Showing papers in "Soil Science in 2019"

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

Abstract: Abstract 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 soil-forming 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.

The possibility of using sewage sludge for energy crop cultivation exemplified by reed canary grass and giant miscanthus

Abstract: Abstract Energy crops, on account of high biomass yields, have high nutrient requirements in relation to macroelements. Municipal sewage sludge can be a potential source of micronutrients for plants with high nutrient requirements. The use of macronutrients from sewage sludge by energy crops is an alternative form of nutrient recycling from organic waste. The aim of the research was to assess the content, uptake and use of N, P, K, Ca, Mg and Na from municipal sewage sludge by reed canary grass (Phalaris arundinacea L.) and giant miscanthus (Miscanthus × giganteus Greef et Deu). The effect of sewage sludge on the ratios between macroelements in the biomass of the tested plants was also assessed. The multi-year field experiment involved four levels of fertilization with sewage sludge at doses of 0, 10, 20, 40, 60 Mg DM·ha−1. Due to the low potassium content in this waste, supplementary potassium fertilization (100 kg K·ha−1 in the form of 40% potassium salt (KCl)) was applied once on all plots. It was established that the increasing doses of sewage sludge had a considerable effect on the increase in the content and uptake of N, P, K, Ca, Mg and Na by the biomass of the tested energy crops. The research shows that, compared to giant miscanthus, reed canary grass had a higher macronutrient content. The largest amount of uptaken N, P, K, Ca and Mg was found in reed canary grass (at a dose of 40 Mg DM·ha−1), whereas Na was detected in giant miscanthus (at a dose o 20 Mg DM·ha−1). It was established that giant miscanthus, on account of its higher yielding, recovers macroelements from sewage sludge applied to soil at a dose of 10 Mg DM·ha−1 to the greatest extent. The increasing doses of sewage sludge considerably decreased the value of K:Mg, Ca:Mg, Ca:P ratios in miscanthus biomass yield. The applied doses of sewage sludge (40–60 Mg DM·ha−1) increased the value of K:Ca, Ca:P, K:Na ratios in miscanthus biomass yield.

Chernozem (czarnoziem) – soil of the year 2019 in Poland. Origin, classification and use of chernozems in Poland

Abstract: The Soil Science Society of Poland has elected chernozem to be the Soil of the Year 2019. Although chernozems cover less than 2% of Poland, they have high importance for agriculture due to their productivity and play a specific scientific role for understanding of soil development and functioning in an environment. Chernozems are also crucial for the reconstruction of Neolithic agriculture development and human impacts on soil and landscape. This introductory paper presents (a) a specific definition of chernozem in Poland, connected with a separate distinction of black earths and colluvial chernozemic soils; (b) a review of the present and former classification schemes for chernozems in Poland and their correlation with international soil classification systems (WRB and Soil Taxonomy); (c) the spatial distribution of chernozems in Poland, their agricultural evaluation and threats for chernozems’ quality and future existence related to intense land use.

Properties and classification of heavily eroded post-chernozem soils in Proszowice Plateau (southern Poland)

Abstract: The morphology and properties of heavily eroded soils found in chernozems in the upland landscape of the Proszowice Plateau (southern part of Poland) was presented. The issue of classification of these soils was also discussed. Taking into account the terrain context, it should have been assumed that these soils were formed as a result of strong erosion (truncation) of chernozems. These (post-chernozem) soils were relatively young, in which only the development of humus horizon can be documented. However, the accumulation of humus was hampered by constantly intense erosion processes. Evidence of the occurrence of the illuviation process as well as formation of cambic horizon is not visible macroscopically and microscopically. These soils are often classified as weakly developed soils though despite the poor development of the soil profile, they are characterized by potentially high productivity, which results both from the properties of their parent material (texture, porosity) and from their youthfulness (carbonate content both in fine earths and in nodules, high pH in whole profile). Therefore, the name proposed in Polish Soil Classification, 6th edition (‘pararedzina’) seems to be justified. These soils would be classified as Entisols according to USDA Soil Taxonomy and as Regosols according to WRB.

Soil cover patterns in the forest-steppe and steppe zones of the East European Plain

Abstract: The soil cover of the forest-steppe and steppe zones of the East European Plain is characterized by diverse soil combinations revealed during large-scale and detailed soil mapping against the background of a traditional zonal sequence of dominant automorphic soils alternating from the north to the south and clearly displayed on small-scale soil maps. The composition, configuration and functioning of particular soil cover patterns are determined by the soil forming factors acting within a given area. The elementary soil areas (detailed scale) and elementary soil cover patterns maps (large scale) of the Central Russian, Kalach, and Volga Uplands are created by both traditional and digital soil mapping methods. Low-contrasting soil combinations with the background Haplic Chernozems (Loamic or Clayic, Pachic) alternating with zooturbated Haplic Chernozems (Loamic or Clayic, Pachic) on convex elements of the microtopography and Luvic Chernozems (Loamic or Clayic, Pachic) on concave elements of the microtopography prevails under conditions of thick clay loamy parent materials and free drainage. Under conditions of shallow embedding by low-permeable clayey sediments, the soil cover includes Chernozems or Chernic Phaeozems with stagnic features in some part of the soil profile or even Mollic Stagnosols. The presence of shrink-swell clays of different ages leads to the formation of Bathyvertic Chernozems, Vertic Chernozems, Vertic Chernic Phaeozems and/or Pellic Vertisols. The presence of soluble salts in the parent material leads to the development of solonetzic soil complexes consisting of Protosodic or Sodic Chernozems and different types of Solonetzes.

Immediate- and Short-term Wildfire Impact on Soil Microbial Diversity and Activity in a Mediterranean Forest Soil

Abstract: Wildfires are a driving factor of forest soils and their biota, especially in fire-prone ecosystems. Fire effects on soil microbial community are complex and still largely unknown. Greater knowledge is needed as fire frequency is expected to increase with human-induced climate change. This study aims at assessing the effects of a single moderately severe wildfire on microbial community diversity and activity in a Mediterranean forest soil by DNA molecular screening (polymerase chain reaction–denaturing gradient gel electrophoresis). For this purpose, the soil of a burned area was sampled 3 days and 10months after the fire and compared with the soil of an unburned contiguous area. For the DNA fingerprinting, we analyzed both extracellular and intracellular DNA fractions of the soil metagenome. The fire impact on soil was also rated in terms of selected enzyme activities, as reliable bioindicators of biogeochemical cycles. An immediate fire-induced general decrease in enzyme activities and more durable changes in the bacterial and fungal communities structure were found, although microbial biomass was not significantly affected. Litter layer was completely turned to char and ash by the fire, but after 10 months, it showed a fair amount of DNA, a structured microbial community, and a good enzymatic activity. Overall, such relatively fast recovery was likely caused by the microbial biomass that survived the fire, which evidently adapted to the new soil conditions.

Morphological diversity of chernozemic soils in south-western Poland

Abstract: Abstract Diverse chernozemic soils featured by thick mollic horizon, rich in humus, dark-coloured, structural, and saturated with base cations are relatively common in the loess-belt of SW Poland. It is postulated, that most of these soils may have similar initial (chernozemic) history of thick humus horizon, related to climate conditions and vegetation in the Late Pleistocene and the Neolithic periods. However, these soils exist on various bedrocks and under different moisture conditions that led to the development accompanying features and variable classification of soils, both in Polish and international soil classifications. The aim of the paper is to presents the most important variants of loess-derived chernozemic soils of SW Poland, in relation to local conditions, which influenced soil transformation and present spatial diversification. ‘Typical’ chernozems (WRB: Calcic Chernozems), which have a mollic horizon and secondary carbonates, but are free of strong redoximorphic features, are rather uncommon in the region. Whereas, the black earths (WRB: Gleyic/Stagnic Chernozems/Phaeozems), featured by the presence of mollic horizon and strong gleyic or stagnic properties in the middle and bottom parts of the profiles, are predominant loess-derived chernozemic soils in SW Poland. Their most specific forms, developed on the clayey bedrock, are black earths with a vertic horizon (WRB: Vertic Stagnic Phaeozems). The strongly leached chernozemic soils developed over permeable subsoils, lacking carbonates and free of (strongly developed) stagnic/gleyic properties are called grey soils, often featured by the presence of subsurface diagnostic horizons cambic or luvic (WRB: Cambic/Luvic Phaeozems).

Humic substances of differently matured composts produced from municipal solid wastes and biomass of energetic plants

Abstract: The aim of the study was to assess the transformation of humic substances during composting of biomass of energetic plants and municipal solid waste. The type of the organic material to be composted and the type of technology used affect the course of the humic substances transformation and formation of compost maturity parameters. Compost produced from the mixture of energetic willow and hay biomass contained humic substances with higher share of low-molecular fractions and lower share of humic acids in total organic carbon than those produced from municipal solid wastes. Obtained results also showed that insoluble alkali fraction plays an important role in humification process by its convertion to a new humic substances. Share of humic and fulvic fractions in relation to the total organic carbon appears to be reliable indicator of composting as a process of enhancing organic matter humification.

Prediction of soil properties with machine learning models based on the spectral response of soil samples in the near infrared range

Abstract: One of the basic methods for soil analysis time and cost reduction is using soil sample spectral response in laboratory conditions. The problem with this method lies in determining the relationship between the shape of the soil spectral response and soil physical or chemical properties. The LUCAS soil database collected by the EU’s ESDAC research centre is good material to analyse the relationship between the soil properties and the near infrared (NIR) spectral response. The modelling described in the paper is based on these data. The analysis of the impact of soil properties configuration on absorbance levels in various NIR spectrum ranges was conducted using the stepwise regression models with the properties, properties squared and products of properties being explanatory variables. The analysis of partial correlation of soil properties values with absorbance values and absorbance derivative in the entire spectral range was conducted in order to evaluate the impact of the absorbance transformation (the first derivative of absorbance vector) on the change of significance of relationship with properties values. The Multi Layer Perceptron (MLP) models were used to estimate the absorbance relationship with single soil features. Soil property modelling based on the selection and transformation algorithm of raw values and first and second absorbance derivatives was also conducted along with the suitability evaluation of such models in building digital soil maps. The absorbance is affected by a limited number of tested soil features like pH, texture, content of carbonates, SOC, N, and CEC; P and K contents have, in case of this research, a negligible impact. The NIR methodology can be suitable in conditions of limited soil variation and particularly in development of thematic soil maps.

Short-term effects of biochar application on soil loss during a rainfall-runoff simulation.

Abstract: Application of biochar to soil has been suggested as a nonstructural best management practice to mitigate runoff potential and soil loss. However, empirical data substantiating these effects are still scarce. Rainfall was presently simulated under controlled conditions to study the effects of biochar on erosion and runoff potential with sandy loam soil sampled from a field experiment 2 years after biochar amendment (2 kg m). The field experiment comprised four untreated and four biochar-treated plots that were amended with biochar produced from birchwood. In the laboratory, aggregate stability and organic carbon (OC) in topsoil (0–0.2 m) were analyzed. Soil loss and runoff were measured during a 3.5-h rainfall simulation using a round flume setup. Organic C was also determined in the eroded sediment, soil crust, and bulk soil of each flume after simulations.While runoff was not affected by treatment, biochar-treated soils showed significantly lower soil loss rates compared with untreated soils, reducing the cumulative soil loss by 41%. This was attributed to the aggregating effects of OC from the biochar application anddelayed crust formation. The reduced erosion of OC from biochar-treated soils also resulted in lower OC enrichment ratios in the sediment and thus less OC export than from untreated soils. The results illustrated that biochar application already in the short term (2 years) can lead to an improvement of soil aggregation, thereby enhancing aggregate stability and leading to a reduction in soil loss. However, extrapolation of these positive results must be done with caution because the scale of the flume limited the erosive forces acting on the soil. Before an extrapolation of the results, an upscaling of erosion tests to field scale is therefore required.

Potential of VIS-NIR spectroscopy to characterize and discriminate topsoils of different soil types in the Triffa plain (Morocco)

Abstract: Abstract This study aims to identify the influence of soil organic matter (OM) content and calcium carbonates (CaCO3) on soil reflectance and select the optimum spectral bands for discriminating between topsoils of different soil types situated in the irrigated perimeter of the Triffa plain (Morocco) using VIS-NIR reflectance spectroscopy. Soil samples were collected from the plow layer in 26 sampling sites. The spectral measurements were conducted in the field using an ASD Fieldspec portable spectroradiometer (350–2500 nm), while the soil samples were analyzed in the laboratory. The spectral data were pre-processed to remove the noise effects and then analyzed with the CovSel (selected covariance) method, validated by linear discriminant analysis in order to select the most optimal spectral variables to discriminate between topsoils of different soil types in the plain. The results of the soils reflectance curves showed that low reflectance intensity marked the soils with high OM contents throughout the VIS spectrum. The influence of the soil OM content was very apparent in the VIS range (between 580–750 nm). Regarding the CaCO3 content, it was noted that the soil samples with a high percentage of CaCO3 increase the reflectance in all spectral domains situated between 350 and 2500 nm. The spectral bands of 1999, 686, 1280, 2340 and 1951 nm were the most optimal for the soil discrimination in the Triffa plain. This study concluded that the VIS-NIR spectroscopy demonstrates an excellent ability to characterize and discriminate between topsoils in the Triffa plain.

Effect of long-term organic and mineral fertilisation on selected physico-chemical soil properties in rye monoculture and five-year crop rotation

Abstract: Abstract The research was carried out continuously since 1923 in a permanent fertilisation experiment at the Experimental Station of SGGW in Skierniewice. The objective of the research was to determine the effect of long-term fertilisation (Ca, CaNPK, NPK) and crop rotation systems (rye monoculture without fertilisation with manure and five-field rotation with legume crop and manure fertilisation) on selected physical and chemical soil properties. Long-term fertilisation caused various degrees of change in many physio-chemical properties in three soil horizons (Ap, Eet, Bt): pH in KCl, cation exchange capacity, total exchangeable bases, base saturation, content of carbon, nitrogen and mineral forms of nitrogen (NO3, NH4) as well as the carbon-nitrogen ratio. The combined manure and mineral fertilisation increased the sorption capacity, total exchangeable bases, base cation saturation and total content of C and N in comparison to organic or mineral fertilisation. As a result of lime application, an increase in these parameters was determined with the exception of total contents of carbon and nitrogen, showing no differences or a decrease. A positive effect was confirmed in five-field crop rotation, which improves physicochemical soil properties in comparison to cereal monoculture. The C:N ratio narrows down with growing depth because more nitrogen than carbon migrates down the soil profile.

Vertisols properties and classification in relation to parent material differentiation near Strzelin (SW Poland)

Abstract: Abstract Vertisols are characterized by high content of clay fraction that affects their specific morphological and physical features. The shrink-swell phenomena of clayey materials under specific moisture regime cause formation of cracks, wedge-shaped structural aggregates and slickensides on aggregate surfaces. It was formerly believed that these soils can be found only in tropical/subtropical zones, thus Vertisols have not been expected to form under temperate climate of Central Europe. As a result, Vertisols are insufficiently recognized and documented on soil maps in Poland, including the Lower Silesia region. The aim of this study was to examine soils developed on clayey parent materials near Strzelin, focusing on their morphology, properties and classification issues. There was confirmed that soils developed from Neogene clays have vertic and mollic horizon, accompanied by stagnic or gleyic properties. However, not all soils fulfil the criteria for Vertisols due to the presence of surface or subsurface coarser-textured (sandyor silty-textured) layers. Native differentiation of parent material and geomorphological processes were found the main factors, which control the spatial mosaic of Vertisols and black earths (Chernozems or Phaeozems).

Estimating Soil Hydraulic Conductivity at the Field Scale With a State-Space Approach

Abstract: A precise description of saturated (Ks) and near-saturated hydraulic conductivity (K−10) and their spatial variability is important for understanding water/solute transport in the vadose zone. However, it is laborious to measure K directly. Alternatively, K could be predicted from easily measurable soil properties using pedotransfer functions (PTFs). Because PTFs ignore the spatial relationships and covariance between soil variables, they often perform unsatisfactorily when field-scale estimations of K are needed. Therefore, the objective of this study was to improve the estimation of K at field scale through consideration of spatial dependences between soil variables. K was measured at 48 locations in a 71 × 71-m grid within a farmland under no-till. An autoregressive state-space approach was used to quantify the spatial relations between K and soil properties and to analyze the spatial variability of K in the field. In comparison, multiple linear regression (MLR) was used to derive PTFs for K estimation. Using various combinations of variables, state-space analysis outperformed PTFs in estimating spatial K distribution across the field. While state-space approach explained 69%, MLR method explained only 6% of the total variation in Ks. For K−10, the best state-space model included silt, clay, and macroporosity and performed almost perfectly (R >95%) in characterizing the spatial variability of K−10. In that case, the best MLR-type PTF explained only 60% of the variation. The results indicate that, by considering the spatial relations between soil variables, state-space approach is an effective tool for analyzing the spatial variability of K at field scale.

Suitability of World Reference Base for Soil Resources (WRB) to describe and classify chernozemic soils in Central Europe

Abstract: Chernozemic soils are distinguished based on the presence of thick, black or very dark, rich in humus, well-structural and base-saturated topsoil horizon, and the accumulation of secondary carbonates within soil profile. In Central Europe these soils occur in variable forms, respectively to climate gradients, position in the landscape, moisture regime, land use, and erosion/accumulation intensity. “Typical” chernozems, correlated with Calcic or Haplic Chernozems, are similarly positioned at basic classification level in the national soil classifications in Poland, Slovakia and Hungary, and in WRB. Chernozemic soils at various stages of their transformation are placed in Chernozems, Phaeozems or Kastanozems, supplied with respective qualifiers, e.g. Cambic, Luvic, Salic/Protosalic, Sodic/Protosodic etc. Some primeval Chernozems thinned by erosion may still fulfil criteria of Chernozems, but commonly are shifted to Calcisols. Soils upbuilt (aggraded) with colluvial additions may also retain their original placement in Chernozems, getting supplementary qualifier Colluvic. “Hydromorphic” chernozemic soils, in many CE systems are placed as separate soil type (“czarne ziemie” or “ciernice”) at the same level with “typical” chernozems. Classification of these soils in WRB depends on the presence of chernic horizon, depth of secondary carbonate accumulation and depth of gleyic/stagnic properties, and may vary from Gleyic/Stagnic Chernozems/Phaeozems to Mollic Gleysols/Stagnosols. Although WRB classification differs from national classifications in the concepts and priorities of classification, it provides large opportunity to reflect the spatial variability and various stages of transformation/degradation of chernozemic soils in Central Europe.

Development of the limit values of micronutrient deficiency in soil determined using Mehlich 3 extractant for Polish soil conditions. Part II. Rapeseed

Abstract: The aim of the study was to develop limit values for low microelement concentration in the soil, determined with the use of Mehlich 3 extractant for assessing their deficits in rapeseed crops. The values were prepared on the basis of 1944 fields with rapeseed, covering the whole Poland. In 2017, the samplers of Polish agro-chemical laboratories took soil samples and corresponding plant samples at the BBCH 30/31 stage. In the plant samples, the concentration of microelements was determined, and in the soil samples, apart from microelements, also pH, texture and the concentration of organic carbon and available phosphorus, were determined. Moreover, for each field, data on rapeseed yield were collected. Limit values were determined by two independent methods: 1) the method of regression equations and 2) the so-called high yield method. In the first case, the limit microelement concentration in the soil was calculated from the equation describing the relationship between the R/G bioaccumulation coefficient and a specific soil feature (n=1944). The bioaccumulation coefficient is a quotient of the concentration of a microelement in a plant (R) and its concentration in the soil determined by the Mehlich 3 (G) method. Limit values were calculated after substituting the critical concentration of microelements in the plant (R) to the equation, and subsequently, an appropriate conversion of the equation. The second method was based on the separation of a group of high yields ≥4.0 t ha⁻¹ (n=755) from the whole data set. Then in this group, the lower quintiles (QU1) were calculated for the concentration of individual microelements in the soil determined in Mehlich 3 extract and adopted as limit values. It was found that QU1 is a good indicator of the lowest microelement concentration in the soil at which a yield of at least 4.0 t ha⁻¹ can be obtained. The final limit values were worked out by averaging the values calculated by the equations and high yield method and their appropriate correction. In the combined soil sample collections for wheat and rapeseed (n=3865), the values were checked by evaluating the percentage of soils with microelement shortage separately for rape and wheat. The results of this evaluation were compared with the evaluation using the old system based on the 1 M HCl, which did not take into account the plant species.

Seasonal changes in organic carbon content in post-arable forest soils

Abstract: Abstract The purpose of this work is to determine seasonal changes in the organic carbon content in the mineral topsoil horizon of the Dystric Brunic Arenosols currently used as forest. In addition, the influence of forest age on the soil organic carbon (SOC) content in the A horizon was analyzed. The paper presents the results of studies on temporal changes in the SOC content in the mineral surface horizon of 55-year-old (Sk2) and 13-year-old forest (Sk5) in 2013 and 2014. Soil samples were collected from A horizon once a month between April 2013 and March 2015. Based on the conducted studies, clear seasonal differentiation of the SOC content was observed. Higher contents of SOC in the A horizon of the analyzed soils occurred in the autumn and winter months, and were lower in spring and summer. For Sk2 soil, higher SOC values were observed in autumn and then in winter, which on average were 11.08 g·kg−1 and 9.61 g·kg−1 respectively, while lower in spring and summer (8.85 g·kg−1 and 8.83 g·kg–1 respectively). Also in the mineral topsoil horizon of Sk5 soil, higher SOC contents were recorded in autumn and winter (8.07 g·kg−1 and 7.27 g·kg−1 respectively), and lower in spring and summer (6.19 g·kg−1 and 6.57 g·kg−1 respectively). The periodicity of SOC content in plots studied was related to the seasonality of precipitation and temperature. The research also showed that the age of the forest stand influences significantly the content of organic carbon in the A horizon. Higher content of SOC was observed in the A horizon of the 55 years old forest stand (average 9.69 g·kg−1) than on the 13 years old (7.02 g·kg−1).

Slope position and management practices as factors influencing selected properties of topsoil

Abstract: An interaction between the slope position and type of soil management practices could be one of the most important factor affecting several soil properties including soil structure. Therefore, we evaluated selected soil properties including soil structure parameters in relation to slope gradient and soil management practices between Trakovice and Bucany villages (western Slovakia). The sampling sites were located in two adjacent, gently sloping fields with a NW-SE orientation. The sites also differ in soil management type: Field No. 1 was used as arable land with intensive cultivation (IC) of crops, while a greening system (GS) had been established on Field No. 2. Soil samples were taken from five geomorphological zones at each slope: summit, shoulder, back-slope, toe slope and flat terrain under the slope. Results showed that soil pH, content of soil organic matter (SOM) and carbonates depended on land use of the slopes. In GS, the water-stable macro-aggregates (WSAₘₐ) 0.5–3 mm (favourable size fraction) displayed statistical significant quadratic polynomial trend along the slope gradient. In IC the values of mean weight diameter of dry sieved aggregates (MWDd) decreased significantly along the slope gradient, while in GS the opposite trend was observed. In IC significant correlations between carbonates content (r=-0.775, P<0.01), humic acids (HA) content (r=0.654, P<0.05), colour quotients of humic substances (r=-0.706, P<0.05), colour quotients of HA (r=-0.723, P<0.05) and MWDd were determined. In GS higher content of carbonates was followed by a decrease in content WSAₘₐ, MWDd, mean weight diameter of wet sieved aggregates (MWDw) and stability index of aggregates. At the same time stabile and labile soil organic matter improved soil structure parameters in GS.

Zinc sorption in calcareous soils of the Kurdistan Region of Iraq.

Abstract: Zinc (Zn) sorption was studied in four calcareous soils of the Kurdistan Region of Iraq. The experiment was conducted by equilibrating 5 g of soil in 50 mL of a 0.01 M CaCl2 solution containing different levels of Zn. Suspensions were centrifuged and filtered, and the concentrations of Zn in the filtered solutions were determined. The sorption of Zn was evaluated using four adsorption isotherms (Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich); the data were best fit by a linearized Langmuir model as evidenced by the higher coefficient of determination (R) values and lowest standard error (SE) values. For the Langmuir and Freundlich isotherms, the separation factor (RL) was 0 < RL < 1, and the adsorption intensity (n) was 1 < n < 10, respectively, indicating a favorable (spontaneous) Zn sorption process in the soil. The Dubinin-Radushkevich isotherm indicated a physisorption process of Zn in the soil (E < 8 kJ mol). Thermodynamic parameters ΔG, ΔH, and ΔS were also determined at three different temperatures. The ΔG values were negative and ranged from −7.45 to −7.80, −9.56 to −10.28, and −11.36 to −12.85 kJ mol, at 278, 298, and 318 K, respectively, where negative values of ΔG indicate the Zn sorption was endothermic. The values of ΔH were positive and ranged from 17.23 to 29.25 kJ mol, and the values of ΔS were positive and ranged from 89.87 to 132.15 J mol K. The positive values of ΔH and ΔS indicate that the sorption of Zn in the soil is an endothermic process. The results indicate that the studied soils had a high capacity of Zn sorption, which leads to decline in the availability of Zn.

Chernozems of Ukraine: past, present and future perspectives

Abstract: The aim of the paper was to show the significance of chernozems for the Ukrainian economy, science and culture. The spatial distribution as well as variation of features of chernozems in Ukraine (including the uniqueness of these soils) was described. Also a brief history of investigation of Ukrainian chernozems was outlined. Particular emphasis was placed on the problems of degradation and protection of chernozems.

Linking coffee to soil: can soil health increase coffee cup quality in Colombia?

Abstract: Understanding the effects of soil health (SH) on the quality of high-value crops such as coffee may enable farmers to receive financial benefits prompted by product differentiation and price premiums. This study assessed the existence and nature of the relationship between coffee cup quality and SH. Soil and coffee seed samples were collected from 68member-farms of a cooperative participating in a high-quality coffee value chain and 67 non–member-farms located across six municipalities in Cauca, Colombia, and 117 farms across twomunicipalities in Antioquia, Colombia. Elevation was recorded on each farm. Soil samples were tested for 13 SH indicators including wet aggregate stability, available water capacity, active carbon, organicmatter (OM), protein, respiration, pH, P, K, Mg, Mn, Fe, and Zn. Coffee samples were tested by professional cuppers for physical, granulometric, and sensorial traits including fragrance/aroma, flavor, aftertaste, acidity, body, uniformity, sweetness, clean cup, and balance. Pearson correlation tests, principal component analysis, and canonical correlation analysis were conducted on all measured variables for Cauca and Antioquia separately and combined. Results show that coffee quality and sensorial traits tended toward a negative relationship with physical and biological SH, primarily with the indicators available water capacity and OM and the labile OM-related soil properties active carbon and respiration, whereas chemical indicators variably correlated with coffee quality. This suggests that coffee may be similar to wine grapes in that high-quality products not necessarily derived from soils with high values of SH indicators. The results of this study can guide further work to identify suitable management strategies that maximize coffee quality without significantly jeopardizing production or the environment.

Impact of long-term liming on sandy soil phosphorus sorption properties

Abstract: Abstract The static fertilisation experiment conducted in Skierniewice (Central Poland) since 1923 investigates the effect of mineral fertilisation with lime (CaNPK) or without lime (NPK) on the accumulation and release of phosphorus in reference to phosphorus sorption properties in the sandy soil profile. In the case of application of same doses of mineral fertilisers, the content of total phosphorus was higher in NPK than CaNPK soil. Parameters related to sorption capacity and bonding energy from Langmuir and Freundlich model of P sorption were significantly lower in CaNPK than NPK soil profile. This was particularly caused by a lower content of poorly crystallised hydro(oxide) aluminium and iron forms in CaNPK than NPK soil. Higher content of oxide-extractable and bioavailable phosphorus extracted with double lactate solution, dissolved reactive phosphorus in water solution as well as degree of phosphorus saturation in the CaNPK soil profile suggests higher mobility and possibility of occurrence of losses of phosphorus from the profile of limed soil than from acidified soil. Therefore, management of phosphate fertilizers on permanently limed sandy soils requires the optimisation of phosphorus doses to a greater degree corresponding to the actual take-off of the element with crop. An additional finding of the study was evidence of the possibility of re-estimating contents of bioavailable phosphorus and, as a consequence, the degree of phosphorus saturation with Mehlich3 method in strongly acid soil receiving P mineral fertilisers, which can make it difficult to use the test for fertiliser recommendation.

Forest habitats and forest types on chernozems in south-eastern Poland

Abstract: The objective of the study is the presentation of the chemical properties of forest chernozems and the features of forest habitats developed on chernozems in south-eastern Poland. The assessment of the trophic status of chernozems was presented based on the Trophic Soil Index (SIG). Moreover, the paper presents the diversity of forest vegetation on chernozems. The research covered 15 plots from the habitat inventory performed for the Mircze and Strzelce Forest Districts (SE Poland). Habitat conditions were characterised on the research plots, with particular consideration of the soil and vegetation. The analysed soils were featured by the presence of thick humus horizons and the occurrence of calcium carbonate. High SIG values confirm the eutrophic status of the analysed soils. In general, fresh and wet habitats of broadleaved forests (Lśw and Lw), as well as fresh habitats of broadleaved upland forest (Lwyzśw) develop on chernozems in Poland. They are associated with multi-species broadleaved tree stands. The conducted research indicates that, in current environmental conditions, the potential plant community is oak-hornbeam forest with predominance of oak, hornbeam, and abundant admixtures of other broadleaved species. High trophic status of the analysed chernozems is confirmed by high bonitation of tree stands and richness of forest floor vegetation.

Anthropogenic impact on concentration of selected trace elements pools in transformed organic soils in Trzcińskie Mokradła Peatland, SW Poland

Abstract: Drainage and peat extraction may have a negative impact on existing hydrological conditions and, consequently, on the conditions of wetland ecosystems. The aim of this study was to assess human impact on the studied Trzcinskie Mokradla Peatland by comparing the concentrations and trace element (Pb, Zn, Cu, Cr and Ni) pools in the study area (extracted vs. non-extracted areas of peatland). The concentration of trace elements in organic soils and their pools were analysed in relation to their depth in the soil profiles, content of organic matter, soil pH values and the degree of decomposition of organic materials (peat, mursh). Fifteen soil profiles (90 samples) were examined. The total soil elements content was determined after digestion in a mixture of HCl+HNO₃. The element pools were calculated and expressed in g m⁻² of soil in 0–30 cm and 30–50 cm layers. Soils showed acidic or slightly acidic reactions. The high concentrations of Pb and Zn were mainly observed in the upper horizons. The deeper layers enriched with mineral fractions were also enriched in metals like Cr and Ni.

Proposal of the correlation between cartographic units on the agricultural soil map and types and subtypes of Polish Soil Classification (6th edition, 2019)

Abstract: Agricultural soil maps (ASM), prepared since mid-1960s until 1980s and digitalised recently, are important source of information on the quality and spatial variability of arable soils in Poland. Basic standard information in each map contour includes the indication of a (genetic) soil type (often also the subtype or variety related to parent material or other specific properties), soil texture classes throughout the profile, and the category of soil agricultural suitability, which covers the complex information about the soil conditions, land morphology, climate and moisture regime. Unfortunately, the genetic classification on ASM is simplified compared to soil classifications in Poland and does not reflect numerous modernisations of the classification systems, including the modifications of existing units and newly introduced soil types and subtypes. Thus, the reinterpretation of ASM is necessary to simplify the further use of ASM by various users, to allow the creation of modern soil maps based on archival databases, and to correlate the soil data with other modern national and international classifications. This paper includes a proposal of equivalents for the soil units indicated in agricultural soil map (using all soil data available in a map contour), correlated with a recent, the 6th edition of Polish Soil Classification.

Availability of Fe, Zn, Cu, and Mn in Soils of Sulaimani Governorate, Kurdistan Region, Iraq

Abstract: This study was conducted to determine the availability of micronutrients in soils of Sulaimani Governorate and to evaluate their capacity to sustain agriculture. Soil samples were collected in 10 locations at two depths: 0 to 15 and 15 to 30 cm. Available forms of iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) were determined using a diethylenetriamine pentaacetic acid extraction, and the corresponding total amounts of these elements were determined in the samples by aqua regia digestion. The geochemical model—PHREEQC—was used to determine the speciation of elements and saturation indices in the studied soils. Physical and chemical parameters were assessed to determine their importance to the availability of these micronutrients. Results for available forms of Fe were lower than the critical range in all the studied locations. In general, there were low amounts of available Fe, Zn, and Mn in the studied soils, although there was a high amount of available Cu. Total concentrations of Fe ranged between 2.93% and 4.12%, Zn between 68 and 122 mg kg, Mn between 642 and 1,030 mg kg, and Cu between 31 and 64 mg kg. Saturation indices showed that many minerals such as aragonite, cuprous ferrite, dolomite, goethite, hematite, lepidocrocite, magnesioferrite, rhodochrosite, and smithsonite were supersaturated or had precipitated in these locations. The high Cu content of these Vertisols makes them suitable for agriculture, provided there is appropriate management of soil andwater resources. Themajor factors affectingmicronutrient availability were organic matter content and interaction between elements. Electrical conductivity had a significant positive effect on the availability of Mn, whereas total and active CaCO3 had negative impacts on the availability of Fe, Zn, and Mn in the studied soils.

Chernozems of Lubelszczyzna (eastern Poland)

Abstract: The purpose of the work was to characterize the variously used humus in the south-eastern part of the Lublin region. The basic research material were data taken from the literature on the subject. Standard soil science methods were used in the study. The humus level of humus varieties ranged from 30 to 80 cm. The researched molds were formed from loess deposits, which most often showed graining of clay dust. Organic carbon content in humus levels did not exceed 2.9%. The surface levels of the analyzed molds showed clear decalcification. The CaCO₃ content in the loess mother rock was a maximum of 15.5%. These are soils with high saturation of the sorption complex with basic cations. The content of available phosphorus and potassium in humus levels was low and medium. According to Systematics of Poland’s soils (2019), the analyzed molds mainly represented leached molds and typical molds, while according to the international soil classification WRB (IUSS Working Group WRB 2015) they are primarily Phaeozems. All the analyzed humus plants belong to soils with the highest utility value. Phenomena lowering the quality of molds in the Lublin region related to human activity are the use of improper agrotechnics, and above all water surface erosion. The unfavorable processes are favored by the undulating terrain and the grain size of the soils studied, characteristic for this area.

Contributions of Carbonates to Carbon Dioxide Release From a Calcareous Soil in Response to Experimental Warming

Abstract: Seasonal asymmetric warming is a distinguishing feature of climate change, which is not often considered when evaluating the effects of global change on terrestrial ecosystems. Responses of soil CO2 efflux from organic and inorganic sources to asymmetric and symmetric warming are not well understood. A 5-year warming experiment was performed to evaluate the effects of symmetric and asymmetric warming on soil organic carbon (SOC)–derived and carbonate-derived effluxes from a calcareous soil in the karst region of southwestern China. On average, the carbonate-derived efflux represented 31% of the total CO2 efflux in the six treatments. Warming of 2.0°C substantially stimulated soil CO2 efflux from both sources, except for the carbonate-derived efflux in summer-autumn. Soil CO2 efflux and SOC-derived efflux were appreciably reduced when ratios of warming in winter-spring to summer-autumn ratio of asymmetric warming (RAW) increased, while no changes (full year or in summer-autumn) were found for the carbonate-derived efflux. However, soil CO2 efflux from both sources were considerably enhanced in winter-spring with increasing RAW values. Temperature sensitivity temperature coefficient (Q10) of CO2 efflux from both sources decreased with increasing RAW values. The average Q10 of SOC-derived efflux was 1.3 times greater that of the carbonate-derived efflux. Symmetric warming potentially overestimates CO2 efflux from calcareous soils, compared with the projected asymmetric warming scenario, likely because of overestimation of SOC-derived effluxes in summer-autumn.

Phosphorus availability in entisols, inceptisols, and mollisols of Iraqi Kurdistan.

Abstract: In this work, we investigated phosphorus (P) availability of three soil orders (Entisols, Inceptisols, and Mollisols) in the Kurdistan Region of Iraq. Addition of P fertilizers causes chemical and physical fixation of P due to the high amounts of calcium carbonate often present in the soils of this region. Understanding these fixation processes is important for predicting and managing P availability in this area. Two methods were used to assess P availability in this study: solubility diagrams and the Diagnosis Recommendation Integrated System chart (DRIS chart) method, which utilizes corn P concentration as a plant indicator of available P. A pot experiment was conducted during the spring corn growing season in 2014 (March 15, 2014, to July 1, 2014) to study the effects of five application levels of P (0, 80, 160, 240, and 320 kg P2O5 ha) on P availability. The double function parameters—phosphate potential (logH2PO4–pH) and lime potential (logCa + 2pH)—were used to study P solubility equilibria. The DRIS chart was used to study the balance between P and, separately, nitrogen (N) and potassium (K). The results of both methods indicated that an application of 320 kg P2O5 ha yielded the highest corn dry matter weight and highest P availability; that is, we found the best nutrient balance between P and both N and K at an application rate of 320 kg P2O5 ha. In addition, we found that the P for this treatment was in the most available form (dicalcium phosphate dihydrate) CaHPO4 · 2H2O. Our results indicated low P availability in the Inceptisol and high availability of P in the Mollisols studied. Phosphorus availability followed the following order: Mollisols > Entisols > Inceptisols. The high P availability in Mollisols was due to its relatively high organic matter content. Except the Inceptisols, the increase in levels of applied P caused a decrease in dry matter weight per pot. Both the solubility digram and DRIS chart method indicated low available P in the Bakrajo Inceptisol and adequate available P in the other soil orders studied. This is because of Inceptisols in the region have high calcium carbonate and low organic matter content when compared with Mollisols and Entisols.