No abstract

No abstract

No abstract

Nonsustainable agricultural practices often lead to soil carbon loss and increased soil carbon dioxide (CO 2 ) emissions into the atmosphere. A research study was conducted on arable fields in central lowland Croatia to measure soil respiration, its seasonal variability, and its response to agricultural practices. Soil C-CO 2 emissions were measured with the in situ static chamber method during corn (Zea mays L.) and winter wheat (Triticum aestivum L.) growing seasons (2012 and 2013, n = 288) in a field experiment with six different tillage treatments. During corn and winter wheat growing season, average monthly soil C-CO 2 emissions ranged, respectively, from 6.2-33.6 and 22.1-36.2 kg ha´1 day´1, and were decreasing, respectively, from summer > spring > autumn and summer > autumn > spring. The same tillage treatments except for black fallow differed significantly between studied years (crops) regarding soil CO 2 emissions. Significant differences in soil C-CO 2 emissions between different tillage treatments with crop presence were recorded during corn but not during winter wheat growing season. In these studied agroecological conditions, optimal tillage treatment regarding emitted C-CO 2 is plowing to 25 cm along the slope, but it should be noted that CO 2 emissions involve a complex interaction of several factors; thus, focusing on one factor, i.e., tillage, may result in a lack of consistency across studies.

The study was conducted on 18 locations and 11 dominant soil types in the Republic of Croatia including their evolution-genetic horizons. In total, 51 soil samples were examined. Analysis of soil was done by saturating patterns using barium chloride solution in three replications. Descriptive statistics of the analyzed data was conducted. Basic statistical parameters were calculated, and functional dependence between the base saturation (V%) of analyzed soil samples and their pH was observed. The correlation coefficient (r) between base saturation (V%) and pH for all examined soils was r=0.79 (n=51; very strong correlation). For acid soils it was r=0.82 (n=17; very strong correlation), for neutral soils r=0.75 (n=8; very strong correlation), and finally for alkaline soils r=0.15 (n=26; very weak correlation). Cation exchange capacity values ranged from 2.39 cmol + *kg-1 to 33.8 cmol + *kg-1 depending on soil type, pH, organic content and other soil parameters. The content of exchangeable cations in the sum of basic cations ranged from: Ca 2+ (16%-94%), Mg 2+ (2%-41%), K + (1%-68%) and Na + (<0.01%) also depending on soil type, depth, location and other physical and chemical soil parameters.

The determination of the effects of cadmium and mercury on the growth, biomass productivity and phytoremediation potential of Miscanthus × giganteus (MxG) grown on contaminated soil was the main aim of this paper. the use of bioenergy plants as an innovative strategy in phytotechnology gives additional benefits, including mitigation and adaptation to climate change, and soil remediation without affecting soil fertility. An experiment was set up as a randomized complete block design with the treatments varied in concentrations of Cd (0, 10 and 100 mg kg −1 soil) and Hg (0, 2 and 20 mg kg −1 soil) added to the soil. Three vegetative years were studied. Yield values ranged from 6.3-15.5 t DM ha −1 , cadmium concentration in plants varied from 45-6758 µg kg −1 and Hg varied from 8.7-108.9 µg kg −1 . Values between treatments and years were significantly different. MxG can accumulate and remove very modest amount (up to 293.8 µg Cd and 4.7 µg Hg) per pot per year in aboveground biomass. Based on this data it can be concluded that MxG, as a valuable energy crop, is a potential candidate for the phytostabilization and biomass production on soils contaminated with Cd and Hg moderately.Phytoremediation is considered as a simple and a natural technology that uses plants which can be utilize for efficient absorption of pollutants from contaminated soils 1,2 . Generally, remediation of heavy metal polluted soils could be classified as physico-chemical and biological remediation techniques 3 . Compared to physico-chemical techniques (vitrification, soil washing, solidification and stabilization), phytoremediation technology could reduce dust emission, risk of exposure to soil, provide erosion control and prevent runoff 4 . Unlike physical and chemical treatments that irreversibly alter soil properties, phytoremediation generally improves physical, chemical, and biological quality of contaminated soils, improving soil quality and functionality and carbon sequestration 5,6 . Phytoremediation is suitable for different types of contaminants (organic, metals and radionuclides), with relatively low financial costs, does not require additional energy delivery (energy is obtained from solar radiation) and with minimally influence to the site destruction and destabilization. Additionally, it contributes to the improvement of the visual aspect of the landscape, provides habitats for animals, and reduces leaching and mobilization of contaminants in soil 7 . Disadvantages of phytoremediation include: long remediation time requirement (the process is slow and requires 3-20 growing seasons to achieve remediation goals); relatively shallow cleaning depths; potentially contamination of the food chain; a site-specific technology (structure of the soil profile, pH, presence of salt or other toxins, water quality including nutrients, oxygen content) with a choice of plants being critical, and the fate of contaminants often unclear (the technology may relocate contaminants from the subsurface to the plant, creating residual waste to be disposed ...

Heavy metals accumulation in crops and soils poses a significant threat to the human health. A study was carried out in 2016 in order to assess hemp (Cannabis sativa L.) ability to accumulate heavy metals and to reveal its possibility as a phytoaccumulator or phytostabilizer. Two soil types from Croatia were used in experimental pots: Gleysoils (alkaline soil) and Stagnic Luvisol (acid soil). Majority of the varieties accumulated more heavy metals in roots than in above-ground biomass. Removal of Cd, Ni, Pb, Hg, Co, Mo and As was higher in acid soil. Potential ability for phytostabilization was observed in alkaline soil in order Cu>Cr> Cd>Mo>Hg>Zn>Ni>Co>As>Pb, while for acid soil in order Zn>Cd>Cr>Ni>Hg>Cu> Mo>As>Co>Pb. Some varieties exhibited a translocation coefficient (TC) more than 1 and shown the ability of hyper-accumulation for Zn, Hg, Mo and Cd. Higher accumulation of heavy metals in some varieties could lead to their general application for phytoaccumulation of heavy metals from polluted soils.

The multiyear cultivation of Miscanthus × giganteus Greef et Deu (M.×giganteus) at the soils polluted by metal(loid)s were researched. The biomass parameters and concentrations of elements: Ti, Mn, Fe, Cu, Zn, As, Sr, and Mo were determined in the plant's organs at harvest. The same metal(loid)s were monitored in the plant's leaves throughout three vegetation seasons. The principal component analysis and general linear model approaches were applied for statistical evaluation followed by Box-Cox transformation. The difference in the distribution of elements in the plant, the content of elements in the soil, various regime of uptake to the plant tissues, and the year of vegetation were analyzed as driving factors of the phytoremediation. The results showed that the leading promoter was the factor of the zone, which was the most essential for Ti, Fe, and Cu and the smallest for Mn. The factor of differences in soil pollution was essential for Zn and Mo, much less for As, Sr, and Mn, limited for Fe, and was not seen for Ti and Cu. The factor of the interrelation effects of the zone and experiment reflected the different regime of uptake for the plant tissues was seen for two elements: more prominent for Cu and smaller for Ti. While analyzing the dynamic of foliar concentrations of the metal(loid)s during 3 years, two groups were defined. Firstly, Fe, Ni, Mn, and Sr showed stable curves with limited distribution of the plant life cycle. Secondly, As, Zn, Cu, and Mo showed different fluctuations in the curves, which can be attributed to essential influence of those elements to the plant life cycle. Further research will be focused on the application of M.×giganteus to the polluted soil in a bigger scale and comparison results of laboratory and field experiments.