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Rates of nitrogen transformations support quantitative descriptions and predictive understanding of the complex nitrogen cycle, but measuring these rates is expensive and not readily available to researchers. Here, we compiled a dataset of gross nitrogen transformation rates (GNTR) of mineralization, nitrification, ammonium immobilization, nitrate immobilization, and dissimilatory nitrate reduction to ammonium in terrestrial ecosystems. Data were extracted from 331 studies published from 1984–2022, covering 581 sites. Globally, 1552 observations were appended with standardized soil, vegetation, and climate data (49 variables in total) potentially contributing to the observed variations of GNTR. We used machine learning-based data imputation to fill in partially missing GNTR, which improved statistical relationships between theoretically correlated processes. The dataset is currently the most comprehensive overview of terrestrial ecosystem GNTR and serves as a global synthesis of the extent and variability of GNTR across a wide range of environmental conditions. Future research can utilize the dataset to identify measurement gaps with respect to climate, soil, and ecosystem types, delineate GNTR for certain ecoregions, and help validate process-based models. [ABSTRACT FROM AUTHOR]

The current guidelines of waste management are aimed at the recovery and recycling of biowaste while respecting the protection of human health and the environment. The recent European legislation on fertilizers provides for the use of digestates derived from the organic fraction of municipal solid waste (OFMSW). The objectives of this study were to verify the fertilizing effect of three types of OFMSW digestates on the ryegrass culture comparing mineral fertilization and to evaluate the nitrogen lost to leaching in soil diversely fertilized following simulated rainfall. The ryegrass was grown in pots. The soil was fertilized with mineral fertilizer or OFMSW digestates. For each treatment, five mowing procedures were performed on the crop, and the ryegrass biomass production and nitrogen concentration were determined from the ryegrass samples. During the experiment, six rains were simulated, and the leached nitrogen was analyzed. The results showed that: (i) the fertilizing effect of OFMSW digestates on nitrogen nutrition of ryegrass was similar to ammonium sulphate fertilization, confirming the agronomic validity of these by-products to reduce the use of synthetic fertilizers; (ii) soil fertilization with OFMSW digestates had a positive effect limiting nitrogen loss due to leaching compared to mineral fertilization, highlighting the soil-improving properties of these by-products, in particular of the composted digestate. [ABSTRACT FROM AUTHOR]

Old-growth forests play a key-role in reducing atmospheric carbon dioxide (CO2) concentrations by storing large CO2 amounts in biomass and soil over time. This quantifies the carbon pool into different forest compartments in three Mediterranean old-growth forests of Southern Italy populated by Pinus laricio, Fagus sylvatica and Abies alba. Ecosystem carbon pools have been assessed per compartment, i.e., living trees, deadwood, litterfall (foliar and woody), roots and 0–20 cm topsoil, combining the whole old-growth forest mass, (i.e., using tree allometric relationships, deadwood factor conversions, root-to-shoot ratios, litterfall and soil samplings) by the respective organic carbon concentrations. The results show the considerable capacity of these forest ecosystems in storing CO2 in biomass and soil, with carbon pool values ranging from 532.2 to 596.5 Mg C ha−1. Living trees and 0–20 cm topsoil had larger carbon pool, contributing 53.0 and 22.1%, respectively. In most cases, organic carbon concentration was higher (more than 60%) than the average carbon conversion rate of 50%, especially in living trees, deadwood, and woody litterfall. This study contributes further scientific evidence of the capacity of old-growth forests in storing CO2 in their different compartments, with special evidence on tree biomass, litterfall and mineral soil, thereby highlighting the key role of old-growth forests within the challenge of climate change mitigation. [ABSTRACT FROM AUTHOR]

In the Mediterranean area many organic farms oriented toward the marketing of fresh products or toward agro-food processing have been interested in the conversion of at least a part of their horticultural production to natural cultivation systems in order to supply "natural" food to satisfy a particular market demand. In this study, the role of natural agriculture has been investigated in order to evaluate its effects in environmental safeguarding and organic farm production, contrasting soil erosion and soil organic matter decline, maintaining general soil fertility on hilly farms and supporting income in the context of climate change. This study is a field trial on a hilly farm, which compared a natural plot to an organic one. It showed that in the plot conducted with natural farming, total soil organic C increased significantly compared to the organic plot, from 1.97% to 4.16%. In organic farming system a significant increase of Total Organic Carbon (TOC) at the lower part of plot was observed as a consequence of soil loss (+ 25%). An economic analysis of the two farming systems on four farms, carried out considering the average costs and the average revenues, highlighted for the first time the greater profitability of natural cultivation compared to organic farming (+43%). The balance between safe food production, natural resources management and economic performance, obtained by substituting the organic farming with natural techniques, provides new and effective resilient agricultural practices to the organic farm sector. [ABSTRACT FROM AUTHOR]

Lepidoptera are the phytophagous group most at risk of impact by insect-resistant genetically modified (GM) plants since most of these crops have been developed to express toxins to specifically target lepidopteran pests. In the case of Bt-maize cultivation, pollen grains released by GM plants could dust larval host plants growing inside or nearby maize fields, thus leading to the exposure of caterpillars to the Cry toxins. This way of exposure has been studied mainly for butterflies, whereas moths, in spite of their great diversity and abundance, were rarely considered. To evaluate the potential exposure of moth species to maize pollen in absence of Cry-expressing plants, macro-moths were sampled by means of light traps in three protected areas of Northern, Central and Southern Italy where conventional maize is among the main crops. Light traps were activated in two consecutive years (2010- 11) from the beginning of June to the end of July, a period that encompasses the anthesis of most maize cultivars grown in Italy. Overall, 11446 individuals belonging to 201 species and nine families were collected. Given that larvae of several sampled species are likely to match the criteria of potential exposure to maize pollen and susceptibility to Cry toxins, macro-moths might be considered among the potential assessment endpoints for environmental risk assessment of GM plants, especially in the vicinity of protected areas. [ABSTRACT FROM AUTHOR]

Lepidoptera are the phytophagous group most at risk of impact by insect-resistant genetically modified (GM) plants since most of these crops have been developed to express toxins to specifically target lepidopteran pests. In the case of Bt-maize cultivation, pollen grains released by GM plants could dust larval host plants growing inside or nearby maize fields, thus leading to the exposure of caterpillars to the Cry toxins. This way of exposure has been studied mainly for butterflies, whereas moths, in spite of their great diversity and abundance, were rarely considered. To evaluate the potential exposure of moth species to maize pollen in absence of Cry-expressing plants, macro-moths were sampled by means of light traps in three protected areas of Northern, Central and Southern Italy where conventional maize is among the main crops. Light traps were activated in two consecutive years (2010-11) from the beginning of June to the end of July, a period that encompasses the anthesis of most maize cultivars grown in Italy. Overall, 11446 individuals belonging to 201 species and nine families were collected. Given that larvae of several sampled species are likely to match the criteria of potential exposure to maize pollen and susceptibility to Cry toxins, macro-moths might be considered among the potential assessment endpoints for environmental risk assessment of GM plants, especially in the vicinity of protected areas. [ABSTRACT FROM AUTHOR]

A field experiment was conducted on an alluvial soil with winter lettuce [Lactuca sativa (L.) cv. Bacio] plants to study, in the second year of testing and in both field and laboratory conditions, the effects of fertilizers—compost by farm residues [(FC, 2.0% nitrogen (N)], mineral (MIN, 21% N), organomineral (OM, 10% N), mycorrhizas inoculum (MYC), wine-production residue [distiller's residue (DR, 3.6% N), anaerobic digestate (AD), and mycorrhizas (ADM)—on soil physical and mechanical parameters. Application of DR plus mycorrhizas improved the available phosphorus (P) and copper (Cu) contents of the surface (0–0.20 m) soil. The soil surface macroporosity increased significantly (>20%) in treatments FC, MYC, and OM, compared to the control. Results of the oedemeter test showed that with a load of 10 daN the compression susceptibility was greater in the compost treatment compared to other fertilizers, whereas with a load of 200 daN this parameter was lower in FC, AD, MYC, and ADM treatments. The least penetration resistance in the 0- to 20-cm layer of AD and MYC treatments showed lesser values and only in treatment AD in the 20- to 40-cm layer. Hydraulic conductivity values were enhanced in AD, MYC, and ADM plots. [ABSTRACT FROM AUTHOR]

The present study investigated the effects of using arsenic (As) contaminated irrigation water in Lactuca sativa L. cropping. Two different arsenic concentrations, i.e., 25 and 85 μg L and two different soils, i.e., sandy and clay loam, were taken into account. We determined the arsenic mobility in the different soil fractions, its amount in groundwater, and the phytotoxicity and genotoxicity. Nuclear magnetic resonance (NMR) and inductively coupled plasma (ICP) were used to assess the lettuce metabolic profile changes and the arsenic uptake by the plant, respectively, as a function of the various conditions studied, i.e., As content and type of soil. Data indicated that at both concentrations in sandy soil, arsenic is in part quickly leached and thus present in groundwater and in part absorbed by the vegetable, being therefore readily available for assimilation by consumption. NMR results reported a large modification of the metabolic pattern, which was depending on the pollutant amount. In clay loam soil, the groundwater had a low As content with respect to sandy soil, and NMR and ICP performed on the lettuce did not reveal severe changes related to As, most likely because the metalloid is bound to the colloidal fraction. [ABSTRACT FROM AUTHOR]

Arsenic (As) is a highly toxic element and its presence in food is a matter of concern for the well-being of both animals and humans. Arsenic-contaminated groundwater is used in agriculture to irrigate crops for food and animal consumption with a potential contamination of the food chain. The purpose of this study was the evaluation of arsenic effect on radish tuber (Raphanus sativus L.). Experimental plots with sandy and clay-loamy soil were cultivated with radish and treated with three different concentrations of As water solution: 19, 44 and 104 µg/L. Magnetic resonance imaging was used to visualize the tuber structural changes, and the content of elements and the As amount were evaluated by inductively coupled plasma atomic emission spectroscopy. The data obtained demonstrate that As contamination in radish tuber is underlined with the dual approach. PRACTICAL APPLICATIONS The scope of this research is the evaluation of the effects on the toxicology and the morphology because of the arsenic (As) uptake by edible plants. The focus is on the contamination of the plant, which has implications for food safety and human health. The results obtained by magnetic resonance imaging and inductively coupled plasma atomic emission spectroscopy show that several changes of the internal structure occurred and that some parameters can be used as indicators of the As contamination in food. [ABSTRACT FROM AUTHOR]

Investigating the relation between concentration or release of phosphorus (P) into soil solution (CaCl 2 ‐P, determined by 0.01 M CaCl 2 extraction of soils) and soil test phosphorus (Olsen P, or 0.5 N NaHCO 3 ‐extractable soil phosphorus) for 10 widely ranging and variously managed soils from central Italy, a change point was evident where the slopes of two linear relationships meet. In other words, it was possible to distinguish two sections of the plots of CaCl 2 ‐P against Olsen P, for which increases of CaCl 2 ‐P per unit of soil test P increase were significantly ( p -1 Olsen P and were very closely correlated ( p [ABSTRACT FROM AUTHOR]

Effect of application of different fertilizer phosphorus (P) sources (diammonium phosphate—DAP, single super phosphate—SSP, phosphate rock—PR, partially acidulated phosphate rock—PAPR, basic slag phosphate—BSP, and humo phosphate—HP), and time (up to three years of soil-fertilizer P equilibration) on soil extractable P was studied on two representative Italian soils, principally differing in pH values and the capacity to retain P. Phosphorus extractability was measured by seven chemical and two nonconventional soil P test methods based on the use of anion exchange resin membranes and iron oxide coated paper strips. The increases in the amount of extracted P following soil P fertilization were practically in the same order for both Ravenna and Paliano soils: DAP > SSP > HP > BSP > PAPR > PR; that order reflecting the corresponding scale of P water solubility. More P tended, however, to be dissolved from PR treatment in more acidic soil. On an average, the effectiveness of the different soil P test procedures in extracting P from two soils was in the order: Egner-P > Bray2-P > Olsen-P > Mehlich3-P > resin-P > iron oxide-strip-P > Bray1-P > water-P > CaCl2-P. The Egner soil P test method appeared to overestimate P bioavailability of all P treatments in the calcareous soil, while both the Egner and Bray2 soil tests overestimated the amount of extractable P of the PR treatment in the other soil. Data of P extracted by the Olsen and Mehlich3 procedures resulted the most closely correlated with the corresponding data obtained with the nonconventional soil P test procedures, currently considered with potential for use in widely ranging soils fertilized with water soluble as well as water insoluble P fertilizers. [ABSTRACT FROM AUTHOR]

Simple Summary: Olive oil is the most common vegetable oil used for human nutrition, and its production represents a major economic sector in Mediterranean countries. The milling industry generates large amounts of liquid and solid residues, whose disposal is complicated and costly due to their polluting properties. However, olive mill waste (OMW) may also be seen as a source of valuable biomolecules including plant nutrients, anthocyanins, flavonoids, polysaccharides, and phenolic compounds. This review describes recent advances and multidisciplinary approaches in the identification and isolation of valuable natural OMW-derived bioactive molecules. Such natural compounds may be potentially used in numerous sustainable applications in agriculture such as fertilizers, biostimulants, and biopesticides in alternative to synthetic substances that have a negative impact on the environment and are harmful to human health. Olive oil production generates high amounts of liquid and solid wastes. For a long time, such complex matrices were considered only as an environmental issue, due to their polluting properties. On the other hand, olive mill wastes (OMWs) exert a positive effect on plant growth when applied to soil due to the high content of organic matter and mineral nutrients. Moreover, OMWs also exhibit antimicrobial activity and protective properties against plant pathogens possibly due to the presence of bioactive molecules including phenols and polysaccharides. This review covers the recent advances made in the identification, isolation, and characterization of OMW-derived bioactive molecules able to influence important plant processes such as plant growth and defend against pathogens. Such studies are relevant from different points of view. First, basic research in plant biology may benefit from the isolation and characterization of new biomolecules to be potentially applied in crop growth and protection against diseases. Moreover, the valorization of waste materials is necessary for the development of a circular economy, which is foreseen to drive the future development of a more sustainable agriculture. [ABSTRACT FROM AUTHOR]