Annual Yield Research Articles

Hydrological changes in a plain basin in central Argentina following expansion of rainfed agriculture and climate change

AbstractThe characterization of long‐term streamflow in regions undergoing climatic change and agricultural expansion is relevant for achieving sustainable development goals and for assessing the vulnerability of water‐dependent populations and agricultural activities. The objective of this work was to characterize the temporal patterns of water yield in the plain basin of the Carcarañá River (33,063 km2), located in central Argentina and to analyse its relationship with a fast expansion of rainfed cultivation and climate change. The streamflow data for the period 1980–2020 were analysed in conjunction with climatic data (rainfall, reference evapotranspiration), satellite data (NDVI) and cropping statistics (sown area of summer crops) data. The annual water yield averaged ~10% of the rainfall and showed a clear upward trend throughout the study period, both in absolute terms and relative to rainfall (i.e., runoff coefficient), which was not explained by rainfall or reference evapotranspiration temporal patterns. Conversely, we found that the trend in water yield was positively associated with the agricultural area (p < 0.05), which more than doubled during the study period (from 29% to 66%). Likewise, the mean NDVI of the basin, a proxy for primary productivity and vegetation transpiration, has decreased steadily over the last 20 years (p < 0.05). The separation between base flow and quick flow suggested that both flows increased during the analysed period (p < 0.05), though the latter would have been more relevant in explaining the trend observed in total flow. Taken together, our results suggest that agricultural expansion, rather than climate change, is the dominant factor explaining the hydrological changes observed in the study basin. Understanding the key role of land use in shaping the hydrology of a landscape is critical to developing policies and practices for more efficient and sustainable use of environmental resources.

Spatio-temporal change of winter wheat yield and its quantitative responses to compound frost-dry events – An example of the Huang-Huai-Hai Plain of China from 2001 to 2020

Extreme climate events such as frost and drought have great influence on wheat growth and yield. Understanding the effects of frost, drought and compound frost-dry events on wheat growth and yield is of great significance for ensuring national food security. In this study, wheat yield prediction model (SCYMvp) was developed by combining crop growth model (CGM), satellite images and meteorological variables. Wheat yield maps in the Huang-Huai-Hai Plain (HHHP) during 2001–2020 were generated using SCYMvp model. Meanwhile, accumulative frost days (AFD), accumulative dry days (ADD) and accumulative frost-dry days (AFDD) in different growth periods of wheat were calculated, and the effects of frost and drought on wheat yield were quantified by the first difference method and linear mixed model. The results showed that wheat yield increased significantly, while the rising trend was obvious at more than half of the regions. Extreme climate events (ECEs) showed a relatively stable change trend, although the change trend was significant only in a few areas. Compared with frost and drought in the early growth period, ECEs in the middle growth period (spring ECEs) had more negative effects on wheat growth and yield. Wheat yield was negatively correlated with spring ECEs, and yield loss was between 4.6 and 49.8 kg/ha for each 1 d increase of spring ECEs. The effects of spring ECEs on wheat yield were ranked as AFDD > AFD > ADD. The negative effect of ADD on wheat yield in the late growth period was higher than that in the other periods. The negative effects of spring ECEs on yield in southern regions were higher than those in northern regions. Overall, due to the adverse effects of frost and drought on wheat yield in the middle and late growth periods, the mean annual yield loss was 6.4 %, among which spring AFD caused the greatest loss to wheat yield (3.1 %). The results have important guiding significance for formulating climate adaptation management strategies.

Ecosystem services dynamics and their influencing factors: Synergies/tradeoffs interactions and implications, the case of upper Blue Nile basin, Ethiopia

Understanding the relationships among ecosystem services (ESs) and their interactions with influencing factors is essential for spatially targeted ecosystem governance. However, classifying the spatial distribution of these diverse interactions still needs improvement. Furthermore, existing studies have insufficiently addressed the specific impacts of bidirectional land cover transitions on ESs. Taking the upper Blue Nile basin as a study area, we estimated the spatiotemporal distribution of annual water yield (AWY), carbon storage (CS), habitat quality (HQ), and soil retention (SR) from 2000 to 2020, using InVEST models and associated formulas. Changes in ESs per inward-outward land cover transition were quantified based on the Cross-Tabulation Matrix. An improved pairwise method was employed to assess the spatially diverse interactions between ESs pairs and their relationship with influencing factors. The statistical significance of influencing factors was evaluated using partial least square regression. The findings indicated that high HQ values were prevalent in the west, while they were in the east for SR. The central and southern areas experienced higher CS and AWY values. During the study period, variations were observed in the mean values of SR (ranging from 22.89 to 23.88 × 102 t/ha/y), AWY (32.13–42.2 × 102 mm/ha/y), CS (90.5–102.9 × 103gC/ha/y) and HQ (0.62–0.64). Synergies were predominant in AWY-CS, AWY-SR, and CS-SR pairs. HQ revealed more of a no-effect and tradeoff relationship with other ESs. The interactions between ESs and influencing factors were dominated by synergies, followed by tradeoffs and no-effect. The influence of landscape structure (gyrate and landscape shape index) and land surface temperature on all ESs and precipitation on AWY and SR was significant (1.049 ≤ Variable Importance in the Projection ≤ 1.371). Overall, the spatiotemporal dynamics of key ESs and the modeling of their drivers are essential policy information for taking spatially explicit conservation measures. This study will also serve as a valuable methodological reference for future research.

A long-term study of the impact of the invasive species Eurasian minnow Phoxinus phoxinus on brown trout Salmo trutta production in a high mountain lake, Southern Norway

The shallow Lake Skjerja was originally one of the most outstanding brown trout lakes on the Hardangervidda mountain plateau. During the period 1973–1985, the annual yield was on average 3.35 kg ha-1. In the mid-1980s, Eurasian minnow established a dense population in the lake. Since 1994, 5304 kg of Eurasian minnow have been removed with baited traps, which correspond to an annual mean catch of 177 kg year-1 or 1.12 kg ha-1. The competition for food, in addition to longer food chains, has had a strong negative impact on the brown trout production, with an annual yield reduced to 1.07 kg ha-1, or 32% of the historical catches (1973-1985). The total removed biomass of the two fish species correspond to 65% of the brown trout yield before the invasion of the Eurasian minnow. In Lake Skjerja, the two crustacean species Gammarus lacustris and Lepidurus arcticus, have historically been staple food items for brown trout. Fishing with baited traps on the minnows, and the presence of a large fraction of predatory brown trout, may have reduced the predation pressure on the two crustacean species, and they are still a part ofthe brown trout diet. The availability of fish as food has resulted in a significant increase in the presence of large individuals of brown trout with maximum weights above four kg. Despite reduced annual yield of brown trout, Lake Skjerja is still a popular fish destination with nearly 200 big-sized brown trout (mean annual weight 1065 grams) landed annually. On Hardangervidda, an increase in air temperature has been observed since the 1980s, with a corresponding change in water temperature which may benefit Eurasian minnow. In warm summers, water temperature approaches 14°C which has proved to be near to the upper thermal threshold for Lepidurus arcticus.

Vertical Agrivoltaics System on Arable Crops in Central France: Feedback of the First Year of Operation

Since the development of Agrivoltaics with panels placed above the plants, a new system is tested with vertical mounted bifacial photovoltaic panels, of which we present the results of the first year of two experimental sites. Such installations bring a lower shading level on the plant compared to fixed tilt or single axis tracking systems and could potentially suit fields with crops having low demands of shading. However, unlike more standard PV systems, few studies have detailed the effects of such devices on field crops. In this first experimental year, bifacial vertically mounted PV system showed interesting results with a stable or even a slight increase in annual crop yields. Also, harvest quality indicators are maintained or present favorable evolution indicating a high potential of vertical PV systems for Agrivoltaics.

Intelligent crop management system for improving yield in maize production: evidence from India

PurposeManaging weeds and pests in cropland is one of the major concerns in agriculture that greatly affects the quantity and quality of the produce. While the success of preventing potential weeds and pests is not guaranteed, early detection and diagnosis help manage them effectively to ensure crops’ growth and healthDesign/methodology/approachWe propose a diagnostic framework for crop management with automatic weed and pest detection and identification in maize crops using residual neural networks. We train two models, one for weed detection with a labeled image dataset of maize and commonly occurring weed plants, and another for leaf disease detection using a labeled image dataset of healthy and infected maize leaves. The global and local explanations of image classification are obtained and presentedFindingsWeed and disease detection and identification can be accurately performed using deep-learning neural networks. Weed detection is accurate up to 97%, and disease detection up to 95% is made on average and the results are presented. Further, using this crop management system, we can detect the presence of weeds and pests in the maize crop early, and the annual yield of the maize crop can potentially increase by 90% theoretically with suitable control actionsPractical implicationsThe proposed diagnostic models can be further used on farms to monitor the health of maize crops. Images obtained from drones and robots can be fed to these models, which can then automatically detect and identify weed and disease attacks on maize farms. This offers early diagnosis, which enables necessary treatment and control of crops at the early stages without affecting the yield of the maize cropSocial implicationsThe proposed crop management framework allows treatment and control of weeds and pests only in the affected regions of the farms and hence minimizes the use of harmful pesticides and herbicides and their related health effects on consumers and farmers.Originality/valueThis study presents an integrated weed and disease diagnostic framework, which is scarcely reported in the literature

Slope Gradient Effects on Sediment Yield of Different Land Cover and Soil Types

Water majorly contributes to soil erosion. Considering Japan’s humid and rainy climate, severe soil erosion challenges persist even though forests are the country’s dominant land type. Although numerous studies have emphasized the impact of factors such as land use, soil type, and slope steepness on sediment yield, the synergetic effects of slope gradient with varying land cover and soil types are underexplored. Herein, we used the Soil and Water Assessment Tool (SWAT) on a steep catchment to identify high sediment yield areas—as well as factors influencing high sediment yield—and evaluate the effect of slope gradient on the sediment yield of different land cover and soil types. The findings reveal an average annual sediment yield of 0.55 tons ha−1 yr−1 in the Takahashi catchment, with yields tripling in some western subbasins under heavy rainfall. Furthermore, the slope gradient effect is most considerable in bare land, agriculture, and rice land cover, with the average sediment yield of bare land resulting in 2.2 tons ha−1 yr−1 at slope > 45%. Meanwhile, deciduous forests on steep slopes exhibit extreme sediment yield, peaking at 7.2 tons ha−1 yr−1 at slope > 45%. The regosol soil type has one of the highest sediment yield variations in all soil types due to slope gradient.

Waste-to-Energy Processes as a Municipality-Level Waste Management Strategy: A Case Study of Kočevje, Slovenia

The escalating challenge of waste management demands innovative strategies to mitigate environmental impacts and harness valuable resources. This study investigates waste-to-energy (WtE) technologies for municipal waste management in Kočevje, Slovenia. An analysis of available waste streams reveals substantial energy potential from mixed municipal waste, biodegradable waste, and livestock manure. Various WtE technologies, including incineration, pyrolysis, gasification, and anaerobic digestion, are compared. The results show that processing mixed municipal waste using thermochemical processes could annually yield up to 0.98 GWh of electricity, and, separately, 3.22 GWh of useable waste heat for district heating or industrial applications. Furthermore, by treating 90% of the biodegradable waste, up to 1.31 GWh of electricity and 1.76 GWh of usable waste heat could be generated annually from biodegradable municipal waste and livestock manure using anaerobic digestion and biogas combustion in a combined heat and power facility. Gasification coupled with a gas-turbine-based combined heat and power cycle is suggested as optimal. Integration of WtE technologies could yield 2.29 GWh of electricity and 3.55 GWh of useable waste heat annually, representing an annual exergy yield of 2.98 GWh. Within the Kočevje municipality, this amount of energy could cover 23.6% of the annual household electricity needs and cover the annual space and water heating requirements of 10.0% of households with district heating. Additionally, CO2-eq. emissions could be reduced by up to 20%, while further offsetting emissions associated with electricity and district heat generation by 1907 tons annually. These findings highlight the potential of WtE technologies to enhance municipal self-sustainability and reduce landfill waste.

Study on the optimal layout of roof vents and rooftop photovoltaic of the industrial workshop

Roof vents are crucial for facilitating natural ventilation within industrial workshops. However, their substantial size and height can limit available roof space and create extensive shadow areas, thereby impeding the installation of photovoltaic (PV) systems on industrial roofs. This study quantitatively assesses the influence of roof vent positioning, morphology, and roof architecture on the natural ventilation efficiency of workshops with varying indoor heat sources. Subsequently, the study evaluates how different vent configurations affect the installable area for rooftop solar panels. Findings suggest that shifting from traditional roof ridge vents directly above a heat source to north-side vents inclined towards the roof can marginally decrease the ventilation flow rate by approximately 5 %, translating to a minor temperature rise of around 0.46 °C within the occupied zone. Nonetheless, the Predicted Mean Vote (PMV) thermal comfort indices remain consistent across scenarios. Notably, adopting north-side vents, either flush with the roof or inclined, can enhance the annual energy yield of the rooftop PV system by 15.49 % and 22.67 %, respectively, under equivalent solar irradiation. Thus, strategic adjustments to vent positioning, form, and roof design can substantially boost the photovoltaic system's power output without compromising the workshop's natural ventilation performance.

From Sunrise to Sunset: Unraveling Metastability in Perovskite Solar Cells by Coupled Outdoor Testing and Energy Yield Modelling

AbstractPerovskite‐based solar cells exhibit peculiar outdoor performance which is not yet fully understood. The results of outdoor tests may contain hidden, but valuable information that cannot be fully extracted from measurements alone. One such phenomenon is the effect of nighttime degradation and the subsequent light‐soaking recovery, which can take from a few hours in the morning up to the entire day. In this work, long‐term outdoor monitoring is combined with energy yield modeling to qualitatively and quantitatively investigate the effect of light‐soaking recovery in both single junction and tandem perovskite‐based devices. Following the novel methodology presented in this study, it is observed that the light‐soaking effect depends not only on the daily irradiation but also on the device temperature, and it can be described using a simple empirical formalism. Incorporating this dependency into the energy yield model results in an excellent agreement between the simulated and the measured outdoor data, which allows to perform long‐term prediction studies. The model estimates that the light‐soaking metastability effect decreases the attainable annual energy yield by up to ≈5% for the studied single junction devices, and for tandems by up to ≈3%, depending on the geographical location, and even more for non‐optimal device orientation.

Impact of Mechanized Crop Establishment Techniques on Growth, Yield, and Microbial Dynamics under Rice-Wheat Cropping System: A Review

The rice-wheat cropping system, predominant across the Indo-Gangetic plains, generates a substantial volume of crop residue, with an annual yield of 7-9 tonnes per hectare of rice residue. Effective management of this residue, whether in-situ or ex-situ, has become an urgent necessity. However, the economic feasibility of transporting residue beyond 20 km from the field is limited. Consequently, in-field residue management through the adoption of specialized machinery has emerged as an imperative solution. The narrow window between paddy harvesting and wheat sowing, compounded by labor scarcity during peak periods, underscores the need for mechanized crop establishment techniques. Machines such as happy seeders, super seeders, turbo seeders, spatial drills, and seed-cum-fertilizer drills are crucial tools in this regard. This paper examines the benefits of mechanized crop establishment techniques on wheat growth, productivity, and soil biological health within the rice-wheat cropping system. These techniques have revolutionized agricultural practices by significantly influencing growth dynamics, yield parameters, and microbial ecology. The adoption of precision seed drills and mechanized tillage equipment has transformed traditional farming methods, facilitating efficient seed placement, soil preparation, residue incorporation, and weed management. This has resulted in improved crop growth parameters, enhanced yield dynamics, better root development, increased nutrient uptake, and overall plant vigor. Furthermore, reduced soil disturbance and decreased weed pressure associated with mechanized operations have created a conducive environment for beneficial microbial communities to thrive. The integration of mechanized crop establishment techniques has a positive impact on both crop productivity and sustainability, highlighting their importance in modern agricultural practices within the rice-wheat cropping system of the Indo-Gangetic plains.

Effects of Controlled-release Blended Fertilizer on Crop Yield and Greenhouse Gas Emissions in Wheat-maize Rotation System

The increasing use of nitrogen fertilizers exerts extreme pressure on the environment (e.g., greenhouse gas emissions, GHGs) for winter wheat-summer maize rotation systems in the North China Plain. The application of controlled-release fertilizers is considered as an effective measure to improve crop yield and nitrogen fertilizer utilization efficiency. To explore the impact of one-time fertilization of controlled-release blended fertilizer on crop yield and GHGs of a wheat-maize rotation system, field experiments were carried out in Dezhou Modern Agricultural Science and Technology Park from 2020 to 2022. Five treatments were established for both winter wheat and summer maize, including no nitrogen control (CK), farmers' conventional nitrogen application (FFP), optimized nitrogen application (OPT), CRU1 (the blending ratio of coated urea and traditional urea on winter wheat and summer maize was 5:5 and 3:7, respectively), and CRU2 (the blending ratio of coated urea and traditional urea on winter wheat and summer maize was 7:3 and 5:5, respectively). The differences in yield, nitrogen fertilizer utilization efficiency, fertilization economic benefits, and GHGs among different treatments were compared and analyzed. The results showed that nitrogen application significantly increased the single season and annual crop yields of the wheat-maize rotation system (P < 0.05). Compared with those of FFP, the CRU1 and CRU2 treatments increased the yields of summer maize by 0.4% to 5.6%, winter wheat by -5.4% to 4.1%, and annual yields by -1.1% to 3.9% (P > 0.05). N recovery efficiency (NRE), N agronomic efficiency (NAE), and N partial factor productivity (NPFP) were increased by -8.6%-43.4%, 2.05-6.24 kg·kg-1, and 4.24-10.13 kg·kg-1, respectively. Annual net income increased by 0.2% to 6.3%. Nitrogen application significantly increased the annual emissions of soil N2O and CO2 in the rotation system (P < 0.05) but had no effect on the annual emissions of CH4 (except for in the FFP treatment in the first year). The annual total N2O emissions under the CRU1 and CRU2 treatments were significantly reduced by 23.4% to 30.2% compared to those under the FFP treatment (P < 0.05). Additionally, nitrogen application significantly increased the annual global warming potential (GWP) of the rotation system (P < 0.05), but the intensity of greenhouse gas emissions was reduced due to the increase in crop yields. Compared with that under FFP, the annual GWP under the CRU1 and CRU2 treatments decreased by 9.6% to 11.5% (P < 0.05), and the annual GHGs decreased by 11.2% to 13.8% (P > 0.05). In summary, the one-time application of controlled-release blended fertilizer had a positive role in improving crop yield and economic benefits, reducing nitrogen fertilizer input and labor costs, and GHGs, which is an effective nitrogen fertilizer management measure to promote cleaner production of food crops in the North China Plain.

Assessment of Water Resources Potential of Ogun River for Irrigation Purposes at Middle Ogun Irrigation Project

The Middle Ogun Irrigation Project (MOIP) was conceived by the Federal Government of Nigeria to boost agricultural food production in the southwestern part of the country using modern irrigation facilities. However, water supply from the Ikere Gorge dam has been intermittent, particularly at the intake weir of this project, despite the enormous water resources on the dam. Therefore, this project assessed the water resources potential at the Odo Ogun intake weir guage station of the Middle Ogun Irrigation Project and evaluated the seasonal irrigation requirements on irrigation fields. The Flow Duration Curve (FDC) was derived at the gauge site for streamflow discharge from four quartiles and percentage reliability of Q95%, Q75%, Q50% and Q25%, which gave 32.40, 55.01, 60.00 and 90.00 m3/s, respectively. Hydrological modelling of the catchment was carried out using the MapWindow Soil and Water Assessment Tool (MWSWAT) for ten delineated sub-basins on the catchment and the average annual yield from the catchment was 10,094.00 mm/year. The net seasonal irrigation requirement of crops grown was evaluated using CROPWAT 8.0 and gave 428.46 mm per planting season.

Data Analysis and Optimization Strategies in Financial Management

In the increasingly fierce market competition, the decision-making level of enterprises can directly affect their future. Once a decision is made incorrectly, it can cause a significant crisis for the company. The information data in enterprise financial management is the most important reference for company leaders when making decisions. In corporate governance, financial analysis can comprehensively reflect the operational situation of a company. Financial analysis can provide strong data support for the production and operation of enterprises, and it is an effective way to improve operational efficiency. This article optimizes asset allocation based on data analysis and optimization strategies to achieve maximum return on investment portfolio. The current value, annual return, and risk level of stocks for different asset classes are 10 million yuan, with an annual return of 15%. The current value of the bond is 8 million yuan, with an annual yield of 6%. This article provides a reliable basis for financial management and business decision-making.

Impact of climate change and genetic development on Iowa corn yield

The vulnerability of corn yield to high temperature and insufficient rainfall in the US mid-west is widely acknowledged. The impact of extreme weather and genetic development on corn yield is less well known. One of the main reasons is that the multicollinearity in the variables can lead to confounding results. Here we model the impact of climate and genetic development by employing an elastic net regression model to address the multicollinearity issue. This allows us to develop a more robust multiple regression model with higher predictive accuracy. Using granular data for Iowa from 1981-2018, we find that corn yield is vulnerable to high mean summer temperatures particularly in July, a widening diurnal temperature range in June and dry summer conditions (due to extremely low rainfall) from June-August. We find that overall climate impact reduced average annual yield by 0.7%. We also find that genetic development which led to earlier planting dates, widening duration of the reproductive interval, higher growing degree day accumulation and larger net planted area had a beneficial impact on the Iowa corn yield during 1981-2018 resulting in an average annual yield improvement of 1.8% per annum. This provides a basis for optimism that these genetic developments and management practices will continue to adapt and improve in the future to counter the impact of climate change on corn yield. We have also modelled the impact of future climate change using the latest climate projections from the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR6). These climate projections show that the average temperature during the growing season (MayO-October) will increase by 2.4 -2.9 o C by mid-century while the average spring temperature (March and April) will increase by a relatively slower 1.9 -2.3 o C by mid-century. Additionally, climate projections show that both temperature and rainfall will also become more extreme in the future with the changes varying from spring to summer. Our results show that, just due to climate change alone in Iowa corn yield will decline between 1.4-1.7% per annum until mid-century (or 1.2-2.1% per annum until the late twenty first century).

Wind energy feasibility and wind turbine selection studies for the city Surat, India

Abstract Wind energy represents a clean, abundant and cost-effective power source, fostering job growth and environmental mitigation. Although wind energy harnesses several gigawatts today, its availability hinges on diverse factors, with geographical location standing out. Commercial turbines, with varying capacity ranges, saturate the market. Locating site-specific suitability and matching the appropriate turbine to meet specific requirements are of paramount importance. This study aims to assess the feasibility of wind energy in Surat, Gujarat, India and select an optimal small commercial turbine for residential use. The research involves Rayleigh and Weibull probability distribution functions based on yearlong velocity data. These distributions are fitted with actual data, revealing the most probable velocity (vmf = 3 m/s) and velocity at maximum power (vpmax = 5 m/s). The power availability of the site has been assessed as 42.6 W/m2 using both graphical and analytical methods. Several commercial turbines have been shortlisted based on on-site power criteria and their specifications are evaluated against site power availability. A comparative analysis culminates in identifying the most suitable turbine for the location. The best suitable turbine for the site with an annual energy yield of 8 MW has been suggested amongst selected turbines for small-scale residential applications.

An Assessment of a Photovoltaic System’s Performance Based on the Measurements of Electric Parameters under Changing External Conditions

This article presents an analysis of the performance of a 14.04 kWp grid-connected photovoltaic (PV) installation consisting of monocrystalline silicon, polycrystalline silicon and bifacial glass–glass monocrystalline silicon modules. The photovoltaic system was mounted in Poland, a location characterized by temperate climate conditions. On the basis of the obtained results, the photovoltaic parameters were determined in accordance with the international standard. The annual energy yield of the entire system was 1033 kWh/kWp, and the performance ratio achieved was 83%. The highest average daily final yield was in the range of 4.0–4.5 kWh/kWp for each photovoltaic technology under investigation. In the cold part of the year, the efficiency of the photovoltaic modules was estimated to be 15%, and it was estimated to be 7% during the warm part of the year. Array capture losses accounted for around 0.75 kWh/kWp of energy loss per day, whereas the inverter efficiency was over 95% during the months that are beneficial for energy production.

Tropospheric Ozone levels in and around southern city Bengaluru, India

The diurnal to seasonal ozone (O3) pre-cursors (NO, NO2, CO, VOCs) trends over local climatic zones (LCZs) with the changes in weather patterns with respect to land cover classes determines the O3 trends and useful for air quality management. In this work, diurnal to seasonal patterns of O3 concentrations are analysed across the different LCZs in Bengaluru region. The Central/State Pollution Control Boards (CPCB/SPCB) operate more than 500 continuous air quality and weather monitoring stations across the India. Hourly O3 concentration data were collected from CPCB for 5 different LCZs within the Bengaluru region over a period of four years (2019-2022). Time series analyses were conducted to examine the temporal variations in O3 levels. The results showed significant fluctuations in diurnal trends of O3 due to the influence of air temperature and relative humidity variations across the five LCZs within Bengaluru region. There were distinct seasonal trends in O3 concentrations with maximum (60-65 ppb) observed during the winter and summer seasons and that of minimum concentration in the range 20-25 ppb during the monsoon months. The observed maximum ozone levels (60 -65 ppb) found to be beyond the threshold national ambient air quality standard (NAAQ) and the accumulation exposure over threshold of 40 ppb (AOT 40) during the winter and summer. The O3 concentration trends are in line with the published research on premature mortality about 1200 annually for Karnataka state for chronic obstructive pulmonary disease owing to population exposure to O3 beyond its threshold level of NAAQ. Also, the annual rice yield loss is about 2% (~0.1 Metric Tonne) with the AOT 40 to paddy crop for Karnataka state. Thus, O3 diurnal to seasonal trends serve the first-hand information to local authorities for the action plan of air quality management taking into consideration O3 precursors, wind speed, and wind direction.

Assessing the Theoretical, Minimal Intervention Potential of Floating Solar in Greece: A Policy-Oriented Planning Exercise on Lentic Water Systems of the Greek Mainland

According to the recent revision of the Greek National Energy and Climate Plan, the country sets out to accomplish an ambitious target concerning the integration of renewables in the local electricity mix during the ongoing decade, at the levels of 80% by 2030. This implies the need to more than double the existing wind and PV capacity at the national level, which in turn introduces numerous challenges. Amongst them, spatial planning for new RES installations seems to be the most demanding, with the adoption of novel technological solutions in the field of RES potentially holding a key role. New technologies, like offshore wind and floating solar, are gradually gaining maturity and may offer such an alternative, challenged at the same time however by the need to entail minimum disruption for local ecosystems. To that end, we currently assess the theoretical potential of floating PVs for lentic water systems of the Greek mainland. We do so by looking into 53 different lentic water systems across the Greek territory that meet the constraint of 1 km2 minimum surface area, and we proceed with the estimation of the relevant floating PV capacity per system under the application of a minimal intervention approach, assuming PV coverage of 1% over the total lentic water system area. In this context, our findings indicate a maximum, aggregate theoretical capacity that could exceed 2 GWp at the national level, with the respective annual energy yield reaching approximately 4 TWh or, equivalently, >6% of the country’s anticipated annual electricity consumption in 2030. Finally, our results extend further, offering a regional level analysis and a set of policy directions and considerations on the development of floating solar in Greece, while also designating the energy merits of floating PVs against similar, land-based installations.

Optimization of inter-seasonal nitrogen allocation increases yield and resource-use efficiency in a water-limited wheat–maize cropping system in the North China Plain

Winter wheat–summer maize cropping system in the North China Plain often experiences drought-induced yield reduction in the wheat season and rainwater and nitrogen (N) fertilizer losses in the maize season. This study aimed to identify an optimal interseasonal water- and N-management strategy to alleviate these losses. Four ratios of allocation of 360 kg N ha−1 between the wheat and maize seasons under one-time presowing root-zone irrigation (W0) and additional jointing and anthesis irrigation (W2) in wheat and one irrigation after maize sowing were set as follows: N1 (120:240), N2 (180:180), N3 (240:120) and N4 (300:60). The results showed that under W0, the N3 treatment produced the highest annual yield, crop water productivity (WPC), and nitrogen partial factor productivity (PFPN). Increased N allocation in wheat under W0 improved wheat yield without affecting maize yield, as surplus nitrate after wheat harvest was retained in the topsoil layers and available for the subsequent maize. Under W2, annual yield was largest in the N2 treatment. The risk of nitrate leaching increased in W2 when N application rate in wheat exceeded that of the N2 treatment, especially in the wet year. Compared to W2N2, the W0N3 maintained 95.2% grain yield over two years. The WPC was higher in the W0 treatment than in the W2 treatment. Therefore, following limited total N rate, an appropriate fertilizer N transfer from maize to wheat season had the potential of a “triple win” for high annual yield, WPC and PFPN in a water-limited wheat–maize cropping system.