Carbon Storage Potential and Carbon Dioxide Emissions from Mineral-Fertilized and Manured Soil

Two important goals of sustainable agriculture are food production and preserving and improving soil health. The soil organic carbon content is considered an indicator of soil health. The evaluation of the methods to increase the soil organic carbon content in long-term experiments is usually carried out without considering its environmental effects, (e.g., CO2–C soil emission). This study hypothesized that sandy soils have a low carbon storage potential, and that the carbon accumulation in the soil is accompanied by increased CO2–C emissions into the atmosphere. The study was carried out as a long-term fertilization experiment in Central Poland using a rye monoculture. The changes in the soil organic carbon content (SOC), CO2–C emissions from soil, and plant yields were examined for two soil treatments: one treated only with mineral fertilizers (CaNPK) and one annually fertilized with manure (Ca + M). Over the 91 years of the experiment, the SOC content of the manure-fertilized treatment increased almost two-fold, reaching 10.625 g C kg−1 in the topsoil, while the content of the SOC in the soil fertilized with CaNPK did not change (5.685 g C kg−1 in the topsoil). Unlike mineral fertilization, soil manuring reduced the plant yields by approximately 15.5–28.3% and increased the CO2–C emissions from arable land. The CO2–C emissions of the manured soil (5365.0 and 5159.2 kg CO2–C ha−1 in the first and second year of the study, respectively) were significantly higher (by 1431.9–2174.2 kg CO2–C ha−1) than those in the soils that only received mineral fertilizers (3933.1 and 2975.0 kg CO2–C ha−1 in the first and second year of the study, respectively). The results from this experiment suggest that only long-term fertilization with manure might increase the carbon storage in the sandy soil, but it is also associated with higher CO2–C emissions into the atmosphere. The replacement of mineral fertilizers with manure, predicted as a result of rising mineral fertilizer prices, will make it challenging to achieve the ambitious European goal of carbon neutrality in agriculture. The increase in CO2–C emissions due to manure fertilization of loamy sand soil in Central Poland also suggests the need to research the emissivity of organic farming

Genetic and Functional Diversity of Bacterial Microbiome in Soils With Long Term Impacts of Petroleum Hydrocarbons

Soil contamination with petroleum, especially in the area of oil wells, is a serious environmental problem. Restoring soil subjected to long-term pollution to its original state is very difficult. Under such conditions, unique bacterial communities develop in the soil that are adapted to the contaminated conditions. Analysis of the structure and function of these microorganisms can be a source of valuable information with regard to bioremediation. The aim of this study was to evaluate structural and functional diversity of the bacterial communities in soils with long-term impacts from petroleum. Samples were taken from the three oldest oil wells at the Crude Oil Mine site in Węglówka, Poland; the oldest was established in 1888. They were collected at 2 distances: (1) within a radius of 0.5 m from the oil wells, representing soil strongly contaminated with petroleum; and (2) 3 m from the oil wells as the controls. The samples were analyzed by 16S rRNA sequencing and the community level physiological profiling (CLPP) method in order to better understand both the genetic and functional structure of soil collected from under oil wells. Significant differences were found in the soil samples with regard to bacterial communities. The soils taken within 0.5 m of the oil wells were characterized by the highest biodiversity indexes. Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria were strongly correlated with biological activity in these soils. Families of Alphaproteobacteria were also dominant, including: Bradyrhizobiaceae, Rhizobiaceae, Rhodobacteraceae, Acetobacteraceae, Hyphomicrobiaceae, and Sphingomonadaceae. The study showed that the long term contamination of soil changes bacterial communities and their metabolic activity. Even so, natural bioremediation leads to the formation of specific groups of bacteria that actively grow at the site of contamination in the soil

Rapid functional but slow species diversity recovery of steppe vegetation on former arable fields in southern Ukraine

Questions: European steppes are among the most threatened ecosystems in the Palaearctic region, mainly because of conversion to arable land. Abandonment may allow for the passive recovery of steppes. We made use of an exceptional old-field succession chronosequence of nearly 100 years to answer the following questions: (a) Are the plant species composition, species richness and functional characteristics typical of virgin grass steppes able to self-restore during ca. 100 years after abandonment? (b) Do the rates of recovery of the above vegetation characteristics differ over the studied chronosequence? (c) Do topsoil carbon and nitrogen content change over the succession chronosequence, leading to concentrations similar to that of virgin steppes? Location: Southern Ukraine. Methods: We sampled vegetation and soil in a virgin grass steppe and in old fields abandoned for 6, 15, 31, 50 and ca. 97 years. We subjected the composition data to multivariate analysis. To test whether species richness, functional and soil characteristics of the old fields diverge from those of the virgin steppe, we used one-way analysis of variance with Tukey's honestly significant difference (HSD) statistic to create 90% confidence intervals. Results: The vegetation composition of the three most recently abandoned old fields differed significantly from that of the virgin steppe. The species richness of vascular plants was lower in old fields than in the virgin steppe. The share of steppe habitat specialists was similar to the virgin steppe only in the field abandoned for ca. 97 years. Functional characteristics were significantly different from the virgin steppe only in the most recently abandoned old field. Contents of Corg and Ntot in fields abandoned for ≤50 years were lower compared with the virgin steppe. Conclusions: The functional characteristics of steppe vegetation seem to recover much faster than its biodiversity. However, based on our results, 100 years can be enough time for the spontaneous re-establishment of typical steppe vegetation

Polish Soil Classification, 6th edition – principles, classification scheme and correlations

The sixth edition of the Polish Soil Classification (SGP6) aims to maintain soil classification in Poland as a modern scientific system that reflects current scientific knowledge, understanding of soil functions and the practical requirements of society. SGP6 continues the tradition of previous editions elaborated upon by the Soil Science Society of Poland in consistent application of quantitatively characterized diagnostic horizons, properties and materials; however, clearly referring to soil genesis. The present need to involve and name the soils created or naturally developed under increasing human impact has led to modernization of the soil definition. Thus, in SGP6, soil is defined as the surface part of the lithosphere or the accumulation of mineral and organic materials permanently connected to the lithosphere (through buildings or permanent constructions), coming from weathering or accumulation processes, originated naturally or anthropogenically, subject to transformation under the influence of soilforming factors, and able to supply living organisms with water and nutrients. SGP6 distinguishes three hierarchical categories: soil order (nine in total), soil type (basic classification unit; 30 in total) and soil subtype (183 units derived from 62 unique definitions; listed hierarchically, separately in each soil type), supplemented by three non-hierarchical categories: soil variety (additional pedogenic or lithogenic features), soil genus (lithology/parent material) and soil species (soil texture). Non-hierarchical units have universal definitions that allow their application in various orders/types, if all defined requirements are met. The paper explains the principles, classification scheme and rules of SGP6, including the key to soil orders and types, explaining the relationships between diagnostic horizons, materials and properties distinguished in SGP6 and in the recent edition of WRB system as well as discussing the correlation of classification units between SGP6, WRB and Soil Taxonomy

Expansion of Agriculture in Northern Cold-Climate Regions: A Cross-Sectoral Perspective on Opportunities and Challenges

Agriculture in the boreal and Arctic regions is perceived as marginal, low intensity and inadequate to satisfy the needs of local communities, but another perspective is that northern agriculture has untapped potential to increase the local supply of food and even contribute to the global food system. Policies across northern jurisdictions target the expansion and intensification of agriculture, contextualized for the diverse social settings and market foci in the north. However, the rapid pace of climate change means that traditional methods of adapting cropping systems and developing infrastructure and regulations for this region cannot keep up with climate change impacts. Moreover, the anticipated conversion of northern cold-climate natural lands to agriculture risks a loss of up to 76% of the carbon stored in vegetation and soils, leading to further environmental impacts. The sustainable development of northern agriculture requires local solutions supported by locally relevant policies. There is an obvious need for the rapid development of a transdisciplinary, cross-jurisdictional, long-term knowledge development, and dissemination program to best serve food needs and an agricultural economy in the boreal and Arctic regions while minimizing the risks to global climate, northern ecosystems and communities

Assessment of Pesticide Residue Content in Polish Agricultural Soils

Pesticides belong to a group of xenobiotics harmful to humans and wildlife, whose fate and activity depends on their susceptibility to degradation. Therefore, the monitoring of their residue level in agricultural soils is very important because it provides very valuable information on the actual level of soil contamination and environmental risk resulting from their application. The aim of this study was to evaluate contemporary concentrations of organochlorine (OCPs) and non-chlorinated pesticides (NCPs) in arable soils of Poland as an example of Central and Eastern European countries. The results were assessed in relation to Polish regulations, which are more restrictive compared to those of other European countries. The sampling area covered the territory of arable lands in Poland (216 sampling points). The distribution of sampling points aimed to reflect different geographical districts, conditions of agricultural production, and various soil properties. The collected soil samples were extracted with organic solvents in an accelerated solvent extractor (ASE 2000). The OCPs, including α-HCH, β-HCH, γ-HCH, and p,p’DDT, p,p’DDE, and p,p’DDD, were extracted with a hexane/acetone mixture (70:30 v/v) and determined by gas chromatography with an electron capture detector (GC-μECD). NCPs included atrazine, carbaryl, and carbofuran were extracted with a dichloromethane/acetone mixture (50:50 v/v), while maneb was extracted by intensive shaking the sample with acetone (1:1 v/v) and ethylenediamine-tertraacetic acid. The NCPs were identified by a dual mass- spectrometry (GC-MS/MS). The total content of individual OCPs ranged from 0.61 to 1031.64 µg kg−1, while the NCP concentrations were significantly lower, from 0.01 to 43.92 µg kg−1. DDTs were detected in all soils samples (p,p’DDD (23.60 µg kg−1) > p,p’DDT (18.23 µg kg−1) > p,p’DDE (4.06 µg kg−1), while HCHs were only in 4% of the analyzed samples (β-HCH (339.55 µg kg−1) > α-HCH (96.96 µg kg−1) > γ-HCH (3.04 µg kg−1)), but in higher values than DDTs. Among NCPs, higher concentration was observed for carbaryl (<0.01–28.07 µg kg−1) and atrazine (<0.01–15.85 µg kg−1), while the lower for carbofuran (<0.01–0.54 µg kg−1). Maneb was not detected in analyzed soils. Assessment of the level of soil pollution based on Polish regulations indicated that several percentages of the samples exceeded the criterion for OCPs, such as ∑3DDTs (14 samples; 6.5% of soils) and HCH congeners (α-HCH in one sample; 0.5% of soils), while NCP concentration, such as for atrazine, carbaryl and carbofuran were below the permissible levels or were not detected in the analyzed soils, e.g., maneb. The obtained results indicated that residues of the analyzed pesticides originate from historical agricultural deposition and potentially do not pose a direct threat to human and animal health. The behavior and persistence of pesticides in the soils depend on their properties. Significantly lower NCP concentration in the soils resulted from their lower hydrophobicity and higher susceptibility to leaching into the soil profile. OCPs are characterized by a high half-life time, which affect their significantly higher persistence in soils resulting from affinity to the soil organic phase

Agricultural suitability of rendzinas in Poland

The agricultural value of rendzina soils depends on many factors, including type of parent rock, texture of arable layer, admixture of post-glacial materials and occurrence of coarse fragments. Over 97% of rendzinas in Poland are arable soils, and less than 3% are under permanent meadows and permanent pastures. Rendzinas are soil of high production potential for agriculture. Almost 75% of them were included in the wheat complexes (from 1 to 3) while about 10% are weak and very weak rye soils (complex 6 and 7) in Polish land suitability system. Groups of rendzinas identified for agricultural purposes and the principles of their identification were established on 1950s and 1960s when bonitation maps and soil-agricultural maps were prepared. These principles have not changed so far, therefore the purpose of the work was to describe the divisions of these soils and the characteristics of their properties on the example of arable soils based on the available data

Soil Bioavailability of Cadmium, Lead, and Zinc in Areas of Zn-Pb Ore Mining and Processing (Bukowno, Olkusz)

The study was performed to determine bioavailable amounts of cadmium, lead, and zinc in soils contaminated through the years of Zn-Pb ore mining and processing near Olkusz, Poland, and to identify the environmental risk (RAC) associated with the occurrence of the most mobile forms of these metals in the soil. The authors analyzed topsoil samples for the basic physical and chemical parameters, as well as for total metal content (by aqua regia extraction), and for percentage of 1 M HCl- and 1 M NH4NO3-extractable fractions. Results were compared with the content of these metals in a common grass species, Agrostis capillaris. In the study region, Cd, Pb, and Zn content was (respectively, in mg∙kg-1): 0.5–33.5, 2–529, and 4–7877. This means that in more than 24%, 30%, and 38% of samples, respectively, metal content exceeded the limits defined by the Polish Environment Minister’s Regulation of September 9, 2002, with nearly 24% of soil samples contaminated by all three metals. Based on the Environment Minister’s Regulation of September 1, 2016, which is currently in force, and using the allowed limits for subgroup IV (industrial land), set at 15 mg∙kg-1 for Cd, 600 mg∙kg-1 for Pb, and 2000 mg∙kg-1 for Zn, the analysis also found excessive metal content in a considerable percentage of topsoil samples (33%, 13%, and 38%, respectively). The content of the studied elements in a common grass species, Agrostis capillaris, was significantly higher than the so-called natural content. A strict association was found between total Cd, Pb, and Zn content, and the potentially available 1 M HCl-extractable fraction. The environmental risk presented by the content of mobile Cd, Pb, and Zn forms, assessed in all the studied soil samples using Risk Assessment Codes (RAC), demonstrates very high environmental risk associated with Cd, high environmental risk associated with Zn, and moderate environmental risk associated with Pb