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The potential for carbon sequestration (CSP) in soils is limited by several factors like the geological provenience, the climatic conditions and the land management. Based on the methodology provided by FAO, a national map has been developed for Austria. Additionally to the climatic and topographic data provided by FAO, more detailed data sources have been used to increase the accuracy of the map.To model the CSP, scenarios with increasing carbon inputs have been used: Business as Usual (BAU), plus 5% (low), 10% (medium) and 20% (high) carbon input, projected to 2038 and 2040. The Austrian Soil Organic Carbon (ASOC) map was used as the starting point for the Soil Organic Carbon (SOC) stocks of the soil in the model.The carbon stocks of Austria's agricultural soils range for the most part between 43 and 103 tC/ha in the BAU scenario, between 43 and 104 tC/ha in the "Low" scenario, between 44 and 105 tC/ha in the "Medium" scenario and between 45 and 108 tC/ha in the "High" scenario. The modelling based on the detailed Austrian data showed the smallest increases in each case (BAU: 43 - 70 tC/ha; Low: 43 - 71 tC/ha; Medium: 44 - 72 tC/ha; High: 45 - 74 tC/ha). The differences between the individual scenarios were also not very pronounced.An evaluation of the results at the regional level allows a basic interpretation of the sequestration potential based on soil and climatic conditions and can be used as a basis for estimating the possible effect of measures that either stabilise or increase the humus content.

The interest in soil analyses with visible and near infrared spectroscopy (Vis-NIRS, ~350-2500nm) has increased rapidly (Nocita et al., 2015; Gholizadeh et al., 2013, Stenberg et al., 2010) due to simple use of the technique and its fastness compared to wet and dry chemistry. Vis-NIR soil spectroscopy has been identified as one of the proximal sensor techniques with most information about organic matter and clay minerals (Gholizadeh et al., 2013) that is very interesting for the agricultural community looking for ways to rapidly assess how management practices affect soil organic carbon stocks, for example. Organic molecules and functional groups in the organic matter absorb strongly in the Vis-NIR range and therefore relate to organic carbon (Stenberg et al., 2010).In order to interpret, validate and calibrate the Vis-NIR spectra, reference data analysed with wet and dry chemistry is needed. Here, we will present the development and use of the Austrian soil spectral library that currently consists of around 600 agricultural soil samples. The soil spectral library has been built up from representative agricultural air-dried soil samples from farmers and agricultural long-term experiments that have first been analysed with wet and dry chemistry for soil organic matter characteristics including total organic carbon (TOC), labile carbon, total nitrogen and potentially mineralisable nitrogen, among other soil fertility characteristics. The soil spectral library is continuously being extended by more representative agricultural soil samples from farmers and long-term experiments. Its harmonisation is being carried out under the EJP SOIL ProbeField project on a European scale as well as under the global GLOSOLAN initiative on soil spectroscopy cooperation. This is to ensure generic, robust and well performing models that could be used in a simple and fast manner on local, regional and national scales in Austria, as well as to be connected to larger geographical and soil type coverage on a European and global scales through ProbeField and GLOSOLAN networks. ProbeField is part of EJP SOIL (EU, H2020, grant agreement No 862695)Gholizadeh, A., Borůvka, L., Saberioon, M., and Vašát, R.: Visible, Near-Infrared, and Mid-Infrared Spectroscopy Applications for Soil Assessment with Emphasis on Soil Organic Matter Content and Quality: State-of-the-Art and Key Issues, Applied Spectroscopy, 67, 1349-1362, 10.1366/13-07288, 2013.Nocita, M., Stevens, A., van Wesemael, B., Aitkenhead, M., Bachmann, M., Barthès, B., Ben Dor, E., Brown, D. J., Clairotte, M., Csorba, A., Dardenne, P., Demattê, J. A. M., Genot, V., Guerrero, C., Knadel, M., Montanarella, L., Noon, C., Ramirez-Lopez, L., Robertson, J., Sakai, H., Soriano-Disla, J. M., Shepherd, K. D., Stenberg, B., Towett, E. K., Vargas, R., and Wetterlind, J.: Chapter Four - Soil Spectroscopy: An Alternative to Wet Chemistry for Soil Monitoring, in: Advances in Agronomy, edited by: Sparks, D. L., Academic Press, 139-159, https://doi.org/10.1016/bs.agron.2015.02.002, 2015.Stenberg, B., Viscarra Rossel, R. A., Mouazen, A. M., and Wetterlind, J.: Chapter Five - Visible and Near Infrared Spectroscopy in Soil Science, in: Advances in Agronomy, edited by: Sparks, D. L., Academic Press, 163-215, https://doi.org/10.1016/S0065-2113(10)07005-7, 2010.

Climate models predict an increase in the average temperature, an increase in heat and drought periods in summer and heavier rainfall events for Austria (APCC, 2014; IPCC, 2021). Eventually, advancing droughts can lead to substantial yield losses, which will be more pronounced on soils with low water storage capacity (Eitzinger et al., 2013). Especially in dry regions like the Marchfeld (east of Vienna), Austria’s most productive region for grain and vegetables, this may have severe consequences for food security.In our study, we investigated the combined effects of different soil types and altered precipitation on the soil-plant-nexus in a lysimeter facility from 2017-2019. This facility consists of 18 gravitation lysimeters representing the three main soil types of the Marchfeld, namely calcaric Phaeozem (Ps), calcic Chernozem (Ch) and gleyic Phaeozem (Pg). Half of the lysimeters were irrigated according to current precipitation patterns and half according to the precipitation pattern predicted for the period 2071-2100 in the Marchfeld region, simulating drought periods and heavy rain events. Spring wheat, spring barley and winter wheat were cultivated in all lysimeters in 2017, 2018 and 2019, respectively. Mustard was cultivated as a cover crop after spring wheat and incorporated as mulch. The following spring barley had substantially higher yields than spring wheat. This might be due to the improved water infiltration and organic matter input provided by the cover crop (Kirchman, 2011) and/or the larger crop damage by animals in 2017. Drought events resulted in an average decline of grain yield by 66% (p13C value, an indicator for the stomata conductance, in the “predicted” scenario confirmed that drought stress was limiting plant growth. δ13C values were also higher in the Phaeozem than in the Chernozem, with the first having a lower soil water holding capacity.In contrast to biomass, nitrogen content of grain did not change between current and predicted precipitation patterns, indicating no impairment of grain quality. Furthermore, the nitrogen use efficiency tended to be higher in the current scenario than in the predicted scenario and was highest for winter wheat. Overall, plant biomass, plant nitrogen content and plant δ15N values were differently affected by soil type, however as there were no significant interaction effects with precipitation, plants responded identically to the precipitation pattern on all soil types, i.e. significant decline in crop production under drought stress.Our results exemplify the pressing need to develop and implement adaptation strategies in agriculture, taking into consideration local pedoclimatic characteristics. Introducing more resilient crop species, diversifying the crop rotation and increasing the system’s water use efficiency are promising measures that should be investigated further.

We compiled information from different sources in order to establish a comprehensive map of the stock of soil organic carbon (SOC) in the upper 30 cm under different forms of land use for Austria. The information serves as a baseline for the evaluation of the potential of climate-change mitigation measures. SOC sequestration plays an important role in the discussion of terrestrial carbon (C) sinks and the size of the SOC pool is one of several quality measures for crop production and the national and regional food security. The baseline serves also for the evaluation of the effectiveness of adaptive land management in order to cope with climate change. Austrian croplands, grasslands, forests, and settlements contain 300 Mt SOC. Peatlands have the highest SOC density (220 t C/ha), yet cover only about 2% of the country. Forest soils store 106 t C/ha and comprise the largest pool due to the coverage of more than 4 Mha (48% of the country). Intensively and extensively managed grasslands cover 0.8 Mha (10%) and contain between 91 and 113 t C/ha, and cropland on 1.28 Mha (15%) hold on average 62 t C/ha. Due to the geographic heterogeneity of Austria with respect to climatic conditions, geology and soils, and topography the regional differences in SOC stocks are large. Measures to increase the SOC stock in cropland have been applied for 25 years within agri-environmental and climate-smart strategies. An increase of the total SOC pool is expected due to the afforestation and reforestation of marginal agricultural land and to a smaller extent due to the restoration of peatlands. A decline of the SOC stock is a consequence of land development for settlements and infrastructure.

Phosphorus (P) is indispensable for crop production, and mineral fertilizers processed from rock phosphates, such as superphosphates, represent an important P source. In the past, P fertilizers from iron and steel slags (basic slag) have also contributed to increased biomass productivity. Both types of fertilizer contain heavy metals as potentially adverse environmental contaminants: they can accumulate in the soil, be taken up by food crops or transferred into aquatic ecosystems. This article reviews the past and current use of P fertilizers and presents the results of two Austrian long-term P field experiments (Fuchsenbigl and Rottenhaus) on superphosphate and basic slag fertilization. The focus is on its impact on the accumulation of cadmium (Cd), uranium (U), chromium (Cr) and vanadium (V) in the soil and their uptake into plants (grain of winter wheat, Triticum aestivum L.). The mining of rock phosphate first began in the mid- to late nineteenth century, before which mainly organic fertilizers were used as P sources. From the 1950s to the 1980s, phosphate rocks were extensively applied to agricultural soils in Central European countries. This marked the onset of more intensive research on the adverse environmental effects of P fertilization. In Austria, 48 years of very high phosphate fertilization (175 kg P ha−1 year−1) significantly increased the aqua regia soluble trace elements in the soil. Superphosphate application led to a +25%/+22% increase of Cd and a +34%/+21% increase of U in 0–25 cm/25–50 cm soil depth at the Fuchsenbigl site. At the Rottenhaus site, which is rich in silt and clay, only U was significantly enhanced (+37%/+25% in 0–25 cm/25–50 cm) after long-term, very high superphosphate fertilization. In Fuchsenbigl, long-term basic slag fertilization also significantly enriched Cr and V at lower application amounts (44 kg P ha−1 year−1) in 0–25 cm soil depth, in 25–50 cm only with very high P fertilization (175 kg P ha−1 year−1). In Rottenhaus, high fertilization significantly increased the Cr concentrations in 0–25 cm (+34%) and the V concentrations in both 0–25 cm (+80%) and 25–50 cm (+50%). After long-term, very high superphosphate fertilization (175 kg P ha−1 year−1), winter wheat grains showed the highest but non-critical Cd concentrations at both experimental sites. Finite natural P resources and the adverse environmental effects of P overuse increasingly require sustainable agricultural P management options to optimize P use efficiency. Careful consideration of the amount and type of P fertilizers and well-planned crop rotations are known as promising strategies. Another potential way forward is P recovery from phosphate salts, municipal waste treatment plants, manure and digestates. These approaches are necessary to meet the challenges of global change and a circular P economy.

Analytical methods used with soilless substrates serve to select the most suitable growing media for a particular application, to compare growing media and to allow quality control for production and trade. Analytical methods also provide the standardized data needed by fertilizer recommendation systems. Assessing a growing medium for an application often requires the combined interpretation of several measured properties as well as the interpretation of the influence of the crop, water supply and nutrient supply systems. As in the related soil sciences, methods are grouped as physical (e.g. water retention characteristics and dry bulk density), chemical (e.g. available nutrients and electrical conductivity) and biological methods (e.g. stability and plant response). The methods are described with separate paragraphs dedicated to the units used, special cases, common values, and the relation to crop growth. A development in practice is the interest in methods which are more dynamic. At present most laboratory methods deliver answers under static conditions, but the plant uptake of water, nutrients, and oxygen by plants is usually highly variable over the course of a day. Another development is the supply of materials from other industries, such as composts, digestates, biochars, and spent mushroom casing which come with quality parameters used in those supplying industries. Important issues are the choice of extraction methods and the expression of water content and organic matter in % V/V. A third development is the interest in the evolution of growing media properties during cultivation as over time, properties may change due to the actions of e.g. root growth and bacterial activity.

This study investigated the long-term effects of different composts (urban organic waste compost (OWC), green waste compost (GWC), cattle manure compost (MC) and sewage sludge compost (SSC)) compared to mineral fertilisation on a loamy silt Cambisol, after a 7-year start-up period. The compost application rate was 175 kg N ha−1, with 80 kg mineral N ha−1 and without. Soil characteristics (soil organic carbon (SOC), carbon-to-nitrogen (C/N) ratio and soil pH), nutrients (nitrogen (N), phosphorous (P) and potassium (K)) and crop yields were investigated between 1998 and 2012. SOC concentrations were increased by compost applications, being highest in the SSC treatments, as for soil pH. N contents were significantly higher with compost amendments compared to mineral fertilisation. The highest calcium-acetate-lactate (CAL)-extractable P concentrations were measured in the SSC treatments, and the highest CAL-extractable K concentrations in the MC treatments. Yields after compost amendment for winter ba...

Spatial planning decisions are frequently driven by short term economic interests influencing zoning regulations which determine subsequent spatial developments in the future. Not only does this frequently place constraints on prospective space for planning measures; it also leads to progressive soil loss. In order to integrate soil-related issues in decision-making processes, a broad range of specific soil services should be considered. Thus, approaches have been developed to convert available soil data to decision-relevant soil information. Soil function evaluation is used as a tool for differentiating soils due to their role in a functional context. This paper outlines development and concepts of this approach on the basis of available soil data records in Germany and Austria. It also demonstrates how an adapted hemeroby ranking can be integrated into soil evaluation. Furthermore, we present some evaluation examples from Austria, showing evaluation results and how to communicate them for better integration into spatial planning decisions. In general, this soil evaluation approach provides evidence that the results are suitable to be introduced into spatial planning procedures, which is crucial for sustainable land use in the future.

Wheat is a crop of global importance that supplies carbohydrates to more than half of the worlds’ population. We examined whether climate change-induced rainfall patterns, which are expected to produce less frequent but heavier rain events, will alter the productivity of wheat and agroecosystem functioning on three different soil types. Therefore, in a full-factorial experiment, Triticum aestivum L. was cultivated in 3-m2 lysimeter plots, each of which contained one of the following soil types: sandy calcaric phaeozem, gleyic phaeozem and calcic chernozem. Predicted rainfall patterns based on the calculations of a regionalised climate change model were compared with the current long-term rainfall patterns, and each treatment combination was replicated three times. Future rainfall patterns significantly reduced wheat yield, leaf area index, and plant height at the earlier growth stages; it equally decreased the arbuscular mycorrhizal fungi colonisation of roots and increased the stable carbon isotope signature (δ13C) of wheat leaves. Sandy soils with inherently lower mineralization potential negatively affected wheat growth, harvest index, and yield but stimulated early season root production. The interaction between rainfall and soil type was significant for the harvest index and early wheat development. Our results suggest that changes in rainfall intensity and frequency can significantly affect the functioning of wheat agroecosystems. Wheat production under future rainfall conditions will likely become more challenging as further concurrent climate change factors become prevalent.

Alarm clocks are important aids that helps us keep a regular routine. This study explores two time-picking interfaces available on Android Smartphones, namely the digit-wheel and dial time-pickers. The digit-wheel time-picker exploits the traditional digit alarm clock metaphor where one cycles through a wheel of hours and a wheel of minutes using multiple small gestures. The dial time-picker is inspired by the analogue clock face and utilizes the real estate of the touch display though single gestures. A mixed experimental design was carried out to compare the efficiency of the two interfaces. The results show that on the first attempt, the digit-wheel time-picker is faster than the dial time-picker, but after a few attempts, the dial time-picker becomes significantly faster than the digit-wheel time-picker. Prior experience with the dial interface had only an interaction effect on the results.

Long-term soil organic matter (SOM) and nutrient dynamics following different crop residue management were studied in two field experiments in Austria: in Marchfeld since 1982 and in Alpenvorland since 1986. The turnover of SOM was modeled with the CCB (CANDY carbon balance) model. SOM parameters such as soil organic carbon (SOC), active C (KMnO 4 ), total nitrogen (N t ), and the N-mineralization potential increased significantly following crop residue incorporation. C/N ratios, however, did not differ significantly. Plant-available potassium (K) increased by 40% (Alpenvorland) and 50% (Marchfeld), magnesium (Mg) only in Marchfeld (+ 9.7%), and no effect was evident for phosphorus at either site. Our results showed a strong agreement between measured and simulated SOC values. SOC can be maintained in the long term with the incorporation of crop residues, but it will decrease with annual removal.

Soil organic matter (SOM) improves soil physicochemical and biological properties, and the sequestration of carbon in SOM may mitigate climate change. Soil organic carbon (SOC) often decreases in intensive cropping systems. Incorporation of crop residues (CR) may be a sustainable management practice to maintain the SOC levels and to increase soil fertility. This study quantifies the effects of CR incorporation on SOC and greenhouse gas (GHG) emissions (CO2 and N2O) in Europe using data from long-term experiments. Response ratios (RRs) for SOC and GHG emissions were calculated between CR incorporation and removal. The influence of environmental zones (ENZs), clay content and experiment duration on the RRs was investigated. We also studied how RRs of SOC and crop yields were correlated. A total of 475 RRs were derived from 39 publications. The SOC increased by 7% following CR incorporation. In contrast, in a subsample of cases, CO2 emissions were six times and N2O emissions 12 times higher following CR incorporation. The ENZ had no significant influence on RRs. For SOC concentration, soils with a clay content >35% showed 8% higher RRs compared with soils with clay contents between 18 and 35%. As the experiment progressed, RR for SOC concentration increased. For N2O emissions, RR was significantly greater in experiments with a duration

FarmClim aims at contributing to a more considerate use of nitrogen in Austrian agriculture. The transdisciplinary research project attempts to tackle the “science-policy gap” by using a participatory approach, that is, stakeholders influence the research process as much as the scientists strive for the implementation of their ideas. This paper describes the project design and communication processes. Full integration of practice partners adds to the complexity of the project's structure, but brings consider able benefits right from the outset. Taking advantage of the existing institutional setting of FarmClim partners, we expect to maintain expert consultancy beyond the lifetime of the project, helping agriculture to meet the challenges of environmental and economic performance of a producing agriculture.

The dispersal of industrial and municipal wastes leads to an increase of contaminated soils and is one of the large concerns in many countries throughout Europe regarding environmental issues. This article proposes a sequence of the microbially aided phytoremediation (phytoextraction and phytostabilization) procedure with the following most important steps: (1) risk assessment, (2) site investigation, (3) determination of the remediation strategy, (4) realization of remediation measures, (5) monitoring, and (6) reuse of the remediated site. UMBRELLA's innovative approach is a proposal of methods to evolve a tool-box which supports phytoremediation by means of microbes and enhances the efficiency of the remediation process at low and heterogeneously metal contaminated sites.

Climate change scenarios for central Europe predict fewer but heavier rains during the vegetation period without substantial changes in the total amount of annual rainfall. To investigate the impact of rainfall patterns derived from regionalised IPCC scenarios on agroecosystems in Austria, we conducted an experiment using 3 m2 lysimeters where prognosticated (progn.) rainfall patterns were compared with long-term current rainfall patterns on three agriculturally important soil types (sandy calcaric phaeozem, gleyic phaeozem and calcic chernozem). Lysimeters were cultivated with field peas (Pisum sativum) according to good farming practice. Prognosticated rainfall patterns decreased crop cover, net primary production (NPP) and crop yields, but increased root production and tended to decrease mycorrhization. Soil types affected the NPP, crop density and yields, weed biomass and composition, as well as the root production with lowest values commonly found in sandy soils, while other soil types showed almost similar effects. Significant interactions between rainfall patterns and soil types were observed for the harvest index (ratio crop yield versus straw), yield per crop plant, weed density and weed community composition. Abundance of the insect pest pea moth (Cydia nigricana) tended to be higher under progn. rainfall, but was unaffected by soil types. These results show that (a) future rainfall patterns will substantially affect various agroecosystem processes and crop production in the studied region, and (b) the influence of different soil types in altering ecosystem responses to climate change should be considered when attempting to scale-up experimental results derived at the plot level to the landscape level.

The Long-term Fertilisation Experiment was established in 1986 near Vienna with a three-year crop rotation (sugar beet-winter wheat-winter barley). The most distinct yield effects of organic fertilisation occurred with missing and low mineral N fertilisation. In the treatment without mineral N fertilisation, significantly higher sugar yields (+2.52 t ha−1) were obtained with the application of farmyard manure (FYM) compared to the control. Without mineral N fertilisation significant winter wheat increases through after effects of FYM and slurry application (+0.74 and 0.55 t ha−1) appeared. N surpluses in the variant with incorporating crop residues could be reduced by the omission of mineral N fertilisation with the incorporation of the straw. The highest mean P balances occurred with the application of FYM and slurry, the highest K surpluses were detected in the treatments where crop residues (especially K rich sugar beet leaves) remained on the field. The N, P and K balances correlated significantly (p ...

Eighteen representative sites for the Austrian grain-growing and eight for the potato-growing zones (soils and crops) were investigated. On each site, total element contents (B, Ba, Ca, Cd, Co, Cu, Fe, K, Li, Mg, Mn, Mo, Na, P, Sr and Zn) were determined in 4-12 varieties of winter wheat (n = 136), 6 varieties of spring durum wheat (n = 30), 5 varieties of winter durum wheat (n = 15), 7 varieties of rye (n = 49), 5 varieties of spring barley (n = 30) and 5 varieties of potatoes (n = 40). Element accumulations in grain species and potato tubers varied significantly with site conditions, with the main exceptions for B in potatoes and wheat as well as for Zn, Cu and Co in durum wheat. On average, across all investigated sites, differences in varieties occurred concerning the elements Ca, Cd, Ba, Sr and Zn (except Zn in potatoes and winter durum). A rough estimation revealed that an average Austrian consumer of wheat, rye and potatoes meets more than 50% of the needs of daily element intake for K, P and Mg, between 36 and 72% for Fe, Zn and Cu, and more than 100% for Co, Mo and Mn. In particular, the elements Ca and Na have to be added from other sources.

Field mesocosms can overcome the simplicity and deficiencies of laboratory based experimental designs. This study deals with a number of possible side effects of a mesocosm technique that involves deep-freezing of soil monoliths to eliminate soil fauna, wrapping in nets of various mesh-size to control fauna1 immigration and replanting in the field. We used Berlese-Tullgren sets in the field to directly inoculate mesocosms with microarthropods. After 6 months of exposure, the number of collembolans equalled control level whereas immigration and inoculation of oribatids accounted for only 30 '70 of the control. The number of ciliates, their distribution into feeding groups, and the numbers of nematodes, tardigrades and rotifers were not significantly affected by the elimi- nation of mesofauna. We also did not detect significant treatment specific effects on microclimatic conditions within the litter layer of the mesocosms. Furthermore, we compared the monolith approach with a technique using sieved soil as a time-saving alternative. Water capacity and infiltration rate of mesocosms made of sieved soil did not differ from mesocosms made of monoliths, but NH; losses were significantly higher in sieved soil when defaunated by deep-freezing. We conclude that the investigated mesocosm tech- nique has little side effects and recommend the use of monoliths in mesocosm studies. 0 2000 Editions scientifiques et medicales Elsevier SAS

A field study in an acidic spruce forest soil using soil mesocosms was conducted to investigate the effects of mesofauna and macrofauna on exchangeable cations, organic matter content, base saturation, and Ca-lactate extractable nutrients. In the field, intact soil monoliths were taken from the ground, defaunated by deep-freezing and wrapped in nets of various mesh-sizes to control immigration of different faunal size classes. The monoliths were then replanted in the field. Three types of treatments for the mesocosms were prepared: (1) microbiota only, (2) microbiota and mesofauna, (3) microbiota, mesofauna, and macrofauna (=complex fauna). After eight months the mesocosms and unmanipulated control plots (treatment 4) were destructively sampled and submitted to chemical analysis. Generally, the exchangeable base cations and Mn2+ showed higher contents with increasing faunal complexity, whereas the exchangeable acidic cations of Fe3+ and Al3+ decreased in the monoliths with complex fauna. These effects were significant for K+, Mg2+ and Mn2+ in the L/F-layer and for Ca2+, Mn2+, Al3+ and Fe3+ in the H-layer. As a possible explanation a rise of ion-binding sites in the course of enhanced humification processes is discussed. In the L/F-layer base cations showed higher concentrations in the monoliths with complex fauna as compared to the control plot, which contained intact roots. This might be due to nutrient uptake by roots in the control plot or enhanced mineralization in the monoliths with complex fauna, where roots had been cut.

According to the method for estimating soil aggregate stability (SAS) described by Kemper and Koch, a new sieving device has been constructed to improve manipulation and the rapidity of the analysis. The method of determination is described. Multiple replications of several samples that have been carried out by the members of the Austrian Soil Physics Research Group, showed a small standard deviation on the same soil samples. Storage of soil samples before measuring may cause a variation (increase) in SAS. The spatial variability of SAS on three field plots turned out to be relatively low. However, statistically significant differences were obtained, which proofs the high precision of the modified machine. Furthermore a significant influence of cattle slurry treatments on SAS of permanent grassland soil could be detected.

Recent studies show that a labile soil carbon (C) fraction determined with potassium permanganate (KMnO4) reflects the type of soil management. The present study combines the method for determining the active C (AC) pool with an alternative titration of the 0.02 m KMnO4 solution with sodium oxalate (Na2C2O4) for routine laboratory analyses. Three long-term field experiments investigated: (i) different cropping systems and 14C-labelled organic amendments, (ii) three different tillage systems, and (iii) the application of four different kinds of compost. The results showed the depletion of AC in the permanent bare-fallow system of the 14C-labelled field experiment. When calculating the ratio AC/total organic C (TOC), the depletion of the AC/TOC curve reflected a priming effect, in accord with previous work. We obtained significant positive correlations of AC with TOC, total nitrogen (Nt), humic acid-C and remaining 14C-labelled material. The AC in the tillage systems experiment was significantly (P