CHARAKTERISTIKA PŮDNÍCH HUMINOVÝCH LÁTEK METODAMI ULTRAFIALOVÉ- VIDITELNÉ A SYNCHRONNÍ FLUORESCENČNÍ SPEKTROSKOPIE

We focused our study on ultraviolet-visible and synchronous fluorescence spectra and indexes of humic subctances isolated from five Czech soil samples: Haplic Chernozem, Luvic Chernozem, Gleyic Luvisol, Haplic Cambisol and Leptic Cambisol. Results indicated the following HS quality: Haplic Chernozem > Luvic Chernozem > Gleyic Luvisol > Haplic Cambisol > Leptic Cambisol. Humic acids and fulvic acids ratios (HA/FA) were increasing together with decreasing values of Q4/6 measured in visible spectral range. Highest absorbance in visible spectral range was detected in Haplic Chernozem and Luvic Chernozem. Maximum relative fluorescence was found in Haplic Chernozem. SFS spectra (in emission mode) at Δλ=20 nm showed five main fluorophore peaks at: 360, 470, 488, 502 and 512 nm. Fluorescence behaviour of studied samples was compared with Elliot soil humic acid standard (IHSS). Correlation between fluorescence indexes (F) and humification degree (HD) R2= 0.88 and between calculated humification degree (HD*) and humic acids content (HA sum) R2=0.84 and between fluorescence indexes F and HA/FA ratios (R2=0.88) were found.Práce byla zaměřena na studium optických vlastností půdních huminových látek metodami UV-VIS a synchronní fluorescenční spektroskopie. Vzorky byly izolovány z následujících půdních typů České republiky: černozem modální, černozem luvická, luvizem oglejená, kambizem modální a kambizem litická. Kvalita huminových látek zjištěná metodou krátké frakcionace je dána (klesá) v následujícím pořadí: černozem modální > černozem luvická > luvizem oglejená > kambizem modální > kambizem litická. Poměr obsahu huminových a fulvinových kyselin (HA/FA) vzrůstá s klesající hodnotou barevného indexu Q4/6, který byl určen ve viditelné části spektra. Bylo zjištěno, že nejvyšší hodnoty absorbance ve viditelné části spektra měla černozem modální a černozem luvická. Nejvyšší hodnotu relativní intenzity fluorescence měl vzorek černozem modální. SFS spektra měřená v emisním modu při Δλ=20 nm obsahovala pět hlavních píků při: 360, 470, 488, 502 and 512 nm. Fluorescence studovaných vzorků byla porovnána se standardem (Elliot soil humic acid standard, IHSS). Byly nalezeny korelace mezi fluorescenčními indexy (F) a stupněm humifikace (HD) R2= 0.88, dále mezi vypočítanými stupni humifikace (HD*) a obsahem huminových kyselin (HA sum) R2=0.84 a mezi fluorescenčními indexy (F) a poměry HA/FA (R2=0.88)

Carbon Dynamic after Conversion of Permanent Grassland into Arable Soil

Carbon input and balance in soils is regarded as the main criterion of agricultural sustainability. Generally, carbon dynamic depends not only on the carbon input and its decomposition rate, but it is also influenced by various agronomic practices. Therefore, changes in organic carbon stock and humic substances quality were evaluated in two different agricultural management systems (permanent grassland and intensive crop sequences). Haplic Cambisol (Czech-Moravian Highland, locality Vatín, Czech Republic) was sampled twice a year (spring and autumn) in the depth 0-20 cm during the period 2010-2016. Soil was sandy-loam textured, with middle organic carbon content and very low humic substances quality. Results showed that crop management practices directly influenced soil cumulative potential, quality of humic substances, soil reaction and amount of nutrients. Statistically significant differences were found

STRUCTURE OF HUMIC ACIDS AS INFLUENCED BY PLOUGH TILLAGE AND MINIMUM PLOUGHING SYSTEM

Objective of this study was to show the effect of different soil tillage systems onto humic substances content and quality. Furthermore chemical composition and structural differences in humic acids molecule in selected tillage systems were assessed. Long-term experiments were carried out on Luvi-haplic Chernozem (locality Unčovice, Olomouc region) during the period 2008-2011. Two types of tillage systems were studied: 1. plough till 0.35 – 0.40 m; 2. minimum loosening till 0.15 m. Humic acids were isolated according to the international standard method and characterized by elemental composition and 13C NMR spectroscopy. Spectrometer Varian INOVA 600 (frequency 150,830 MHz) was used. Results showed differences in quality of humic substances and higher content of fulvic acids in fractional composition under minimum tillage system. Analysis of chemical composition and structure of humic acids indicated higher content of aliphatic groups in HA molecule due to minimum loosening system. On the other hand humic acids isolated from ploughing soil were more aromatic. 13C NMR spectroscopy could be a useful tool to assess changes in structural composition of humic acids isolated from the different eco-systems

Potencial de biocarbón después de su activación biológica por microflora nativa del suelo

Objective. Dehydrogenase activity after the biological activation of biochar by the native soil microorganisms was studied. The main aim was to improve biochar properties by activation and make it more friendly for the soil microflora. Materials and methods. The activation was reached by aerating with the soil solution for two weeks. No special inoculum of microorganisms was applied. The following treatments in four replicates were prepared: conventional raw biochar (BR), activated biochar (BA), mineral fertilizer DAM 390 (NF), and control (C). A statistical test for comparing treatments means (Fisher p≤0.05; program STATISTICA 12.0; StatSoft software Inc., Tulsa, Oklahoma, USA) was used. Results. Statistically significant differences in the dehydrogenase activity between the treatments BR, BA, and C were found. Application of mineral fertilizers had a negative effect and increasing of nitrogen leaching was observed. Conclusions. Activating of biochar is suitable metods for impove soil biota conition compared with convention biochar.Objetivo. Se estudió la actividad de la deshidrogenasa tras la activación biológica del biocarbón por los microorganismos nativos del suelo. El objetivo principal era mejorar las propiedades del biocarbón mediante su activación y hacerlo más amigable para la microflora del suelo. Materiales y métodos. La activación se logró mediante la aireación del suelo con la solución durante dos semanas. No se aplicó ningún inóculo especial de microorganismos. Se prepararon los siguientes tratamientos en cuatro réplicas: biocarbón crudo convencional (BR), biocarbón activado (BA), fertilizante mineral DAM 390 (NF) y control (C). Se utilizó una prueba estadística para comparar las medias de los tratamientos (Fisher p≤0.05; programa STATISTICA 12.0; StatSoft software Inc., Tulsa, Oklahoma, USA). Resultados. Se encontraron diferencias estadísticamente significativas en la actividad deshidrogenasa entre los tratamientos BR, BA y C. La aplicación de fertilizantes minerales tuvo un efecto negativo y se observó un aumento de la lixiviación de nitrógeno. Conclusiones. La activación del biocarbón es un método adecuado para mejorar la condición de la biota del suelo en comparación con el biocarbón convencional

Haplic Chernozem Properties as Affected by Different Tillage Systems

During 2007–2011 we assessed content and quality of humic substances with relationship to soil structure. Object of study was Haplic Chernozem (Hrušovany nad Jevišovkou, Czech Republic) under three different tillage systems: – conventional ploughing to a depth of 0.22 m (CP); – reduced tillage with shallow harrowing to a depth of 0.15 m (RTSH); – reduced tillage with subsoiling to a depth of 0.35–0.40 m (RTS). Isolation of humic acids was made according to IHSS standard method using spectrometer Shimadzu 8700. Aggregates stability was determined by wet sieving method. Results showed that macrostructure stability was directly connected with time of sampling and content and quality of humic substances. After five years of experiment statistically significant differences in humic substances content were found. The highest structure stability, quantity and quality of humic substances were achieved under reduced tillage with shallow harrowing

The Soil Organic Matter in Connection with Soil Properties and Soil Inputs

The content of organic matter in the soil, its labile (hot water extractable carbon–HWEC) and stable (soil organic carbon–SOC) form is a fundamental factor affecting soil productivity and health. The current research in soil organic matter (SOM) is focused on individual fragmented approaches and comprehensive evaluation of HWEC and SOC changes. The present state of the soil together with soil’s management practices are usually monitoring today but there has not been any common model for both that has been published. Our approach should help to assess the changes in HWEC and SOC content depending on the physico-chemical properties and soil´s management practices (e.g., digestate application, livestock and mineral fertilisers, post-harvest residues, etc.). The one- and multidimensional linear regressions were used. Data were obtained from the various soil´s climatic conditions (68 localities) of the Czech Republic. The Czech farms in operating conditions were observed during the period 2008–2018. The obtained results of ll monitored experimental sites showed increasing in the SOC content, while the HWEC content has decreased. Furthermore, a decline in pH and soil´s saturation was documented by regression modelling. Mainly digestate application was responsible for this negative consequence across all soils in studied climatic regions. The multivariate linear regression models (MLR) also showed that HWEC content is significantly affected by natural soil fertility (soil type), phosphorus content (−30%), digestate application (+29%), saturation of the soil sorption complex (SEBCT, 21%) and the dose of total nitrogen (N) applied into the soil (−20%). Here we report that the labile forms (HWEC) are affected by the application of digestate (15%), the soil saturation (37%), the application of mineral potassium (−7%), soil pH (−14%) and the overall condition of the soil (−27%). The stable components (SOM) are affected by the content of HWEC (17%), soil texture 0.01–0.001mm (10%), and input of organic matter and nutrients from animal production (10%). Results also showed that the mineral fertilization has a negative effect (−14%), together with the soil depth (−11%), and the soil texture 0.25–2 mm (−21%) on SOM. Using modern statistical procedures (MRLs) it was confirmed that SOM plays an important role in maintaining resp. improving soil physical, biochemical and biological properties, which is particularly important to ensure the productivity of agroecosystems (soil quality and health) and to future food security

Changes in soil properties due to land reclamation and climate change in South Moravian floodplain forest

Land use changes together with riverbed regulations to avoid the annual floods affect the ecosystem of floodplain forests. Later subsequent revitalization measures, transboundary controlled river management, wetland restoration, and integrated planning were realized to reduce the negative effect of groundwater dropping and other environmental problems. This study aimed to follow the dynamic of groundwater level, soil properties and forest vitality as affected by climate change. The continuous dataset (2019-2022) of soil physical and hydrophysical parameters and tree radial growth parameters were obtained. Groundwater level was evaluated by z-score and the means, and standard deviation values were considered. The monthly assessment of soil and climatic conditions showed that the uneven distribution of rainfall and the increase in temperatures have significantly affected the soil hydrological regime and forest growth. Continual monitoring is necessary to prepare projection models, which can help better understand both the soil and tree growth parameters in the changing environment

Click for updates Acta Agriculturae Scandinavica, Section B -Soil & Plant Science Fate of humic acids isolated from natural humic substances Fate of humic acids isolated from natural humic substances

Composition of humic acids (HA) is a function of plant-derived inputs, degradation processes regulated by microorganisms, organo-mineral interactions and age. Characterization of different origin humic substances is important for evaluation of their contribution to stabile and labile carbon pool in the environment. The relative abundance of chemical components in HA isolated from soils, compost, commercial lignohumates, alginite, acadiane and lignite was studied with aim to quantify content of important biomarkers such as amino acid, lipids and polyphenols. HA were considered as a heterogeneous complex and high concentration of peptides, polyphenols and lipids was determined in acadian-HA to compare with soil-HA. Compost-HA contained much more amino acids to compare with soil-HA samples. Alginite-HA and lignite-HA were similar in biomarkers content to soil-HA. Fourier transform infrared spectroscopy confirmed that chemical composition and functional groups content differs with the origin, humification degree and the age of studied samples. Soil-HA are typically composed of a variety of −OH, COOH−, C-O, C-H 2 , (aliphatic and aromatic) groups, quinines, lignin fragments, polysaccharide, monosaccharide and proteins fragments, which are linked together by −O−, −NH−, −H=, >C=O, metal ions and -S− groups. 13 C NMR spectroscopy showed that aromatic carbon content was the highest in lignite-HA and soil-HA