Input Regimes Research Articles

The benefits of floral border crops in smallholder rice production depends on agronomic inputs and landscape context

Abstract Ecological intensification (EI) provides an important and increasingly adopted pathway for achieving more sustainable agricultural systems. However, the implementation and success of on‐farm EI practices may vary depending on landscape context and local management practices. We evaluated how EI interventions, including two different agricultural input regimes (high or low use of synthetic pesticides and fertilizers) and floral border crops, affected local natural enemy biodiversity, pest abundance and crop yield, and how this was influenced by the surrounding landscape context across 12 rice fields on smallholder farms in Puducherry, India. Reducing agricultural inputs positively impacted the overall natural enemy assemblage; however, responses to landscape factors varied. For example, coccinellid beetles were negatively correlated with higher densities of field edges (landscape configuration). In contrast, spiders, the most abundant group surveyed, were not significantly influenced by any landscape metric. Furthermore, pest abundance was greatest in fields with reduced inputs but only at sites where floral border crops were not present. Mean rice grain yield was lower across low‐input sites compared with high‐input sites and floral border crops had opposing effects across high‐ and low‐input sites. At low‐input sites, mean yields were 33% higher where floral border crops were present. At high‐input sites, the presence of floral border crops was correlated with a lower mean yield (16%). These findings show that ecological intensification practices can benefit smallholder crop systems but highlight the need to account for variations in landscape context and local management practices for developing effective sustainable management practices.

Physical effects of learning.

Interacting many-body physical systems ranging from neural networks in the brain to folding proteins to self-modifying electrical circuits can learn to perform diverse tasks. This learning, both in nature and in engineered systems, can occur through evolutionary selection or through dynamical rules that drive active learning from experience. Here, we show that learning in linear physical networks with weak input signals leaves architectural imprints on the Hessian of a physical system. Compared to a generic organization of the system components, (a) the effective physical dimension of the response to inputs decreases, (b) the response of physical degrees of freedom to random perturbations (or system "susceptibility") increases, and (c) the low-eigenvalue eigenvectors of the Hessian align with the task. Overall, these effects embody the typical scenario for learning processes in physical systems in the weak input regime, suggesting ways of discovering whether a physical network may have been trained.

Soil Microbial Community in Relation to Soil Organic Carbon and Labile Soil Organic Carbon Fractions under Detritus Treatments in a Subtropical Karst Region during the Rainy and Dry Seasons

Climate and detritus influence soil organic carbon (SOC) and labile SOC fractions by affecting soil microbial communities. However, it is not clear how, or to what extent, different detritus treatments affect soil microbial communities and SOC content in karst landscapes during different seasons. Plots in a karst landscape were treated with different detritus input regimes (control, no litter, no roots, no litter or roots, and double litter), and samples were collected during the dry and rainy seasons. We used Illumina sequencing of 16S rRNA to examine shifts in the diversity and composition of the associated soil microbial communities. Additionally, labile SOC fractions, including dissolved organic carbon (DOC) and microbial biomass carbon (MBC), along with soil physicochemical properties and C-degrading enzyme activities, were analyzed. The results revealed that the responses of soil properties and labile SOC fractions to detritus treatments were more pronounced during the rainy season than during the dry season, which mainly reflected that the levels of available potassium (AK), DOC, and MBC were significantly increased during the rainy season. Moreover, SOC and total nitrogen (TN) demonstrated significant changes with the double litter (DL) treatment during the rainy season. The responses of soil microbial communities to detritus treatments varied with the season, as reflected primarily in changes in the relative abundance of Ascomycota, unclassified_K_fungi, Proteobacteria, and Actinobacteriota. Climate, detritus treatments, and their interactions had significant effects on the species richness of soil bacterial communities, but did not influence fungal community diversity. Furthermore, structural equation modeling (SEM) revealed that the soil bacterial composition had the largest total effects on SOC, DOC, and MBC. In addition to directly influencing SOC, DOC, and MBC, soil properties (TN, AK, and pH) indirectly affected SOC, DOC, and MBC by altering C-degrading enzyme activity and the microbial community. We conclude that detritus treatments affect the soil microbial community and labile carbon fractions during both the rainy and dry seasons. Relationships among SOC, labile SOC fractions, enzyme activities, microbial communities, and function differed between seasons and among treatment types. This research advances our knowledge of how variation in detritus treatments affects biogeochemical cycling in karst soils during the rainy and dry seasons.

Investigating the machinability behaviour of Al7075/SiC5CS5 hybrid composite with the variation of tool geometry

This research investigates the machinability behavior of an Al7075 hybrid composite fabricated with micro-sized cenosphere (CS) and silicon carbide (SiC) particles. The composite was fabricated using stir-casting with ultrasonic assistance. The experimental study investigated the effect of variation of machining regimes (i.e., feed rate, cutting speed, and depth of cut) and tool geometry (tool nose radii) on main cutting force and tool tip temperature. For the study, the Cermet tool was considered as tool material for the dry turning of aluminum alloy and composite. In addition, a regression model was created using the response surface method (RSM) technique. The results indicate that the developed model can accurately predict output regimes with an accuracy ranging from 80.44 to 99.98%. Further, by using sequential approximation optimization, the optimal combination of input regimes for maximal metal removal rate was identified.

Exploring molecular dynamic indicators associated with reproductive performance of Bos indicus cattle in blood plasma samples through data-independent acquisition mass spectrometry

Improving reproductive performance of cattle is of paramount importance for sustainable dairy farming. Poor reproduction performance (RP) hinders the genetic improvement of important Bos indicus cattle breeds. It is well known that incorporation of molecular information along with conventional breeding method is far better than use of conventional method alone for the genetic improvement of reproductive performance traits in cattle. Therefore, the present study sought to investigate the plasma proteome of the Deoni cows in cyclical (n = 6) and pregnant (n = 6) reproductive phases with varying reproductive performance (high and low). High-throughput data independent acquisition (DIA) based proteomics was performed to understand corresponding proteome. We identified a total of 430 plasma proteins. Among cyclic cows, twenty proteins were differentially regulated in low RP as compared to high RP. BARD1 and AFP proteins were observed upregulated in cyclical cows whose upregulation reported to affect reproductive performance in cattle. Among the pregnant cows, thirty-five proteins were differentially regulated, including the downregulation of FGL2 and ZNFX1 that modulates the maternal immune response mechanism which is required for successful implantation of the embryo. Also, proteins such as AHSG, CLU and SERPINA6 were upregulated in the pregnant cows whose upregulation reported to reduced reproductive performance. The results of this study will be helpful in establishing a framework for future research on the aspect of improving reproductive performance in Bos indicus cattle breeds. SignificanceThe Indian subcontinent is the center of domestication for Bos indicus cattle breeds and they are known for their disease resistance, heat tolerance, ability to survive in low input regime and harsh climatic conditions. In recent times, population of many important Bos indicus breeds including Deoni cattle is declining due to various factors, especially due to reproductive performance. Traditional breeding methods are not sufficient enough to understand and improve the reproductive performance traits in important Bos indicus cattle breeds. Proteomics approach is a promising technology to understand the complex biological factors which leads to poor reproductive performance in cattle. The present study utilized DIA based LC- MS/MS analysis to identify the plasma proteins associated with reproductive performance in cyclical and pregnant cows. This study if improved further, can be used to develop potential protein markers associated with reproductive performance which is useful for the selection and genetic improvement of important Bos indicus breeds.

Statistical mechanics of thermostatically controlled multizone buildings.

We study the collective phenomena and constraints associated with the aggregation of individual cooling units from a statistical mechanics perspective. These units are modeled as thermostatically controlled loads (TCLs) and represent zones in a large commercial or residential building. Their energy input is centralized and controlled by a collective unit-the air handling unit (AHU)-delivering cool air to all TCLs, thereby coupling them together. Aiming to identify representative qualitative features of the AHU-to-TCL coupling, we build a simple but realistic model and analyze it in two distinct regimes: the constant supply temperature (CST) and the constant power input (CPI) regimes. In both cases, we center our analysis on the relaxation dynamics of individual TCL temperatures to a statistical steady state. We observe that while the dynamics are relatively fast in the CST regime, resulting in all TCLs evolving around the control set point, the CPI regime reveals the emergence of a bimodal probability distribution and two, possibly strongly separated, timescales. We observe that the two modes in the CPI regime are associated with all TCLs being in the same low or high airflow states, with an occasional collective transition between the modes akin to Kramer's phenomenon in statistical physics. To the best of our knowledge, this phenomenon has been overlooked in building energy systems despite its direct operational implications. It highlights a trade-off between occupational comfort-related to zonal temperature variations-and energy consumption.

Positive Effects of Organic Substitution in Reduced-Fertilizer Regimes on Bacterial Diversity and N-Cycling Functionality in Greenhouse Ecosystem.

Conventional fertilization in the greenhouses of North China used excessive amounts of chemical and organic fertilizer, resulting in soil degradation and severe agricultural non-point source pollution. A nine-year study was conducted on a loamy clay soil in Shijiazhuang, Hebei province, to investigate the effects of reduced-fertilizer input regimes on soil property, bacterial diversity, nitrogen (N) cycling and their interactions. There were four treatments, including high organic + chemical fertilizer application rate and three reduced-fertilizer treatments with swine manure, maize straw or no substitution of 50% chemical N. Treatments with reduced-fertilizer input prevented soil salinization and acidification as in local conventional fertilization after being treated for nine years. In comparison to chemical fertilizer only, swine manure or maize straw substitution maintained higher nutrient availability and soil organic C contents. Fertilizer input reduction significantly increased bacterial richness and shifted bacterial community after nine years, with decisive factors of EC, Olsen P and C/N ratio of applied fertilizer. Soil chemical characteristics (EC, pH and nutrients), aggregation and C/N ratio of applied fertilizer selected certain bacterial groups, as well as N-cycling functions. Reduced-fertilizer input decreased the potential nitrification and denitrification functioning of bacterial community, but only in organic substitution treatments. The results of this study suggested that fertilizer input reduction combined with organic C input has potential in reducing non-point source pollution and increasing N-use efficiency in greenhouse vegetable production in North China.

Effects of chicken manure substitution for mineral nitrogen fertilizer on crop yield and soil fertility in a reduced nitrogen input regime of North-Central China.

Organic manure has been proposed to substitute part of the chemical fertilizers. However, past research was usually conducted in regimes with excessive nitrogen (N) fertilization, which was not conducive to the current national goal of green and sustainable development. Therefore, exploring the potential of organic fertilizer substitution for mineral N fertilizer under regimes with reduced N inputs is important to further utilize organic fertilizer resources and establish sustainable nutrient management recommendations in the winter wheat (Triticum aestivum L.) - summer maize (Zea mays L.) rotation system in North-central China. In this study, a 4-year field experiment was conducted to investigate the effects of different chicken manure substitution ratios on crop yield, N recovery efficiency (REN), soil N and soil organic matter contents, to clarify the optimal organic substitution ratio of N fertilizer under reduced N application (from 540kg N ha-1 year-1 to 400kg N ha-1 year-1). Six substitution ratios were assessed: 0%, 20%, 40%, 60%, 80% and 100% under 200kg N ha-1 per crop season, respectively, plus a control with no N application from chemical fertilizer or chicken manure. Results showed that the highest yield was achieved under the 20% substitution ratio treatment, with 1.1% and 2.3% higher yield than chemical N alone in wheat season and maize seasons, respectively. At the chicken manure substitution ratios of 20% in wheat season and 20%-40% in maize season, the highest REN reached to 31.2% and 26.1%, respectively. Chicken manure application reduced soil residual inorganic N with increasing substitution ratio. All organic substitution treatments increased soil organic matter and total N content. Implementing 20% organic substitution in wheat season and 20%-40% in maize season under the reduced N application regime in the North-central China is therefore recommended in order to achieve high crop yields and REN, improve soil fertility and enhance livestock manure resource utilization.

Small-scale farmers’ willingness to adopt chemical-free inputs and engage in collaborative arrangements –A discrete choice experiment in Central Mexico

Objetive: Explore small-scale Mexican farmers’ willingness to adopt chemical-free fertilizers and pesticides, and to engage in two collaborative arrangements. Methodology: A discrete choice experiment has been designed based on two non-monetary attributes (use/no use of chemical inputs and two collaborative arrangements) and a monetary attribute (percentage change in price of crop that generates most of net revenues). Data has been analyzed with a two-class latent class logit specification. Findings: 60% of respondents is not willing to transition to a chemical-free input regime, is willing to receive management support from municipality, and is not interested in a shared insurance. On the opposite side of the preferences, 40% of respondents is willing to adopt chemical-free inputs, is not interested in management support, and is willing to participate in a shared insurance. Limitations: Our sample is not nationally representative, and further studies are needed to corroborate and generalize our findings. Contribution: This is the first study exploring whether preferences of small-scale farmers in Mexico align with Federal government’s goal of phasing out glyphosate. Conclusions: With 40% of small-scale farmers willing to adopt chemical-free inputs, if the Federal government wants to convice the other 60% of phasing out glyphosate, a possibility is to implement a slower strategy that starts with providing management support. Once management support is in place, and trust is gained, doors may open for a transition to chemical-free production regimes.

Initiation and evolution of coarse-grained deposits in the Late Quaternary Lake Chenghai source-to-sink system: From subaqueous colluvial apron (subaqueous fans) to Gilbert-type delta

Investigating the formation and evolution of coarse-grained deposits in modern lakes and the relevant controlling conditions is indispensable to the prediction of reservoir sandbodies, disaster prediction, and limnological research. The source-to-sink system of coarse-grained deposits in Lake Chenghai, a deep, scarped Late Quaternary lake, was investigated in this study based on 62 outcrops, Advanced Land Observing Satellite (ALOS) digital elevation model (DEM) data, and regional geological survey data. The findings include the following: (1) the source areas of coarse-grained deposits in Lake Chenghai were lithologically classified into carbonate source areas, basaltic source areas and siliciclastic source areas, and were geomorphically categorized as scarp type or confluence type. Subaqueous colluvial aprons have formed downstream of the carbonate source areas and scarp-type basaltic source areas, while Gilbert-type deltas have formed downstream of siliciclastic source areas and confluence-type basaltic source areas. (2) The formation and evolution of coarse-grained deposits are controlled by the sediment flux that evolves in synchrony with the geomorphic evolution of the source areas and the sink regimes. Scarps represent the initial landform of the source areas. Source material rolls off or slides down scarps or forms small-scale debris flows before entering the lake. The source material initially formed subaqueous colluvial apron (synonymous with subaqueous fans) where sufficient space was present to accommodate sediments and the basement angle exceeded than the natural angle of repose. As weathering and denudation have progressed, the initial scarps have transformed into confluence-type slopes, and the source material has formed medium- and large-scale debris flows that have entered the lake, resulting in an increase in sediment flux. Consequently, the subaqueous colluvial aprons have rapidly grown and developed subaerial deposits, which have evolved into larger-scale Gilbert-type deltas that overlie the initial aprons. (3) The morphology and distribution of coarse-grained deposits vary in response to differences in quantity and composition of materials from different source areas, which resulting from different rates of weathering and denudation and different sediment input regimes. Firstly, the size and surface slope angle of a subaqueous colluvial apron from a carbonate source are smaller than those of a subaqueous colluvial apron of basaltic origin. Secondly, a Gilbert-type delta from a basaltic source features a greater slope angle and a thicker topset than does a Gilbert-type delta of siliciclastic origin, and the latter exhibits a longer foreset and a thicker bottomset than in the former. Thirdly, the sizes of subaqueous colluvial aprons are not strongly correlated with the sizes of the source areas, while the sizes of Gilbert-type deltas are.

Experimental and Numerical Investigation of a Surface Sliding Discharge in a Supersonic Flow with an Oblique Shock Wave

This study presents an experimental and numerical investigation on a surface sliding discharge in a supersonic airflow in the presence of an oblique shock wave. In experiments, flow Mach numbers were 1.20–1.68 in the shock tube combined with the discharge chamber. A single high-voltage 25 kV pulse sustains the plasma; the discharge current has a duration of ~500 ns. A surface sliding discharge is developed as a localized channel in a zone of interaction of an oblique shock wave with a boundary layer on the upper wall of the discharge chamber. The discharge channel acts as a linear source of heat and is at the origin of the induced shock wave. The flow field in the discharge chamber is spatio-temporally surveyed using high-speed shadowgraphy imaging with a frequency of up to 525,000 frames per second. The experiments show that the perturbed flow restored the initial structure after more than 100 μs. Numerical simulation with local energy input into the supersonic flow in a flat channel is carried out on the base of unsteady two-dimensional Navier–Stokes equations. It is determined that the dynamics of an induced shock wave are dependent on the energy input regime and on the flow parameters. The thermal energy release in the discharge channel of 0.22–0.29 J was estimated from a comparison of experimental data and numerical simulations.

Reproductive hormones profiles in Malnad Gidda cows during estrous cycle

Malnad Gidda cows are famous for regular calving under low input regime. However, Malnad Gidda cattle are poorly studied with regard to their reproductive efficiency. The present study was undertaken to establish the baseline values for reproductive hormones in Malnad Gidda cows. Malnad Gidda cows (6) aged between three to four years were selected. Upon confirming the regular estrous cycles, blood was collected on the day of estrus (day 0) and the day 3, 6, 9, 12, 15, 18, 20 of estrous cycle and subsequent estrus (day 0). Serum was separated by centrifugation at 3,000 rpm at 30°C for 20 min and stored at -20°C until analyzed. 17β-estradiol and progesterone concentration in serum was measured using commercial radioimmunoassay (RIA) kit (BRIT, Mumbai). The serum 17β-estradiol hormone concentration showed a significant decrease from day 0 to day 3. Later, the concentration increased significantly up to day 6 and then decreased by day 9. The concentration of estradiol showed significantly increasing trend from day 12 and onwards up to day 20. The concentration of progesterone increased significantly from day 3 to day 9. Thereafter, the concentration decreased significantly from day 12 to day 20. The present study revealed the normal functioning of the Hypothalamo-Pituitary-Ovarian relationship axis which is responsible for normal estrous cycles in Malnad Gidda cows. The peak progesterone level was observed from 9th to 12th day and on the same days, the estradiol level was at its lowest levels.

Effects of fertilizar on growth performance of tilapia and shing in rice cum-fish culture

Field experiments demonstrated that rice-fish farming indeed increased the productivity of rice field and help to achieve ecological, economical, and social benefits. An experiment was accompanied in the rice field plots to ascertain the felicitous fertilization effects on the growth performance of Nile Tilapia (Oreochromis niloticus) and Shing (Heteropneustes fossilis) cultured in the rice fish farming system. Each treatment of fish species cultured with different doses of fertilizer such as T1 control: without any fertilization; T2 with 10 kg/decimal compost and T3 with 100% recommended fertilizer: Urea 100g, TSP 100g, MOP 50g, MOK100g/decimal respectively for fish culture. Current study showed a direct relationship between nutrient supplies and yielding of rice; increasing nutrient supply highlighting an increase of yielding fish. These indicated significantly greater fish yield at treatment T3 followed by treatment T2 and T1 in Shing with rice culture. Concerning Tilapia with rice culture, the same occurrence was observed. The gross production of Tilapia were found 5.04 ± 2.66, 8.65 ± 2.42 and 12.02 ± 1.45 kg/decimal in T1, T2 and T3, respectively and gross production of Shing were found 3.06± 1.76, 6.17 ± 1.84 and 8.83 ± 2.88 kg/decimal in T1, T2 and T3, respectively. During the experimental period the ranges of water temperature were (27.26 to 31.22 °C), dissolved oxygen (5.66 to 7.20 mg/L), pH (7.25 to 7.65 mg/L), total alkalinity (148.00 to 176.00 mg/L), free CO2 were (1.40 to 3.00) mg/L and found within the productive limit and more or less similar in all the plots under the T1, T2 and T3. The outcome in T3 provided the maximum yields amongst all treatments, followed by treatments T2 and T1 representing that the fertilizer is the furthermost suitable nutrient input regime aimed at the rice- fish integrated culture scheme. The results of the study revealed that polyculture of tilapia and Shing could be practiced in rice field.

Comprehensive characterization of oscillatory signatures in a model circuit with PV- and SOM-expressing interneurons

Neural circuits contain a wide variety of interneuron types, which differ in their biophysical properties and connectivity patterns. The two most common interneuron types, parvalbumin-expressing and somatostatin-expressing cells, have been shown to be differentially involved in many cognitive functions. These cell types also show different relationships with the power and phase of oscillations in local field potentials. The mechanisms that underlie the emergence of different oscillatory rhythms in neural circuits with more than one interneuron subtype, and the roles specific interneurons play in those mechanisms, are not fully understood. Here, we present a comprehensive analysis of all possible circuit motifs and input regimes that can be achieved in circuits comprised of excitatory cells, PV-like fast-spiking interneurons and SOM-like low-threshold spiking interneurons. We identify 18 unique motifs and simulate their dynamics over a range of input strengths. Using several characteristics, such as oscillation frequency, firing rates, phase of firing and burst fraction, we cluster the resulting circuit dynamics across motifs in order to identify patterns of activity and compare these patterns to behaviors that were generated in circuits with one interneuron type. In addition to the well-known PING and ING gamma oscillations and an asynchronous state, our analysis identified three oscillatory behaviors that were generated by the three-cell-type motifs only: theta-nested gamma oscillations, stable beta oscillations and theta-locked bursting behavior, which have also been observed in experiments. Our characterization provides a map to interpret experimental activity patterns and suggests pharmacological manipulations or optogenetics approaches to validate these conclusions.

Turbid Coral Reefs: Past, Present and Future—A Review

Increasing evidence suggests that coral reefs exposed to elevated turbidity may be more resilient to climate change impacts and serve as an important conservation hotspot. However, logistical difficulties in studying turbid environments have led to poor representation of these reef types within the scientific literature, with studies using different methods and definitions to characterize turbid reefs. Here we review the geological origins and growth histories of turbid reefs from the Holocene (past), their current ecological and environmental states (present), and their potential responses and resilience to increasing local and global pressures (future). We classify turbid reefs using new descriptors based on their turbidity regime (persistent, fluctuating, transitional) and sources of sediment input (natural versus anthropogenic). Further, by comparing the composition, function and resilience of two of the most studied turbid reefs, Paluma Shoals Reef Complex, Australia (natural turbidity) and Singapore reefs (anthropogenic turbidity), we found them to be two distinct types of turbid reefs with different conservation status. As the geographic range of turbid reefs is expected to increase due to local and global stressors, improving our understanding of their responses to environmental change will be central to global coral reef conservation efforts.

Versatile Super-Sensitive Metrology Using Induced Coherence

We theoretically analyze the phase sensitivity of the Induced-Coherence (Mandel-Type) Interferometer, including the case where the sensitivity is "boosted" into the bright input regime with coherent-light seeding. We find scaling which reaches below the shot noise limit, even when seeding the spatial mode which does not interact with the sample – or when seeding the undetected mode. It is a hybrid of a linear and a non-linear (Yurke-Type) interferometer, and aside from the supersensitivity, is distinguished from other systems by "preferring" an imbalance in the gains of the two non-linearities (with the second gain being optimal at low values), and non-monotonic behavior of the sensitivity as a function of the gain of the second non-linearity. Furthermore, the setup allows use of subtracted intensity measurements, instead of direct (additive) or homodyne measurements – a significant practical advantage. Bright, super-sensitive phase estimation of an object with different light fields for interaction and detection is possible, with various potential applications, especially in cases where the sample may be sensitive to light, or is most interesting in frequency domains outside what is easily detected, or when desiring bright-light phase estimation with sensitive/delicate detectors. We use an analysis in terms of general squeezing and discover that super-sensitivity occurs only in this case – that is, the effect is not present with the spontaneous-parametric-down-conversion approximation, which many previous analyses and experiments have focused on.

Increasing the productivity of an upland pasture with the least environmental impacts

The environmental impacts of increasing pasture productivity in the United Kingdom’s (UK) uplands is under-researched. A field trial on a representative upland farm investigated the effect of implementing pasture improvement options on unimproved land between 2017 and 2019. The options were cultivation (ploughing and rotovating) and reseeding in combination with lime and fertiliser inputs. Soil pH, grass growth, pasture quality and nitrous oxide (N2O) emissions from soil were measured throughout the growing seasons. Carbon dioxide (CO2) emissions were also measured from cultivation until pasture establishment in 2017. In the year of establishment, reseeding and increased nitrogen (N) fertiliser application led to greater daily grass growth, with the mean over two times greater from the ploughed and reseeded treatment (20.0 kg DM ha−1 day−1) as opposed to the control (8.2 kg DM ha−1 day−1) during the growing season (p < 0.05). Yield effects in subsequent years were dependent upon nutrient input regimes. Despite a significant difference in pasture energy values between the treatments in the year of establishment, there was no effect of reseeding and targeted lime and fertiliser applications on pasture quality in the two subsequent years. Rotovating and ploughing increased soil N2O emissions, with higher N fertiliser emission factors in 2017 (2.26% ± 0.79 from the rotovated treatment) compared with the IPCC default value of 1.6%. However, low N2O fluxes in 2018 meant that the emission factors during this growing season were also low (highest value of 0.25% ± 0.04 from the lime and fertiliser input only treatment). Rotovating and ploughing did not significantly impact CO2 emissions in the establishment period. From a purely production perspective, the results would favour reseeding similarly unproductive upland pastures typical in much of the UK. However, yield-scaled N2O emission calculations showed that reseeding was not the most effective method in reducing N2O emissions per unit of grass yield, rather, applying lime and fertiliser resulted in the lowest N2O emissions per unit of grass produced (0.07 g N2O kg−1 DM of grass). These findings demonstrate the importance of considering both pasture production and N2O emissions together when improving upland pasture for maximum nitrogen use efficiency and to reduce environmental impacts.

Low-input cultivation of camelina (&lt;em&gt;Camelina sativa&lt;/em&gt; (L.) Crantz) in a Mediterranean semi-arid environment

The cultivation of oil crops for biofuel production has often been accused of not being environmentally sustainable due to the high inputs needed. To explore the effect of reduced input on productive and qualitative traits of camelina (Camelina sativa (L.) Crantz), a trial was carried out over a two-year period. This study analysed two different levels of input: a low input treatment (shallow non-inversion tillage and low fertilisation rate) and a high input treatment (deeper tillage and high fertilisation rate). Camelina was positively, even though to a limited extent, affected by high input treatment as highlighted by the increase in seed yield (from 1.8 to 2.0 t ha–1), crop residues (from 4.8 to 5.2 t ha–1), seed protein content (from 26.5 to 28.9%), seed oil content (from 41.5 to 43.4%) and oil yield (from 0.75 to 0.88 t ha–1). So, from a sustainable point of view, we must consider negligible the effect of high input and satisfactory the performances of camelina in the low input regime. Low input management resulted in satisfactory yields in terms of both quantity and quality, results which were not very different from high input, indicating promising potential for conservation agriculture practices in camelina in a semi-arid environment.&#x0D; Highlights - Camelina showed high adaptability to conservation agriculture practices. - Seed yield of 1.9 t ha–1 was obtained under reduced tillage and low fertilisation rate. - High inputs (fertilisation and tillage) determined a 12-d longer crop cycle. - α-linolenic, erucic and eicosenoic acids were affected by input levels.

The morphosedimentary record of glacial to postglacial environmental changes in fjord-lake Mékinac and adjacent areas (southeastern Canadian Shield)

Fjords can transition from marine embayments to lacustrine waterbodies under glacio-isostatic change following their deglaciation. However, little is known on how a transition from fjord to lake is influenced by glacial dynamics and how it influences sedimentation in and around the basin. Here, we analyse swath bathymetry imagery and subbottom profiles pri in Lake Mékinac (southern Québec) as well as glacial landforms from LiDAR imagery around the lake to document the evolution of a fjord basin into a lacustrine body during the transition from the Late Pleistocene to the Holocene. These analyses helped refine local glacial history and show that the study area was probably under the up-ice reach of the St. Lawrence Ice Stream during full glacial conditions. The mapping of moraines in and around Lake Mékinac shows that deglaciation of the study area was marked by stabilization of the ice-margin during the Mars-Batiscan Event, which is traditionally correlated to the climate deterioration at the end of the Younger Dryas. The architecture of acoustic facies in the lake indicates a transition from glacial conditions (U1), to proglacial-paraglacial (U2) and to postglacial conditions (U3). The bottom of Lake Mékinac also contains multiple mass movement deposits related to progradation of the Du-Milieu River delta and probably to late-Holocene earthquakes. The acoustic architecture of sediments within the lake indicates that the sedimentation regime was most dependant on the sediment input regime and that the transition from fjord to lake did not significantly influence sedimentation during deglaciation of the watershed. Further work on dating the mass movement deposits that characterise the sediment architecture should provide a better assessment of natural hazard associated with seismological events.

Controlling the porosity using exponential decay heat input regimes during electron beam wire-feed additive manufacturing of Al-Mg alloy

Electron beam wire-feed additive manufacturing is given less attention in research community compared with other additive manufacturing methods, despite it allows higher deposition rate and less porosity. However, both gas and shrinking porosity are still met even with this method especially if applied to light alloys. The excess heat input may be the reason for evaporation of volatile metals, and forming the gas pores especially in the top layers of the built sample where cooling rate is reduced. Therefore, exponential decay heat input was used to grow AA5356 samples. Microstructural and mechanical characterization of the samples obtained at mean low, medium, and high heat input levels was carried out. An optimal heat input gradient was determined which allowed growing a defect-free metal in the bottom part of the sample and forcing out the shrinkage cavities to the top part. Shrinkage and gas pore structure formation was analyzed as a function of the heat input gradient and along the building direction. Gas pores resulted at two higher heat input regimes as a result of evaporation of magnesium as supported by the results of EDS and XRD. Tensile test showed the ultimate strength of the defect-free part equal to that of the base AA5356.