AFM Microbial Biomass and Activity

CAT significantly affected soil respiration and CEM (Table 6.2). Moreover, significant differences between bulk soil and rhizo soil were found for all microbial parameters (Table 6.2). The differences between sites were significant for Cmic in 2007 and 2008, as well as for respiration and CEM in 2008. Moreover, a significant interaction soil x site was observed for AFM and Cmic (Table 6.2). As for bulk soils, AFM in Napoli was larger in CAT than in No-CAT, though the differences were not...

Current Concepts and Technologies

A sustainable use of soil means its exploitation in a way and at a rate that preserves at the long term its multitude of functions and protects or improves its quality, thereby maintaining its potential to meet the likely needs and aspirations of present and future generations (Van-Camp et al. 2004). Soil organic matter (SOM) plays a fundamental role in plant nutrients status maintenance of soil functions and release of CO2, methane, and other gases in the atmosphere. Two factors influence SOM...

European and Italian Legislation Related to Climate Reporting

Under the UNFCCC agreement, all parties must report on the steps undertaken to implement the Climate Convention (Articles 4.1 and 12). This report is provided in a national communication that usually contains information on national approaches, such as vulnerability assessment, financial resources and transfer of technology, education and training. Additionally, information is made available on domestic policies and measures to limit or reduce GHG emissions and enhance their removal by sink...

Conclusions

Porphyrins and metal-porphyrins represent a vast class of chemically reactive compounds that are being used in several biotechnological applications (Smith 1975 Lesage et al. 1993). In particular, a synthetic iron-porphyrin was recently used as a biomimetic catalyst to promote oxidative coupling reactions in soil, in order to increase both the chemical protection of organic C pool (Smejkalova et al. 2006 Fukushima et al. 2010 Piccolo et al., 2011) and the removal of toxicants from the soil...

Contents

1 The Nature of Soil Organic Matter and Innovative Soil Managements to Fight Global Changes and Maintain Agricultural Productivity 1 2 The Kyoto Protocol and European and Italian Regulations Davide Savy, Antonio Nebbioso, Roc o D nica C ndor, and Marina Vitullo 3 Field Plots and Crop Yields Under Innovative Methods Carlo Grignani, Francesco Alluvione, Chiara Bertora, Laura Zavattaro, Massimo Fagnano, Nunzio Fiorentino, Fabrizio Quaglietta Chiaranda, Mariana Amato, Francesco Lupo, and Rocco...

Direct CAT Effects on Root Growth and Morphology

In the Arabidopsis model species, neither germination rate nor germination time was changed by the presence of CAT (data not shown). Conversely, the fresh weight of the maize plants after 14 days of exposure to CAT was reduced, as compared to untreated plants (Table 10.2). Such reduction was considerable for both roots and shoots, being larger in the former, and directly correlated to CAT concentration in the medium (Fig. 10.18). At the larger CAT concentrations (9 and 27 mM), the shoot root...

Analytical Methods

Two alternative methods are available to measure 15N abundance in samples mass spectrometry and emission spectrometry. Mass spectrometry is the only sufficiently precise method for measurements at the level of natural abundance, while emission spectrometry can only be used with enriched materials. Hence, mass spectrometry is the most commonly used technique (Knowles and Blackburn 1993). Before analysis, N in samples needs to be converted to N2. Two possible methods are available the Dumas and...

Increasing Microbial Stability of SOM by In Situ Catalyzed Polymerization of Humic Components

Soil Oxidative Enzyme Image

Understanding humus as a supramolecular association of small molecules means overcoming the limitations imposed by the paradigmatic polymeric model. In fact, another important implication of the supramolecular view of SOM resides in the fact that some self-assembled small soil humic molecules can then be coupled together into larger molecular weight materials, thereby increasing the amount of energy-rich intermolecular interactions (covalent bonds) in the superstructures. This would signify an...

Biological and Biotechnological Evaluation of Carbon Dynamics in Field Experiments

Carmine Crecchio, Silvia Pascazio, and Pacifico Ruggiero Abstract Bacteria and fungi play a key role in promoting soil organic matter (SOM) turn over and consequent nutrient availability to plants uptake. During SOM degradation, they contribute to transform highly complex biomolecules to smaller compounds, which are either immobilized by soil microflora or self-associated in humified and microbially stable superstructures. These processes rapidly occur in the rhizosphere where soil adheres to...

Materials and Methods 821 Experimental Setup

Bacteria diversity has been investigated in soils collected from the experimental sites of Torino, Napoli, and Piacenza (see Chap. 3) where the following soil management practices were applied for maize cropping COM traditional tillage (35 cm) and organic matter amendment consisting of 20 t ha of compost and corresponding to 260 kg N ha. TRA traditional tillage (35 cm) and chemical fertilization corresponding to 260 kg N ha. MIN minimal tillage (10 cm) and chemical fertilization as for TRA and...

Control Soils

The distribution of water-stable aggregates obtained from fractionating the initial soils before the start of field experiments revealed a marked influence of textural composition on soil structural properties in the three field sites (Table 4.2). The lowest aggregate stability was found for the silty-loamy soil of Torino that was characterized by both the lowest clay content (Table 4.1) and the largest yield of unstable microaggregates (< 0.25 mm). Conversely, the significantly larger...

I

Fig. 6.5 Coefficient of endogenous mineralization (CEM) of soils sampled from the Napoli (Na) and Torino (To) experimental sites. The values are mean SE. TRA conventional tillage, COM-2 compost amendment, MIN minimum tillage. CAT conventional tillage with addition of biomi-metic catalyst, No-CAT conventional tillage without catalyst. Different letters indicate significant differences among treatments (ANOVA-Holm-Sidak test p < 0.05) within site and year their interaction. CEM was always lower...

New Modeling Approach to Describe and Predict Carbon Sequestration Dynamics in Agricultural Soils

Stefano Mazzoleni, Giuliano Bonanomi, Francesco Giannino, Guido Incerti, Daniela Piermatteo, Riccardo Spaccini, and Alessandro Piccolo Abstract The contribution of agro-ecosystems to carbon sequestration in the form of soil organic matter (SOM) is increasingly considered as a mitigating factor for climate change. The ecosystem carbon storage depends on the balance between C inputs and outflows due to SOM breakdown. SOM decomposition has been reported as mostly affected by temperature and water...

References

Acosta-Mart nez V, Dowd S, Sun Y, Allen V (2008) Tag-encoded pyrosequencing analysis of bacterial diversity in a single soil type as affected by management and land use. Soil Biol Biochem 40 2762-2770 Boon N, De Windt V, Verstraete W, Top EM (2002) Evaluation of nested PCR-DGGE (denaturing gradient gel electrophoresis) with group-specific 16S rRNA primers for the analysis of bacterial communities from different wastewater treatment plants. FEMS Microbiol Ecol 39 101-112 Britschgi TB, Giovannoni...

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Fig. 10.4 Total length of (a) fine roots (< 1.2 mm) and (b) coarse roots (> 1.2 mm) within diameter classes in maize plants as in Fig. 10.1. Treatments acronyms and statistics as in Fig. 10.1. Asterisks indicate a statistically significant difference in respect to control (CONT Tukey's test, at p < 0.05) 10.3.2 Soil Chemical Properties and CO2 Emissions from Microcosm-Confined Plant-Soil Systems Compost amendment markedly affected all selected soil chemical properties. The pH and EC...

The Nature of Soil Organic Matter and Innovative Soil Managements to Fight Global Changes and Maintain Agricultural

Abstract A new era in soil management is emerging on the basis of the novel understanding of soil organic matter (SOM), as a noncovalent supramolecular association of small molecules surviving microbial degradation of plant and animal tissues. The recognition of such molecular nature of humus may have technological implications in agricultural soil management that are yet to be developed. Here we discuss the implications of the supramolecular structure of humus on innovative methods for carbon...

The Mechanism of Hydrophobic Protection of SOM to Sequester Carbon in Soil

The recognized importance of hydrophobicity in stable SOM has a relevant implication in soil carbon sequestration. In fact, the hydrophobic character of OM represents a biochemical hindrance to microbial decomposition (Piccolo et al. 1999 Spaccini et al. 2000), the basis for a persistent soil aggregate stability (Piccolo and Mbagwu 1999), and an overall SOM stabilization (Rumpel et al. 2004 Winkler et al. 2005 Zhou et al. 2010). The recalcitrant hydrophobic molecules are the constituents of the...

Microbial Counts

Microbial counts were performed according to Italian official methods (Picci and Nannipieri 2003). Briefly, soil samples (10 g) were shaken for 30 min in 90 ml of physiological solution containing 0.162 g of tetrasodium pyrophosphate to detach the bacteria from soil particles. After soil particles were allowed to settle for 15 min, the solution was diluted tenfold in a series. Selected populations of soil microbial community were detected at 28 C by using the Surface Spread Plate Count Method...

The Conformational Flexibility of Humic Supramolecular Structures

The energetic implications behind the supramolecular structure of SOM are well depicted by molecular simulations through conformational softwares. A minimization of conformational energy was conducted using HyperchemT 4.0 software to describe the interactions of humic supramolecular associations with an organic acid. Eleven different molecular structures of compounds identified as components of HS (Stevenson 1994) were grouped together in the simulation to form a supramolecular association. The...

Theoretical Scenarios and Future Applications

The SOMDY model presents some innovative features in comparison to other existing published models of decomposition processes of either litter or soil organic matter. In particular, this model is new in its capability to represent the interactions between the chemical nature of organic matter and its physical structure as mineral organic complexes in the soil. The concepts implemented in SOMDY allow capturing several complex phenomena that may play a major role in controlling labile component...

Preface

As part of the international quest to reduce greenhouse gas emissions into the atmosphere and on recommendation of the Kyoto Protocol, this book highlights alternatives to current soil management practices for turning agricultural soils into sinks of organic carbon. While common agronomic practices are based on traditional knowledge of soil transformation processes, this book indicates that modern or progressive understanding of complex biological systems in the soil ecosystem may already be...

Impacts of Desertification on Socio Economic Systems

Desertification is a cause of direct and indirect social and economic effects. The first approximation to assess the costs related to reduced productivity is the estimate of soil physical damages and loss of fertile soil. A United Nations source in 1992 reported that Turkey, Tunisia, and Morocco lost due to soil erosion 54,237, 18,000, and 2,200 ha of cultivated land each year, respectively (UNEP 1992). A more recent study (Matallo 2006), based on the use of the Universal Soil Loss Equation...

Microbial Biomass

Microbial biomass (Cmic) was determined by the SIR method (Anderson and Domsch 1978) that is based on the measurement of CO2 evolution from soil in response to addition of glucose, an easily mineralizable substrate. The magnitude of the respiratory response, as measured after incubation under controlled temperature and humidity conditions, is related to the amount of active biomass in the soil sample, and can be converted to mg of microbial biomass carbon using a conversion factor introduced by...

Conceptual Innovations

To meet the described need, it is required to introduce in agriculture more scientifically reliable, effective, and persistent soil management practices for carbon sequestration in soil. For the overall societal benefit, it is necessary to fully develop new technologies in agriculture with the added value given by advanced science that goes beyond traditional views. An important feature involved in the stabilization and accumulation of OC in soils and sediments is the quality of organic matter....

Organic Carbon in Bulk Soil and Water Stable Aggregate Sizes

Assessing the content of total SOC by an elemental analyzer (Interscience EA1108) is the simplest and most direct measurement to evaluate the effect of soil management practices and cropping systems on SOC accumulation or decomposition. However, an estimate of the total amount of organic carbon (TOC) in the bulk soil does not inform on the mechanism of SOM incorporation, but it is only an indirect evaluation of both SOM dynamics and stabilization process. A large number of chemical or physical...

Italian Research Supporting Climate Reporting

Two main lines are significant to improve estimations of GHG emissions from agriculture. A first line is related to collection of information on methods of agricultural production. For instance, agricultural statistics related to housing and storage facilities used by farmers and modality of land spreading are relevant information required by the inventory. Currently, the National Institute of Statistics (ISTAT), with the support of ISPRA, incorporated these specific queries in the 6th...

Effects of the Addition of Biomimetic Catalyst on Wheat Trials

A very innovative part of the MESCOSAGR project is the introduction of a soil management practice comprising the soil amendment with a biomimetic catalyst. This practice previews a stabilization and or improvement of soil organic carbon content by the in situ photo-polymerization of the humic soil fraction (Piccolo et al. 2005 Smejkalova et al. 2006 Gelsomino et al. 2010). Field results indicate that the treatments with the iron-porphyrin catalyst (CAT) had no effect in Napoli plots on total...

Napoli Experimental Site

Differently from previous experimental sites, the first year of cultivation produced a deterioration of soil structural properties in the field plots of Napoli (Table 4.5). With respect to the initial control soil, nearly all treatments showed lower yields of large size aggregates, with consequent decrease in soil stability index. The loss of structural stability in maize cultivated plots may be due to specific properties of the sandy-clay loam soil of this site. An exception was the soil...

Discussion of Results

We have used both bibliographic and original data from the MESCOSAGR project to compare the effects of C sequestration methods on selected biochemical indicators of soil quality, such as enzymatic activities and PLFAs. We found (Tables 7.1-7.6) that much information is available in literature in response to soil treatments such as addition of humified composted matter and different tillage systems, but it has never been summarized and critically evaluated. In the case of the carbon...

General Remarks as Rationale for Future Experimentations

Our overall results highlighted some general remarks that are summarized as it follows 1. On the basis of the long-term data set on field fluxes that was obtained for the Napoli site, we hypothesize a root effect on soil N2O fluxes. It appears that the N dependence of N2O fluxes could be strictly linked with crop phase and soil water content. During the early growth phase of the maize crop, where the root system was still poorly developed, nitrifiers and denitrifiers did not compete with roots...

Impacts of Floods and Landslides on Socio Economic Systems

Although floods are natural events in ecological and agricultural systems, they may cause considerable damages, including mainly loss of people lives. Serious damages are also due to the impact on houses and industrial structures of debris 2003 2004 2005 2006 2007 2008 2009 Year Fig. 2.1 Number of landslides in Europe from 2003 to 2009 (from Spizzichino et al. 2010) 2003 2004 2005 2006 2007 2008 2009 Year Fig. 2.1 Number of landslides in Europe from 2003 to 2009 (from Spizzichino et al. 2010)...

Measurements of CO2 and N2O Emissions in the Agricultural Field Experiments of the Mescosagr Project

Abstract Soil organic matter (SOM) under agricultural management is a labile reservoir of C in the planet, and plays a key role in the production and emission to the atmosphere of two main greenhouse gases, CO2 and N2O. This chapter will overview one of the activities of the MESCOSAGR project that is the monitoring of CO2 and N2O emissions from soils under different agronomic treatments. The first part highlights the primary importance at global scale of SOM related to climatic change and...

The Risks of Climate Change

The Fourth Assessment Report (FAR) from the IPCC (2007a) confirms that the consequences of climate change will not only be restricted to an increase in average planet temperature, but it will also entail the change of the entire climate system, including precipitation, wind, frequency and intensity of extreme events, having different impact in the diverse world regions. Studies carried out with global circulation models (GCM) and regional circulation models (RCM) with regard to Europe have both...

Water Stable Soil Aggregates and Soil Stability

The dynamics of SOM is closely related to soil physical properties, such as particle sizes distribution and soil aggregation (Tisdall and Oades 1982). Organic matter components are involved in the different steps of soil aggregate hierarchy, from the formation of organo-mineral complexes up to stabilization of aggregate-size classes (Oades and Waters 1991 Six et al. 2004). Since the role of OM in soil physical aggregation determines the processes of OC decomposition and accumulation (Plante and...

Soils Characteristics and Experimental Setup

Three different experimental sites along a North-South climate gradient were chosen to setup soil treatments. Soil classification textural composition and organic carbon content of the selected soils are shown in Table 4.1. The effect of mature compost addition on soil carbon sequestration was evaluated by comparing the following field management during a 3-year experiment (2006-2008), using a monocolture of mais (Zea mais) as annual crop (see Chap. 3) Table 4.1 Textural composition ( ), bulk...

Measurements of CO2 and N2O Fluxes from Soil 921 State of the Art on Soil Gases Measurements

Although agricultural soils are important source of anthropogenic CO2 and N2O, no alternative soil managements have been developed to limit their fluxes, particularly for N2O. Since pedo-climatic conditions are key factors, a monitoring activity at territorial scale is needed, not only for testing different soil managements but also to obtain data from Mediterranean soil-crop systems. Freibauer (2003) has pointed out already that large uncertainties are present in the GHGs inventory for...

Principal Component Analysis of NMR Spectra of Humic Substances Extracted from Soil Treatments

In order to compare the effect produced by soil treatments on the molecular composition of HS extracts at different experimental times, the areas of C signals in NMR spectra were integrated and their values elaborated with principal component analysis (PCA). The multivariate analysis for the first and third experimentation year at Torino, Piacenza, and Napoli sites of the MESCOSAGR project is shown in Figs. 4.3-4.5, respectively. The relative values ( ) associated with the x and y axes in PCA...

Effects of Methods of Carbon Sequestration in Soil on Biochemical Indicators of Soil Quality

Abstract Here we describe the effects of carbon sequestration managements on soil enzymatic activities and PLFA patterns, as viable parameters to establish soil biochemical quality and its changes. We extensively review the available scientific literature related to experimental results on soil enzymatic activities and PLFA values from different soil treatments. This knowledge was then compared with the experimental results obtained within the MESCOSAGR project. It was found that MESCOSAGR...

Monitoring System in Field Plots

Within the MESCOSAGR project, soil CO2 and N2O fluxes were measured for each soil treatment in both the experimental sites of Torino (Tetto Frati) and Napoli (Torre Lama). Detailed information of study sites and experimental design are described elsewhere (Chaps. 3 and 4). Two periods of gas-fluxes measurements (May 21-28 and July 16-24) were carried out in Torino (Tetto Frati) during the maize crop in 2008. The first period in May began immediately after nitrogen fertilization (where...

Concluding Notes on Soil Organic Carbon

The field experiments of the MESCOSAGR project have provided sound indications that the innovative soil treatments, such as amendment with mature hydrophobic compost and in situ SOC photo-polymerization through biomimetic catalysis, sequestered carbon and stabilized SOM more than conventional soil management practices. In fact, the variability in SOC content throughout the experimentation period shown by both MIN and GMAN suggests that these treatments were not able to persistently stabilize OC...

The Humified SOM Fraction and Its Characterization by Nuclear Magnetic Resonance Spectroscopy

The humified organic matter in soil, operationally separated in humic acid (HA), fulvic acid (FA), and humin (HU), is considered the most microbially stable reservoir of SOC, and the most important component for the maintenance of the soil physical-chemical and biological quality (Piccolo 1996). While the operationally non-extractable HU is the most passive fraction of humified matter (Hayes et al. 1989 Simpson et al. 2007), the extractable humic and fulvic fractions exert the essential role of...

Chapter

Carbon Sequestration in Soils by Hydrophobic Protection and In Situ Catalyzed Photo-Polymerization of Soil Organic Matter (SOM) Chemical and Physical-Chemical Aspects of SOM in Field Plots Riccardo Spaccini and Alessandro Piccolo Abstract The application of innovative practices of soil organic matter (SOM) management, based on either soil amendment with hydropohobic mature compost or with a water-soluble biomimetic catalyst, has shown to enhance organic carbon sequestration in agricultural...

NMR Spectra of Initial Soils and Composts Before Amendments

Mvb Pathwy

The 13C-CPMAS-NMR spectra of compost used for field treatments in the three experimental sites are shown in Fig. 4.1, whereas the relative distribution of signal areas is reported in Table 4.9. Since compost samples had a common origin, a similar C distribution was found in NMR spectra. The spectra of mature composts were dominated by the alkyl-C (0-45 ppm) and O-alkyl-C (60-110 ppm) signals. The alkyl-C region comprised a prominent peak at around 30 ppm, mostly due to methylene carbon chains...

Results and Discussion

5.7.4.1 Carbon Isotopic Signature in the Sorghum Plants Figure 5.2 shows the average isotopic signature of various parts of the sorghum plant, as evaluated at the end of the vegetative cycle. Generally, data indicated that the roots were more 13C-enriched than the grain and leaves, and in the first 15 cm of roots appeared more 13C-enriched than at deeper soil depths. Our results are consistent with previous studies on isotope ratios in plant biomass which showed that roots are generally more...

Effects of Soil Tillage

Deep soil tillage is the crop management with most impact on soil properties (Fagnano and Quaglietta Chiaranda 2008). Soil tillage may have contrasting agronomic and environmental effects on soil structure and aeration of the tilled layer. The destruction of soil aggregates decreases macroporosity and infiltration rate, with enhanced risk of soil erosion and reduced oxygen diffusion rate. The consequent anaerobic conditions limit root growth and may increase denitrification and methanogenesis...

Effects of the Biomimetic Catalyst

Metal Sequestration

Humic substances comprise the major part of stable organic matter in environmental compartments and their formation and decomposition processes regulate global carbon cycling. An increase in the conformational stability of humus may be achieved by increasing the intermolecular covalent bonds among heterogeneous humic molecules through a photo-oxidative coupling mediated by a biomi-metic (enzyme-like) catalyst, such as synthetic water-soluble metal-porphyrins (Piccolo et al. 2005). It was found...

The Stable Isotopes Approach to Study C and N Sequestration Processes in a Plant Soil System

Giuseppe Celano, Francesco Alluvione, Mostafa Abdel Aziz Ali Mohamed, and Riccardo Spaccini Abstract This chapter reviews the main methods for tracing N and C stable isotopes in natural and agricultural systems following organic and mineral amendments to soil. Moreover, we present the results obtained from two field experiments conducted, within the MESCOSAGR project, to evaluate either the fate and flow rate of N added as 15N-compost in a maize-soil system or the contribution of sorghum roots...

Natural Abundance Method

The use of 13C NAM in soil studies provides a highly accurate method to trace carbon transfer among pools, and has been successfully used in studies on SOC dynamics (Martel and Paul 1974 Nissenbaum and Schallinger 1974 Leavitt et al. 1994 Paul et al. 2001 Stevenson et al. 2005). NAM is based on the discrimination of 13C and 12C isotopes during CO2 assimilation by plants due to different photosynthesis pathways, which lead to plants with distinct d13C values. Plants with a C3 photosynthetic...

Cloning of PCR Amplicons

PCR amplicons were cloned by the pGEM -T Easy Vector Systems (II) kit (Promega) (Felske and Weller 2004). 5 U of T4 DNA ligase were used to ligate PCR products for 16 h at 4 C into pGEM-T vector at an insert plasmid ratio of 6 1. The ligation product was added to 50 ml of E. coli JM109 competent cells and the transformation was carried out by heating for 45 s at 42 C, cooling in ice, and incubating at 37 C for 90 min under shaking (750 rpm) in SOC growth medium (20 g Bacto -tryptone, 5 g Bacto...

Soil Properties

Soil properties are different among experimental sites (Table 3.3), with soil texture the most distinct. In top layers, soil texture was sandy loam for TO with a low content of clay (7-8 ), while it was silty clay loam in the other two experimental sites with a clay content of 30-33 at NAP and of 31-40 at BAS. SOM was larger in TO (1.7-1.8 ) than in both NA (1.2 ) and BAS (1.1-1.2 ). Total N was greater and exchangeable K2O smaller in TO than for the other two sites. Soil classification (USDA...

Materials and Methods 1021 Microcosm Style Experiments 10211 Experimental Setup

The microcosm-scale experiment was carried out in a greenhouse facility of the Mediterranean University of Reggio Calabria. The microcosms consisted of 9.5 L PVC pipes (30 cm height x 20 cm diameter) filled with approximately 13 kg of a soil perlite (80 20, v v) mixture. The soil was a clay loam sand 36.0 , silt 32.0 , clay 32.0 bulk density 1.23 0.04 kg dm-3 pH-H2O 7.2 0.2 pHKa 6.4 0.1 total organic C (TOC) 19.3 0.4 g (kg dw dry weight basis soil)-1 total N (TN) 1.8 0.2 g kg-1 C N ratio 10.7...

Model Description 1121 Concept

The SOMDY model presented here has been conceived to represent soil organic matter dynamics taking into account the following major issues - Improved definition of chemical composition of SOM - Assessment of SOM physical structure - Chemical and physical protection effects on mineralization processes - Microbial turnover and chemical evolution of SOM during the decomposition - Impact of agricultural practices on SOM dynamics Then, the general structure and logic of SOMDY model is represented in...

Impact of Different Agricultural Practices on Soil Microbial Communities The Mescosagr Case Study

Within the National project MESCOSAGR, we investigated the impact on soil microorganisms of two innovative technologies applied to sequester carbon in agricultural soils. The hypothesis was that the structure and activity of microbial communities would be influenced by (1) addition of compost, a humified and hydrophobic material that protects the easily degradable organic fraction, and (2) in situ photo-oxidative polymerization of native SOM under the action of a biomimetic catalyst (CAT)...

Extraction and Purification of Nucleic Acids

Total DNA was extracted adopting the direct lysis method by using the FastPrep System, a bead beater that allows to desorb microbial cells from soil particles and provides a large lysis yield. In combination with the commercial FastSPIN kit Fig. 8.1 Flow sheet of employed molecular techniques Fig. 8.1 Flow sheet of employed molecular techniques for Soil (MoBio) this method gives a highly purified DNA from small amount (0.5 g) of soil. One milliliter of sodium phosphate buffer and 0.1 ml lysis...

Nitrogen Dynamics in Soil Plant Systems

The 15N tracer technique can be applied to evaluate both the net gross mineralization rates of indigenous or added N, and the efficiency of plants to assimilate added N (Barraclough 1995). If the objective is to estimate the plant assimilation of added N, it is usually not convenient to use N tracers, and a lower cost alternative is to apply non-isotopic techniques (Powlson and Barraclough 1993). There are two methods (a) Control plot method N uptake of the unfertilized crop is subtracted from...

Microbial Activity

Soil Microb Key Effect Carbon

Soil microbial activity can be estimated by measuring CO2 respired from soil, as a well-established parameter to monitor SOM decomposition (Anderson 1982). Soil respiration is highly variable and its natural fluctuation depends on substrate availability, moisture, and temperature (Alvarez et al. 1995 Brookes 1995). For valid comparisons among soils, respiration measurements must be conducted under controlled laboratory conditions (Anderson 1982). Here, the basal respiration of soil samples was...

Conclusion and Future Recommendations

First of all, our results highlight the importance of combining different approaches to obtain complementary information on the microbiological status of agricultural soils. Amendment with compost appears to have a promising environmental application, although its use depends on soil texture and clay content, as shown by our studied sites. In fact, compost was found to decrease cultivable microorganisms, microbial carbon, and coefficient of SOM mineralization in clayey soils, possibly due to an...

Implications in Soil of the Supramolecular Structure of Humus

A clarification of the aggregate structures of HS has represented a major innovation in humus chemistry. A model of soil humus as a supramolecular association of small molecules, originated from extended microbial degradation of different plant Fig. 1.3 Computer simulation of the optimum conformational energy (in vacuo) of a hypothetical covalently linked humic polymer (MW 6,326 Da) as hypothesized by Stevenson (1994). (a) Upper picture humic polymer having an energy of 627.40 Kcal mol_1 (b)...

The Kyoto Protocol and European and Italian Regulations in Agriculture

Davide Savy, Antonio Nebbioso, Roc o Danica Condor, and Marina Vitullo Abstract Climate change represents the most important challenge for the international scientific community, for the inherent and irreversible modification brought about in natural ecosystems. International institutions increasingly adopt measures to promote preservation of ecosystems and counteract the social and economical consequences of environmental decline. Here we review the actions undertaken by both the...

Italian Greenhouse Gas Emissions

Emission estimates comprise ten GHG carbon dioxide, methane, nitrous oxide, HFCs, PFCs, sulfur hexafluoride, nitrogen oxides, carbon monoxide, non-methane volatile organic compounds, sulfur dioxide. The first six GHGs directly contribute to climate change owing to their positive irradiative forcing effect. The national Kyoto target is a reduction in the period 2008-2012 of 6.5 of GHG, as compared to the 1990 base year level. In spite of it, total GHG emissions, in CO2 equivalent, decreased by...

Concluding Notes on Soil Physical Quality

As mentioned earlier, the yields of aggregate fractionation and values of soil stability index suggested a predominant influence of specific texture and clay content on the physical and structural properties of soils. However, all treatments in each site, despite the specific soil structural properties, showed a comparable macroaggregate dynamics throughout the experimental period, consisting first in a decrease and then in a recovery of soil stability. In fact, our results revealed a similar...

Active Fungal Mycelium

Metabolically active hyphae were estimated by fluorescence microscopy. Soil samples were sieved through a 2-mm mesh, suspended in a solution (1 g of fresh soil in 100 ml) of phosphate buffer (60 mM, pH 7.5), and homogenized at 6,000 rpm for 2 min. 0.5 ml of suspension were collected and filtered under vacuum on nitrocellulose filter with a pore size of 0.45 mm. The sample was treated with fluorescein diacetate (FDA) (Soderstrom 1977, 1979). This stain penetrates rapidly in cells and is...

Enzymatic Activities and Soil Carbon Sequestration Strategies

The expression enzymatic activities is usually preferred to enzymes, the reason being that applied methods do not isolate and measure the enzyme itself in soils, but quantify (mainly by absorbance or fluorescence) the rate of transformation of an enzyme substrate added to soil. Already in the 1940s a paper was published reporting the effect of copper nitrogen complex on soil potential nitrification, as assessed by this substrate-induced approach (Lees 1946), and it was followed by a series of...

Contributors

Maria Rosa Abenavoli Dipartimento BIOMAA, Universita Mediterr nea, Reggio Calabria, Italy Francesco Alluvione Dipartimento di Agronomia, Selvicoltura e Gestione del Territorio, Universita di Torino, Turin, Italy Mariana Amato Dipartimento di Scienze dei Sistemi Colturali, Forestali e dell' Ambiente, Universita della Basilicata, Potenza, Italy Maurizio Badiani Dipartimento BIOMAA, Universita Mediterranea, Reggio Calabria, Italy Chiara Bertora Dipartimento di Agronomia, Selvicoltura e Gestione...

Carbon Sequestration References

Aita C, Recous S, Angers DA (1997) Short-term kinetics of residual wheat straw C and N under field conditions characterization by 13C15N tracing and soil particle size fractionation. Eur J Soil Sci 48 283-294 Angers DA, Voroney RP, Cote D (1995) Dynamics of soil organic matter and corn residues affected by tillage practices. Soil Sci Soc Am J 59 1311-1315 Bakken LR (1990) Microbial growth and immobilization mineralization of N in the rhizosphere. Symbiosis 9 37-41 Balesdent J, Balabane M (1992)...

The Supramolecular Structure of SOM

A major breakthrough in understanding SOM chemistry in the last decade came with the recognition that soil humus is a self-assembled supramolecular associations of small heterogeneous molecules held together mainly by weak hydrophobic linkages, rather than being composed of large molecular weight macropolymers (Piccolo 2001). Humus, otherwise referred to as Humic Substances (HS), is the natural organic matter comprising up to 80 of SOM. Because of the beneficial effects that HS have on the...

Effects of Cover Crops Mulching and Green Manure

Cover and catch crops, mulch, residue, and green manure provide many services to agroecosystems, from erosion and weed control to deposition and protection of organic matter (Jackson 2000) and promotion of genes for disease resistance (Kumar et al. 2004). Some of such services reduce yield of the main crop, especially in intercropping systems and in environments where water and or nutrients availability are limited. Therefore appropriate management is required, and trade-offs between ecological...

SOM Chemical Composition and Physical Aggregation

In the model, soil organic matter is a state variable represented by the sum of dissolved (DOM) and aggregated organic matter (AOM). Addition of exogenous organic matter (EOM) is also taken into account with external inputs added to DOM and partitioned according to their specific chemical composition. Solid-state 13C NMR spectroscopy has been used to assess the chemical composition of organic matter in litter decomposition studies, with different classes of organic-C compounds related to...

Soil Amendment with Biomimetic Catalyst Under Wheat Trials

The action of the iron-porphyrin biomimetic catalyst, at the rate of 10 kg ha-1, was tested at TO and NA in soils cropped with wheat (Triticum aestivum L., cv. Blasco). In 10 m2 plots (three replications per site), aim2 soil surface was identified where iron-porphyrin was distributed before wheat emergence at the rate of 1 g m-2 (previously dissolved in 21 of water). All plots were plowed at 30 cm and wheat was fertilized at the rate of 130 kg N ha-1 with ammonium nitrate. Phosphorus and K...

Effects of Carbon Sequestration Methods on Soil Respiration and Root Systems in Microcosm Experiments and In Vitro

Antonio Gelsomino, Maria Rosaria Panuccio, Agostino Sorgona, Maria Rosa Abenavoli, and Maurizio Badiani Abstract In the framework of an interdisciplinary research devoted at increasing soil capacity to act as carbon sink by means of innovative and sustainable strategies (the MESCOSAGR Project), we studied, in microcosm-scale model systems, changes of selected soil chemical properties, soil CO2 efflux, and root morpho-topology after addition of either mature compost or a biomimetic catalyst...

Sustainable Agriculture to Reduce Environmental Impact Soil Organic Matter as a Source and Key Factor of Greenhouse

Croplands play a key role for the sustainability of world's life. The exponential growth of global population and the need to produce alternative energy to fossil fuel has placed increased demands on agriculture to produce more food and biomass. For these reasons the agriculture poses a huge challenge for the sustainability at global and local environments, because of the different forms of environmental impacts related to agricultural management. The loss of soil organic matter (SOM) through...

Experimental SetUp and Soil Climatic Conditions for Maize Trials

Maize (TO and NA) and sorghum (BA) were grown in the field sites because their large N demand is liable to better reveal the treatment effects. Soil treatments at the TO and NA sites were the following 1. TRA traditional soil tillage (moldboard plowing, 30 cm deep), mineral fertilization with urea at the rate of 130 kg ha-1 of N. 2. MIN minimum tillage (rotary hoeing, 10 cm deep), mineral fertilization with urea at the rate of 130 kg ha-1 of N. 3. GMAN green manure with hairy vetch (Vicia...

Impact of Innovative Agricultural Practices of Carbon Sequestration on Soil Microbial Community

Valeria Ventorino, Anna De Marco, Olimpia Pepe, Amalia Virzo De Santo, and Giancarlo Moschetti Abstract This chapter deals with the impact on soil microbiology of innovative management techniques for enhancing carbon sequestration. Within the MESCOSAGR project, the effect of different field treatments was investigated at three experimental sites differing in pedo-climatic characteristics. Several microbiological parameters were evaluated to describe the composition of soil microbial communities...

Pulse Labelling Method

The pulse labelling method (PLM) is based on the artificial labelling of plants. The technique can be roughly divided into three methods based on the levels of 13C enrichment achieved in the plant-soil system natural abundance (Heim and Schmidt 2007 Klumpp et al. 2007 Thornton et al. 2004), near natural abundance (50-500 ) (Evershed et al. 2006 Leake et al. 2006) or (highly) enriched > 500 (Zak and Kling 2006). Shoots are exposed to CO2 in an atmosphere labelled with 14C, 13C or C. The shoots...

The Concept of Humification

It has been increasingly proved that simple, mainly alkyl, recalcitrant organic compounds deriving from both plant residue decomposition and microbial resyn-thesis are progressively incorporated into the most stable SOM fractions (Piccolo 1996 Lichtfouse 1998). Piccolo (1996) proposed that hydrophobic humic components in soil protect easily degradable compounds. He postulated that incorporation of polar molecules in associations of hydrophobic components may contribute to prevent an otherwise...

N2O Production and Emission from Soils

Soil N2O production and emission is directly related to land use and soil management practices, since it is the biogenic product of microbial processes of denitrifi-cation and nitrification, as affected by physical-chemical characteristics of soil. Bacterial denitrification is a respiratory reduction of nitrate and or nitrite to gaseous NO, N2O and N2, coupled to phosphorylation electron transport. Many aerobic microorganisms use NO3 as electron acceptor to derive energy from organic compounds...

Microbial Parameters as Indexes of Soil Quality

Because of the fundamental role in mediating soil processes and the responsiveness to soil managements, microbial abundance, diversity, and activity are among the most important soil quality parameters (Andrews and Carroll 2001 Karlen et al. 2001, 2003 Andrews et al. 2003 Anderson and Domsch 2010). In fact, the effect of agricultural management on microbial community is directly related to changes in soil quality (Schloter et al. 2003), that encompass the size and diversity of specific...

Tracing N in Landscapes

Bedard-Haughn et al. (2003) reviewed the use of 15N as a tracer for N cycling in landscapes. They concluded that natural 15N abundance can provide valuable estimates of the contribution of different sources or identify variation in landscape processes. Unfortunately, the large 15N spatial and temporal variabilities can limit source discrimination by masking sources' differences, whereas 15N-enriched materials are widely accepted as tracers. The use of N-enriched materials is limited by their...

Scaling Up Innovative Concepts into Agricultural Field Experiments

The described innovative concepts whose theoretical mechanism and functioning were derived from laboratory experiments, need not only to be verified in real field scale conditions, but also to be proved harmless to the physical, chemical, nutritional, and biomolecular quality of soils. This overall objective was looked for in the MESCOSAGR project. At the basis of this project there was the intention to go beyond the traditional practices for carbon sequestration and put in practice the...

Units of Measurement

The units of measurement for 15N tracer materials are aimed at expressing the relative abundance of 15N compared to 14n using different notations. There are two main units of measurement one is commonly used with 15N-enriched materials, while the other approach is more useful when natural variations in 15N abundance are used to trace N. The unit expresses the isotope abundance as a percentage It is also common to express the 15N abundance as a variation with respect to N2 natural abundance,...