Evaluation of organic matter stability during the composting process of agroindustrial wastes.

Composting of wastes from citrus industrial processing (pastazzo and sludge) was studied in order to evaluate the evolution of organic matter during the process and to individuate chemical and/or biochemical techniques able to set the stability of the final product. Composts from two open-air piles of different composition were sampled every month during the whole period of composting (5 months) and the organic matter of each sample was characterised by chemical and biochemical techniques. Humification rate (HR%) and humification index (HI) were determined. Extracted organic matter of six samples collected for each compost was investigated by isoelectric-focusing technique (IEF). The biochemical analysis was based on the study of C-mineralisation after the addition of each collected sample to soil. Results obtained clearly demonstrated organic matter evolution during composting processes. Humification rates increased and humification indexes decreased over time, while extracted organic matter showed electrophoretic behaviour typical of stabilised organic compounds. Moreover, mineralisation patterns confirmed the increased level of organic matter stability during the composting process

The ‘Little Ice Age’ in the Southern Hemisphere in the context of the last 3000 years : Peat-based proxy-climate data from Tierra del Fuego

DM’s research (at Department of Earth Sciences, Uppsala University) was supported through a European Community Marie Curie Fellowship (Contract HPMF-CT-2000-01056).Peer reviewedPostprin

Site adjusted organic matter balance method for use in arable farming systems

Common humus balance methods give distinct inexact results and do not meet nowadays requirements in Germany. Outgoing from the method of KOERSCHENS et al. (2004) an improved, site adjusted, semi-quantitative method was developed for manual use in agricultural practice and consultation. In the validation and optimization process over 300 variants from 39 long-term field trials were used, which represent the most important site conditions of Central Europe (Germany). The optimization work was done in four steps. Identification of site specific groups with homogenous humification levels. Distinct different humification characteristics were recognized for the organic matter of different German site conditions (soil, climate). Six site specific groups could be identified when comparing the results of the humus balancing with the field trial organic matter content changes of the soils. Humification coefficients of the crop species. The effects of the crop species cultivation, and the climate and soil conditions on the humification process were combined and expressed in the crop species humification coefficients. Optimal values were obtained when the results of the humus balancing were in accordance with the organic matter content chance of the trials (objective function: 0 kg Corg ha-1 ≈ 0 % Corg content change). Equal assessments of the site specific groups were reached by systematic adjustments of the humification coefficients of the crop species until the objective function was observed. Humification coefficients of the organic materials. Additional analyses of multiple long-term field trial results have shown, that the organic material coefficients of the common balance method were fixed at somewhat too high values. Over this, the humification values were negatively related to increasing supply of organic materials. Therefore, these coefficients were corrected according to the field trial results. Classification system for the humus balance results. The nitrogen surface balance of the field trials was suitable for to evaluate the soil fertility and environmental tolerance of the humus balance results. Under a specific N surplus constraint (e.g. 50 kg N ha-1), arable cultivation systems without mineral nitrogen fertilization (e.g. organic farming) can tolerate much higher humus surplus values than systems with increasing nitrogen fertilization. For use in different arable farming systems, therefore, the common classification scheme (A to E system of VDLUFA) was corrected. Through installation of humification coefficients in site-specific groups adjusted to the Corg content change in the soil, and adaptation of the humification coefficients of the organic materials, the optimization process resulted in a large improvement of the method accuracy (s2=0,034 to s2=0,011). For practical use, only a little information about site specific characteristics, the crop species in the crop rotation and the amounts of added organic materials are necessary in the calculations

The Influence of short-term land use change on soil evolution in the centre-south coastal areas of Sardinia

The land use change in short-term (time and space) in the Mediterranean context can be induced by phenomena like destruction of the autochthonous plant species, land abandonment, overgrazing, fire, urbanization (above all for touristic purpose), etc. These phenomena can lead to soil’s degradation conditions causing a loss of physical and biological productivity and the consequent emphasis in desertification processes. Desertification is considered one of the biggest environmental problems in Mediterranean areas (ICCD, 1994), and Sardinia is one of the most affected regions in Europe (UNEP, 1992; Imeson and Emmer, 1992). In Sardinia changes happened during the last decades (such as industrialization, coastal urban areas expansion, etc.) have often resulted in repercussions on the environmental ecosystems and foremost on soils. An important decrease of fertile lands and a consequent increase of marginal and unproductive areas have been observed; this fact has taken to manifest environmental and economic repercussions. In Sardinia such degradation phenomena are particularly evident in coastal areas, where the uncontrolled urbanization and the natural touristic vocation represent relevant impact types. In fact, in 1897 km of coastal lands (500 km are represented by dunal systems) 40% is subjected to deep erosion phenomena, that often are caused by wrong management actions. For these reasons the knowledge of their nature and expansion is of primary importance to carry out correct choices in land use. This work shows an example of a comparative investigation on coastal ecosystems particularly under human pressure. The investigated areas are located along the Centre–North coast of Sardinia. Particularly they concern: a) soils on limestone formations, forestry live oak cover and pasture land use (goat and swine); b) soils on fixed dunes, reforestation with pine and touristic-recreational land use foremost. In the areas several soil profiles have been realized to investigate the influence of the land use change, occurring in short-term in both places, on the evolution and degradation processes of soils

Soil fertility comparison among organic and conventional managed citrus orchards in Sicily.

In recents years, organic farming is expanding in Southern Italy and in the Mediterranean area, due to interest of consumers and EU agricultural policies. Evaluation of organic farming system introduction on soil quality and fertility status should be taken into account in order to define medium-long term environmental and agricultural strategies, on both locol and national scale. Soil physical, chemical and biological parameters represent effective tools to evaluate soil quality and changes in soil fertility status, as a consequence of different agronomic management (i.e. organic vs coventional). The aim of this work was to compare soil fertility of conventional and organic managed citrus Orchards, using specific soil system descriptors. The research was carried out in a Mediterranean environment (Sicil Region, Southern Italy), on Navelina and Tarocco orchards. Soil characteristics were analysed in 54 farms under both organic and conventional management. Farms were selected to obtain similar pairs (27) in the same environmental conditions. Moreover, orchards pairs were homogeneous for age, cultivar and rootsock to reduce effects not linked to soil management. For each soil, total organic carbon, total nitrogen, mineral NO3-N and NH4-N were determined. In addition, in order to evaluate biological fertility of the considered soils, carbon mineralisation and nitrogen mineralisation in anaerobic conditions were studied. Soils' humic fraction was at least characterised qualitatively by isoelectric focusing technique,to obtain information on soil organic matter stability. Potenzially mineralisable carbon and cumulative mineralised carbon determined on 21 days experimental trials differed significantly in organic and conventional soils. Since this significance was detected also for cumulative mineralised carbon after 7 days, probably C-mineralisation represents the more reliable and prompter indicator to discriminate soil biological fertility with respect to the other tested ones. Moreover, it should be remarked that some parameters (as total nitrogen content, mineralised carbon after 1 days and the more humified organic matter fraction), even if not yet significantly different, revealed a strong tendency to increase in organic managed soils, attesting that the organic citrus orchards can be considered systems able to conserve energy and store nutrients more than the conventional ones

Properties and functions of organic materials in poor agricultural soil condition

A field experiment was conducted under different soil strata in poor agricultural soil condition. Each soil stratum was treated separately with different organic material for soil fertility management. These organic materials are cow dung, sheep dung, goat dung, donkey dung, rice husks, millet husks, Acacia albida, Acacia nilotica, wood ash, house refuses, and combination of all ‘ani-cro-ber’. In the first assessment, soil structure, texture, colour, consistency, bulk density were determined in the field, while in the second assessment N, P, K, Na, Ca, OC, OM and pH were determined under specific laboratory analysis. It is believed that the use of organic materials in soil management is a good way to improve and maintain soil quality and soil fertility rehabilitation in poor agricultural soil condition

An archaeological mystery revealed by radiocarbon dating of cross-flow nanofiltrated amino acids derived from bone collagen, silk, and hair: case study of the bishops Baldwin I and Radbot II from Noyon-Tournai

Excavations in the cathedral of Tournai revealed two sepultures, which were identified by the excavators as those of bishops because of their special location in the cathedral. One burial was assigned to Baldwin I, who died in AD 1068, because (1) a ring with the inscription "BAL" was found and (2) a funeral stone with text was present on top of the grave mentioning the name Baldewinus. The second burial probably belongs to Radbot II, who was the successor of Baldwin I, and died in AD 1098. Both burials contained textiles (silk), the skeleton, a wooden pastoral staff, and human hair was still present on the skull of what was presumed to be Radbot II. All the protein-containing materials were degraded and/or contaminated. Standard sample pretreatment methods were not able to remove all the contaminants. Single and double cross-flow nanofiltration of the hydrolyzed protein-containing materials were performed. The sample quality for radiocarbon dating was improved and C-14 data revealed interesting and surprising results. The C-14 dates of the wooden pastoral staff and permeate femur confirm that the skeleton and tomb belong to bishop Baldwin I. The C-14 dates of hair and permeate skull indicate that the skeleton may indeed belong to bishop Radbot II. The younger C-14 dates of the wooden pastoral staff and silk samples indicate a postburial disturbance of the site burial during the 12th-13th century

Study of Hydrophobic Domains in Humic Acids

Fyzikálně-chemická povaha hydrofobních domén huminových kyselin byla studována z několika hledisek. K objasnění významu fluorescenčních spekter byly vzorky podrobeny sekvenční frakcionaci, která pomohla k částečnému objasnění vlivu vodorozpustných složek, volných a vázaných lipidů na optické vlastnosti huminových kyselin. Výsledky naznačily, že fluorescenční píky tradičně přiřazované superpozici jednotlivých struktur jsou spíše důsledkem agregačních vlastností huminových molekul tvořících vlivem hydrofobního efektu zdánlivě vysoce aromatické struktury. Dále pak bylo zjištěno, že na optických vlastnostech huminových kyselin mají podíl i molekuly, které nemají primárně fluoroforní nebo chromoforní vlastnosti. Tento pohled je v souladu s teorií supramolekulárního uspořádání huminových kyselin. Dále byly studovány agregace, konformační chování a termodynamická stabilita huminových kyselin pomocí metody vysoce rozlišovací ultrazvukové spektroskopie. Bylo prokázáno, že huminové kyseliny mají schopnost agregovat už od velmi nízkých koncentrací (The nature of hydrophobic domains in humic acids was studied from different points of view. To shed light on the meaning of fluorescent spectra, the measured samples underwent the sequential extraction which partially revealed the role of water-soluble components, free and bond lipids in optical properties of humic acids. The results indicated that the fluorescence peaks traditionally attributed to the superposition of individual chemical structures are rather a result of aggregation properties of humic molecules and hydrophobic effect driving aromatic molecules together forming aggregates apparently large molecular weight. Further, it seems that there is a significant influence of non-fluorophores and non-chromophores on the optical properties of humic acids. Results are consistent with the theory on supramolecular structure of humic acids. Next, the aggregation, conformational behaviour and thermodynamic stability of humic acids were studied by high resolution ultrasonic spectroscopy. It was demonstrated that humic molecules are able to interact and form aggregates at very low concentration (

Land use affects the soil C sequestration in alpine environment, NE Italy

Soil carbon sequestration is strongly affected by soil properties, climate, and anthropogenic activities. Assessing these drivers is key to understanding the effect of land use on soil organic matter stabilization. We evaluated land use and soil depth influencing patterns of soil organic matter stabilization in three types of soil profiles located under the same pedogenetic matrix and alpine conditions but with different vegetation cover. The stock in soil organic carbon in the mean 0–20 cm layer increased from prairie (31.9 t ha−1) to prairie in natural reforestation (42 t ha−1) to forest (120 t ha−1), corresponding to increments of 1.3-fold prairie, for prairie in natural reforestation, and of 3.8-fold prairie for forest. The forest showed the highest humic carbon (21.7 g kg−1), which was 2.8 times greater than the prairie in natural reforestation and 4 times higher than the prairie. 13C-NMR spectroscopic measurements suggested a different C pattern. The prairie in natural reforestation and the prairie were characterized by a higher content in O,N-alkyl C with respect to the forest. Alkyl C and aromatic C in the prairie in natural reforestation and prairie did not show relevant differences while they decreased with respect to the forest. Carboxyl and phenolic C groups were markedly higher in forest and prairie than prairie in natural reforestation. Alkyl C, carboxyl C, and phenolic C prevailed in the Ah horizons whereas aromatic C and O,N-alkyl C were dominant in the B horizons. Overall, the marked distribution of O,N-alkyl C and alkyl C in humic substances (HS) indicates a low degree of humification. Nevertheless, in forest, the relatively high presence of aromatic C designated HS endowed with a relatively high humification degree. Thus, our results might suggest that in the alpine environment of NE Italy differences in soil organic matter (SOM) stocks and characteristics are affected by land use and anthropic activities