402 research outputs found
Combining no-till with rye (Secale cereale L.) cover crop mitigates nitrous oxide emissions without decreasing yield
No full textNo-till (NT) often increases soil carbon (C) sequestration compared with conventional tillage (CT), yet its net
effect on N2O emissions is controversial. Cover crops (CCs) adoption is promoted in NT systems because CCs
growth curbs nitrate losses via leaching. However, incorporating CC residues into the soil may have positive or
negative effects on N2O emissions depending on CC species and agro-ecosystem management. A better understanding
of how tillage practices and CC species affect N2O emissions is therefore needed for the development of
productive agroecosystems that contribute to climate change mitigation. The objectives of this three-year
(2015–2017) field experiment on a Udertic Haplustalf soil in the Po Valley were to compare N2O emissions and
crop yield of soybean under NT and CT, and to examine how contrasting residues from two CCs (rye, Secale
cereale L. vs hairy vetch, Vicia villosa Roth) affect N2O emissions in NT soybean and maize. We hypothesized that
N2O emissions would be lower with NT than with CT and with rye residues than with vetch ones. Nitrous oxide
was continuously sampled using automatic chambers during three periods (emergence, N-fixation and maturity)
over the soybean-cropping season in 2015 and during the entire cropping maize season in 2017. The DNDC
model was calibrated (2015 data) and validated (2017 data), and then used to estimate the annual cumulative
N2O emissions in different treatments. Overall, N2O emissions in NT were 40–55% lower than in CT, for both in
situ measurements (Period I) and modelled estimations. These differences could be ascribed to the higher waterfilled
pore space (WFPS) and soil nitrate availability in CT than in NT. No-till also increased SOC content (28%;
0–5 cm) and earthworm abundance (5 times) compared with CT. Within NT systems, N2O emissions were
20–36% lower with rye CC than with vetch CC (P < 0.05), which was a consequence of the lower availability of
soil mineral N under rye than under vetch due to the high C/N ratio of rye residues. Yield of soybean and maize
under NT was higher with rye CC than with vetch CC. The combination of NT and rye CC that led to the lowest
N2O emissions and highest yields should be recommended in the Po Valley region
Cover crops, compost, and conversion to grassland to increase soil C and N stock in intensive agrosystems
No full textAbstract: Organic fertilization or conversion to grassland may increase soil organic carbon (SOC) and soil total nitrogen (STN). However, responses of net SOC and STN accumulation are sometimes inconsistent and little is known about temporal patterns when those strategies are stopped. We (a) assessed the effects of rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth) cover crops (CCs) on SOC and STN during a 4-year “enriching” period (EP), and a following 2-year “depleting” period (DP); (b) compared these strategies with compost application and conversion to permanent fescue (Festuca arundinacea Schreb.); and (c) determined the responses of maize (Zea mays L.), soybean (Glycine max L. Merr.), and sunflower (Helianthus annuus L.) yields. Crop yield increased only in maize with compost and hairy vetch, which downsizes the role of these strategies to support productivity. SOC and STN increased with 4-year compost (+ 10.2 Mg C ha−1; + 0.5 Mg N ha−1), rye (+ 8.8 Mg C ha−1; + 0.6 Mg N ha−1), and hairy vetch (+ 6.9 Mg C ha−1; + 0.6 Mg N ha−1). Afterwards, SOC stock loss during 2-year DP tended to be higher than annual C input where there were CCs, and accounted for about 70% of annual C input where there was compost. High SOC loss highlights the weak effect of CCs for long-term SOC stabilization. Conversely, STN increased even during DP, which indicates a more lasting effect. Green manuring with CCs may be relevant for enhancing SOC and STN, although the beneficial effects are short-lived. Conversion to grassland remains the reference strategy. Graphic abstract: [Figure not available: see fulltext.
May conservation tillage enhance soil C and N accumulation without decreasing yield in intensive irrigated croplands? Results from an eight-year maize monoculture
No full textIntensive management of agroecosystems has been widely indicated as major responsible for soil degradation, thus negatively impacting on relationships between agriculture and climate change. Conservation tillage (i.e. no-till and minimum tillage) has been recommended for enhancing soil organic carbon (SOC) and total nitrogen (STN) stocks while having a positive impact on food security, biodiversity, water quality and the environment. Nevertheless, positive responses were mainly reported in hot and semiarid climates, with rainfed crops and low N fertilization rates. Therefore, the main objective of this study was to test the adoption of conservation tillage in intensive maize cropping systems under temperate soil, with high N fertilization rate (> 200 kg N ha−1 yr−1) and organic matter input (i.e. manure distribution and high biomass return), and with permanent optimum water moisture due to irrigation. We conducted an 8-year field experiment on a maize (Zea mays L.) monoculture to assess: (i) the effect of no-till (NT) and minimum tillage (MT), on grain yield and biomass return as compared with conventional tillage (CT); (ii) how tillage systems affect the evolution of SOC and STN levels over time under these conditions; (iii) soil aggregation processes and mechanisms leading to SOC and STN changes in the long-term. Results showed that MT increased maize grain yield (+7 %) and total biomass (+10 %) compared with CT. Conversely, NT reduced maize grain and biomass production during the initial 5-year transition, but afterwards increased maize yield up to that of CT. At the end of the experiment, SOC sequestration was increased under NT and MT by 1.45 and 1.52 Mg C ha−1 yr−1 compared with CT, respectively. Also, STN accumulation was higher under NT and MT than under CT (+0.15 and +0.17 Mg N ha−1 yr−1, respectively). Most of such a SOC and STN increase was located into C- and N-rich macroaggregates. Within those macroaggregates (large macroaggregates, LM; small macroaggregates, sM), we found that C and N pools associated to mM accounted for between 41 and 65 % of total C and N content in NT and MT systems across the different soil layers, which is beneficial for long-term C and N stabilization in soils. Thus, introducing conservation tillage within intensive agricultural context devoted to maize monoculture as that of the Po Valley should be recommended to: (i) maintain (or even increase) maize yield, and (ii) enhance SOC and STN accumulation and stabilization
Soil type and cropping system as drivers of soil quality indicators response to no-till: A 7-year field study
No full textConventional agricultural practices (CAP) highly impacted soil functions involved in the provision of multiple
ecosystem services. No-till (NT) has been repeatedly indicated as a key way to enhance soil fertility and biodiversity,
while having a positive effect on the environment and climate change. However, experimental evidence
to date shows contrasting effects of NT on physical parameters of soil fertility, as well as on soil organic
carbon (SOC) storage and soil biodiversity especially if different soil types and cropping systems are considered.
The objectives of the present 7-year field study were: (i) to unravel the effect of NT on SOC, soil bulk density,
and water stability index (WSI) of soil aggregates across five different soil types (Silty Clay, Silty Clay Loam, Clay
Loam, Silt Loam, and Sandy Loam) and cropping systems (silage vs grain production), (ii) to examine how soil
fauna (i.e. microarthropods and earthworms) is affected by NT practices under those soil-crop conditions, and
(iii) to assess relationships among responses of soil physical indicators (i.e. soil bulk density and WSI), SOC, and
soil fauna.
Our results showed that soil bulk density was generally not affected by 7-year NT across all soil types. At the
same time, NT increased WSI. It follows that NT may increase stable rather than artificial tillage-derived porosity
due to reduced soil disturbance, and increased SOC and biological activity. However, reduced importance for
boosting aggregates stability should be attributed to NT where initial SOC is high, clay and silt are predominant
soil fractions, and the rate of crop residue is low.
Our findings suggest that NT may enhance SOC stock (on average 0.66 Mg C ha−1 year−1) in the 0–30 cm soil
layer. However, we found (i) a tendency of NT to decrease SOC concentration in the 15–30 cm soil layer (on
average −1.18 g C kg−1), and (ii) no SOC increase induced by NT if crop residues were not left onto the soil
surface.
Nevertheless, NT practices promoted (i) the microarthropods adaptation measured with the QBS-ar index
(105.5 vs 64.7), and (ii) the increase of earthworm abundance (412 vs 123 individuals m−2), which are fundamental
for enhancing nutrient cycling and soil porosity.
Correlations among soil fauna (i.e. QBS-ar and earthworm density), soil physical parameters (i.e. soil bulk
density and WSI), and SOC (i.e. concentration and stock) corroborates the hypothesis that soil fauna adaptation
and proliferation are main detectors of soil quality and sensitive indicators of changes in soil tillage
Correction to: Monoallelic KIF1A-related disorders: a multicenter cross sectional study and systematic literature review
No full textUnfortunately, the given name and family name of the first author was incorrectly tagged in the xml data, therefore it is abbreviated wrongly in Pubmed. The correct given name is Stefania and family name is Della Vecchia
Author Correction: Thyroid hormone induces progression and invasiveness of squamous cell carcinomas by promoting a ZEB-1/E-cadherin switch (Nature Communications, (2019), 10, 1, (5410), 10.1038/s41467-019-13140-2)
No full textThe original version of this Article contained an error in the author affiliations. Silvia Varricchio, Gennaro Ilardi and Stefania Staibanow were incorrectly associated with ‘Department of Public Health, University of Naples "Federico II", Naples, Italy’ instead of the correct ‘Department of Advanced Biomedical Sciences, University of Naples “Federico II”, Naples, Italy.’ This has now been corrected in both the PDF and HTML versions of the Article
The first Latin Translation of Sextus Empiricus, Outlines of Phyrronism (I)
No full textThe present article examines the characteristics and trans- mission of an anonymous Latin translation of the Outlines of Pyrrhonism by the Skeptic philosopher Sextus Empiricus (c. 160-c. 210). In particular, it provides a palaeographical and codicological analysis of one of the three manuscripts that preserve this translation, Paris, BnF, lat. 14700. It ap- pears to have been written by one textual hand of North- ern French origin at the very end of the thirteenth centu- ry (Part I). The other two manuscripts will be studied in a subsequent article (Part II). Moreover, the article attempts to identify the author of the translation, who, in the light of his style, must have been active in the same milieu and at the same time as Bartholomew of Messina (fl. 1260)
Cover crops during transition to no-till maintain yield and enhance soil fertility in intensive agro-ecosystems
No full textIntroducing no-till and cover crops in arable agro-ecosystems leads to the restoration of soil fertility, through the increase of soil organic matter (SOM), soil total nitrogen (STN), and available phosphorus (P), therefore maintaining or enhancing crop yield and reducing costs. Although the effects of those practices have been widely examined, many studies show conflicting results and little is known about the combined effects of no-till (NT) and cover crops (CCs) under intensive arable cropland in the Po Valley (Northern Italy). The objectives of this study were: (i) to evaluate if NT management coupled with CCs negatively affects yields during the transition period and how yields evolve; (ii) to assess SOM, STN, and P dynamics in the 60-cm soil depth layer; and (iii) to evaluate the effects of different types of winter cover crops on yield and soil parameters. A six-year field experiment was established in Piacenza, on a silty-clay soil under temperate climate conditions. The crop sequence was: winter wheat, maize, maize, soybean, winter wheat, and maize. The four experimental treatments were: (1) conventional tillage (CT) as control; (2) NT with CC of rye (NT-R); (3) NT with CC of hairy vetch (NT-V); and (4) NT with a mixture of CCs (rye, hairy vetch, crimson clover, Italian rye-grass and radish) [NT-M]). Dry biomass yield of CCs ranged between 2.2 and 3.1 Mg ha−1 for rye; 1.9 and 3.0 Mg ha−1 for hairy vetch; and 1.9 and 3.2 Mg ha−1 for mixture. In the present study, yields of winter wheat, maize, and soybean were generally not reduced with NT-CCs since the first year after conversion. The different composition and thickness of cover crop mulch showed an opposite yield response to rainfall pattern: under NT-R, a negative correlation was observed between grain yield and rainfall, while under NT-V this correlation was positive. After six years, SOM and STN concentrations in the 0-30 cm soil layer increased in NT-CCs. SOM concentration was +30%, +23% and +20% higher than CT for NT-R, NT-M and NT-V, respectively. STN was +28% higher under NT-R and NT-V, and +21% higher under NT-M, than CT. Conversely, P concentration was not influenced by the NT-CCs system, although we observed a tendency to increase under NT-V. In the 30-60 cm soil, layer, the tillage systems did not affect SOM and STN. We concluded that introducing NT with winter CCs into intensive arable agricultural systems is an effective strategy for enhancing soil fertility in fine-textured soils under temperate climates, without penalizing yields
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
Un monde partagé: la Sicile du premier siècle av. J.-C. entre Diodore et Cicéron
No full textThis volume is the result of a scientific collaboration between the research centres of the MMSH in
Aix-en-Provence and the Department of Humanities at Ca' Foscari University, whose study
interests converged in a joint experimental project.
A detailed comparison between Cicero and Diodorus has never been proposed until now, probably
because of the obvious disparity between their works. There is, on the one hand, an illustrious
orator at the centre of the political and cultural experience of Rome, and on the other hand, a minor
Greek historian whose intellectual profile has only recently been enhanced by critics. Yet, they
have quite a lot in common: they both lived in the turbulent late Republican age, both came from
wealthy families without any political role; both received rhetorical training, travelled and
frequented cultured circles.
The area where the comparison between the two authors is most instructive is undoubtedly Sicily,
the homeland of Diodorus and the scene of the beginnings of Cicero's political career. The two
writers shared a deep personal knowledge of the island: Sicily is constantly present in Diodorus'
Bibliotheca, and is the focus of the judicial and political case exposed in the Verrinae. Aspects of
the island's history and culture emerging from the work of each author have already been
extensively considered. This study, however, aims to offer a more analytical comparison of the
representation of Sicily in both works, examining how the same geographical, historical and
religious information, originating from a shared cultural background and from personal knowledge,
is reinterpreted by the two authors according to their different rhetorical and intellectual projects.
We defined four major categories of informations relating to the island: geography, history of great
men, religious traditions and practices, artistic and monumental heritage. For each of these
categories, we conducted parallel analyses on each work, focusing on the selection of data, the way
they were presented and their function in the overall economy of the works of Diodorus and Cicero.
These parallel analyses highlight similarities and dissimilarities between the two authors: the
affinities show the existence of a codified representation of Sicily, its history and its specificity in
the context of the first century BC; the discrepancies result both from the divergences in method
and aims of the two authors and, more deeply, from their differences in terms of personal, cultural
and linguistic backgrounds and perspectives
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