Assessment Of Budget Research Articles

Influence of Precipitation Change on Soil Respiration in Desert Grassland

Global climate change has significantly changed precipitation patterns. Soil respiration (SR), as an important pathway through which CO2 is released from the soil carbon pool into the atmosphere, may affect the carbon cycle process of terrestrial ecosystems and have a feedback effect on global climate change in response to precipitation change. However, at present there is limited understanding of how SR is affected by precipitation change. Field precipitation control experiments were conducted (with -40%, -20%, natural, 20%, and 40% precipitation) on desert grassland in the west of the Loess Plateau, to investigate the influence of precipitation change on SR dynamics and its relationship with soil water content, soil temperature, aboveground biomass, soil organic carbon, microbial biomass carbon, carbon-nitrogen ratio, and other factors. The results show that the diurnal variations of SR under different precipitation treatments were consistent in unimodal and bimodal models over three years. SR showed an increasing trend with added precipitation, relative to the control, and significant differences were observed between the second year (wetter) and the third year (drier) of the precipitation-manipulation experiment, indicating that precipitation changes had a legacy effect on SR. At the same time, SR was lowest under the -40% treatment and highest under the 40% treatment during the wetter year. The negative response of SR to precipitation exclusion treatments was stronger than the positive response to precipitation addition treatments. SR in drier years was significantly higher under precipitation addition treatments than the control, and the positive response of SR to increased precipitation treatment was significantly stronger than that under decreased precipitation treatment. In addition, soil water content, aboveground biomass, soil organic carbon, and carbon-nitrogen ratio were the environmental factors that obviously affected SR and increased with additional precipitation. SR increased with increases in soil water content, aboveground biomass, soil organic carbon, and carbon-nitrogen ratio, but decreased with increases in microbial biomass carbon. Among these factors, soil water content had the highest interpretation rate for SR, indicating that soil water content was the main environmental factor controlling SR in desert grassland. In both wetter and drier years, the amplitude of plant biomass input was lower than the amplitude of SR output under precipitation change, indicating that precipitation change may be unfavorable to soil carbon sequestration, especially in drier years, when precipitation change has a stronger influence on carbon pool output. Therefore, precipitation changes on SR in desert grassland in various dry and wet years may have different influences on the carbon cycle process of ecosystems, thus providing a reference for regional carbon budget assessment.

Shrinking thermokarst lakes and ponds on the northeastern Qinghai‐Tibet plateau over the past three decades

AbstractIdentifying the changes in thermokarst lake dynamics has a significant contribution to landscape‐scale hydrology, ecology, and assessment of carbon budgets in permafrost regions. Changes in the number and areal extent of thermokarst lakes and ponds were quantified in a representative permafrost area (150 km2) in the south‐central Headwater Area of the Yellow River (HAYR). Water‐body inventories were generated from Landsat satellite imageries using the supervised Maximum Likelihood Classification method for three periods: 1986, 2000, and 2015. From 1986 to 2015, the number of water bodies larger than 0.36 ha decreased by 40% (461–277), while the total surface area decreased by 25% (542–406 ha). The ponds category (smaller than 1 ha) recorded the most substantial change, as their number decreased by 44% and their water‐surface area by 41%. Many lakes disintegrated, partially drained, and formed several remnant ponds, while the majority of the ponds did not drain completely, but shrank below 0.36 ha. These shrinking patterns are consistent with the warming climate in the HAYR, which suggests intense permafrost degradation. Future research will be focused on a better understanding of water–heat dynamics of thermokarst lakes and ponds in association with permafrost degradation at a landscape scale.

Methodology for estimating the energy reserve of a mobile ad-hoc communication network with UV-C channel

Communication systems of the solar-blind ultraviolet range UV-C from 200 to 280 nm provide the possibility of communication in the absence of line of sight due to the strong scattering of UV radiation in the atmosphere. For the effective use of UV-C communication systems, an adequate assessment of the energy budget of the UV channel is necessary. Analytical expressions are obtained that characterize the energy reserve of the UV-C system in relation to the specified characteristics of the optical receiver, transmitter, and UV channel. Based on the analytical and numerical model of losses in the UV channel, the energy reserve of the UV-C communication system is modeled on the distance between the transmitter and receiver, the elevation angles and the azimuthal deviation of the transmitter and receiver. The results obtained can be used to calculate and optimize ad-hoc communication networks with UV-C channel, characterized by changes in the spatial location of network nodes during operation.

Preliminary Research: Validation of the Method of Evaluating Resistance to Surface Wetting with Liquid of Protective Materials Intended for Polymer Protective Gloves.

The article presents validation argumentation of the novel method of evaluating resistance to surface wetting with different liquids of protective materials intended for polymer protective gloves based on the three parameters: water permeability index, non-wettability index and absorption index. Using our own method of evaluating resistance to surface wetting, it was shown that the knurled structure of the palm part of polymer protective gloves may inhibit transport of harmful and hazardous liquids outside the area of the protective glove. Currently, there is lack of objectifying methods for evaluation of surface wettability focused on the mentioned aspects. In view of the above facts, an original method for evaluating the resistance of protective materials to surface wetting with mineral oils and water has been invented and validated. It was assumed that the non-wettability index will be subjected to metrological analysis. Consequently, the validation process refers to this index. A precise assessment of the uncertainty budget of the individual components was obtained. On the basis of the obtained results, the measurement errors that may affect the quality and reliability of the test result performed in the laboratory were identified.

Land-use harmonization datasets for annual global carbon budgets

Abstract. Land-use change has been the dominant source of anthropogenic carbon emissions for most of the historical period and is currently one of the largest and most uncertain components of the global carbon cycle. Advancing the scientific understanding on this topic requires that the best data be used as input to state-of-the-art models in well-organized scientific assessments. The Land-Use Harmonization 2 dataset (LUH2), previously developed and used as input for simulations of the 6th Coupled Model Intercomparison Project (CMIP6), has been updated annually to provide required input to land models in the annual Global Carbon Budget (GCB) assessments. Here we discuss the methodology for producing these annual LUH2-GCB updates and extensions which incorporate annual wood harvest data updates from the Food and Agriculture Organization (FAO) of the United Nations for dataset years after 2015 and the History Database of the Global Environment (HYDE) gridded cropland and grazing area data updates (based on annual FAO cropland and grazing area data updates) for dataset years after 2012, along with extrapolations to the current year due to a lag of 1 or more years in the FAO data releases. The resulting updated LUH2-GCB datasets have provided global, annual gridded land-use and land-use-change data relating to agricultural expansion, deforestation, wood harvesting, shifting cultivation, regrowth and afforestation, crop rotations, and pasture management and are used by both bookkeeping models and dynamic global vegetation models (DGVMs) for the GCB. For GCB 2019, a more significant update to LUH2 was produced, LUH2-GCB2019 (https://doi.org/10.3334/ORNLDAAC/1851, Chini et al., 2020b), to take advantage of new data inputs that corrected cropland and grazing areas in the globally important region of Brazil as far back as 1950. From 1951 to 2012 the LUH2-GCB2019 dataset begins to diverge from the version of LUH2 used for the World Climate Research Programme's CMIP6, with peak differences in Brazil in the year 2000 for grazing land (difference of 100 000 km2) and in the year 2009 for cropland (difference of 77 000 km2), along with significant sub-national reorganization of agricultural land-use patterns within Brazil. The LUH2-GCB2019 dataset provides the base for future LUH2-GCB updates, including the recent LUH2-GCB2020 dataset, and presents a starting point for operationalizing the creation of these datasets to reduce time lags due to the multiple input dataset and model latencies.

Cliff Retreat Contribution to the Littoral Sediment Budget along the Baltic Sea Coastline of Schleswig-Holstein, Germany

Mobile coastal sediments, such as sand and gravel, build up and protect wave-dominated coastlines. In sediment-starved coastal environments, knowledge about the natural sources and transport pathways of those sediments is of utmost importance for the understanding and management of coastlines. Along the Baltic Sea coast of Schleswig-Holstein (Germany), the retreat of active cliffs—made of cohesive Pleistocene deposits—supplies a wide size range of sediments to the coastal system. The material is reworked and sorted by hydrodynamic forcing: the less mobile stones and boulders remain close to the source area; the finest sediments, mostly clay and silt, are transported offshore into areas of low energy; and the fractions of sand and fine gravels mostly remain in the nearshore zone, where they make up the littoral sediment budget. They contribute to the morphodynamic development of sandy coastlines and nearshore bar systems. Exemplarily for this coastal stretch and based on an extensive review of local studies we quantify the volume of the potential littoral sediment budget from cliff retreat. At an average retreat rate of 0.24 m yr−1 (<0.1–0.73 m yr−1), the assessment indicates a weighted average sediment volume of 1.5 m3 yr−1 m−1 (<0.1–9.5 m3 yr−1 m−1) per meter active cliff. For the whole area, this results in an absolute sediment budget Vs,total of 39,000–161,000 m3 yr−1. The accuracy of the results is limited by system understanding and data quality and coverage. The study discusses uncertainties in the calculation of littoral sediment budgets from cliff retreat and provides the first area-wide budget assessment along the sediment-starved Baltic Sea coastline of Schleswig-Holstein.

Better irrigation management using the satellite-based adjusted single crop coefficient (aKc) for over sixty crop types in California, USA

Several Surface Energy Balance (SEB) models are currently used to unleash the boundless potential of Geographic Information System (GIS) and Remote Sensing (RS) techniques. Their main output, namely the actual evapotranspiration (ETa), is required for the assessment of water budget at basin, regional and national levels. Still, the lack of the required expertise coupled with sometimes missing input data limits their usage by researchers, policy makers, water managers and farmers. In this study, a novel comprehensive monthly adjusted crop coefficients (aKc) list was produced, in which these coefficients are usually used to retrieve the much-needed ETa using the climate-sensitive reference crop evapotranspiration (ET0). More particularly, the ETa is calculated for more than sixty different crop types present in the Mediterranean-climate California, United States. It is based on the two consecutive years of 2018 and 2019, which were wet and dry, respectively. The Google Earth Engine (GEE) version of the Surface Energy Balance Algorithm for Land-Improved (SEBALI), surnamed SEBALIGEE, with an Absolute Mean Error (AME) of 9.56 mm/month in the study area was used along the annual crop map from the United States Department of Agriculture (USDA). The main results showed that the average monthly aKc values ranged between 0.45 and 1.53. More specifically, October and November presented the lowest aKc values averaged among all crop types with aKc values around 0.76. On the other hand, March, April and June had the largest average aKc values at nearly 1.17. The monthly aKc values of the 60 crops studied in the plain of California, would potentially assist authorities and hydrologists to better calculate the actual monthly plant water consumption, in a simpler way over the upcoming years.

Spatial Pattern Analysis of the Ecosystem Services in the Guangdong-Hong Kong-Macao Greater Bay Area Using Sentinel-1 and Sentinel-2 Imagery Based on Deep Learning Method

Assessment of ecosystem services supply, demand, and budgets can help to achieve sustainable urban development. The Guangdong-Hong Kong-Macao Greater Bay Area, as one of the most developed megacities in China, sets up a goal of high-quality development while fostering ecosystem services. Therefore, assessing the ecosystem services in this study area is very important to guide further development. However, the spatial pattern of ecosystem services, especially at local scales, is not well understood. Using the available 2017 land cover product, Sentinel-1 SAR and Sentinel-2 optical images, a deep learning land cover mapping framework integrating deep change vector analysis and the ResUnet model was proposed. Based on the produced 10 m land cover map for the year 2020, recent spatial patterns of the ecosystem services at different scales (i.e., the GBA, 11 cities, urban–rural gradient, and pixel) were analyzed. The results showed that: (1) Forest was the primary land cover in Guangzhou, Huizhou, Shenzhen, Zhuhai, Jiangmen, Zhaoqing, and Hong Kong, and an impervious surface was the main land cover in the other four cities. (2) Although ecosystem services in the GBA were sufficient to meet their demand, there was undersupply for all the three general services in Macao and for the provision services in Zhongshan, Dongguan, Shenzhen, and Foshan. (3) Along the urban–rural gradient in the GBA, supply and demand capacity showed an increasing and decreasing trend, respectively. As for the city-level analysis, Huizhou and Zhuhai showed a fluctuation pattern while Jiangmen, Zhaoqing, and Hong Kong presented a decreasing pattern along the gradient. (4) Inclusion of neighborhood landscape led to increased demand scores in a small proportion of impervious areas and oversupply for a very large percent of bare land.

Practices and Attitudes of Swiss Stakeholders Regarding Investigator-Initiated Clinical Trial Funding Acquisition and Cost Management

Randomized clinical trials (RCTs) are an essential method of evaluating health care interventions and a cornerstone for evidence-based health care. However, RCTs have become increasingly complex and costly, which is particularly challenging for independent investigator-initiated clinical trials (IICTs). IICTs have an essential role in clinical research, and it is important that efforts are made to ensure IICTs are adequately funded and are conducted cost-effectively. To examine the practices and attitudes of Swiss stakeholders regarding IICT funding acquisition and cost management. For this qualitative study, interviews were conducted in Switzerland between February and August 2020. The purposive sample comprised 48 stakeholders from 4 different groups: primary investigators (n = 27), funders and sponsors (n = 9), clinical trial support organizations (n = 6), and ethics committee members (n = 6). Practices and attitudes of stakeholders regarding IICT funding acquisition and cost management were assessed using individual semistructured qualitative interviews. Interviews were analyzed using conventional content analysis. After interviews with 48 IICT stakeholders (75% male presenting), these participants identified a systemic problem of IICTs being underfunded, which can lead to compromises being made regarding the quality and conduct of IICTs. Participants identified 2 overarching and interconnected groups of reasons why IICTs in Switzerland are regularly underfunded. First, it was reported that IICT budget estimations are often inaccurate because of poor planning and preparation, unforeseeable events, investigators intentionally underestimating budgets, and limited budget assessment and oversight. Second, with the exception of a specific IICT funding program by the Swiss National Science Foundation, it was reported that limited funding sources and unrealistic expectation of funders led to underlying challenges in getting IICTs fully funded. A number of measures that could help reduce the underfunding of IICTs were identified, including improving the support of investigators and IICTs, strengthening networking and guidance, harmonizing and simplifying bureaucracy, and increasing public funding of IICTs. This study highlights the inadequate expertise of Swiss stakeholders to correctly, systematically, and reproducibly calculate RCT budgets and the need for transparency on trial costs as well as training in budgeting practices. Limited financial resources for academic clinical research and issues regarding the professional planning and conduct of IICTs are persistent issues that many other countries also face.

Budget Evaluation and Economic Development in Nigeria

The major goal of this research was to see how budget assessment affected Nigeria's economic progress. The inspiration stemmed from a number of inconsistencies in the Nigerian economy's budget preparation and execution. This study employed an ex-post-facto design, with data gathered from the Central Bank Statistical Bulletin and the Federal Ministry of Finance for analysis. A model based on empirical and theoretical reviews was developed to attain this wide purpose. The model's dependent variable was the Human Development Index (HDI), while the model's independent variables were the government's capital budget, recurrent budget, and yearly budget implementation rate. To evaluate data, the researchers used the Ordinary Least Squares (OLS) Model. Budget assessment had a favorable and considerable influence on Nigeria's economic progress, according to the inferential findings. According to the report, Nigeria's government should make an effort to raise capital and recurring expenditures in its yearly budget, since both have a substantial influence on economic development. Finally, the government should make an effort to put in place effective budget monitoring and assessment equipment that will increase the rate of budget implementation while simultaneously ensuring strict adherence to due process.

Global carbon budget of reservoirs is overturned by the quantification of drawdown areas

Reservoir drawdown areas—where sediment is exposed to the atmosphere due to water-level fluctuations—are hotspots for carbon dioxide (CO2) emissions. However, the global extent of drawdown areas is unknown, precluding an accurate assessment of the carbon budget of reservoirs. Here we show, on the basis of satellite observations of 6,794 reservoirs between 1985 and 2015, that 15% of the global reservoir area was dry. Exposure of drawdown areas was most pronounced in reservoirs close to the tropics and shows a complex dependence on climatic (precipitation, temperature) and anthropogenic (water use) drivers. We re-assessed the global carbon emissions from reservoirs by apportioning CO2 and methane emissions to water surfaces and drawdown areas using published areal emission rates. The new estimate assigns 26.2 (15–40) (95% confidence interval) TgCO2-C yr−1 to drawdown areas, and increases current global CO2 emissions from reservoirs by 53% (60.3 (43.2–79.5) TgCO2-C yr−1). Taking into account drawdown areas, the ratio between carbon emissions and carbon burial in sediments is 2.02 (1.04–4.26). This suggests that reservoirs emit more carbon than they bury, challenging the current understanding that reservoirs are net carbon sinks. Thus, consideration of drawdown areas overturns our conception of the role of reservoirs in the carbon cycle.

Seasonal variations in temperature sensitivity of soil respiration in a larch forest in the Northern Daxing’an Mountains in Northeast China

Temperature sensitivity of respiration of forest soils is important for its responses to climate warming and for the accurate assessment of soil carbon budget. The sensitivity of temperature (Ti) to soil respiration rate (Rs), and Q10 defined by e10(lnRs−lna)/Ti has been used extensively for indicating the sensitivity of soil respiration. The soil respiration under a larch (Larix gmelinii) forest in the northern Daxing’an Mountains, Northeast China was observed in situ from April to September, 2019 using the dynamic chamber method. Air temperatures (Tair), soil surface temperatures (T0cm), soil temperatures at depths of 5 and 10 cm (T5cm and T10cm, respectively), and soil-surface water vapor concentrations were monitored at the same time. The results show a significant monthly variability in soil respiration rate in the growing season (April–September). The Q10 at the surface and at depths of 5 and 10 cm was estimated at 5.6, 6.3, and 7.2, respectively. The Q10@10 cm over the period of surface soil thawing (Q10@10 cm, thaw = 36.89) were significantly higher than that of the growing season (Q10@10 cm, growth = 3.82). Furthermore, the Rs in the early stage of near-surface soil thawing and in the middle of the growing season is more sensitive to changes in soil temperatures. Soil temperature is thus the dominant factor for season variations in soil respiration, but rainfall is the main controller for short-term fluctuations in respiration. Thus, the higher sensitivity of soil respiration to temperature (Q10) is found in the middle part of the growing season. The monthly and seasonal Q10 values better reflect the responsiveness of soil respiration to changes in hydrometeorology and ground freeze-thaw processes. This study may help assess the stability of the soil carbon pool and strength of carbon fluxes in the larch forested permafrost regions in the northern Daxing’an Mountains.

Substantial hysteresis in emergent temperature sensitivity of global wetland CH4 emissions

Wetland methane (CH4) emissions ({F}_{{{CH}}_{4}}) are important in global carbon budgets and climate change assessments. Currently, {F}_{{{CH}}_{4}} projections rely on prescribed static temperature sensitivity that varies among biogeochemical models. Meta-analyses have proposed a consistent {F}_{{{CH}}_{4}} temperature dependence across spatial scales for use in models; however, site-level studies demonstrate that {F}_{{{CH}}_{4}} are often controlled by factors beyond temperature. Here, we evaluate the relationship between {F}_{{{CH}}_{4}} and temperature using observations from the FLUXNET-CH4 database. Measurements collected across the globe show substantial seasonal hysteresis between {F}_{{{CH}}_{4}} and temperature, suggesting larger {F}_{{{CH}}_{4}} sensitivity to temperature later in the frost-free season (about 77% of site-years). Results derived from a machine-learning model and several regression models highlight the importance of representing the large spatial and temporal variability within site-years and ecosystem types. Mechanistic advancements in biogeochemical model parameterization and detailed measurements in factors modulating CH4 production are thus needed to improve global CH4 budget assessments.

Managing the uncertainty of the U-value measurement using an auxiliary set along with a thermal camera

The building elements’ thermal transmittance index (known as U value) is the most essential parameter for the estimation of its thermal losses, and subsequently its energy performance. Laboratory measurements of the U value are practically of interest only for pre-fabricated or standardised building elements; hence, the commonly acceptable practice is to use theoretical estimations, taking into account the thermal resistance indexes of the building elements’ layers. In this context, this paper aims at the assessment of the uncertainty budget of one of the already used in-situ building elements’ thermal transmittance measurement, as long as this is applied using a thermal camera instead of contact thermometers. A specially designed and easily constructed auxiliary measurement set-up is presented and is used in comparison with simultaneous thermocouple measurements, to verify the adequacy of the auxiliary set up response time. This study concludes with the analysis of the uncertainty that affects the proposed procedure, along with an assessment of the impact in the final result. The uncertainty of these measurements is strongly related with the respective decisions on building upgrade and renovation. Therefore, managing it with a simplified procedure will be rather profitable both for those seeking to perform an in-situ U value measurement and for those who are engaged into a decision process upon renovating or not an existing building.

Activity Time Budgets—A Potential Tool to Monitor Equine Welfare?

Simple SummaryHorses’ behavior is a good indicator of their welfare status. However, its complexity requires objective, quantifiable, and unambiguous evidence-based assessment criteria. As healthy, stress-free horses exhibit a highly repetitive daily routine, horses’ time budget (amount of time in a 24 h period spent on specific activities) can assist in equine welfare assessment. A systematic review of the literature yielded 12 papers that assessed equine time budgets for eating, resting and movement for a minimum of 24 continuous hours. A total of 144 horses (1–27 years old), 59 semi-feral and 85 domesticated horses, are included in this review. The reported 24 h time budgets for eating ranged from 10% to 66.6%, for resting from 8.1% to 66%, for lying from 2.7% to 27.3%, and for movement from 0.015% to 19.1%. The large variance in time budgets between studies can largely be attributed to differences in age and environmental conditions. Management interventions (free access to food, increased space, decreased population density) in domesticated horses yielded time budgets similar to semi-feral horses. The data support the importance of environmental conditions for horses’ well-being and the ability of time budgets to assist in monitoring horses’ welfare.Horses’ behavior can provide valuable insight into their subjective state and is thus a good indicator of welfare. However, its complexity requires objective, quantifiable, and unambiguous evidence-based assessment criteria. As healthy, stress-free horses exhibit a highly repetitive daily routine, temporal quantification of their behavioral activities (time budget analysis) can assist in equine welfare assessment. Therefore, the present systematic review aimed to provide an up-to-date analysis of equine time budget studies. A review of the literature yielded 12 papers that fulfilled the inclusion criteria: assessment of equine time budgets for eating, resting and movement for a minimum of 24 continuous hours. A total of 144 horses (1–27 years old), 59 semi-feral and 85 domesticated horses, are included in this review. The 24 h time budgets for foraging or eating (10–6.6%), resting (8.1–66%), lying (2.7–27.3%), and locomotion (0.015–19.1%) showed large variance between studies, which can largely be attributed to differences in age and environmental conditions. Management interventions in domesticated horses (ad libitum access to food, increased space, decreased population density) resulted in time budgets similar to their (semi-)feral conspecifics, emphasizing the importance of environmental conditions and the ability of time budgets to assist in monitoring horses’ welfare.

Long-term assessment of nutrient budgets for the four reservoirs of the Seine Basin (France).

Artificial reservoirs represent one of the most significant human disturbances of water flows and associated water quality, including nutrients and SM (suspended matter). However, most of the previous studies were only focused on few years or even single year, and the long-term dynamics of nutrient retention in reservoir are under explored. In this study, we present the long-term (1998-2018) hydrological characteristics and water quality in four reservoirs (Marne, Aube, Seine, and Pannecière reservoirs) and their related rivers (Marne, Aube, Seine, and Yonne rivers) of the Seine Basin, France. Based on the hydrology and water quality data, the long-term budgets of nutrients and SM were evaluated in these reservoirs according to mass balance calculation. The results indicated that the four reservoirs play important roles in the retention/elimination of nutrients and SM, and the retention/elimination rates may be affected by hydrophysical and biogeochemical processes. The mean annual retention rates accounted for 16-53% of the inputs of DIN (dissolved inorganic nitrogen), 26-48% of PO43--P (orthophosphates), 22-40% of Si (dissolved silicon), and 36-76% of SM in the four reservoirs during the 1998-2018 period. Further analysis suggested that the annual residence time and the percentage of water released from reservoirs during the filling period significantly correlated with DIN retention rates in the four reservoirs (p<0.01), which highlights the importance of reservoir water management strategies for the DIN concentrations in the downstream rivers. Interestingly, the Wilcoxon test results also revealed that the three diverted reservoirs (Marne, Aube, and Seine reservoirs) indeed lowered the nutrient concentrations in their downstream rivers during the emptying period, thereby modifying the biogeochemical functioning in the downstream river networks. Finally, these results emphasized the importance of hydrological characteristics in better understanding nutrient retention in reservoirs.

Comparison of carbon footprint and net ecosystem carbon budget under organic material retention combined with reduced mineral fertilizer

BackgroundExcessive application of chemical fertilizer has resulted in lower nitrogen uptake and utilization efficiency of crops, decreasing soil fertility, increasing greenhouse gas emissions, and worse environmental pollution. Organic material retention is regard as the key to solve these problems. The objective of this study is to conduct an assessment of carbon budget under Astragalus sinicus L. and rice straw retention combined with reduced mineral fertilizer based on the 2-year field experiment in a paddy field in the south of China. The experiment was randomized complete block design including four treatments with triplicates: control CK (winter follow, 120 kg ha−1 N fertilizer for each rice season) and three treatments with Astragalus sinicus L. and rice straw retention named RA, RB, and RC (reduced N fertilizer by 15%, 27.5%, and 40% in each rice season).ResultsTreatments RA, RB, and RC increased greenhouse gas emissions by 9.30–101.25%, among which CH4 accounted for more than 60%; Carbon input of crops from treatments RA, RB, and RC increased by 2.25–12.10% compared with control CK over the 2 years. Though treatments RA, RB, and RC enhanced CO2 emissions, treatment RB decreased carbon footprint and became carbon sink.ConclusionsThe results of this study reveal that treatment RB (Astragalus sinicus L. and rice straw retention with reduced N fertilizer by 27.5%) is better in reducing chemical fertilizer amount, increasing crop yield and carbon input, which is more conductive to sustainable development of agriculture.

Integrated assessment of carbon footprint, energy budget and net ecosystem economic efficiency from rice fields under different tillage modes in central China

Currently, the effects of different tillage modes on greenhouse gas (GHG) emissions, carbon footprint (CF), energy budget and net ecosystem economic efficiency (NEEE) in rice fields remain unclear. In the present study, three tillage modes were tested, including rice conventional cultivation with intensive till (CT), conventional flat cultivation with no-till (FNT) and ridge cultivation with no-till (RNT) in Dafasi town, Wuxue city, Hubei province, China. This study for the first time evaluates the effects of RNT on agricultural GHG emissions, grain yield, CF, energy budget and NEEE. Compared with CT and FNT, RNT reduced the soil CH4 emissions by 29.5% and 9.9%, respectively. CT resulted in 15.8% and 23.1% lower total GHG emissions than FNT and RNT, respectively, due to lower soil CH4 emissions. Moreover, RNT significant decreased the CF by 35.7% and 18.2% relative to CT and FNT, respectively. The net energy, energy efficiency and energy productivity under RNT were 41.2%, 25.0% and 26.7% higher than those under CT, respectively, while the specific energy under RNT was 24.7% lower than that under CT. The NEEE under RNT was 1.66 and 1.20 folds of that under CT and FNT, respectively. In conclusion, this study recommends that RNT is an environmentally safe tillage mode for reducing GHG emissions and CF, and improving energy use efficiency and NEEE for rice production in China and similar agro-eco-regions elsewhere in the world.

Assessment of the agricultural water budget in southern Iran using Sentinel-2 to Landsat-8 datasets

This paper is a first attempt to compute the total water needs of an agricultural plain with remote sensing and ground data in Iran. The cropping areas were mapped with Sentinels-2 images, based on NDVI profiles classification. This model was validated and 85% of the areas were correctly classified. Second, the crop water needs were computed using PYSEBAL and Landsat-8 images. Crop evapotranspiration (ETseason) and Irrigation Requirements (IRseason) were calculated for each crop and then validated by comparing IR collected in the field from farmers with computed IRPYSEBAL on 5 plots. IRPYSEBAL underestimated the reality with an average of 10% while the overestimation average was 17%. The second validation was the comparison of Daily ET from FAO-56 method and Daily ET PYSEBAL showed a RMSE of 0.67 mm/day and MAE of 0.52 mm/day, which assesses the accuracy of PYSEBAL. ETseason varies according to weather parameters in the plain and IRseason, according to different irrigation practices. The most water demanding crops were identified: rice (IR: 1427 mm) and corn (669). The total water balance of Marvdasht was negative in 2018 with 0.2859 km3 of extracted groundwater for irrigation for only 0.098 km3 of available water for aquifers recharge.

Surface CO2 system dynamics in the Gulf of Anadyr during the open water season

The Gulf of Anadyr (GA), one of the largest and most poorly investigated gulfs of the Bering Sea, is an important part of the Pacific Arctic. Drivers and mechanisms responsible for the spatial variations in surface seawater CO2 system parameters and associated air–sea CO2 fluxes were investigated during three oceanographic cruises conducted in the GA during the open water season of 1992, 2002, and 2011. It was shown that the surface waters of the GA were moderate to strong sinks for atmospheric CO2 during this season: mean air-sea CO2 fluxes for the investigated areas of the GA, for the three cruises, were −31, −15, and −30 mmol CO2 m−2 d−1, respectively. The summer air-sea CO2 flux was attributed to intensive phytoplankton bloom, and fall CO2 uptake coincided with a period of strong winds and seasonal enhanced primary production. The surface waters of the GA were supersaturated with respect to aragonite during the investigated period. Anadyr Strait, a region of high hydrodynamic activity, was the only area where CO2 efflux was observed. Surface waters of the strait were supersaturated with respect to CO2 and in quasi-equilibrium with respect to aragonite. We found that during the late summer/fall season, the Anadyr Current exported a well-mixed, relatively cold, salty, nutrient- and CO2-rich water through the western Anadyr Strait into the Chirikov Basin. Our research highlights the need for mesoscale studies of the western Bering Sea to produce the most accurate assessment of the regional CO2 budget.