Eutric Cambisol Research Articles

Assessment of the Ecotoxicity of Thallium According to the Biological Properties of Soils

In laboratory model experiments, the ecotoxicity of Tl was assessed by changing the microbiological, biochemical and phytotoxic properties of soils in the South of Russia: ordinary chernozem (Haplic Chernozem (Loamic)), seropesks (Eutric Arenosol) and brown forest slightly unsaturated soil (Eutric Cambisol), differing in granulometric composition, pH and organic matter content. As a rule, there was a direct relationship between the concentration of Tl and the degree of deterioration of the studied soil properties. Tl nitrate showed higher ecotoxicity than oxide. The strongest ecotoxic effect of Tl was manifested on chernozem and seropesks 10 days after contamination, on brown forest soil — 30 days later. Restoration of biological properties of soils was observed for 90 days. Ordinary chernozem showed the greatest resistance to Tl contamination, and seropeski showed the least. The results obtained indicate a high ecotoxicity of Tl.

An Evaluation of the Biometric Parameters and Chemical Composition of the Florets, Leaves, and Stalks of Broccoli Plants Grown in Different Soil Types

Soil affects plant growth and development, and it is one of the factors that determine crop yields and quality. Broccoli (Brassica oleracea var. italica Plenck) plants cv. Cezar were grown in an experiment conducted in 2021–2022 on a horticultural farm. The biometric parameters of broccoli plants were determined in the first stage. The chemical composition of the edible parts of broccoli was determined in the second stage, which involved two experimental factors. The first factor was the edible parts of broccoli: florets, leaves, and stalks. The second factor was the effect of soil type on the chemical composition of the edible parts of broccoli. Albic Luvisol (II) had a significant positive effect on floret height and the number of florets. Leaf yield was significantly lower when broccoli plants were grown in Eutric Cambisol (I) compared with Albic Luvisol (II) and degraded chernozem (III). Soil type had no significant influence on the macronutrient content of broccoli florets, leaves, and stalks, but the accumulation of macronutrients varied across the edible plant parts. The content of iron, zinc and manganese in broccoli plants was not significantly affected by soil type, but soil type exerted a significant effect on copper content.

Maps of Soil Organic Carbon Sequestration Potential in the Russian Croplands

Adoption of the farming systems that aim to sequester carbon in agricultural soils is one of the ways to mitigate global climate change. This study focuses on the estimation of organic carbon sequestration potential of the Russian croplands in the upper (0–30 cm) soil layer by creating a set of maps using the data from global and national databases as the input data. The maps are generated within the FAO Global Soil Organic Carbon Sequestration Potential Map (GSOCseq) project according to the unified methodology using the RothC model to predict the rate of carbon sequestration in 2020–2040 under a business as usual scenario (BAU), as well as under sustainable soil management scenarios with additional different C input (+5, +10, and +20%) resulting from the use of sustainable soil management (SSM) scenarios. The total potential sequestration rate by the croplands of the Russian Federation in the 0–30-cm layer under a BAU scenario is assessed at 8.5 Mt/year and the estimate under SSM scenarios, up to 25.5 Mt/year. The carbon sequestration by the cropland of each soil ecological zone (except for the light chestnut (Eutric Cambisols (Protocalcic)) and brown semidesert (Luvic Calcisols) soils, where it is around zero) and on a national scale is positive. The Altai krai, Omsk oblast, Novosibirsk oblast, and Krasnoyarsk krai have the greatest potential for sequestration. Several subjects of the Russian Federation—Krasnodar krai, Republic of Crimea, Rostov oblast, Primorskii krai, Republic of Adygea, and Kaliningrad oblast—demand the adoption of sustainable management of soil resources.

Catalase activity as a diagnostic indicator of the health of oil-contaminated soils after remediation.

The work objective was to assess the ecological state of soils by changing the residual oil content and restoring catalase activity after remediation. The soils were selected in various ecosystems: a steppe of the Rostov Region (Haplic Chernozem), beech-hornbeam forests in the Republic of Adygea (Haplic Cambisols), and semi-desert of the Caspian province of the Republic of Kalmykia (Eutric Cambisols). Soil samples were polluted with oil at a concentration of 5% of the soil mass. After that, ameliorants (biochar, nitroammophoska, sodium humate, and Baikal EM-1) were introduced into the oil-contaminated soil. The catalase activity of Haplic Cambisols was stimulated only with the introduction of D2 biochar by 11% relative to the control, and in Haplic Chernozem, catalase was most stimulated with the addition of nitroammophoska D0.5 and D1 by 65% and 57% of the control, respectively. Nitroammophoska in all doses significantly stimulated the enzymatic activity, in Eutric Cambisols by four to six times compared to the control. The range of soil stability determined by catalase activity: Eutric Cambisols > Haplic Chernozem > Haplic Cambisols. Thus, it is most effective to apply biochar in doses of D and D2 and D0.5 and D nitroammophoska during the remediation of oil-contaminated Haplic Chernozem. For the remediation of Haplic Cambisols, it is effective to introduce biochar in dose of D2, and Eutric Cambisols-biochar and sodium humate in dose of D0.5 and nitroammophoska (all doses). The results of the study allow using catalase activity as a very informative and statistically significant diagnostical indicator of the health of oil-contaminated soils after remediation.

Effect of watershed characteristics on river flow for the case of two watersheds, Megech and Gumaro, Upper Blue Nile Basin, Ethiopia

Land degradation is a series of problems in Ethiopia’s highlands, particularly in the Upper Blue Nile River Basin reflected in the form of soil erosion and reduce soil fertility from time to time. The effect of watershed characteristics on the river flow of those watersheds was evaluated by distributing a physically based hydrological model known as the soil and water assessment tool model. The model was calibrated for the river flow from 1992 to 2006 and validated for the period from 2007 to 2014. The performance of the model was evaluated based on performance rating criteria, coefficient of determination, and Nash and Sutcliff efficiency on monthly based value, the coefficient of determination (R2) and Nash–Sutcliffe coefficient was greater than 0.6 and 0.5 for all scenarios on both watersheds, respectively. The land-use land-cover change scenario, the climate characteristics, and the slope change scenario was developed, from those analyses, it was found that has been a substantial decrease or increase in forest land, shrubland, grassland, and expansion of agricultural land. The mean annual streamflow of 2010 LULC decreased by 1.44% for 2010 from 2003 LULC and 5.23% for 2018 from 2010. Because of reduced cultivated land from 2010 up to 2018 and increased grassland and plantation in the Megech watershed and 2010 LULC decreased by 0.9% for 2010 from 2003 LULC and 2.04% in 2018 from 2010. This distributed physically based hydrological model has been applied for the evaluation of physical catchment characteristics with significant differences which was Cropland for Megech and Gumaro watersheds which were 67.28% and 61.5%, respectively, for the 2003 LULC, 64.94% Megech, and 58.89% for Gumaro watershed for 2010LULC and 51.95% for Megech and 42.12% for Gumaro watershed, similarly, Eutric Cambisols were covering large areas for both watersheds.

Long-Term Fertilization Contributes to Carbon Saturation in Neutral-To-Alkaline Soils but not in Acidic Soils

ABSTRACT The study investigated the adsorption of dissolved organic carbon (DOC) on Chinese soils from four long-term experiments involving five treatments: (1) no fertilization (control), (2–4) inorganic nitrogen (N), phosphorus (P), and potassium (K) fertilization (N, NP, and NPK), (5) NPK plus manure (NPKM). The results showed that DOC adsorption followed a modified Langmuir isotherm model effectively (R2 = 0.912 ~ 0.991). The maximum adsorption capacity (Q max ) (i.e. saturation deficits) generally increased with increasing soil organic carbon (SOC) due to fertilization in Luvic Phaeozem, Haplic Gypsisols, and Eutric Cambisols. However, it decreased significantly in acidic soils (Haplic Acrisols) from 15.59 g/kg for control, to 13.96, 13.03, 9.30 and 8.02 g/kg for N, NP, NPK and NPKM, respectively. Moreover, long-term fertilization, particularly with organic fertilization (e.g. NPKM), resulted in an increase of carbon (C) saturation by 1.42 g/kg (5.52%) in Luvic Phaeozem, 9.27 g/kg (44.29%) in Haplic Gypsisols, and 3.75 g/kg (27.66%) in Eutric Cambisols; however, there was a slight decrease by 1.70 g/kg (−7.49%) in Haplic Acrisols. Canonical correlation analysis (CCA) revealed that clay content and soil available iron (AFe) might be the crucial factors controlling C deficits, and subsequently, C saturation, along with current SOC. In conclusion, long-term fertilization contributed to C saturation in neutral-to-alkaline soils, but not in acidic soils. Thus, further attention should be paid to the long-term effects of fertilization on C saturation.

Comparative analysis of different-age vineyards in Fruska Gora National Park, in the Autonomous province of Vojvodina, Republic of Serbia, on the characteristics of lateral migration of mobile sulphur

Data on the content and lateral migration of mobile sulfur in brown forest soil of residual carbonate (Eutric Cambisols/ Haplic Cambisols) of autonomous and transit landscapes under vineyards in the Autonomous Province of Vojvodina, Republic of Serbia, are presented. The content of mobile sulfur in horizons 0-5 and 5-15 cm was highly contrasting from very low (less than 5 mg/kg) to high (more than 35 mg/kg) depending on the age of vineyards, landscape features of their location and applied cultivation systems. The content of mobile sulfur in the lateral structure of elemental landscapes under age (more than 200 years) vineyards with high slope steepness increased from trans-eluvial facies of upper parts of slopes to lower transaccumulative facies. In an industrial vineyard of intensive type 15 years old, the absence of inter-row sodding and the arrangement of rows along a long slope with a complex shape contributed to increased migration. Migration flows and accumulation of mobile sulfur in transaccumulative elemental landscapes can cause deterioration of quality characteristics of produced wine materials and contamination of adjacent environments.

Improving soil fertility through dual inoculation with arbuscular mycorrhizal fungi and Rhizobium on a eutric cambisol cultivated with forage legumes in a semi-arid region

The Sub-Saharan region of southern Africa is characterized by high temperatures, low rainfall, and poor land-use management practices such as continuous cropping without replenishment of soil nutrients. The combination of these factors has resulted in nutrient depletion and land degradation. The current study aimed at investigating the effect of arbuscular mycorrhizal fungi (AMF) and Rhizobium bacteria inoculation on soil chemical properties in field-grown forage legumes, namely, Mucuna pruriens (mucuna), Lablab purpureus (lablab) and Vigna unguiculata (cowpea), in the semi-arid region of the Eastern Cape Province (South Africa). Forage legumes were inoculated with the AMF species Paraglomus occulum and the Rhizobia bacteria species Bradyrhizobium strain and grown for 120 days. Soil samples were collected in the following sequence: prior to planting, before flowering and after harvesting the forage legumes in each of the two seasons (2017/2018 and 2018/2019) and soil chemical properties were determined using standard procedures. The results showed that the addition of dual inoculation over time greatly improved soil chemical properties when compared to the control treatment. This was advocated by the significant (P ≤ 0.05) increase in soil pH, soil organic carbon, soil organic matter, total nitrogen, phosphorus, calcium, potassium, magnesium, sodium, sulfur and iron in soils. The concentration of cation exchange capacity was significantly (P ≤ 0.05) higher in cowpea treated with Rhizobium as compared to other treatment combinations. The control treatment of mucuna forage greatly improved the concentrations of manganese, boron, copper, molybdenum, and zinc over other treatment combinations only before the flowering stage. However, the concentrations of micronutrients were significantly higher on the treatment combination of lablab and single inoculation of AMF after harvesting. Generally, dual inoculation with AMF and Rhizobia enhanced soil properties when compared to a single inoculation or untreated control.

Effect of sulcotrione and terbuthylazine on biological characteristics of soil

Excessive and inappropriate use of herbicides in crop protection can lead to soil contamination and thus to changes in this environment, which involves a serious ecological problem. A pot experiment was, a study was conducted to determine how individual and combined application of sulcotrione and terbuthylazine affect the population, diversity and structure of bacterial and fungal communities, soil enzyme activity, as well as growth and development of Zea mays L. These parameters were evaluated during a plant pot experiment conducted in a soil classified to the Eutric Cambisols type. Amending the soil with 0.115 mg kg−1 sulcotrione and 0.165 mg kg−1 terbuthylazine (whether separately or in tandem) did not significantly impact biological activity in the soil. Only the application of sulcotrione in the amount of 1.15 mg kg−1 and terbuthylazine in the amount of 1.65 mg kg−1 disturbed the microbiological and biochemical balance of the soil. Both sulcotrione alone and the sulcotrione-terbuthylazine mixture reduced the number of organotrophic bacteria and actinobacteria, whereas terbuthylazine alone increased the number of fungi. The two chemicals boosted the activity of catalase and acidic phosphatase, while also reducing the dry matter yields of maize. Dehydrogenases activity decreased under the mixture of sulcotrione-terbuthylazine. Terbuthylazine and the sulcotrione-terbuthylazine mixture additionally decreased the SPAD greenness index in maize leaves. The chemicals also affected values of the microbial colony development index and the ecophysiological diversity index. There were also shifts in the structure of bacteria from phyla Actinobacteriota and Proteobacteria, as well as fungi from phyla Ascomycota and Mortiellomycota, though the extent of these changes varied across different soils samples. It can be concluded that microbiological and enzymatic properties of soil are suitable indicators used in diagnosing the quality of soil ecosystems. Bacteria and fungi identified in soil contaminated with sulcotrione and terbuthylazine may have high potential in inactivating these chemicals. The conducted research allowed us to assess the functioning of the soil environment under the influence of single and combined use of sulcotrione and terbuthylazine. They filled the gap regarding the impact of single and combined use of sulcotrione and terbuthylazine on the number and structure of bacterial and fungal communities, enzyme activity and the growth and development of Zea mays L.

Determination of Nitrate Migration and Distribution through Eutric Cambisols in an Area without Anthropogenic Sources of Nitrate (Velika Gorica Well Field, Croatia)

Natural potential sources of nitrate contamination involve decaying of organic matter, bacterial production, atmospheric deposition, and soil N. The study presents the first results of nitrate distribution and migration through soil horizons of the Eutric Cambisols, one of the most common soils developed in the area of the Zagreb aquifer and situated in an area without potential anthropogenic sources of nitrate (first sanitary protection zone of the Velika Gorica well field). A total of 16 parameters of soil water and 16 parameters of soil were used to conduct statistical techniques and analyse associated factors within the soil zone. The results indicate that in the deepest soil horizon, nitrogen is present mostly as nitrate due to nitrification under aerobic conditions which promote stability and the potential for nitrate transport. It was found that nitrate concentrations are the result of soil N nitrification, caused by a NO3−/Cl− molar ratio higher than 1 and the absence of precipitation isotopic signature. The results also show that within the coarse-grained Eutric Cambisols N primarily migrates to deeper parts of unsaturated zone in the form of nitrate and nitrite.

Barley Growth and Phosphorus Uptake in Response to Inoculation with Arbuscular Mycorrhizal Fungi and Phosphorus Solubilizing Bacteria

ABSTRACT Biostimulants and bioinoculants offer the potential to enhance nutrient use efficiency within agricultural cropping systems and thus reduce the amount of mineral fertilizers needed to support crop growth. Considerable uncertainty, however, exists about their efficacy under different management regimes. The present field-based study investigated the effects of phosphorus (P) solubilizing bacteria (PSB) and mycorrhizal (AMF) inoculants in the presence of a range of mineral-based P fertilizers, including triple superphosphate (TSP), struvite and rock phosphate (RP), on the growth, yield, and P uptake of barley (Hordeum vulgare L.). Two consecutive field experiments performed in a low P soil (Eutric Cambisol) revealed that the bioinoculants (PSB and AMF) promoted plant P uptake and grain yield. Moreover, in comparison to P fertilizers lacking bio-inoculants, the application of external P sources combined with bio-inoculants led to significant increases in leaf P concentration, total P uptake, plant dry matter, grain P concentration, and crop yield. Grain yield significantly correlated with P uptake by roots and above-ground parts (i.e. stems, leaves, and spikes) as well as grain P concentration in both seasons. It is concluded that bioinoculants can help improve sustainable P use ultimately leading to greater sustainability of cropping systems and resilience in soil P cycling.

Soil Formation on Sugar Industry Waste in the Central Chernozemic Zone

Soils formed in treatment facilities of sugar beet factories in the forest-steppe zone of Kursk oblast were studied. Technogenic factors of soil formation associated with the industrial sugar beet activity and post-technogenic processes during the abandonment of treatment facilities are considered. The alternation of settling ponds and the earth walls separating them are the main factors determining “cellular” pattern of the soil cover. The mode of inflow and discharge and the composition of wastewater, as well as the duration of the abandonment of settling ponds determine the specifics of soils forming in the bottoms of the ponds. Mucky–humus quasi-gley stratified soils (Calcaric Gleysol) are formed in operating settling ponds under the periodic impact of sewage mixed with other wastes. When calcareous sewage sludge (press mud) is previously removed from abandoned ponds, dark-humus quasi-gley soils (Gleyic Cambisol) are formed in 30 years in the presence of perched water table, and quasi-gley zooturbated Chernozems are developed in 40 years under the conditions of periodic moistening. Soil formation in settling ponds with preserved sewage sludge and abandoned 20 years ago is noticeably intensive only in the upper 10–15 cm, and properties of the stratified sediment are preserved below. Dark-humus technogenic artistratified soils (Spolic Technosols) are identified there. Typical dark-humus soils (Eutric Cambisols (Organotransportic) are formed on earth walls in about 50–60 years, and incompletely developed strongly alkaline technogenic pelozems (Spolic Technosols (Transportic)) are formed on earth walls covered with calcareous sewage sludge; these soils consist of the virtually unchanged mixed material of technogenic sediments. All soils are alkaline and strongly alkaline and rich in organic matter, carbonates, phosphates, nutrients and some heavy metals from wastewater. According to the combination of properties, the soils of the sugar industry treatment facilities have no direct natural analogues in the central chernozemic region and are a vivid example of soils forming under extreme conditions of resource excess.

Soil Formation on Sugar Industry Waste in the Central Chernozem Zone

Soils formed in treatment facilities of sugar beet factories in the forest-steppe zone of the Kursk region were studied. The technogenic factors of soil formation associated with the industrial sugar beet activity, and post-technogenic processes, acting during the abandonment of treatment facilities, are considered. The alternation of settling ponds and the earth walls separating them is the main factor determining the kind of “cellular” pattern of the soil cover. The mode of inflow and discharge of wastewaters, their composition, as well as the duration of the abandonment of settling ponds determine the specifics of the soils formed in the bottoms of the ponds. In operating settling ponds, under the periodic impact of sewage mixed with other wastes, dark-humus quasigleyic soils are developed (Calcaric Gleysol). When ponds are abandoned with previously removed calcareous sewage sludge (press mud), in the presence of perched water dark-humus quasigleyic soils (Gleyic Cambisol) are formed in 30 years; and in conditions of a variable-humid regime, quasigleyic zooturbated Chernozems are formed in 40 years. In settling ponds with preserved sewage sludge abandoned 20 years ago, soil formation has been noticeably active only in the upper 10–15 cm; below, the properties of the layered sediment are retained. Dark-humus technogenic arti-stratified soils are identified here (Spolic Technosols). On the earth walls, dark-humus typical soils (Eutric Cambisols (Organotransportic) are formed in 70 years; on the surfaces covered with calcareous sewage sludge, underdeveloped highly alkaline technogenic pelozems (Spolic Technosols (Transportic) are identified, in which the mixed material of technogenic sediments remains practically unchanged. All soils are alkaline and strongly alkaline, rich in organic matter, carbonates, phosphates, nutrients and some heavy metals from wastewater. According to the combination of properties and characteristics, the soils of the sugar industry treatment facilities have no direct natural analogues in the Central Chernozem region and are a vivid example of soils developing under ext-reme conditions of “resource excess”.

Changes in Molecular Structure of Humic Substances in Cambisols under Agricultural Use

Soil organic matter stability and transformation affected by agriculture is a global problem of great concern. This study aimed to reveal structural changes in humic molecules under conventional soil tillage in Cambisols of the Transbaikal area. Humic acids were isolated from the humus horizons of native and arable variants of Eutric Cambisol Cryic (gleyic, humic, loamic) from the forest steppe, and Haplic Cambisol (arenic, humic, protocalcic) from the steppe zone. The changes in the humic substances’ quality were evaluated by means of an elemental analysis and 13C nuclear magnetic resonance spectroscopy. The results indicate that different agronomic management affected the changes in the composition and molecular structure of humic acids. Soil tillage induced an increase in the carbon content, the proportion of aromatic compounds and carboxyl groups and the depletion in nitrogen. As measured by 13C NMR spectroscopy, the intensity of these changes was determined by soil properties and the hydrothermal regime. Organic matter from Eutric Cambisol Cryic was suggested as providing significant environmental resistance to the agricultural impact due to the optimization of the water regime and a loamy texture. Prolonged ploughing of sandy Haplic Cambisol under the arid conditions promoted deep changes in the humic substances’ composition and chemical structure.

Effectiveness of mycorrhizal inoculants on sweet potato (Ipomoea batata) in Eutric Cambisol soils of Cuba

Introduction. The effective use of mycorrhizal inoculants is a challenge for Cuban agriculture. Sweet potato is an important crop for human and animal nutrition, being a mycorrhizal dependent crop with a successful breeding program. Objectives. To know if all sweet potato cultivars respond to inoculation and if its effectiveness varies with cultivars and growing seasons. Materials and methods. Two experiments were carried out during 2010 - 2012 on Eutric Cambisol soils from Villa Clara, Cuba. One at each planting time and repeated twice. The response of 17 cultivars to three inoculants application in the presence of a half dose of fertilization, and three non-inoculated treatments with fertilization levels of 0, 50, and 100 % of nitrogen, phosphorus, and potassium dose (100 % NPK) was evaluated, using a split plot design. Edible root yields, mycorrhizal colonization frequency and spores were evaluated as response variables. Results. Cultivars responded positively to inoculation and fertilization, showing differences in their yields, however, highest yields were always found when inoculated with Rhizoglomus irregulare/ INCAM-11, which were higher (p<0.05) than those obtained when receiving only 50 % NPK dose. In the rainy season with higher yields, the differentiation between inoculants was higher and in thirteen and nine of the cultivars, the yields obtained with INCAM-11 were higher (p<0.05) than those obtained with Glomus cubense/ INCAM-4 and with 100 % NPK respectively. In the low rainy season, no significant differences were found between yields obtained by inoculating INCAM-11 or INCAM-4 or applying 100 % NPK. In both seasons, inoculation with Funneliformis mosseae/ INCAM-2 was always lower. Colonization frequencies and spore production were always higher (p<0.05) when inoculating INCAM-11. Conclusion. Under these soil conditions, INCAM-11 inoculation presented better effectivity for all cultivars and planting seasons originating the highest yields and indicators of mycorrhizal performance.

Assessment of Soil Resistance to Contamination by Platinum Nanoparticles by Biodiagnostic Methods

Soil contamination with platinum nanoparticles is reproduced at a rapid rate, primarily because of the operation of vehicles with platinum exhaust gas converters. Already present on the territory with a concentration of platinum in the soil of more than 2 mg/kg, which is the maximum background content of 750 times. At the same time, the environmental risks of the adverse impact of platinum nanoparticles on the soil are practically not studied. The purpose of this work is to assess the consequences of different buffering capacities of soils to contamination with platinum nanoparticles in terms of biological parameters. Laboratory studies of soil resistance to pollution with platinum nanoparticles (PtNP) in the South of Russia were carried out, and their genetic properties were compared: Ordinary Chernozem (Haplic Chernozem (Loamic)), Brown Forest Soil (Eutric Cambisol), and Gray Sands (Eutric Arenosol). PtНЧ concentration studies 0.01, 0.1, 1, 10 and 100 mg/kg. Soil stability is assessed by the most sensitive and informative biological indicators of the state. It was found that the low content of PtNP (0.01, 0.1 and 1 mg/kg) in most cases does not lead to following the analysis of the biological state of the soil, and higher concentrations (10 and 100 mg/kg) lead to biological indicators. Soil enzymatic activity under PtНЧ contamination was inhibited to a lesser extent than phytotoxic and microbiological indicators. Common chernozem caused greater penetration to PtNP contamination than brown forest soil and gray sands. The results obtained were used to predict environmental risks in case of pollution of paid soils and to develop maximum allowable concentrations of platinum in soils of different buffering capacity.

Using Water Stable Isotopes and Cross-Correlation Analysis to Characterize Infiltration of Precipitation through Unsaturated Zone at the Velika Gorica Site of Zagreb Aquifer

The unsaturated zone plays a crucial role in the hydrological cycle and is a key factor in modeling and understanding hydrological processes. It regulates water transfer from the land surface to the groundwater while providing protection, transfer, and attenuation of potential groundwater contaminants. This research presents the first results of continuous in situ monitoring of all soil horizons of the Eutric Cambisols and the remaining unsaturated zone of the Zagreb aquifer (Velika Gorica well field). The Zagreb aquifer is the main source of potable water for the inhabitants of the City of Zagreb and Zagreb County, which is protected by the Republic of Croatia. Cross-correlation analysis and water stable isotopes (δ2H and δ18O) were used to investigate whether there is a hydraulic connection between precipitation and groundwater, the approximate duration of percolation, and whether there are indicators that suggest the presence of preferential flow or processes such as water mixing and/or evaporation. The cross-correlation analysis showed and confirmed the assumption of the presence of preferential flow with average lag times ranging from 1.59 up to 3.63 h. The results also indicate that low organic matter content may contribute to higher lag times associated with precipitation infiltration. It was found that only high-intensity precipitation events allow effective infiltration, and that the amount of infiltration depends on the water content of the soil at the beginning of each precipitation event. The isotopic results showed that the isotopic composition of the soil water in the first three soil horizons follows the one of precipitation, while deuterium excess confirmed that the sampled water is mobile water and that an evaporation process is possible in the A horizon. The results also show that suction cups can be used to determine the isotopic signature of both bulk and mobile water, depending mainly on the granulometric composition of the material in which they are installed.

Phosphorus hotspots in pedogenic carbonate coatings determined by zoned microscale arrangement and organo-mineral interactions

Subsoils of calcareous soils are often characterized by pedogenic carbonate precipitates coating soil aggregate and rock surfaces. Numerous studies identified the key mechanisms of pedogenic carbonate formation in calcareous soils. Still, little is known about the ecosystem function of carbonate precipitates for nutrient supply, their microscale structure and the interaction of microscale structure with nutrient distribution such as P. We investigated the mineral composition and P speciation of lithogenic carbonate coated by pedogenic carbonate precipitates. Subsoil horizons of a Rendzic Leptosol (Tuttlingen, C horizon) and a Eutric Cambisol (Benediktenwand, BC horizon) in Central Europe were sampled. We combined wet-chemical methods with X-ray diffraction, synchrotron-based P XANES spectroscopy, and specific surface area analysis (N2-BET). To investigate the spatial arrangement and elemental distribution at the microscale, a complementary approach using light microscopy, scanning electron microscopy with energy dispersive x-ray spectroscopy (SEM-EDX) as well as XANES spectroscopy at the microscale (µXANES) was conducted. In both soils, the pedogenic carbonate coatings showed an intricate porous microstructure and large specific surface area. The δ13C values of the coatings were halfway between those of the primary bedrock and soil organic matter (SOM), proving their formation by re-precipitation of dissolved carbonate through organic and inorganic (H2CO3) acids. Compared to the primary rocks, the coatings were enriched in Al, Fe, Mn, and K and in organic C, N, and P; additionally, they contained silicate minerals (muscovite, illite) and quartz. Whereas the P in the rock interior was mainly present as apatite, the P in the coatings was mainly organic P bound to Ca and Al minerals. NanoSIMS and µXANES analyses at Tuttlingen revealed a zoned microstructure of the pedogenic coating: An inner zone with most P co-localized and bound to Al minerals and an outer zone enriched again in Ca and SOM. The formation of these zones indicates the infiltration and residual accumulation of Al minerals which may contribute to mitigate P losses by leaching. Intensive penetration by fine plant roots and observations of fungal hyphae within the coatings indicate the potential of pedogenically altered carbonates as microbial habitat and ecosystem nutrient source, thus contributing to the scarce ecosystem P nutrition of initial calcareous soils.

The coupling between iron and carbon and iron reducing bacteria control carbon sequestration in paddy soils

The coupling between iron (Fe) and carbon (C) and the activity of Fe reducing bacteria (FeRB) can strongly affect C sequestration in paddy soils. Although the geochemical cycling of C and Fe has been reported at individual sites, a lack of information exists across soil types and regions. In this study, we investigated the coupling of Fe-C and the role of FeRB across five contrasting paddy soils, which account for 60 % of China’s rice cultivation area: Haplic Solonchaks (SCh), Calcaric Fluvisols in Henan (FLc1) and in Tianjin (FLc2), Cumulic Anthrosols (ATc), and Eutric Cambisols (CMe). ATc and CMe were in oxidizing environments and contained significantly higher Fe (III), free Fe oxide (Fed), amorphous Fe oxide (Feo), and organic matter complexed iron oxides (Fep) than SCh, FLc1, and FLc2 which were in reducing environments with higher relative abundance of FeRB. Nonmetric multidimensional scale analysis (NMDS) demonstrated the variability of FeRB in different soil types (r = 0.928, P = 0.001). The higher Fe-soil organic carbon (Fe-SOC) in CMe (2.27 g kg−1; 2.72 g kg−1) and ATc (1.32 g kg−1; 1.6 g kg−1) was likely due to the complexation of Fe (III) and its oxides within SOC and minimal dissimilatory Fe reduction. The existence of the “iron gate” in ATc and CMe also revealed the inhibitory effect of low quantities of Fe (II) on phenol oxidase (PO) enzyme activity and SOC mineralization. According to canonical correspondence analysis (CCA), our study indicates the importance of DOC aromaticity as characterized by UV light absorption at 254 nm (SUV254) (16.6 %), Fed (10.9 %), Feo (9.2 %) to FeRB. Moreover, the structural equation model (SEM) further revealed that SOC and DOC were regulated by PO activity, Fe, and FeRB (χ2 = 7.002, P = 0.536). Our study highlights the importance of soil characteristics on Fe-C coupling in the biogeochemical cycle through interactions among Fe morphology and microorganisms via different oxidation–reduction conditions.

VITICULTURE IN SERBIA/ROMANIAN BORDER ZONE

Total length of the Republic of Serbia border is 2351.8 km, from which border zone length between Republic of Serbia and Romania is 546.5 km. According to wine-growing areas zoning in the Republic of Serbia, three wine-growing areas are defined: Central Serbia, Vojvodina and Kosovo and Metohija. Vojvodina area in the border zone include South Banat region with two sub-regions: Vršački and Belocrkvanski, while in Central Serbia area, also in the border zone, there is Mlava Region with three sub-regions: Braničevsko, Požarevačko and Resavsko and region of Negotinska Krajina with four sub-regions: Ključko, Brzopalanačko, Mihajlovačko and Negotinsko. In South Banat region, under vineyards are 1730 ha, of which is 1567 ha under wine and 163 ha under table varieties. This region is characterized with flat landscape dominated by the Vršac Mountains in central part. The dominant soil types are vertisol and chernozem. Grape and wine production is characterized by small family farms with high-intensive plantations. In varietal composition are dominant international and new created white wine varieties such as: Sauvignon blanc, Semyon, Riesling white, Riesling Italien, Chardonay, Kreaca, Muscat otonel, Rkaciteli, Smederevka and Župljanka, and from red wine varieties: Pinot noir, Portugizac and Limberger. In Mlava region under vineyards are 814,7 ha. Dominant are wine varieties. In this region climate is specific under natural borders: Carpathian mountain system and Danube, Mlava and Pek river. This region is characterized with both, traditional and modern grape growing technology. The region of Negotinska Krajina is located in east part of Serbia and cover area of ​​978 ha, from which is 890 ha are under wine and 88 ha under table varieties. Climate conditioned of this region is affected by the Carpathian mountain system and Danube river. Vertisol, eutric cambisol and sandy soils are present in most vineyards. The region of Negotinska Krajina is characterized with traditional grapes production at small family wineries. This region is famouse by autochthonous varieties: Prokupac, Bagrina, Tamjanika crna, Začinak, Smederevka and Plovdina.