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In this study, we investigated the influence of pedological parameters and variation of altitude on the mineral nutrients, phenolic compounds, and antioxidant activities of olive leaves. Samples of the Chetoui cultivar were collected from eight geographical locations with different altitudes. Levels of phenolic compounds varied according to the altitude. Classification of the locations revealed that altitude 1 (>500 m) was characterized by high levels of secoiridoids and simple phenols, while altitude 2 (500–300 m) and altitude 3 (

Agricultural waste, which is produced in large quantities annually, can be a threat to the environment. Biochar (BC) production represents a potential solution for reducing the amount of grapevine pruning residues and, accordingly, the impact on the environment and climate change. Biochar produced by the process of pyrolysis from grapevine pruning residues was investigated and characterized to be applied as an adsorbent of polyphenolic compounds with the aim of using the waste from viticultural production to obtain a quality product with adsorption and recovery potential. Standards of caffeic acid (CA), gallic acid (GA), and oleuropein (OLP) were used as polyphenolic representatives. The obtained data were fitted with the Langmuir and Freundlich isotherms models to describe the adsorption process. The best KL (0.39) and R2 (0.9934) were found for OLP using the Langmuir model. Furthermore, the adsorption dynamics and recovery potential of BC were investigated using an adapted BC column and performed on an HPLC instrument. The adsorption dynamics of biochar resulted in the adsorption of 5.73 mg CA g−1 of BC, 3.90 mg GA g−1 of BC, and 3.17 mg OLP g−1 of BC in a 24 h contact. The online solid phase extraction of the compounds performed on an HPLC instrument yielded a recovery of 41.5 ± 1.71% for CA, 61.8 ± 1.16% for GA, and 91.4 ± 2.10% for OLP. The investigated biochar has shown a higher affinity for low-polar compound adsorption and, consequently, a higher polar compound recovery suggesting its potential as an efficient polyphenolic compound adsorbent.

In the Mediterranean basin, the treatment and disposal of olive mill pomace (OMP) remain a salient environmental issue for the olive oil- producing industry. This study assesses the effects of olive-processing technology (three- phase and two-phase systems) on the potential use of OMP as a soil amendment. Samples from 12 Croatian olive mills were analysed for their total phenolic content (TPC), residual oil fraction, and elemental concentration. The samples were profiled using FT-IR spectroscopy and structurally characterised using SEM-EDS. Compared to three- phase samples, two-phase OMP was more acidic (pH 4.5 vs pH 5.0), with a higher TPC (3835 vs 1576 mg/kg f.w.), oil content (11.7 vs 7.5 % d.w.), EC (5.1 vs 3.0 mS/cm), and levels of Ca (1.34 vs 1.20 g/kg d.w.) and Cu (10.4 vs 7.0 mg/kg d.w.). Similar values of C/N (61 vs 72), N (10 vs 8.1 g/kg d.w.), P (1040 vs 691 mg/kg d.w.), and K (13.7 vs 8.1 g/kg d.w.) were observed. The amounts of Cr, Cu, Ni, and Zn were below EC limits in both cases. The EDS mapping revealed that Ca was concentrated at sharp-edged OMP particles while K was evenly distributed, suggesting that pelletized OMP compost is preferable for amending soil to obtain a homogeneous distribution of nutrients. It was also possible to distinguish between OMPs based on oil and lignin absorption bands in their FT-IR spectra. According to the obtained results, composting is recommended for both types of OMP to produce a safe product for amendment purposes.

The addition of compost or biochar to soils is a viable strategy to increase soil organic matter (SOM), especially if the amendments are produced from biomass wastes. The need for sustainable land management without sacrificing agricultural production is critical to alleviate negative impacts on soil quality, including loss of SOM and nutrients. Turning sewage sludge (SS) into compost or biochar can help in lowering its potential negative effects on soil and providing a viable strategy for SS management through its recycling in agriculture. The aim of this study was to evaluate the short-term impact of SS in its composted or biochar form on the fungal and bacterial communities of the Terra Rossa soil by high-throughput sequencing. A greenhouse pot trial was conducted using a 2-factor experiment consisting of amendment type (compost, biochar) and sampling time (Day 0, 30, and 60) as the main factors. The results showed no effect of SS addition on fungal and bacterial species richness, as well as a shift in relative abundance of the fungal phylum Zygomycota and bacterial phylum Firmicutes and Thermomicrobia. Both bacterial and fungal community analyses showed changes when composted sewage sludge was applied. However, only the fungal community differed from the control soil by the end of the 60-day vegetation period of Chinese cabbage.

The potential effect of pre-inoculation of processing tomato (Solanum lycopersicum L.) plants with arbuscular mycorrhizal fungi (AMF) on yield and fruit properties was investigated in conventional production. Tomato seeds were sown in seedling trays filled with a substrate non-inoculated (AMF-) or inoculated (AMF+) by selected mycorrhizal strains. Seedlings were transplanted in Terra rossa soil and grown in conditions with mineral fertilization and irrigation. Tomato fruits were sampled at harvest. Tomato plants under both treatments had high levels of mycorrhizal colonization, due to applied inoculum (AMF+) or indigenous (AMF-) inoculum present in the soil. Applied AMF+ treatment increased P and decreased K content in tomato fruits. Content of trace elements such as As and V significantly increased, while Pb content significantly decreased in the fruits of AMF+ when compared to the AMF- treatment. No significant effect of AMF+ treatment was observed on yield, fruit quality (soluble solids, pH, total acidity, fruit firmness), lycopene and antioxidant activity of tomato fruits. The overall results suggest that processing tomato is highly susceptible to the indigenous AMF, while seedlings inoculation with selected AMF improves only total phenolic and P fruit content. This means that AMF have a potential application in commercial processing tomato production, however a targeted adaptation of management decissions is required for more extensive results.

In recent years, the production and application of biochar as a soil amendment produced from pruning residues has gained attention worldwide. Since the effect of grapevine rootstock type on grapevine-pruning residues used as feedstock for biochar production had not yet been researched, the present research was performed. Two grapevine rootstocks, different in vigor, were selected, with the hypothesis that they would affect their chemical composition and, consequently, the composition of the produced biochar. In this work, grapevine-pruning residues of the indigenous variety “Istrian Malvasia” (Vitis vinifera L.) grafted on 420A and SO4 rootstocks were analyzed and used for biochar production under three peak temperature programs (400 °C, 500 °C, and 600 °C). Higher pyrolysis temperature decreased yield but increased EC, ash, and TC content, as well as the content of most of the studied elements. On the other hand, grapevine rootstock type affected biochar EC, ash content, and specific surface area. Results showed that a more vigorous rootstock affects the produced biochar qualities by enhancing the above-mentioned properties. The present research showed that biochar produced from grapevine-pruning residues, especially at 500 °C or 600 °C, could be a valuable tool for the valorization of this biomass as a soil amendment.

Plant-based fertilizers, such as liquid plant extracts, contribute to the cultivation of vegetables, particularly in organic production. The objective of this study was to determine if aqueous nettle extract could be successfully used as a fertilizer, applied on the soil and foliarly, in green bean production under field conditions. The hypothesis was that it could successfully replace mineral fertilizers and be integrated into sustainable and organic agriculture. The experiment was conducted at two climatically and pedologically different locations (Zadar and Poreč) throughout two growing seasons (spring and autumn). Two types of aqueous nettle extracts were used: a short-term extract (SE) was prepared by the extraction of wild stinging nettle (183 g 10 L−1 of water) in water for 24 h, while a long-term extract (LE) was prepared at the same ratio with water extraction for 14 days. Both extracts were diluted with water at a ratio of 1:3 (extract:water) before use. The SE was applied foliarly, and LE, by pouring it onto the soil. The abovementioned treatments were compared with mineral fertilization with urea (U) and control (no fertilization (C)). Foliar fertilization with SE proved to be almost as efficient as fertilization with LE, poured onto soil, showing a positive effect on green bean vegetative parameters. Furthermore, aqueous nettle extracts showed a positive effect on the iron accumulation in the leaves.

This study evaluated the presence of bioactives in wild nettle leaves and stalks during the phenological stage and in the context of natural habitat diversity. Thus, wild nettle samples collected before flowering, during flowering and after flowering from 14 habitats situated in three different regions (continental, mountain and seaside) were analyzed for low molecular weight polyphenols, carotenoids and chlorophylls using UPLC-MS/MS and HPLC analysis, while the ORAC method was performed for the antioxidant capacity measurement. Statistical analysis showed that, when compared to the stalks, nettle leaves contained significantly higher amounts of analyzed compounds which accumulated in the highest yields before flowering (polyphenols) and at the flowering stage (pigments). Moreover, nettle habitat variations greatly influenced the amounts of analyzed bioactives, where samples from the continental area contained higher levels of polyphenols, while seaside region samples were more abundant with pigments. The levels of ORAC followed the same pattern, being higher in leaves samples collected before and during flowering from the continental habitats. Hence, in order to provide the product’s maximum value for consumers’ benefit, a multidisciplinary approach is important for the selection of a plant part as well as its phenological stage with the highest accumulation of bioactive compounds.

Manganese (Mn) is an essential element that intervenes in several plant metabolic processes. The olive tree, and its fruits and leaves, are known as a source of nutraceuticals since they are rich in biophenols. However, there is still a serious lack of data about biophenolic distribution in olive stems and roots under Mn fertilisation. In this context, our study aimed to examine the effects of Mn fertilisation on the biophenolic profile in the leaves, stems, and roots of the ‘Istarska bjelica’ olive cultivar. The experiment was set up in a greenhouse, during a period of five months, as a random block design consisting of three treatments with varying Mn concentrations in full-strength Hoagland’s nutrient solution (0.2 µM Mn, 12 µM Mn, and 24 µM Mn). The obtained results indicate that the amount of Mn in the examined olive plant tissues was significantly higher under 12 µM Mn and 24 µM Mn treatments compared to that of the 0.2 µM Mn treatment. While the concentration of biophenols varied in roots depending on the compound in question, a strong positive impact of the increased Mn concentration in nutrient solution (12 µM Mn and 24 µM Mn) on the concentrations of the main biophenolic compounds was observed in stems. The concentration of oleuropein in leaves almost doubled at 24 µM Mn, with the highest Mn concentration, as compared to the 0.2 µM Mn treatment. The obtained results led to the conclusion that the supply of Mn could enhance the concentration of some biologically active compounds in olives grown hydroponically, implying a critical need for further investigation of Mn fertilisation practices in the conventional olive farming system.

The effects of different fertilisation treatments with arbuscular mycorrhizal fungi (AMF) inoculation on AMF root colonisation, fruit yield, nutrient and total phenol contents, volatile compound composition, and sensory attributes of tomato (Solanum lycopersicum L.) were investigated. Mineral, organic, and mineral + organic fertiliser application positively affected tomato yield (35%–50%) and phosphorus concentration (24%–29%) compared with controls. AMF application had a significant impact on the total nitrogen (+9%), manganese (+12%), and hydrophilic phenol (+8%) contents in the fruit. Volatile compounds were affected by the interactive effects of fertilisation and AMF application. The response of tomato fruit sensory quality indicators was relatively modest, with only a few sensory characteristics affected to a lesser extent. Although tomato showed susceptibility to field-native AMF, particular combinations of fertilisation and AMF inoculation were more effective at improving the quality parameters of tomatoes under field conditions applied in this study.

This study evaluated the presence of bioactives in wild nettle leaves and stalks during the phenological stage and in the context of natural habitat diversity. Thus, wild nettle samples collected before flowering, during flowering and after flowering from 14 habitats situated in three different regions (continental, mountain and seaside) were analyzed for low molecular weight polyphenols, carotenoids and chlorophylls using UPLC-MS/MS and HPLC analysis, while the ORAC method was performed for the antioxidant capacity measurement. Statistical analysis showed that, when compared to the stalks, nettle leaves contained significantly higher amounts of analyzed compounds which accumulated in the highest yields before flowering (polyphenols) and at the flowering stage (pigments). Moreover, nettle habitat variations greatly influenced the amounts of analyzed bioactives, where samples from the continental area contained higher levels of polyphenols, while seaside region samples were more abundant with pigments. The levels of ORAC followed the same pattern, being higher in leaves samples collected before and during flowering from the continental habitats. Hence, in order to provide the product’s maximum value for consumers’ benefit, a multidisciplinary approach is important for the selection of a plant part as well as its phenological stage with the highest accumulation of bioactive compounds.

'Malvazija istarska' (Vitis vinifera L.) jedna je od najznačajnijih bijelih sorata u Hrvatskoj. Njezina kvaliteta prepoznata je kako u Hrvatskoj, tako i u cijelom svijetu. Stoga se domaći proizvođači sve češće odlučuju za proizvodnju vina i pjenušaca iz ove sorte. Mošt za proizvodnju baznoga vina za pjenušce po svome sastavu trebao bi zadovoljavati svojstva kao što su niža pH vrijednost i sadržaj šećera, te viši sadržaj ukupne kiselosti s većim udjelom vinske kiseline, naspram jabučne. S obzirom da se 'Malvazija istarska' uzgaja pretežito u Istri, gdje je klima mediteranska, a najzastupljenije tlo crvenica teško je zadovoljiti sva navedena svojstva, posebice u suhim i vrućim godinama. Stoga, cilj ovog istraživanja bio je utvrditi mogućnost pozitivnog djelovanja folijarne gnojidbe na navedena svojstva. Pokus je postavljen na sorti Malvazija istarska na podlozi SO4 2013. s četiri gnojidbena tretmana (T1- NPK, T2 - NPK + Agromag 6L (6% MgO), T3 - NPK + Agromag 6L + Fosforo 30L (30% P2O5) i T4 - NPK + Agromag 6L + Fosforo 30L + Bio Prot) u tri ponavljanja po slučajnom bloknom rasporedu (RCBD). Sveukupno određena pH vrijednost u moštu kretala se od 3,02 do 3,29, ukupna kiselost u moštu od 7,80 do 9,03 g/L, a sadržaj šećera od 76,00 – 81,00 °Oe. Najveća utvrđena koncentracija vinska kiselina bila je 4,49 g/l u tretmanu T3, koji je imao i najnižu utvrđenu koncentraciju jabučne kiseline 1,40 g/L. Značajan pozitivan utjecaj na sva svojstva imao je tretman T4., Istrian Malvasia' (Vitis vinifera L.) is one of the most important white varieties in Croatia. Its quality is recognized in Croatia as well as in the whole world. Therefore, producers are increasingly choosing to produce wine and sparkling wine from this variety. The must of base wine for sparkling wine in its composition should satisfy characteristics such as lower pH and sugar content and higher total acidity with higher tartaric acid than malic acid content. Due to the fact that Istrian Malvasia is grown mainly in Istria, where the climate is Mediterranean, and the most widespread soil is red soil, it is difficult to satisfy all the above characteristics, especially in dry and hot years. Therefore, the aim of this study was to determine the possibility of a positive effect of foliar fertilization on these properties. The present reserch was set on Istrian Malvasia variety on rootstock SO4 in 2013 with four fertilization treatments (T1 - NPK, T2 - NPK + Agromag 6L (6% MgO), T3 - NPK + Agromag 6L + Phosphorus 30L (30% P2O5) and T4 - NPK + Agromag 6L + Phosphorus 30L + Bio PROT) in three replicates per randomized complete block design (RCBD). Overall, must pH values varied from 3.02 to 3.29, total acidity in the must ranged from 7.80 to 9.03 g/L, while the sugar content from 76.00 to 81.00 ° Oe. The highest determined concentration of tartaric acid was 4.49 g / l in the T3 treatment, which also had the lowest determined concentration of malic acid 1.40 g / L. Treatment T4 had a significant positive effect on all properties.

Aroma profiles and phenolic components of white wines made from ’Pošip’ and ’Škrlet’ (Vitis vinifera L.) both native Croatian, non-aromatic grape varieties enhances the knowledge about these varieties, prepared without maceration (control) and subjected to the pre-fermentative cold maceration (CM). Individual phenolic compounds in wines were determined by high- performance liquid chromatography (HPLC) system, while total phenolics and flavan-3-ols in wines were determined by spectrophotometric methods. CM had the significant impact on the total phenolic and flavan-3-ols composition of ’Škrlet’ wine. The significant increase of some individual phenolic compounds was observed in ’Pošip’ wine. Volatile aroma compounds in wines were determined by gas chromatography (GC) with the previous extraction on the solid phase micro extraction (SPME). The primary aroma compounds, i.e. terpenes were under the significant influence of CM process in ’Škrlet’ wine. Aroma profiles, based on the content of 24 specific compounds, grouped in eight aroma series that contribute to wine odor were developed. CM significantly increased five aroma series in ’Škrlet’ wine and only three in ’Pošip’ wine.

This study set out to evaluate the effect of using sewage sludge-derived compost (SSC) or biochar (SSB) as a soil amendment on the phytoaccumulation of potentially toxic elements, PTE (Cd, Cr, Cu, Ni, Pb, Zn) and natural radionuclides (U-238 and Th-232) by Chinese cabbage (Brassica rapa L. subsp. pekinensis (Lour.) Hanelt) in terra rossa and rendzina soils, which are the two common soil types in Croatia. The experiment consisted of a greenhouse pot trial using a three-factor design where soil type, sludge post-stabilisation procedure and amendment rate (12 and 120 mgP/L) were the main factors. At harvest, the concentrations of analytes in the substrate, leaves and roots were measured, from which the edible tissue uptake (ETU) and concentration ratios (CR) were determined. Also, the average daily dose (ADD) and hazard quotient (HQ) were determined to assess the health risk, as well as soil contamination factor (CF). The results showed that neither adding SSC nor SSB affected the soil loading at the rates applied, suggesting a low risk of soil contamination (CF ≤1). The ETU of Cd, Cu, and Zn were 0.0061, 1.23, and 0.91 mg/plant from compost-amended soil and 0.0046, 0.78 and 0.65 mg/plant for biochar-amended soil, respectively. This difference suggests that their ETU was higher in compost-amended soils than in soils treated with biochar. The CR data indicate that the bioavailability of Cu (CR of 5.30) is highest at an amendment rate of 12 mgP/L, while for Zn (CR of 0.69), the highest bioaccumulation was observed with an amendment rate of 120 mgP/L. Translocation of Cr, Ni, Pb and 238U to the leaves was limited. Overall, the HQ (

Accelerated grape ripening and high wine alcohol content has become a widespread problem in various grape growing regions worldwide in the recent years. One possibility of adaptation to this situation can be obtained by the use of canopy management practices that decrease the leaf area/yield ratio, in order to reduce sugar concentration in grapes. The purpose of this study was to assess the effects of various leaf area/yield ratios obtained by severe shoot trimming and cluster thinning on yield components and grape composition of Vitis vinifera L. ‘Teran’ vines. Two different canopy heights (70 and 130 cm), obtained by shoot trimming at the beginning of veraison, were combined with cluster thinning by removing 0 or 35% of clusters. Leaf area/yield ratio differed considerably among treatments, ranging from 0.70 for vines with short canopy and no cluster thinning applied to 1.69 for vines with high canopy and cluster thinning applied. Severe shoot trimming reduced sugar concentration in grapes, while titratable acidity and pH were not significantly influenced by the investigated treatments. Total anthocyanins and total phenolics in grapes were not negatively affected if severe shoot trimming was combined with cluster thinning, while if cluster thinning was not applied, total anthocyanins and total phenolics were reduced by severe shoot trimming. It is concluded that wines with reduced alcohol concentration and unaffected phenolic composition may be obtained by combining severe shoot trimming and cluster thinning, although the economic aspect should be considered in this case concerning the yield loss obtained by cluster thinning.

This study assesses the potential use of different types of stabilized sewage sludge as a soil amendment by considering their physicochemical characteristics, nutritional status, and their trace metal and radionuclide content. The concentrations of trace metals and radionuclides were determined using ICP-OES and gamma-ray spectrometry, respectively. For determining nutritional status and chemical characterization, this study followed standard ISO-recommended procedures. Data analysis revealed that anaerobic sludge contains higher concentrations of Cr, Hg, and Ni compared to aerobic and non-biologically stabilized sludge. A similar observation was observed in the case of 226Ra, 210Pb, 228Ra, and 228Th. Furthermore, the high levels of P and N in aerobic sludge suggest that biologically stabilized sludge has the potential to be a good fertilizer. In addition, the study finds strong evidence that nutrients are involved in the adsorption of metals and radionuclides onto sludge biomass. Overall, eight of the nine studied sludge samples are safe for agricultural use since the concentrations of trace metals fall well below the limits set by Croatian legislation (NN 38/08). In addition, the levels of radionuclides do not pose a radiological risk. This means that soil conditioning with sewage sludge remains a viable strategy for nutrient recovery from municipal waste, although long-term impact assessments of repeated applications are necessary.

Fennel (Foeniculum vulgare Mill.) is a well-known aromatic plant, widely used as spice and remedy herb. It provides many beneficial effects and is used as diuretic and expectorant, as well as for various dyspeptic disorders. Beside essential oils, fennel seeds are abundant with various phenols, which are known as strong antioxidants and thereby contribute to human health. Among different extraction methods for phenols isolation, pressurized liquid extraction (PLE) represents a novel technique with numerous advantages over conventional extraction approaches. Its efficiency manifests through combination of high temperature and pressure, enabling extraction time shortening, as well as decreased solvent consumption, thus being environment-friendly technique. In order to achieve maximum extraction yield, it is of great importance to select optimal PLE conditions, e.g., extraction temperature and time. Additionally, solvent selection also affects on content of targeted compounds, where phenols amount depends on polarity of solvent. Hence, the aim of this study was to examine the effect of temperature (75 and 100 °C), static time (5 and 10 min) and cycle number (1, 2 and 3) on total phenols (TP) and total flavonoids (TF) content, as well as the antioxidant capacity (AC) in fennel seeds using three-step exhaustive PLE. Firstly, grinded dry fennel seeds were subjected to PLE using non-polar solvent (hexane) under the mentioned conditions in order to remove seeds' lipid fraction. Afterwards, defatted samples were extracted with polar solvents by the increasing polarity: aqueous acetone solution (30 %, v/v) followed by aqueous methanol solution (30 %, v/v). Obtained acetone (AE) and methanol (ME) extracts (n = 24) were analyzed for TP (Folin-Ciocalteu method), TF (aluminium chloride colorimetric assay) and AC [ferric reducing antioxidant power (FRAP) method]. Multivariate analysis of variance (MANOVA) and Tukey's HSD test (p ≤ 0.05) were applied for statistical analysis of collected data. Expectedly, AE were described with higher values of analyzed parameters (grand means: TP = 416.18 mg/100 g, TF = 41.87 mg/100 g, AC = 359.57 mg AAE/100 g) in comparison with ME (grand means: TP = 80.25 mg/100 g, TF = 16.41 mg/100 g, AC = 96.13 mg AAE/100 g. Furthermore, all examined influences significantly affected TP, TF and AC in all samples, except temperature on TP in ME. Thus, conditions of 100 °C/10 min/3 cycles showed the greatest yield of tested parameters in AE, while 100 °C/5 min/1 cycle were sufficient for maximum TP and AC levels in ME. Regarding TF in ME, slightly longer extraction time was required to achieve the highest efficiency (100 °C/10 min/1 cycle).

Four terroirs where cv. Malvasia Istriana is grown under equal viticultural practices and climatic conditions, but on different soil types, were studied. Grape juice samples were taken during ripening at three grapevine growth stages (S35 – berries begin to colour and enlarge ; S36 – berries with intermediate Brix values ; and S38 – berries harvest ripe). Malvasia Istriana grape juice showed a specific free amino acid profile during all three grapevine growth stages, where arginine was the most abundant free amino acid, followed by alanine, threonine, tyrosine, aspartic acid, serine, histidine and glutamic acid. Leucine was the least abundant free amino acid on all studied terroirs at all grapevine growth stages. Total free amino acids decreased at S38, compared to both S35 and S36, on all terroirs, except Fiorini terroir where total free amino acids concentration at S38 was significantly lower compared to S36, but significantly higher compared to S35.

The present study investigated the effect of boron (B) foliar application on the dynamic changes in the concentration of phenols, especially oleuropein, and volatile compounds of olive leaves during a 90-day period. The trial was conducted in a greenhouse on one year old olive plantlets, sprayed with B at 41.62 mM against a water treated control. It was revealed that total phenols and oleuropein concentration in old and in young olive leaves increased in B treated leaves 90 days after application. Furthermore, B enhanced the concentration of particular terpene and norisoprenoid volatiles in olive leaf infusion. The obtained results may give a new perspective in biochemical farming practice, with a possibility to increase the amounts of phenols and terpenes in olive leaves intended for medical uses, and to enhance olive plant resistance to pathogens and insects.

Organic amendments are often reported to improve soil properties, promote plant growth, and improve crop yield. This study aimed to investigate the effects of the biochar and compost produced from sewage sludge and olive pomace on soil hydraulic properties, water flow, and P transport (i.e., sorption) using numerical modeling (HYDRUS-1D) applied to two soil types (Terra Rosa and Rendzina). Evaporation and leaching experiments on soil cores and repacked soil columns were performed to determine the soil water retention, hydraulic conductivity, P leaching potential, and P sorption capacity of these mixtures. In the majority of treatments, the soil water retention showed a small increase compared to the control soil. A reliable fit with the modified van Genuchten model was found, which was also confirmed by water flow modeling of leaching experiments (R2 0.99). The results showed a high P sorption in all the treatments (Kd 21.24 to 53.68 cm3 g&ndash, 1), and a high model reliability when the inverse modeling procedure was used (R2 0.93 - 0.99). Overall, adding sewage sludge or olive pomace as compost or biochar improved the Terra Rosa and Rendzina water retention and did not increase the P mobility in these soils, proving to be a sustainable source of carbon and P-rich materials.

The present study aimed to examine the effect of foliar (Mn_fol) and soil Zeolite-Mn (Mn_ZA) application on leaf mineral, total phenolic and oleuropein content, and mycorrhizae colonization of self-rooted cv. Leccino plantlets grown on calcareous soil. RESULTS The dissolution of zeolite was 97% when citric acid was applied at 0.05?mM?dm?3, suggesting that organic acids excreted by roots can dissolve modified zeolite (Mn_ZA), making Mn available for plant uptake. The leaf Mn concentration was the highest for Mn_fol treatment at 90 days after transplanting (DAT) (172?mg?kg?1) and 150 DAT (70?mg?kg?1) compared to other treatments. Mn_ZA soil application increased leaf Mn concentration at 150 DAT compared to control and NPK treatments. The oleuropein leaf content was highest for Mn_fol compared to other treatments at 90 DAT and lowest at 150 DAT. Arbuscular mycorrhizal colonization was higher for Mn_fol treatment at 150 DAT compared to all other treatments. CONCLUSION Changes in the arbuscular colonization percentage and oleuropein content may be connected to stress conditions provoked by a high leaf Mn concentration in the Mn_fol treatment at 90 DAT. Mn_ZA application increased leaf Mn concentration at 150 DAT compared to control and NPK treatments. It can be assumed that the dominant mechanism in Mn uptake from modified zeolite is Mn_ZA dissolution through root exudates. ? 2018 Society of Chemical Industry

Soil is a non-renewable resource, so it should be taken care of it. High quality food with sufficient yield for a growing human population can be produced only if plant nutrients are added to the soil by fertilizers to increase soil fertility, but the fertilizers have to be used economically, with the aim of raising the nutrient content available in the soil in order to meet plants’ needs. The goal of the present investigation was to determine the effect of application of organic and mineral fertilizers as well as the effect of research environment on micronutrient content in red beet root. A field trial (2003–2005) was set up in a hilly part of Croatia according to the Latin square method, with four types of fertilization (control, 50 t stable manure*ha-1 , 500 and 1, 000 kg NPK 5-20-30*ha-1 ). After digestion of plant material with concentrated HNO3, iron, manganese, and zinc were determined by an atomic absorption spectrophotometer (AAS). The highest average red beet root micronutrient contents (270 mg Fe*kg-1 in dry matter, 96 mg Zn*kg-1 in dry matter, and 53 mg Mn*kg-1 in dry matter) were determined in the first research environment (Brašljevica in 2003) with low potassium soil content. There was a general decreasing trend in contents of the studied micronutrients (Fe, Mn and Zn) with NPK 5-20-30 fertilization (and by application of high doses of potassium), certainly due to antagonistic activity with potassium. It is suggested to fertilize with both 500 kg NPK 5-20-30*ha-1 and microelement fertilizers.

In modern agriculture, besides providing high and stable yields, it is imperative to produce products with a high nutritive quality. The goal of this study was to determine the effect of different fertilization regimes on the macro- and micronutrients in beetroot. A 3-year field trial was set up according to a Latin square method with four types of fertilization (unfertilized control, 50 t stable manure ha−1, and 500 and 1, 000 kg NPK 5-20-30 ha−1). The mineral content was determined as follows (mg 100 g−1 in fresh weight of beetroot): 14–29 P, 189–354 K, 18–34 Ca, 17–44 Mg, 0.67–1.83 Fe, 0.41–0.65 Mn and 0.28–0.44 Zn. The highest beetroot P content was determined for the treatment with stable manure, especially in a year with dry climatic conditions. The highest beetroot K content was determined for the treatment with 1, 000 kg NPK 5-20-30 ha−1, but at the same time for the same treatment, a general decreasing trend of micronutrient content was determined, due to the possible antagonistic effect of added potassium. For better mineral status of beetroot, application of combined mineral and organic fertilizers supplemented with additional foliar application of micronutrients can be suggested.

Two-year study was conducted on Italian Riesling cultivar with the aim to compare the effect of foliar sprays with different nitrogen forms on grapevine leaf N status, yield, and nitrogen compounds in grape juice. Treatments included no fertilization (control), soil NPK treatment, and three foliar treatments [amino acids, urea, ammonia (NH4+)/nitrate] applied four times during season, also treated with soil NPK. The application of 1% w/v urea significantly increased leaf total leaf N content in the second year of study. However, there were no effects on N compounds in grape juice, since changes in free amino nitrogen (FAN), NH4+, and consequently yeast assimilable nitrogen (YAN) were not consistent among the treatments and experimental years. Although increase of vine leaf N status was achieved by 1% w/v urea, additional modifying of application time (by moving it closer to veraison) is needed, with the aim to increase N compounds in grape juice as well.

Gradski parkovi imaju veliku ulogu u ekologiji ljudskog staništa jer pročišćuju zrak, proizvode kisik, pružaju skloništa i staništa za mnoge životinjske vrste, pogotovo ptice. Također, predstavljaju zelene oaze u kojima ljudi zbog stresnog i brzog ritma života traže mjesto za odmor, pružajući raznolike rekreacijske sadržaje za stanovnike gradova. Ovo istraživanje provedeno je s ciljem utvrđivanja količine makrohraniva (dušik, fosfor i kalij) u listovima trava kao i statusa hraniva u tlu na parkovnim javnim površinama, na temelju čega se preporučila optimalna prihrana travnjaka. Unutar rekreacijsko sportskih javnih objekata Grada Zagreba odabrani su Rekreacijsko športski centar (RŠC) Jarun i Park Bundek, koji uz Park Maksimir čine pluća Grada Zagreba. Uzorkovanje listova trava, kao i uzorkovanje tla provedeno je na oba travnjaka tri puta tijekom vegetacije. Na istraživanim lokalitetima najveći udio trava čini Lolium perenne L. sa 70% udjela, Festuca rubra Huds. sa 20%, a 10% udjela čine ostale biljne vrste. Utvrđeno je da su u oba travnjaka količine dušika uglavnom unutar granica koje sugeriraju literaturni navodi, za rod Lolium spp. L., dok su utvrđene nedostatne količine kalija i fosfora, posebice na RŠC Jarun. Prosječne vrijednosti hraniva u listovima trava kroz vegetaciju za RŠC Jarun iznose 3,14% N, 0,31% P i 2,78% K, a za Park Bundek 3,24% N, 0,41% P i 3,17% K, što ukazuje na općenito nešto bolju ishranjenost travnjaka u Parku Bundek u odnosu na Jarun. Slijedom navedenog, a kako bi održali barem postojeći status hraniva u tlu i biljci, predlažemo proljetnu gnojidbu sa 100 g m–2 NPK 5-20-30 ili 7-14-21 uz dodatak 20 g m–2 superfosfata. S obzirom na česte košnje tijekom vegetacije i na odnošenje dušika, potrebna je i prihrana dva puta tijekom vegetacije s po 10 g m–2 KAN-a., Urban parks play an important role in the ecology of human habitats because they filter the air, produce oxygen and provide shelters and habitats for many species, especially birds. They also represent green oases where people affected by stress or overwork may find a place to rest. Urban parks provide a variety of recreational activities for city residents. The aim of this study is to determine the content of macronutrients (nitrogen, phosphorus and potassium) in grass leaves in the urban parks of public areas in order to recommend optimal lawn fertilization. In addition, nutritional grass leaves statuses as well as analyses were made to determine the amount of macronutrients (N, P, K). Within recreational sport public buildings of the City of Zagreb were selected Recreational Sports Centre (RSC) Jarun and Bundek Park facilities as large green areas that are along with Maksimir Park the “lungs” of the city. Grass leaves and soil sampling were carried out on both lawns three times during the growing season. The content of nitrogen in grass leaves of both lawns is within the limits suggested by current literature whilst there was an determined lack of potassium and especially phosphorus. The determined average value of nutrients in the grass leaves during the vegetation period for Jarun were 3.14% N, 0.31% P and 2.78% K, and for Bundek 3.24% N, 0.41% P and 3.17% K. In general, the results show a slightly higher nutrient value of lawn in the Bundek Park compared to Jarun. On the study sites the largest share of grasses belongs Lolium perenne L. with 70%, Festuca rubra Huds. with 20% and 10% belongs to other plant species. Chemical properties of investigated soils show that the soil on RSC Jarun is alkaline and moderately supplied with nitrogen, very poorly supplied with phosphorus and well supplied with potassium. The soil in the Park Bundek is neutral and moderately supplied with nitrogen, very poorly supplied with phosphorus and slightly supplied with potassium. Consequently, we suggest spring fertilization on both locations with 100 g m–2 NPK 5-20-30 or 7-14-21 with the addition of 20 g m–2 superphosphate because of low P status both in soil and grass leaves and two topdressings during the growing season with 10 g m–2 KAN because of mowing.

Organic fertilizers are an important contribution of organic matter that modify the physical, chemical and microbiological characteristics of the soil. The aim of investigation was to determine the effect of different organic fertilization on soil chemical properties on vineyard calcareous soil. Two-year fertilization trial was carried out in the Plešivica wine-growing region, in a 10-year old vineyard, cv. Sauvignon White grafted on Kobber 5BB rootstock, planted on soil with quite high pH for grapevine growing. The trial was performed according to randomize complete block design with 6 treatments (unfertilized, farmyard manure 20 t ha-1 and 40 t ha-1, peat 20 000 L ha-1 and 40 000 L ha-1, NPK 5-20-30 500 kg ha-1+200 kg UREA ha- 1) in 4 repetitions. Statistically significant differences in soil reaction (pH) in plowing layer (0-30 cm) were found among fertilization treatments in the second year of studies. In the plowing layer (0-30 cm) in both years of the study significant differences between the values of average total nitrogen content and available phosphorus as well were found, while there were no significant differences in the subplowing layer (30-60cm). Regarding to average value of fertilization treatment, statistically significant difference in the content of available potassium in plowing layer were found in the both investigated years, while in subplowing layer statistical differences were found in the first year of investigation only. Therefore, fertilization with different organic fertilizers significantly influenced the most of studied chemical properties of the soil, especially in plowing layer (0-30 cm).

Phosphorus (P) is a component of phospholipids, nucleic acids and molecules that store energy. It increases yield and water and nutrients use efficiency. Phosphorus turfgrass content is essential for root development, and, indirectly, nutrient uptake. The aim of this research was to determine soil and turfgrass blade phosphorus dynamics on two recreational (parks Bundek and Jarun) and two sports (Hippodrome and SP Mladost) turfgrasses in the city of Zagreb and determine adequate fertilization. Soil and plant material sampling was performed three times during the growing season 2012 in each of the four investigated locations. The results showed that, generally, soil phosphorus content was low or even turfgrass blade phosphorus content was on the lower end of optimal supply range. Soil phosphorus values ranged from 1.78 to 6.78 mg P2O5 100 g-1, while turfgrass blade phosphorus content ranged from 0.15 to 0.45 % P. Sampling time does not affect turfgrass blade phosphorus content. Due to the particularly low soil and turfgrass blade phosphorus status, special attention when designing the fertilization program should be given to phosphorus application with at least 10 g of P2O5 m-2 in the early spring, and, if necessary, with 1 g of P2O5 m-2 during the growing season.