lower (by 8-11%) than that in Variant 1, and only the content of NDF was higher (by 9%) than that in Variant 1. A secondary factor that also correlated with changes in the composition of the substrate was the development of undesirable organisms, which further contributed to its degradation and to the production of mycotoxins. It was also demonstrated in this study that during the AD process, the tested mycotoxins were degraded, and their content was reduced by 27-100%. Only the variant with low mold contamination showed a DON concentration increase of 27.8%.

Effect of Drought on the Development of Deschampsia caespitosa (L.) and Selected Soil Parameters during a Three-Year Lysimetric Experiment.

This work presents results from a field experiment which was focused on the impact of the drought period on microbial activities in rhizosphere and non-rhizosphere soil. To demonstrate the effect of drought, the pot experiment lasted from 2012 to 2015. Fifteen lysimeters (plastic containers) were prepared in our area of interest. These lysimeters were filled with the subsoil and topsoil from this area and divided into two groups. The first group consisted of two variants: V1 (control) and V2 (84 kg N/ha), which were not stressed by drought. The second group consisted of three variants, V3 (control), V4 (84 kg N/ha), and V5 (84 kg N/ha + 1.25 L lignohumate/ha), which were stressed by drought every year of the experiment for 30 days. Changes in the soil moisture content caused by drought significantly affect the growth of Deschampsia caespitosa L., the microbial activity, and the soil's capacity to retain nutrients. The measured basal respiration and dehydrogenase activity values confirm the significant effect of drought on microbial activity. These values were demonstrably higher in the period before drought simulation by more than 60%. On the other hand, significant differences between microbial activities in the rhizosphere and non-rhizosphere soil were not found. We did not find a clear effect of drought on the formation of soil water repellency.

Possibility of using tannins to control greenhouse gas production during digestate storage.

The presented paper deals with the testing of a possibility to reduce emissions of undesirable greenhouse gases (CH4, CO2; NOx) and their mixture (biogas) during the storage of digestate using applications of secondary plant metabolites (tannins). The experiment was conducted in laboratory conditions in which the digestate was placed in fermentation chambers. Prior to the fermentation process, preparations were applied to the digestate, which contained tannins: Tanenol Antibotrytis (TA), Tanenol Clar (TC) and Tanenol Rouge (TR) in three concentrations (0.5, 1.0 and 2.0% w/w). The application of these preparations demonstrably affected the production of biogas and the contents of CH4, CO2 and N therein. The application of TR preparation in the concentration of 1.0% and 2.0% significantly reduced the production of biogas as compared with all variants. The preparation further inhibited the process of CH4 development. In contrast, the other preparations with the content of different kinds of TA and TC increased the production of biogas (on average by 15%), CH4 (on average by 7%) and CO2 (on average by 12%) as compared with the control variant and TR variant. These two variants reduced the concentration of N in biogas on average by 38%. Thus, the tested Tanenol tannin preparations can be used in different concentrations either to control emissions of greenhouse gases during the storage of digestate or, in case of increased production of CO2 for its reuse in order to increase methane yields in the process of anaerobic fermentation.

Assessment of digestates prepared from maize, legumes, and their mixed culture as soil amendments: Effects on plant biomass and soil properties.

Digestate prepared from anaerobic digestion can be used as a fertilizer, as it contains ample amounts of plant nutrients, mainly nitrogen, phosphorous, and potassium. In this regard, digestates produced from mixed intercropped cereal and legume biomass have the potential to enrich soil and plants with nutrients more efficiently than monoculture-based digestates. The objective of this study was to determine the impact of different types of digestates applied at a rate of 40 t·ha-1 of fresh matter on soil properties and crop yield in a pot experiment with lettuce (Lactuca sativa) as a test crop. Anaerobic digestion of silages was prepared from the following monocultures and mixed cultures: broad bean, maize, maize and broad bean, maize and white sweet clover, and white sweet clover. Anaerobic digestion was performed in an automatic custom-made system and applied to the soil. Results revealed that fresh and dry aboveground biomass as well as the amount of nitrogen in plants significantly increased in all digestate-amended variants in comparison to control. The highest content of soil total nitrogen (+11% compared to the control) and urease (+3% compared to control) were observed for maize digestate amendment. Broad bean digestate mediated the highest oxidizable carbon (+48%), basal respiration (+46%), and N-acetyl-ß-D-glucosamine-, L-alanine-, and L-lysine-induced respiration (+22%, +35%, +22%) compared to control. Moreover, maize and broad bean digestate resulted in the highest values of N-acetyl-ß-D-glucosaminidase and ß -glucosidase (+35% and +39%), and maize and white sweet clover digestate revealed the highest value of arylsulfatase (+32%). The observed differences in results suggest different effects of applied digestates. We thus concluded that legume-containing digestates possibly stimulate microbial activity (as found in increased respiration rates), and might lead to increased nitrogen losses if the more quickly mineralized nitrogen is not taken up by the plants.

Effect of Sowing Date on the Development of Lacy Phacelia (Phacelia Tanacetifolia Benth.).

Experiments with lacy phacelia (Phacelia tanacetifolia Benth.) were carried out in the period 2017-2021, during which the effect of sowing date on the stand development was assessed (height, coverage, accomplishment of individual growth stages, and weed infestation). It was demonstrated that the sowing date affects the stand growth and development. In earlier sowing dates, plants developed slower than in later sowing dates but reached a greater average height (926 mm). The lowest height (802 mm) was exhibited by plants from May (sowing 3). The third sowing date also showed the worst stand canopy closure and at BBCH 31, the stand canopy closure in Sowing 1, 2, and 3 was 82.3%, 77.8%, and 67%, respectively. The third sowing date was also the highest weed infestation. The effect of sowing date on yield and yield parameters was also monitored (weight of a thousand of grains and germinative capacity). Based on the measured data, it can be concluded that the influence on the weight of thousands of grains was minimal and in germinative capacity. Significant differences were recorded only in first year in which the germinative capacity of plants from the later sowing dates was reduced.

Effect of Seed Coating and PEG-Induced Drought on the Germination Capacity of Five Clover Crops.

The effect of coating the seed of clover crops by water absorbing seed process (WASP) technology pelletization on its germination capacity was studied in conditions of diverse drought intensities simulated by different concentrations of polyethylenglycol (PEG) 8000 solution. Drought resistance was monitored in the seed of five fodder clover species: Anthyllis vulneraria L., Medicago lupulina L., Trifolium repens L., Melilotus albus Medik. and Onobrychis viciifolia Scop. In the seed of given plant species, germination capacity was determined along with the share of dead and hard seeds. Although the coating significantly (p < 0.05) affected the drought resistance of seeds, the germination capacity increased only in conditions of milder drought (simulation with PEG: 0.1-0.3 mol). With the increasing intensity of drought induced by higher PEG concentrations (0.4-0.7 mol) the number of germinable seeds demonstrably decreased and the number of dead seeds increased in the coated seed as compared with the uncoated seed. The coated seed can be appropriate for use in M. lupulina, M. albus and T. repens, while the uncoated seed can be used in A. vulneraria and O. viciifolia.

Comparison of Proximal and Remote Sensing for the Diagnosis of Crop Status in Site-Specific Crop Management.

The presented paper deals with the issue of selecting a suitable system for monitoring the winter wheat crop in order to determine its condition as a basis for variable applications of nitrogen fertilizers. In a four-year (2017-2020) field experiment, 1400 ha of winter wheat crop were monitored using the ISARIA on-the-go system and remote sensing using Sentinel-2 multispectral satellite images. The results of spectral measurements of ISARIA vegetation indices (IRMI, IBI) were statistically compared with the values of selected vegetation indices obtained from Sentinel-2 (EVI, GNDVI, NDMI, NDRE, NDVI and NRERI) in order to determine potential hips. Positive correlations were found between the vegetation indices determined by the ISARIA system and indices obtained by multispectral images from Sentinel-2 satellites. The correlations were medium to strong (r = 0.51-0.89). Therefore, it can be stated that both technologies were able to capture a similar trend in the development of vegetation. Furthermore, the influence of climatic conditions on the vegetation indices was analyzed in individual years of the experiment. The values of vegetation indices show significant differences between the individual years. The results of vegetation indices obtained by the analysis of spectral images from Sentinel-2 satellites varied the most. The values of winter wheat yield varied between the individual years. Yield was the highest in 2017 (7.83 t/ha), while the lowest was recorded in 2020 (6.96 t/ha). There was no statistically significant difference between 2018 (7.27 t/ha) and 2019 (7.44 t/ha).

Composting versus mechanical-biological treatment: Does it really make a difference in the final product parameters and maturity.

One of crucial waste management problems is the management of organic waste. This activity employs the composting. In case of green waste, its application seems reasonable, whereas the use of selected mixed waste raises problems related to the compost quality. Across countries, the non-sterile organic fraction of municipal solid waste is being separated through the mechanical-biological treatment. The technology is a solution of waste treatment and meets objectives set out in the Landfill Directive. There are many problems associated with the use of output products. The use of compost as a fertilizer requires determination of its impact on the environment. Compost quality can be assessed using analytical methods and phytotoxicity tests. Therefore, the aim of this study was to describe changes in physico-chemical, enzymatic, phytotoxicity and vegetation parameters occurring in composts from two systems - a prismatic installation for green waste, and a mechanical-biological treatment installation. The compost from green waste exhibited greater stability. Values of dehydrogenase activity were lower if compared with the mechanically and biologically treated compost, which indicates lower compost maturity. The biomass production of Brassica napus L. and Fetuca rubra L. was higher in the variant with the application of green compost. The influence on Hordeum vulgare L., Cannabis sativa L., and Sinapis alba L. depended on the plant type and the compost used. Nevertheless, the compost from green waste was less toxic. The evidence from this study suggests that the mechanical-biological treatment had problems associated with the maturation and quality of the final product.

Assessment of phytotoxicity, environmental and health risks of historical urban park soils.

Urban soil areas can be contaminated with potentially dangerous heavy metals (HM), which might have got there by means of the human activity. The aim of the present study was to determine the contamination level of the city park soils and its impact on urban ecosystem. The indices assessing soil contamination such as Enrichment Factor (EF), Geoaccumulation Index (Igeo), Nemerow Pollution Index (IPIN), and indices assessing health risks, namely Hazard Index (HI) and Carcinogenic Risk (CR), have been calculated. Furthermore, the phytotoxic effect of the soil samples has been determined. The soil contains in average 58.6 mg/kg Zn, 0.3 mg/kg Cd, 27.2 mg/kg Pb and 16.6 mg/kg Cu. Based on EF index, it has been confirmed that the increased amounts of Zn, Cd and Pb in the soil are of the anthropogenic origin. The soil may be classified as moderately to strongly polluted in the case of Zn and Pb according to Igeo. Nevertheless, soil contamination in the park is at a safe level as per IPIN. Based on HI and CR indices, it is possible to state that the soil in the park does not pose any health risks. Subject to the outcomes of the toxicity test, the concentrations of HMs found out in the soils are not inhibitory for plants.

Environmental risk assessment and consequences of municipal solid waste disposal.

Effective and efficient assessments of the site conditions are required for the sustainable management of landfills. In this study we propose an evaluation method to determine the degree of environmental contamination by the contest of heavy metals (HM) concentrations in soil and plants (Tanacetum vulgare L., Carduus L., Plantago major L.). We compared HM concentrations in the soil, leaves, stem and roots of those native plants. Content of HM in samples was at the same level in all localities, except content of Zn. These values confirm that the area is not naturally burdened by increased HM content in the soil, and also that the deposited municipal waste or the material used for reclamation and composting does not contain risk elements. The content of selected HM was monitored in plants naturally occurring in the area of interest. We can state that the content of individual HM was in the plant biomass at the same level. The measured values confirmed that the largest number of HM was in roots, then in stem and the least in leaves. In addition, specific indexes were determined: BAC, TF, CF, PLI and Igeo. The BAC values confirmed that the individual plants had the ability to accumulate Pb and Cd (BAC> 2) but were limited to bind Mn and Zn (BAC <1). TF values confirmed that plants had a different ability to transport HM from roots to aboveground biomass. Potential soil contamination was detected using CF, PLI and Igeo indexes but contamination by HM was not confirmed.

Environmental assessment of the effects of a municipal landfill on the content and distribution of heavy metals in Tanacetum vulgare L.

Heavy metal pollution is an important concern because of its potential to affect human health. This study was conducted to analyze plants growing on a landfill body and in its surroundings to determine their potential for heavy metal accumulation. In addition, the enrichment coefficient (EC) for the plant/soil system was used for determining the environmental contamination from a landfill in terms of heavy metal accumulation. The samples were taken in 2013-2014. Of the analyzed metals, iron achieved the highest values in the samples, i.e. - stalk (103.4-6564.6 mg/kg DM), roots (6563.6-33,036.6 mg/kg DM), leaf (535.1-11,275 mg/kg DM) and soil (12,389-39,381.9 mg/kg DM). The highest concentrations were determined in 2013 for Fe, Mn and Zn. Iron achieved the highest concentrations in the years 2013-2014. Next, EC values were then calculated, with the highest noted for Cd. Cd, as well as Cr, Ni and Zn are accumulated mostly in the leaves, whereas Co, Cu, Fe, Hg, Mn and Pb are accumulated mainly in the roots of T. vulgare.