Search

The Neretva River Delta is one of the most vulnerable coastal areas to soil salinization as a result of climate change, especially sea level rise and seawater intrusion. In 2020, as part of the DELTASAL project (funded by the European Union - European Regional Development Fund), on location Vidrice frequency-domain soil sensors (FDR) were installed at four depths from 25 cm to 1 m monitoring soil temperature, water content, and soil electrical conductivity (ECb) at high temporal resolution. The objective of this work was to assess the seasonal variation of soil ECb considering irrigation and rainfall in mandarin orchards in 2021. During the irrigation season, the mean value of water EC used for irrigation was 2.1 dS m-1 with a maximum value of 2.6 dS m-1 (August). Prior to the irrigation season (January- June), ECb values were stable at all horizons because most salts leached before January 2021 (475 mm of precipitation fell from October 2020 to January 2021). More significant changes in ECb occurred during and especially after the irrigation season. Mean values of ECb before the start of irrigation were 2.4 dS m-1 (25 cm), 3.5 dS m-1 (50 cm), 4.0 dS m-1 (75 cm), and 4.9 dS m-1 (100 cm). After irrigation started, only the mean value of the first horizon was higher than before irrigation (3.2 dS m-1). The most important observation was that the maximum values of ECb changed from 3.2 dS m-1 to 4.9 dS m-1 in the first horizon and from 4.0 dS m-1 to 5.2 dS m-1 in the second horizon. Although the results presented cover only one season, they demonstrate the importance of monitoring soil salinity in irrigated coastal areas, especially for sensitive crops such as citrus, where elevated salt concentrations can lead not only to yield losses but also to more serious consequences such as permanent soil degradation.

In 2019, wheat was grown on 141, 602 ha in the Republic of Croatia, making it the second most widely grown crop. The success of cultivation depends not only on the yield, but also on the quality of wheat grains. The specifi c eff ects of climate change can be seen in the variation of grain yields and quality even in growing areas that have traditionally had stable production. In this sense, insuffi cient crop water supply and pest infestations, especially in sensitive phenophases, are the most pronounced threats to production stability. Adapted varieties in terms of drought and pest sensitivity, as well as early detection of stress indicators, are important for wheat production management. Proximal and remote sensing are tools whose potential for early detection of stress indicators is increasingly being exploited in many crops. Proximal sensing using a spectroradiometer in the wavelength range of 350 to 2500 nm is being conducted on experimental crops of fi ve wheat cultivars in the cereal breeding program at two locations in diff erent phenophases. This Summary represents an ongoing study using spectroradiometric methods to detect and evaluate the eff ects of two types of stress in w. wheat crops. Chemometric analysis of spectral response patterns is used to isolate specifi c spectral bands that indicate early signs of stress. The spectroradiometric method will allow the developed spectral vegetation indices to be tested as indicators of the condition of fi ve w. wheat cultivars.

Metal contaminated soils (MCS) are raising global issue which threats human and environmental health and safety. A controlled pot study was performed to investigate the effect of two different wood- derived bioash types (fly - FA and bottom – BA from cogeneration biomass plant) at 1% and 4% w/w rates on: i) release of metals from the MCS matrix (collected near a former mine and metallurgical plant in the town of Zerjav, Slovenia) and ii) their chemical speciation in the water leachate 175 days after the incubation period. The highest pH reaction (7.13), electrical conductivity (EC 27.3 dS/m), Pb (1.40 mg/L), Cd (0.96 mg/L) and Cu (0.18 mg/L) concentration in water percolates were detected in FA 4% treatment. In addition, the lowest pH reaction (6.52) followed by the highest Zn concentration (0.95 mg/L) were found in the water percolates from the Control (MCS without bioash addition) treatment. Chemical speciation modeling performed in Visual Minteq software using the NICA-Donnan approach indicated that all examined metals (Cd, Cu, Pb and Zn) were dominated in all water leachates (including the MSC control without bioash treatment) exclusively as organo- complexes, oscillating among humate and fulvate pools. The most toxic free metallic forms (of Cd and Zn) and chloro-complexes (of Cd) were present in negligible portions (

Urban soils require special attention, either due to various ways of environment usage, the large number of pollution sources or other types of soil quality degradation. Soil pollution in urban environments depends on the type of pollutant, intensity of soil exploitation and environmental conditions. It ultimately affects human health through direct intake through the skin, respiratory or gastrointestinal tract. Therefore, it is important to recognize in time possible threats caused by polluted urban soils, but as well to suggest best practices to sue such soils according to the quality indicators. Urban soils' quality monitoring programme in Zagreb commenced in 2015 and is still ongoing. During 2021 activities of the Programme included soil sampling at 30 urban locations where during 2015. high levels of potentially toxic elements (i.e., higher than the maximum allowed concentrations according to Croatian government regulation on the protection of the agricultural land from pollution) were recorded. Soil analyses included measurements of main chemical properties and trace elements. Results were compared with available governmental data, but as well Central Croatia soil data, soil worldwide and average continental crust composition. Furthermore, soil quality was evaluated using statistical analyses and geostatistics. Results show that although concentrations of some metals (Cd, Cr and Cu) decreased, others (Hg, Ni, Pb and Zn) are still above legally set maximum values.

Although the problem of sea intrusion and salinization of surface and groundwater, and thus the risk of land degradation, occurs throughout the coastal area of Croatia. The objective of this paper was to investigate and compare two different soil monitoring approaches, classical long-term monitoring and monitoring using automatic soil sensors at two locations in Neretva River Valley. For SMS1 mean values for EC were similar both in long-term and automatic sensor monitoring. At SMS2, mean EC value obtained by the sensors was higher compared to long-term monitoring. Variation coefficient on SMS1 vas low in both monitoring approaches indicating low soil EC varibality in the profile. On the other hand, variation coefficient was high at SMS2 especially in the long-term monitoring indicating high soil EC variability in the profile.

Pesticides often become emergent chemicals in aquatic systems shortly after application. As one of the widely used broad-spectrum herbicides, terbuthylazine (TBL) has been frequently detected in all types of natural waters. TBL is a lipophilic compound that tends to adsorb to organic matter in soil and has a high runoff potential to surface waters, where it dissipates very slowly under natural conditions. To date, remediation of TBL-contaminated surface waters has relied on challenging and variably effective processes such as physical adsorption to activated carbon, photocatalytic degradation by titanium oxide, ozonation, and bioremediation. Therefore, there is an economic need to explore the effectiveness of remediation of contaminated matrices using less expensive agents, especially industrial by-products such as biomass ash. In- depth characterization of wood fly ash (FA, from a modern cogeneration power plant facility), using state-of-the-art in situ approaches (Scanning Electron Microscopy, X-ray diffraction) raised the hypothesis that highly developed nano- microstructure and alkaline Ca/Mg/Si-enriched mineralology of FA could be effectively used for removal of TBL from the watercourse. This study showed that FA addition at 1% w/v rate to the watercourse sample reduced the half-life of TBL from 14 days to 9 h vs. the control (distilled water) treatment. TBL was not detected in the alkaline (pH 12.4) treatment 48 h after the addition of FA, while in the control TBL remained at nearly 80% of its initial amount. These results show a promising starting point for the development of novel FA-based polymers, targeted for decontamination of aquatic ecosystems loaded with TBL and similar contaminants.

In Croatia soil monitoring is a legal obligation comprised of monitoring not just the soil, but as well other environmental media, primarily water and air. However, monitoring of urban soils' quality is more complex because of the diverse soil usage. In Zagreb, soil monitoring is associated with sustainable drinking water supply, health aspects of direct intake, proximity to landfills or sources of industrial pollution, food production in urban areas, recreational and sports areas, and aesthetic effects in city parks due to contamination or salinization of the soil along roads. Thus, urban soils' quality monitoring programme in Zagreb commenced in 2015. Within the programme 150 soil samples were collected throughout the city along pre-determined transects, 36 soil samples from 3 localities located near landfills or sources of industrial pollution, and 20 soil samples at 2 localities near high frequency roads. Main chemical soil properties, trace elements, PAH and PCB were determined. The values obtained were compared with available data from Croatian government regulation on the protection of the agricultural land from pollution, as with Central Croatia soil data, soil worldwide and average continental crust composition. Furthermore, soil quality was assessed by applying statistics and geostatistics. TEs and PAH deviate from baseline concentrations, while distribution of the trace metal concentrations interpreted as anthropogenically polluted and/or naturally enriched soil.

Biomass-fuelled facilities generate alkaline and mineral-/nutrient-enriched co-product (ash) that has to be appropriately managed, and preferably reused. The assumption that wood biomass fly ash (BFA) could be used in chemical amelioration of soil acidity and fertility was tested by: i) physicochemical charac terisation of BFA and ii) bioassay with maize grown in acidic (pHKCl 4.68) hydromorphic soil amended with BFA (0e10% w/w). Scanning electron microscopy with energy dispersive X-ray spectroscopy and X ray diffraction revealed non- homogeneous (ir)regular spherical/porous agglomerated particle morphology and distinctive distribution of Si-/Ca-/K-based minerals, while secondary ion mass spec trometry, for the first time, confirmed their isotopic (six Ca, three Si/Mg and two K isotopes) diversity. BFA addition strongly shifted soil pHKCl (up to 9.1), raised salinity (by > 8.2-fold) and the content of most phytonutrients (up to 5.4-fold) ; however, BFA amendments at >1.25% restricted the maize root and shoot growth, likely due to alkaline stress as indicated by necrotic/chlorotic symptoms at >5.0% rate. The BFA amendments increased total concentration of metals in soil (without exceeding the levels recognised as contamination) ; however, phytoextraction of Cd, Zn, Mn, Cu and Mo was significantly supressed (Cd by almost 12-fold), confirming that BFA improved soil-plant metal immobilisation, shifting rhizosphere biogeochemistry towards chemisorption/precipitation reactions. Even though results revealed a strong liming and PeKeCaeMgeZneMneCu enrichment potential of BFA, to avoid possible negative envi ronmental implications (saline/alkaline stress, metal contamination, adverse effects on soil microbiome), quantitative and qualitative ex ante evaluation of the BFA/soil matrix combinations is essential before application to ameliorate suboptimal (acidic, low-nutrient) or metal-contaminated soils

Cities throughout Croatia are turning to urban gardening thereby providing low-cost agri- products, social interactions and healthier lifestyles. The City of Zagreb started the Urban Gardens project in 2013, and today it has a total of 13 urban gardens, all included in urban soils quality monitoring programme aiming to prevent harmful effect of potentially toxic elements in the soils of urban gardens. Therefore, as part of the latter project, the quality of soil (pH, EC, P2O5, K2O, Corg, Cd, Cr, Cu, Hg, Ni, Pb, Zn, PAHs and PCBs), irrigation water (pH, EC, NH4-N, NO3-N, NO2-N, PO4-P, Cl-) ; vegetable crops (dry matter, Ca, Fe, K, Mg, Na, P and S) is being tested. The monitoring sites were spatially referenced using GPS and the results were stored in different GIS layers. The results were examined applying uni- and multivariate statistical analyses. Large differences of soil quality and fertility indicators were found between, but also within each urban garden. Such variations of soil quality are result of combination of inherent soil state and recent agricultural practices. Despite the wide concentration range of some soil TE and PAH concentrations, they do not exceed maximal permissible concentrations as defined by the Croatian government regulation. Furthermore, results of water quality analysis showed that there is no limitation to use groundwater for irrigation. Also, macro- and micronutrient concentrations determined in vegetables are within the recommended ranges for healthy plants.

Adaptation measures to climate change demand developing an advanced system for monitoring, predicting and reporting on the state on various ecosystems. This especially refers to river valleys, estuaries and deltas that are predominantly used for agriculture and at the same time are at high risk of various degradations due to climate change. In order to control risks, it is important to obtain spatially and temporally articulated data on soil quality. Although the problem of seawater intrusion and salinization of surface and groundwater occurs in all of the Croatian coastal areas, hence increasing the risk of soil degradation, these processes are most evident in the area of Neretva river delta which is considered one of the most vulnerable areas to climate change in Croatia. To assess soil salinity risk in this area, seasonal soil monitoring was set (from 2009-now) with sampling campaigns at the end of the dry/wet season. In 2020, the soil monitoring network was upgraded with frequency domain sensors (FDR) to continuously record changes in soil. The aim of this research was to asses soil salinity dynamics taking into account different monitoring approaches and different temporal resolution of data collecting. Two soil monitoring stations (SMS) have been set up at two different locations with a pronounced risk of salinization in Neretva river delta. Two SMS differ regarding depth of gleyic horizon, soil texture, organic matter content, salinity level and land use: SMS1 vegetable production, SMS2 citrus orchard. At each monitoring station extensive characteristisation of soil physical and chemical characteristics was conducted. Frequency domain sensors measuring bulk electrical conductivity (ECb) were installed at 4 different depths (0-25 cm ; 25-50 cm ; 50-75 cm ; 75-100 cm) with 10 minutes measuring interval. Within the research area an automated weather station was installed (Pinova Meteo weatherstation) to record precipitation and other relevant meteo data. According to the long term seasonal soil monitoring in the wet season the soil was non saline at SMS1 with average value of 1, 06 dS/m and slightly saline at SMS2 with average of 3, 17 dS/m. Maximum values recorded with this type of monitoring were 4, 79 dS/m at SMS1 and 4, 95 dS/m at SMS2 respectively. FDR salinity monitoring was set at the beginning of November 2020 and in this paper data for the first 70 days of monitoring were analysed. Within this time frame at SMS1 (1 m depth) average ECb was 2, 86 dS/m with an absolute maximum value of 6, 38 dS/m (50-75 cm). Average ECb at SMS2 (1 m depth) was 4, 07 dS/m with absolute maximum of 6, 21 dS/m (75-100 cm). Higher coefficient of variation of ECb was recorded at SMS1 in all horizons in regard to SMS2 where ECb variation was very low, raging from 3, 7 % (75-100 cm) to 14, 06 % (0-25). Highest coefficients of variability at SMS1 were recorded in horizon 75- 100 cm (44, 79 %) and 0-25 cm horizon (41, 32 %) indicating high soil salinity variation. However SMS2 which had higher ECb in each horizon displayed temporal stability with average coefficient of variation of ECb up to 1 m of 10 %. At SMS1 average coefficient of variation was over 33 % showing temporal instability of ECb. It is important to emphasize that this is an initial set of data and firm conclusions about the dynamics of salinization cannot yet be made but they suggest the importance of developing site specific soil salinity mitigation actions.

In a conventional agriculture extensive use of pesticides is considered necessary to improve crop production but at the same time it can have negative effect on soil and water quality. One of the commonly used chemical in vineyards is glyphosate, a broad-spectrum, post emergence, non-selective herbicide with low mobility in soils due to its strong sorption. However, due to different transport processes present in environment it can still be transported to surface or groundwater resources. The main objective of this study was to evaluate glyphosate mobility at two contrasting vineyards in terms of soil properties and landscape position. Two locations were selected for the field trial: Baštica located on the flat coastal terrain (sandy soil), and Jazbina located on a hillslope terrain characteristic (clay soil). At both field sites, zero tension lysimeters were installed and water balance components monitored throughout the year. Undisturbed soil columns were taken from both sites and used to estimate mobility of pesticides by applying irrigation and a known dosage glyphosate (optimum field quantity) in a controlled environment. Water samples from lysimeters and leachate from soil columns were taken periodically and analyzed for active substances. In addition, soil samples were taken, and initial pesticides concentrations were measured, as well as the soil sorption capacity at each site. First results indicate that the sorption coefficient (Kd) was the main process limiting pesticide mobility in soil. Both soils have high capacity to adsorb glyphosate by the soil particles and organic matter present in the soil surface layer with Jazbina location having larger values as expected due to its higher clay content. It can be concluded that the possible losses of pesticides through surface runoff (e.g. colloidal transport) or by soil water preferential flow pathways are present with respect to different environmental condition at each site.

Soil portfolio is one of the ultimate viticultural considerations when planting grape vines. However, soil composition is also a crucial determining factor for agrochemical transfer to fresh/groundwater resources as a result of chemical-soil particle interactions. Adsorption coefficients are known to be the most sensitive parameters used for water pollution risk assessment. Therefore, adsorption interactions should be studied in as many soil composition as possible scenarios and the adsorption data should be considered with certain physical and chemical pedovariables in order to predict the mobility of agrochemicals down the soil profiles. Glyphosate is one of the most frequently used herbicides in a wide range of cropping, notably in vineyards, for broad- spectrum control of weeds. This study presents the glyphosate adsorption parameters and their variation considering the soil composition in different agroecological conditions. The batch- sorption experiments were performed in two different vitisols of the continental (texture- heavier) and Mediterranean (texture-lighter) part of Croatia. Soil samples from both vineyard locations were collected at four depths from 0 to 100 cm and characterized on certain chemical/physical variables. Soil composition differed between the studied soil layers. Glyphosate was extracted from aqueous phase of soil suspensions by solid-phase extraction procedure using a weak anion exchange sorbent. Derivatization was performed prior to GC-MS analysis with a mixture containing trifluoroacetic anhydride and trifluoroethanol. The analytical results were well fitted to the Freundlich sorption isotherm. Glyphosate adsorption in soils from both origins corresponded to the L-type of isotherm, while glyphosate adsorption intensity was generally higher in heavier silty-clayic vs. lighter sandy- silty soil profiles. The glyphosate adsorption intensity was correlated with selected soil properties (pH, organic matter content, particle size distribution, conductivity, P/K content) and the glyphosate mobility through soil profile was considered.

South and southwest hillslope terrains are favorable areas for vine cultivation, but because of the slope they are susceptible to erosion and surface runoff, especially after intensive precipitation. The study was conducted at the Jazbina experimental station located in Zagreb County (UniZG Faculty of Agriculture, Department of Viticulture and Enology), with a pronounced slope (~20 %) and inter-row grass mulch practice. Surface runoff collectors were set up in the inter-row of the 20 years old Pinot Blanc vineyard, where phosphorus, potassium, copper sulfate and herbicide (glyphosate) were applied. Data were acquired from the automatic meteorological station (Pinova), and in addition to the natural precipitation, different intensity precipitation events were simulated as well. Immediately after precipitation, volume of surface runoff was measured and samples taken for the analyses in an accredited laboratory (MELILAB, UniZG Faculty of Agriculture, Department of Soil Amelioration) and at the Institute for Medical Research and Occupational Health (Zagreb). Results confirm that at the investigated vineyard terrain precipitation intensity significantly affects surface runoff, as well as its chemical composition, i.e., herbicide and macro/microelement concentration. To prevent negative (agro)ecological impacts (e.g., surface and/or groundwater pollution), agrochemicals in vineyards should be applied in accordance with the sustainable agriculture guidelines.

Vineyard fertilization practices is an important part of managing a vineyard since it impacts on vine growth, crop yield and wine quality. However, there are concerns about the of-site impacts of vineyard nutrient losses (especially of N and P) on the water quality standards. This research was carried out in two vineyards chosen as study plots (SP) for their heterogeneous pedological and climate characteristics: (SP1) located in the coastal wine-growing region, prevalent soil type is hydroameliorated- pipe drainage regosol and (SP2) located in the continental wine-growing region, prevalent soil type is Rigosol from Pseudogley of sloping terrains developed on Pleistocene loam and Pliocene clay substrata on a hillslope terrain. The physical and hydrologic characteristics of the soils were determined from soil samples collected from both SP. Lysimeters were installed at both SP and undisturbed soil columns taken from both locations for the assessment of nitrate and phosphate downward mobility through the soil profile by applying irrigation and a known nutrients concentration (in correspondence to the applied agricultural practices). Water samples from lysimeters and leachate from soli columns were taken periodically depending on rainfall occurrence and analyzed for nitrate, nitrite, ammonium and phosphate concentrations. The SP1 generated more intensive drainage and higher nutrient leaching than the SP2. This study demonstrates that the risk of nutrient leaching from each SP is a combination of factors associated with the soil texture, infiltration rate, field capacity. Still, the possibility of nutrients losses from vineyards soils through the erosion, surface runoff and subsurface leaching will be further studied.

Extensive use of pesticides in a conventional agriculture although necessary to improve crop production, may at the same time pose a threat to soil and water quality. Two main active substances were in focus of this research: glyphosate (broad-spectrum, post emergence, non-selective herbicide) and cypermethrin (synthetic pyrethroid insecticide), both commonly used in vineyards. Two locations were selected for the field trial: Baštica located on the flat coastal terrain, and Jazbina located on a hillslope terrain characteristic for vineyard production in the continental part of Croatia. At both field sites, zero tension lysimeters were installed and water balance components monitored throughout the year. Undisturbed soil columns were taken from both sites and used to estimate mobility of pesticides by applying irrigation and a known dosage of both pesticides (optimum field quantity) in a controlled environment. Water samples from lysimeters and leachate from soil columns were taken periodically and analyzed for active substances. In addition, soil samples were taken, and initial pesticides concentrations were measured, as well as the soil sorption capacity at each site. First results indicate that the sorption coefficient (Kd) was the main process limiting pesticide mobility in soil. Both pesticides have high capacity to be adsorbed by the soil particles and organic matter present in the soil surface layer. Thus, the possible losses of pesticides through surface runoff (e.g. colloidal transport) or by soil water preferential flow pathways will be further studied.

Nitrogen fertilizers, which cannot be completely absorbed by plants, are frequently used on agricultural soils in large amounts, and therefore leaching, usually closely linked with the soil water flow, is likely to occur. As computer models are becoming more important in the assessment of groundwater pollution, the objectives of this research were to assess water flow and nitrate transport in gley soils and to validate the HYDRUS-1D model based on the collected field data from lysimeters installed at the Biđ field (12 lysimeters at 6 locations). Extensive measurements of soil physical properties, lysimeter outflow and nitrate concentration were performed and coupled with the climatic data and collected information about the crop rotation and fertilizer application. The results confirmed good reliability of the model that fit the observed lysimeter water outflow and nitrate dynamics during 2014-2016 period. Increased nitrate concentrations were mostly observed during the period without crops, or during the winter/spring period with a large amount of rainfall. The results suggest that groundwater nitrate concentration may significantly increase due to agricultural practices, even in soils with heavier texture. The results also show that the tested model can be used as a tool for the prevention of groundwater pollution by indicating optimal application of different fertilizer (amount, timing, type).

Various agrochemicals are commonly used in vineyard production and even if metals are not their active component, trace amounts still may be present in their composition. However, copper (Cu) is the main active ingredient in a range of chemicals frequently used in vineyards and Cu concentrations in the topsoil may progressively increase. Thus, estimation of Cu mobility in soils may prove as an important component of monitoring vineyard soils quality. Field trials are conducted on two locations: (i) on the flat coastal terrain (Baštica) and (ii), on a hillslope terrain of the Croatian continental part (Jazbina). Lysimeters were installed at both field sites and undisturbed soil columns taken for the assessment of Cu downward mobility through the soil profile by applying irrigation and a known metal concentration. Initial Cu concentrations were determined in soil samples from both sites. Water samples from lysimeters and leachate from soil columns were taken periodically and analyzed for Cu concentrations ; with the distribution of major Cu species estimated using chemical equilibrium software. Results indicate that the sorption and complexation processes with soil organic matter may be the major factor controlling Cu mobility in vineyard soils. Still, the possibility of Cu transfer in a form of complexes with organic ligands (e.g. dissolved organic carbon) through the soil profile by soil water preferential flow pathways and/or through surface runoff will be further studied.

Nitrogen fertilizers are frequently used on agricultural soils in large amounts which cannot be completely absorbed by plants and therefore leaching, which is usually closely linked with the soil water flow, is likely to occur. As computer models are becoming more important in the assessment of groundwater pollution, the objectives of this research were to assess water flow and nitrate transport in gley soils and to validate HYDRUS-1D model based on collected field lysimeter data installed at the Biđ field. The field data was collected at 6 location (12 lysimeters) which included extensive soil physical properties measurement, lysimeter outflow and nitrate concentration, climatic data, cropping rotation and fertilizer application information. The results confirmed good reliability of a model to fit the observed lysimeter water outflow and nitrate dynamics during 2014 – 2016 period. Increased nitrate concentrations were observed mostly during the period without crop or during winter/spring period with a large amount of rainfall. Results indicate that agricultural practices may have a significant role in groundwater nitrate contamination, even in soils with heavier texture. Additionally, tested model can be used as a tool in prevention of groundwater pollution by enabling the optimization of application (amount, timing, type) for different fertilizer.

Joining to EU Croatia, based on the Directive 2009/28/EC on the promotion of the use of energy from renewable sources (ERS) was overtaken obligation to increase national usage of ERS by 2020 to 20% in gross consumption, and accordingly 2013 was adopted National action plan for ERS. Within the scope of that plan, Croatia financially supports construction of electric/heating power plants which use agro/forestry biomass, as one of principal and important ERSs. Annually in Croatia has been running several plants based on biomass, which generate ash material as an important by-product that has to be managed (used) properly. By the chemical properties ash from biomass is extremely alkaline (pH>12) and rich by phyto-nutrients (P, K, Ca, Mg) as well. Great portion of agricultural land areas in Croatia, i.e. globally is quite acidic (pH