Linking dissolved organic carbon, acetate and denitrification in agricultural soils

Castaldelli, Giuseppe; Colombani, Nicolò; Vincenzi, Fabio; Mastrocicco, Micòl

doi:10.1007/s12665-012-1796-7

Cited by 37 publications

(23 citation statements)

References 26 publications

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“…The sampling site had an overall surface of 190,000 m 2 , divided into four fields ( Figure 1 ). Soil samples were collected through grid sampling (n = 23) from an area that had been previously studied with reference to nitrogen fertilization and presently under study for increasing carbon storage and soil organic matter [ 24 ]. An additional 16 samples, to be used as an external validation set, were collected within the same field in points different from the grid sampling and were randomly chosen from topsoil and subsoil.…”

Section: Methodsmentioning

confidence: 99%

Effects of Moisture and Particle Size on Quantitative Determination of Total Organic Carbon (TOC) in Soils Using Near-Infrared Spectroscopy

Tamburini

Vincenzi

Costa

et al. 2017

Sensors

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Near-Infrared Spectroscopy is a cost-effective and environmentally friendly technique that could represent an alternative to conventional soil analysis methods, including total organic carbon (TOC). Soil fertility and quality are usually measured by traditional methods that involve the use of hazardous and strong chemicals. The effects of physical soil characteristics, such as moisture content and particle size, on spectral signals could be of great interest in order to understand and optimize prediction capability and set up a robust and reliable calibration model, with the future perspective of being applied in the field. Spectra of 46 soil samples were collected. Soil samples were divided into three data sets: unprocessed, only dried and dried, ground and sieved, in order to evaluate the effects of moisture and particle size on spectral signals. Both separate and combined normalization methods including standard normal variate (SNV), multiplicative scatter correction (MSC) and normalization by closure (NCL), as well as smoothing using first and second derivatives (DV1 and DV2), were applied to a total of seven cases. Pretreatments for model optimization were designed and compared for each data set. The best combination of pretreatments was achieved by applying SNV and DV2 on partial least squares (PLS) modelling. There were no significant differences between the predictions using the three different data sets (p < 0.05). Finally, a unique database including all three data sets was built to include all the sources of sample variability that were tested and used for final prediction. External validation of TOC was carried out on 16 unknown soil samples to evaluate the predictive ability of the final combined calibration model. Hence, we demonstrate that sample preprocessing has minor influence on the quality of near infrared spectroscopy (NIR) predictions, laying the ground for a direct and fast in situ application of the method. Data can be acquired outside the laboratory since the method is simple and does not need more than a simple band ratio of the spectra.

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Section: Methodsmentioning

confidence: 99%

Effects of Moisture and Particle Size on Quantitative Determination of Total Organic Carbon (TOC) in Soils Using Near-Infrared Spectroscopy

Tamburini

Vincenzi

Costa

et al. 2017

Sensors

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“…The aim of the present work was to evaluate the relative importance of soil denitrification in buffering N excess at the watershed scale in a deltaic, intensively cultivated, and irrigated sub-basin of the Po River plain, the Po di Volano-Sacca di Goro. This basin was selected as a case study for the following reasons: (1) the homogeneous cropping system, i.e., maize and winter cereal rotation in about two-thirds of the agricultural lands developing in a completely flat territory; (2) the N fertilization supplied almost exclusively as synthetic urea and ammonium nitrate; (3) the capillary network of canals distributing irrigation water in the spring-summer period; (4) the extensive information available on hydrogeological and microbial drivers regulating N processing and transport in surface waters [18,19], soil water [20,21], and groundwater [22,23].…”

Section: Introductionmentioning

confidence: 99%

In Search for the Missing Nitrogen: Closing the Budget to Assess the Role of Denitrification in Agricultural Watersheds

et al. 2020

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Although representing a paramount mechanism against nitrogen excess in agricultural landscapes, soil denitrification is still a largely unknown term in nitrogen balances at the watershed scale. In the present work, a comprehensive investigation of nitrogen sources and sinks in agricultural soils and waters was performed with the aim of gaining insights into the relevance of soil denitrification in a highly farmed sub-basin of the Po River delta (Northern Italy). Agricultural statistics, water quality datasets, and results of laboratory experiments targeting nitrogen fluxes in soils were combined to set up a detailed nitrogen budget along the terrestrial–freshwater continuum. The soil nitrogen budget was not closed, with inputs exceeding outputs by 72 kg N·ha−1·year−1, highlighting a potential high risk of nitrate contamination. However, extensive monitoring showed a general scarcity of mineral nitrogen forms in both shallow aquifers and soils. The present study confirmed the importance of denitrification, representing ~37% of the total nitrogen inputs, as the leading process of nitrate removal in heavily fertilized fine-texture soils prone to waterlogged conditions.

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“…Specialized functioning (e.g. denitrification) is largely assumed to be highly dependent on microbial communities (Philippot et al 2013;Powell et al 2015), due to its high dependency on particular physiological pathways; however, despite this, it has been commonly reported to be more sensitive to resource availability than to microbial community (Robertson & Groffman 2007;Wang et al 2013;Castaldelli et al 2013;Graham et al 2014). The above suggests that our current knowledge on how microbial communities and soil properties interact to drive these two types of ecosystems functions is limited (Schimel, Bennett & Fierer 2005;Peter et al 2011).…”

Section: Introductionmentioning

confidence: 99%

Relative importance of soil properties and microbial community for soil functionality: insights from a microbial swap experiment

et al. 2016

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Summary The most accepted theories in soil ecology suggest that broad (e.g. respiration) and specialized (e.g. denitrification) functions are affected differently by resource availability and microbial communities in terrestrial ecosystems. However, there is a lack of experimental approaches quantifying and separating the role of microbial communities from the effect of soil abiotic properties on different aspects of soil ecosystem functionality. Here, we conducted a full‐factorial design microcosm experiment and used random forest and structural equation modelling (SEM) analyses to evaluate the role and the relative importance of soil properties (sterile soils A, B and C differing in abiotic attributes) and microbial communities (microbial inoculums from soils A, B and C) in driving soil respiration (i.e. broad functioning), denitrification (i.e. specialized functioning) and four enzyme activities and carbon (C) and nitrogen (N) availability in soil. Soils with the higher total C (soils B and C) promoted the highest soil C and N availability, enzyme activities and broad functioning (i.e. soil respiration); however, we did not find any effect of total C on specialized functions (i.e. denitrification rates). Random forest analyses showed that both soil properties (i.e. total C and pH) and microbial abundance determined broad functioning (i.e. soil respiration), as well as the production of enzyme activities, and C and N availability in soil. However, we found that microbial communities were more important than soil properties for modulating specialized functioning (i.e. denitrification rates) in soil environments. Finally, our SEM also indicated that broad functioning, which is widely distributed across living organisms, is limited by both resource availability and microbial abundance. Furthermore, specialized functioning, which is conducted by particular groups of organisms, may be highly sensitive to changes in the microbial community. Overall, our findings provide direct experimental evidence for the relative importance of soil properties and microbial communities on broad and specialized functioning. Such evidence helps advance our understanding of different drivers of soil ecosystem functioning which will be crucial to developing an ecologically relevant theory about below‐ground ecosystem functioning. A http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.12674/suppinfo is available for this article.

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Linking dissolved organic carbon, acetate and denitrification in agricultural soils

Cited by 37 publications

References 26 publications

Effects of Moisture and Particle Size on Quantitative Determination of Total Organic Carbon (TOC) in Soils Using Near-Infrared Spectroscopy

Effects of Moisture and Particle Size on Quantitative Determination of Total Organic Carbon (TOC) in Soils Using Near-Infrared Spectroscopy

In Search for the Missing Nitrogen: Closing the Budget to Assess the Role of Denitrification in Agricultural Watersheds

Relative importance of soil properties and microbial community for soil functionality: insights from a microbial swap experiment

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