Water Capacity Research Articles

Evaluation of AquaCrop’s Ability to Simulate Water Stress Based on 2-Year Case Study of Maize Crop

To apply AquaCrop to the study of agricultural soil moisture in the North China Plain, a water-treatment experiment on summer maize was carried out at the Fengqiu experimental station of the Chinese Academy of Sciences from 2017 to 2018. A water treatment was used to achieve field water capacities of 20 (W1), 40 (W2), and 60 (W3) cm soil layers under irrigation, and a rain-fed treatment (W0) was added. The model parameters were calibrated using the measured data in 2017. Then, they were applied to 2018 to verify the ability of the model to simulate water stress. The results showed that the variation trends for crop yield, canopy coverage, total soil water content, and the curve in the growth cycle simulated via AquaCrop were consistent with the actual observations; the results of a discrete analysis showed that the values of b (regression coefficient), R2 (determination coefficient), and EF (efficiency) were close to 1, and the values of the RMSE (root mean square error) were close to 0, which proved that the model could simulate dynamic changes in summer maize yield, canopy coverage, and total soil water content well. AquaCrop had good applicability in the North China Plain and could be applied to the study of agricultural water consumption and water-use efficiency in this area. The simulated values obtained can serve as an easily obtainable source of long-term experimental data in areas with frequent non-extreme weather events.

Spatial-temporal Variation in Water Quality of Rain-source Rivers in Shenzhen from 2015 to 2021 and Its Response to Rainfall

Rain-source urban rivers have the characteristics of small water capacity， lack of dynamic water supply， and being easily polluted. This study analyzed the spatial and temporal distribution characteristics of river water quality and the response of characteristic pollutants to rainfall based on daily rainfall data and 21 water quality indicators of nine major river basins in Shenzhen （excluding Shenzhen-Shantou） from 2015 to 2021 by using the single-factor assessment method， comprehensive pollution index method， hierarchical cluster analysis， and Pearson correlation. The results showed that： ① in 2015， the water quality of most sections in the whole region was inferior Class V water. After October 2018， the overall water quality of rivers was greatly improved， which was consistent with the background of Shenzhen's special water control activities in 2018. By 2021， the water quality of approximately 62% of sections reached Class Ⅰ-Ⅲ water standards. ② The water pollution in the densely populated western part of Shenzhen was more serious than that in the eastern part， and the water pollution in the lower reaches of the estuaries and tributaries was more serious than that in the upper reaches. ③ The water quality of the Pingshan River， Guanlan River， Longgang River， and Maozhou River was significantly affected by rainfall. ④ The main characteristic pollution indexes of the Shenzhen River were DO， permanganate index， COD， BOD5， NH4+-N， TP， petroleum， and anionic surfactant. For the Pingshan River and Longgang River， rainfall increased the concentrations of TP and NH4+-N. For the Maozhou River， rainfall increased the concentrations of TP and COD. For the Shenzhen River， rainfall increased the concentrations of COD， TP， and NH4+-N. The above results reveal the spatio-temporal variation in rain-source river water quality in Shenzhen and its response to non-point source pollution caused by rainfall events and provide a scientific reference for building a higher quality water environment in Shenzhen.

Human-induced rapid siltation within a macro-tidal bay during past decades

Tidal bay evolution is the result of the comprehensive influence of multiple factors. It is crucial to analyze the primary factors to disassemble the comprehensive effects. In this study, remote sensing and bathymetric data were used to investigate anthropogenic activities and geomorphological changes in Puba Bay, China. From 1964 to 2020, the intertidal zone area decreased by 64.5% due to mariculture ponds and coastal reclamation, with the former accounting for 60.4% of the total area. Over five decades, the bay experienced significant silting, with a 61.5% decrease in underwater area, an 88.4% decrease in volume, and considerable reductions in maximum water depth, cross-sectional terrain depth, and width. Anthropogenic activities led to a reduction in tidal prism and tidal velocity, resulting in increased flood dominance and decreased ebb dominance in the main channel, leading to more siltation. Negative and positive feedback mechanisms were observed between anthropogenic activities, seaward expansion of intertidal flats, and bay siltation. The influence of mariculture ponds, as the major factor, on geomorphological changes was found to be similar to that of coastal reclamation. To maintain water depth and capacity for material exchange in the bay, preliminary suggestions for mariculture pond management are proposed.

Influence of Date Palm-Based Biochar and Compost on Water Retention Properties of Soils with Different Sand Contents

Generally, soils of arid and semi-arid regions have low water retention properties due to high sand and low organic carbon contents. This study aimed at quantifying the effect of date palm-based organic amendments (OAs) on the water retention properties of two soils (sandy loam and silty loam), as well as the influence of sand supplementation (0.5–2 mm) on the magnitude of the effect of OAs. Different grain size distributions were obtained by adding sand to natural soils. For this purpose, sand was added to the two soils (1/3 and 2/3) and different soil-OA combinations were tested at a dose of 3% by mass: compost alone, biochar alone and a mixture of biochar and compost (50:50 in mass), in addition to unamended control soils. Soil water contents were measured at nine matric potentials ranging from the saturation to the permanent wilting point. Biochar was more efficient than compost at improving soil water retention. The effect of organic amendments on water retention increased with sand content. In most cases, soil water content values were significantly higher for biochar-amended soils than for unamended or compost-amended soils. The weakness of the effect of compost addition (if alone) was probably due to its properties and notably its high mineral content and electrical conductivity. Soil sand supplementation led to higher differences between the OA-amended soils and unamended soils. Changes in available water capacity reached +26% and +80% in a sandy loamy soil enriched with 2/3 sand and amended with compost and with biochar, respectively, compared to the unamended soil. These results show that sand content (and more generally, soil texture) influences the effect of OA application. Thus, the application of biochar from date palm residues in soil seems to be an effective solution to improve the water retention properties of coarse textured soils and contribute to optimizing the use of water resources in irrigated areas.

Population-level responses of aphids to pulsed drought stress

The first aim of this study was to test the pulsed stress hypothesis on a system consisting of young spring wheat (Triticum aestivum L.) and the rose-grain aphid Metopolophium dirhodum (Walker) by following the age-stage, two-sex life table theory. This hypothesis predicts that fluid-feeding insects benefit from feeding on plants intermittently stressed by drought due to the increased nutrient availability and restored cell turgor. Our second aim was to illustrate the risk of drawing different conclusions if based on a single or a small subset of parameters or if the entire lifespan of a generation is not covered compared to if the study was conducted at the population level. We applied periods of drought stress (soil water capacity, SWC = 40%) on four occasions relative to the population development of the aphids and compared those treatments with well-watered (SWC = 70%) and continuous stress conditions (SWC = 40%). The timing of the stresses appeared to be important in determining the effect on aphid performance. Although we found some improvement in fecundity when the stress occurred before the aphids were placed on the plants, the overall effect of the early-timed pulsed stress treatments on the rate of increase was negative compared to the well-watered control, which was mainly due to prolonged nymph development. The drought pulse that was timed late (the second week of aphid reproduction) did not show any effect relative to the well-watered control. This study therefore provides no clear support for the validity of the pulsed stress hypothesis.

Modeling of Optimal Power Generation in Small Hydropower Plants

Abstract Small hydropower plants (SHPs) have gained international attention as a reliable and versatile renewable energy source. Unfortunately, this energy source is not used efficiently. This is because these systems utilize headwaters with lower water capacity called forebays instead of large water reservoirs like dams. Since this hinders the control of electricity generation, the headwater is either wasted before it can be converted into electricity or it is exhausted very quickly and electricity generation stops after a short time. The aim of this study is to prevent the loss of electricity generation through the efficient use of SHP headwater. For this purpose, a mathematical model was created based on two SHPs operating in tandem. The mathematical model obtained was analyzed, and forebay water level simulation graphs for electricity generation at water flowrates of 2000, 4000, 6000, and 8000 kg/h were obtained. With the help of the obtained graphs, critical wicket gate openings for maximum electricity generation at flowrates of 2000, 4000, 6000, and 8000 kg/h were calculated. The results of this study are applicable to all SHPs. These results are also promising in terms of optimizing the use of a renewable energy source.

The Effect of Drought on the Content of Active Substances of Flax Fibers

ABSTRACT The aim of the research was to identify differences in the content of phenolic acids in flax fibers and antioxidant activity of the fibers depending on the soil moisture level during plant growth and flax variety. The experiment involved cultivating flax under controlled conditions with constant levels of irrigation: 25%, 35%, and 45% of field water capacity (FWC). The experiment conducted in the vegetative hall of the Institute of Natural Fibers and Medicinal Plants, National Research Institute in Poland was repeated three times: in 2019, 2020, and 2021. The fibers were extracted from the straw with use of dew retting method. Flax fibers exhibit biological activity. In current study, the impact of drought during flax growth on the antioxidant activity of fibers was determined, as bioactive fibers of linen clothing touching the skin can contribute to neutralizing free radicals formed next to human body. The antioxidant activity of tested fibers was examined using DPPH and FRAP methods. The quantity of phenolic acids may affect the antioxidant capacity of the fibers. The research results showed that the cultivation of flax plants at a soil moisture level of 45% FWC favors the development of antioxidant activity in the fibers.

Winter wheat irrigation parameters in the Brazilian Cerrado

Wheat is the second most produced cereal in the world. The gap between production and consumption in Brazil shows that wheat production must be increased to meet the domestic demand. In this context, the objective of this study was to determine the crop coefficient of wheat and the ideal moment for irrigation, based on the soil water depletion rate (f). The study was carried out in the tropics, on an Oxisoil (Typic Haplustox), in an experimental field of Embrapa Cerrados in Planaltina, Federal District of Brazil. The experimental design consisted of randomized blocks with three replications. The treatments were differentiated by the soil water depletion index (f) of 0.2, 0.4, 0.6, and 0.8. In other words, irrigation was initiated when 20, 40, 60 and 80% of the available soil water capacity (AWC) at a soil depth of 0.4 m was consumed by the crop. Wheat yield and yield components were evaluated. The phenological development was monitored based on Zadok’s scale, in days after emergence, and the management parameters crop coefficient (Kc) and irrigation timing were determined. The results indicated a soil water depletion index of 0.4 as the best indicator for beginning wheat irrigation. Under this condition, Kc can be estimated daily as a function of days after emergence (DAE) by the quadratic polynomial regression or curve fitting method, adjusted as follows: Kc = −0.000298 × DAE² + 0.036695 × DAE + 0.332486. Alternatively, the means of Kc of each phenological crop phase can be used: Kc = 0.45 (establishment); 0.81 (tillering); 1.21 (booting); 1.43 (flowering); 1.27 (grain formation); and 0.89 (maturation). Thus, there is a limit of consumption of soil available water, at which wheat still achieves the full yield potential, with a rational use of water which varies according to the development phase.

Estimating irrigation requirement and scheduling for major crops: Case study in Kampong Thom, Cambodia

The situation is the outcome of both increased water demand and climate change, the shortage of water resources is increasing in Cambodia. In this regard, efficient irrigation water management for vegetable production is a crucial need for farmers. The main crops farmed in Chroab commune, Santuk district, Kampong Thom province, Cambodia, are cabbage, potato, and tomato. This article uses the CROPWAT model to predict the water requirement. The pressure plant was used to measure the soil’s soil water capacity, and the findings ranged from 45.65 to 234.159 mm/m. The analysis showed that the overall CWR for crop water for the entire growing season for cabbage, potato, and tomato was 589.4 mm/165 days; 442.5 mm/130 days; and 585.4 mm/145 days, respectively. The findings of the study contribute to investigating the irrigation water requirements with scientific soil and climate inputs.

Water resources management in the context of the circular economy concept

The article examines the essence and main goals of the circular economy. The connection between the circular economy and the achievement of the goals of sustainable development has been studied. The positive effect of the introduction of the circular economy for the social, economic and ecological system was determined. Reducing the scarcity of natural resources, as well as the creation of durable goods, allows reducing the negative impact on the environment, which in turn stimulates innovation, which increases competitive advantages in international markets. The peculiarities of the development of circular economy models in developed countries are considered. The peculiarities of the economic category of water and its role in the economy are analyzed. The different roles of water emphasize its uniqueness and prove the difficulty of adopting a unified approach to it in the circular economy. The dynamics of indicators of the water capacity of Ukraine's GDP and volumes of return (waste) water discharged into surface water bodies were analyzed. It was determined that the rethinking of the urban water supply system through the principles of the circular economy and the goals of sustainable development will reduce the amount of polluted water and increase its reuse. It was determined that Ukraine is one of the least water-supplied countries in Europe, the annual runoff reserves available for use per person do not exceed 1,000 m3, while the GDP water capacity indicator remains sufficiently high and exceeds its target value. The dynamics of the indicator of the water capacity of the GDP of Ukraine has been analyzed, it has a tendency to decrease for the years 2015-2022. The characteristic problems of the functioning of urban water supply and drainage systems in the front-line territories and safer cities, where the number of internally displaced people has increased, are analyzed. It was analyzed that not all classic circular economy strategies can be applied to water. Strategies of the circular economy of water are considered and it is emphasized that rethinking is inherent in all water strategies. It has been analyzed that the implementation of the circular economy may face financial, bureaucratic and behavioral problems and regulatory, legislative, managerial and implementation obstacles. Keywords: circular economy, water resources, sustainable development, integrated management of water resources, state policy, goals of sustainable development, strategies, economic model, water supply and drainage system

Future water storage changes over the Mediterranean, Middle East, and North Africa in response to global warming and stratospheric aerosol intervention

Abstract. Water storage plays a profound role in the lives of people across the Middle East and North Africa (MENA) as it is the most water-stressed region worldwide. The lands around the Caspian and Mediterranean seas are simulated to be very sensitive to future climate warming. Available water capacity depends on hydroclimate variables such as temperature and precipitation that will depend on socioeconomic pathways and changes in climate. This work explores changes in both the mean and extreme terrestrial water storage (TWS) under an unmitigated greenhouse gas (GHG) scenario (SSP5-8.5) and stratospheric aerosol intervention (SAI) designed to offset GHG-induced warming above 1.5 ∘C and compares both with historical period simulations. Both mean TWS and extreme TWS are projected to significantly decrease under SSP5-8.5 over the domain, except for the Arabian Peninsula, particularly in the wetter lands around the Caspian and Mediterranean seas. Relative to global warming, SAI partially ameliorates the decreased mean TWS in the wet regions, while it has no significant effect on the increased TWS in drier lands. In the entire domain studied, the mean TWS is larger under SAI than pure GHG forcing, mainly due to the significant cooling and, in turn, a substantial decrease in evapotranspiration under SAI relative to SSP5-8.5. Changes in extreme water storage excursions under global warming are reduced by SAI. Extreme TWS under both future climate scenarios is larger than throughout the historical period across Iran, Iraq, and the Arabian Peninsula, but the response of the more continental eastern North Africa hyper-arid climate is different from the neighboring dry lands. In the latter case, we note a reduction in the mean TWS trend under both GHG and SAI scenarios, with extreme TWS values also showing a decline compared to historical conditions.

Water Deficit Diagnosis of Winter Wheat Based on Thermal Infrared Imaging

Field experiments were conducted to analyze the effectiveness of the crop stress index (CWSI) obtained by infrared thermal imaging to indicate crop water status, and to determine the appropriate CWSI threshold range for wheat at different growth stages. The results showed that the sensitivity of plant physiological parameters to soil water was different at different growth stages. The sensitivity of stomatal conductance (Gs) and transpiration rate (Tr) to soil water was higher than that of leaf relative water content (LRWC) and photosynthetic rate (Pn). The characteristics of plant physiology and biomass (yield) at each growth stage showed that the plant production would not suffer from drought stress as long as the soil water content (SWC) was maintained above 57.0% of the field water capacity (FWC) during the jointing stage, 63.0% of the FWC during the flowering stage and 60.0% of the FWC during the filling stage. Correlation analysis showed that the correlation of CWSI with Gs, Tr and Pn was lower than that with LRWC and SWC at the jointing stage. CWSI was extremely significantly negatively correlated with SWC and LRWC (p < 0.01), but significantly negatively correlated with Gs, Tr and Pn (p < 0.05). At the flowering stage, CWSI was extremely significantly negatively correlated with all physiological and soil parameters (p < 0.01). The regression analysis showed that the CWSI of winter wheat was correlated with biomass (grain yield) in a curvilinear relationship at each growth stage. When the CWSI increased to a certain extent, the biomass and yield showed a decreasing trend with the increase in CWSI. Comprehensive analysis of all indexes showed that CWSI can be used as a decision-making index to guide the water-saving irrigation of winter wheat, as long as the CWSI threshold of plants was maintained at 0.26–0.38 during the jointing stage, 0.27–0.32 during the flowering stage and 0.30–0.36 during the filling stage, which could not only avoid the adverse effects of water stress on crop production, but also achieve the purpose of water saving.

A Review of the Research Progress and Application of Key Components in the Hydrogen Fuel Cell System

The hydrogen cycle system, one of the main systems used for hydrogen fuel cells, has many advantages. It can improve the efficiency, the water capacity, and the management of thermal fuel cells. It can also enhance the safety of the system. Therefore, it is widely used in hydrogen fuel cell vehicles. We introduce the structure and principles of hydrogen cycle pumps, ejectors, and steam separators and analyze and summarize the advantages of the components, as well as reviewing the latest research progress and industrialization status of hydrogen cycle pumps and ejectors. The technical challenges in hydrogen circulation systems and the development direction of key technologies in the future are discussed. This paper aims to provide a reference for research concerning hydrogen energy storage application technology in hydrogen fuel cell systems.

A Study on the Biodiversity of Aquatic Invertebrate Fauna of Nizamsagr Irrigation Reservoir, Kamareddy District, Telangana, India

Nizamsagar reservoir constructed across the river Manjeera between Achampeta and Banjapalli villages of newly formed Kamareddy district of Telangana State. The River Manjeera is a tributary river of the Godavari. The height of the dam is 96 meters and length is 3 km having water capacity 30 TMC. The study revealed that a total of 27 invertebrate species belonging to three phyla: Arthropoda, Mollusca, and Annelida. Among these, the Arthropoda phylum species dominated, followed by Mollusca and Annelida. In the Mollusca phylum, the Gastropoda class exhibited rich abundance, with species like Bithynia transsilvanica, Bellamya bengalensis, Perrysisfavidens, and Pila globose being prominent. Within the Annelida phylum, Tubifex tubifex in the Clitellata class showed the highest abundance compared to Limnodrillus hoffmeisteri. In the Arthropoda phylum, specifically in the Insecta class, there were a diverse range of species, including Chironomus Sps., Anophelus mosquito larvae, Culex mosquito larvae, Sympetrum vulgatum, and Orthetrum cancellatum, with the highest diversity observed.

Synergistic Effects of Bicarbonate and Selenium on Cadmium Transport in Karst-Adaptable Plants Based on Plant Electrical Signals

High cadmium (Cd) concentrations associated with geochemical anomalies are prevalent in carbonate-rich karstic areas, posing serious ecological risks, while the karstic soils are rich in bicarbonate (HCO3−). It is known that Selenium (Se) is a mineral element that effectively mitigates the Cd transport in plant species. However, the synergistic effects of HCO3− and Se on Cd translocation in plant species have not yet been indicated. In this study, based on plant electrophysiological measurements, we chose Orychophragmus violaceus (Ov) as experimental material and determined the growth potential, water metabolism, and nutrient translocation capacity under HCO3−-Se6+-Cd2+ treatment to identify the synergistic effects of bicarbonate and selenium on cadmium transport in karst-adaptable plants. We found 5 mM HCO3− and 0.46 mM Se6+ synergistically alleviated the Cd2+ stress on Ov, promoting growth, intracellular water metabolism, nutrient translocation efficiency, and total Se accumulation, and inhibiting the uptake of Cd in Ov. Nevertheless, 15 mM HCO3− and 0.46 mM Se6+ synergistically augmented Cd transport on Ov, resulting in growth reduction, intracellular water metabolism, nutrient translocation efficiency, and total Se concentration. Hence, it not only provides a frontier approach for the real-time monitoring of intracellular water and nutrient utilization capacity in plant species, but is also even more a theoretical idea that reveals the synergistic effects of bicarbonate and selenium on cadmium transport of plants to precisely indicate selenium supplementation to ameliorate cadmium pollution and construct a sustainable karst ecosystem in the future.

More water, less light: how to improve silver fir seeding to convert Norway spruce monocultures into mixed stands in a drier region of Germany

Abstract Adaptive forest management gains importance as climate and disturbance regimes continue to change. Norway spruce monocultures are particularly vulnerable to those changes. Thus, there is a strong demand to convert pure spruce stands toward better adapted forest ecosystems. Silver fir has similar wood properties as Norway spruce, but is less vulnerable to droughts. Yet, little is known how to efficiently admix silver fir into Norway spruce monocultures. We analyzed seedling abundance in mature Norway spruce monocultures 1 year after soil scarification and silver fir seeding in a relatively dry region of southern Germany. Our objectives were to study the effect of soil scarification and seeding on regeneration density and to identify drivers of seedling abundance. We collected data on regeneration, forest structure, as well as soil and light conditions at 103 scarified and 25 untreated control plots. We used non-parametric independence tests to compare scarified and untreated plots. Subsequently, we used boosted regression trees to investigate the drivers of seedling abundance. Norway spruce strongly benefited from soil scarification (P < .001), with seedling numbers even exceeding those of silver fir. Both species thrived in soils with high plant available water capacity. In contrast, seedling numbers were overall negatively affected by light. Moreover, we found a higher density of silver fir regeneration at greater distance from neighboring trees and in soils devoid of carbonate. Our study indicates that water, not light, is the limiting factor for both Norway spruce and silver fir seedlings in the study region. Seeding silver fir will likely be most effective underneath an intact canopy on deep, fine-textured soils without carbonate, while maximizing the distance to Norway spruce trees. In conclusion, silver fir seeding can be optimized to become an effective adaptive measure to diversify Norway spruce monocultures, and thus to create more resistant and resilient forest ecosystems.

Superhydrophilic floral foam-based solar evaporator with excellent salt-resistance and cost advantages for high efficient desalination

Effective management of heat, outstanding water transport paths, and hydrophilicity are essential for porous solar-driven interfacial evaporators, but their development still faces many difficulties. Here, by cross-linking a carbon black (CB)/polyvinyl alcohol (PVA) slurry with three-dimensional super hydrophilic floral foam (FF) to form a CB/PVA functional film on the surface of FF, a CB/PVA-decorated floral foam based (FFCP) solar-driven water evaporator with low-cost was finally obtained. Owing to the super hydrophilicity, sufficient water supply, self-holding water capacity and the special porous structure of the FF, as well as efficient light absorption and photothermal conversion efficiency of the dispersed CB. The gas-liquid interface temperature of the optimized FFCP-1.0 evaporator reaches 41.2 °C under single solar irradiation, obtaining an evaporation rate of up to 1.69 kg m−2 h−1. In addition, the FFCP-1.0 evaporator had a great evaporation rate in highly concentrated salt solutions. Moreover, the FFCP-1.0 evaporator has remarkable purification effects on seawater, organic dye effluents and heavy metal ion solutions. The evaporator has low cost, excessive evaporation rate and excellent durability. Therefore, this work is of considerable scientific significance for promoting the practical application of porous-based solar evaporators and clean water production.

Fermentation of cocoa pod husks with Pleurotus salmoneo-stramineus for food applications.

Cocoa pod husks (CPHs), the major side-stream from cocoa production, were valorized through fermentation with Pleurotus salmoneo-stramineus (PSS). Considering ergosterol as a biomarker for the fungal content, the mycelium accounted for 54% of the total biomass after 8 days in submerged cultures. The crude protein content of fermented CPH (CPHF) increased from 7.3 g/100 g DM in CPH to 18.9 g/100 g DM. CPH fermentation resulted in a high biological value of 86 for the protein. The water and oil binding capacities of CPHF were 3.5 mL/g and 2.1 mL/g, respectively. The particle diameter dv,0,90 of CPHF was 373 μm as compared to 526 μm for CPH. The total dietary fiber was 73.4 g/100 g DM in CPHF and 63.6 g/100 g DM in CPH. The amount of soluble fiber was 2.3 g/100 g DM in CPHF and 10.1 g/100 g DM in CPH; the insoluble fraction accounted for 71.1 g/100 g DM and 53.6 g/100 g DM, respectively. Bread doughs with CPH or CPHF were characterized for texture, color, and farinographic properties. The dough hardness, consistency, and browning index increased with the concentration of CPH, whereas for CPHF, springiness and peak viscosities declined. We demonstrate the upcycling of CPH into nutritious and functional ingredients through PSS fermentation.

Climate change awareness and adaptation strategies by smallholder farmers in semi-arid areas of Zimbabwe

ABSTRACT Agricultural production, food, nutrition and income security of smallholder farmers in sub-Saharan Africa are threatened by extreme weather events, such as increased frequency of mid-season dry spells and increased temperatures. Their impacts are exacerbated by the prevalence of sandy soils, characterized by limited water and nutrient retention capacity leading to low crop productivity. In this study, we aimed at assessing farmers' awareness of extreme weather events, identify adaptation strategies and evaluate maize yield from different soil fertility and water management practices. A household survey including 245 smallholder farmers in Marange, Zimbabwe was carried out. The results revealed that farmers were aware of and had experienced extreme weather events. Among adaptation strategies used were soil water-harvesting, use of improved varieties, mulching and planting trees. Maize yield remains significantly low, averaging 0.62 t ha−1 among farmers using some forms of soil fertility and water management strategies. To further understand the reason for low maize yields and improve climate change related adaptation strategies, more research is needed to quantify and confirm management practices applied by farmers, such as fertilizer use and rates, water and nutrient management, use of improved varieties as well as socio-economic factors.

Characterization of yeast protein isolates extracted via high-pressure homogenization and pH shift: A promising protein source enriched with essential amino acids and branched-chain amino acids.

In the global food industry, plant-based protein isolates are gaining prominence as an alternative to animal-based counterparts. However, their nutritional value often falters due to insufficient essential amino acids. To address this issue, our study introduces a sustainable protein isolate derived from yeast cells, achieved through high-pressure homogenization (HPH) and alkali pH-shifting treatment. Subjected to HPH pressures ranging from 60 to 120MPa and 1 to 10 cycles, higher pressure and cycle numbers resulted in enhanced disruption of yeast cells. Combining HPH with alkali pH-shifting treatment significantly augmented protein extraction. Four cycles of HPH at 100MPa yielded the optimized protein content, resulting in a yeast protein isolate (YPI) with 75.3g protein per 100g powder, including 30.0g of essential amino acids and 18.4g of branched-chain amino acids per 100g protein. YPI exhibited superior water and oil-holding capacities compared to pea protein isolate, whey protein isolate (WPI), and soy protein isolate. Although YPI exhibited lower emulsifying ability than WPI, it excelled in stabilizing protein-stabilized emulsions. For foaming, YPI outperformed others in both foaming ability and stabilizing protein-based foam. In conclusion, YPI surpasses numerous plant-based protein alternatives in essential amino acids and branched-chain amino acids contents, positioning it as an excellent candidate for widespread utilization as a sustainable protein source in the food industry, owing to its exceptional nutritional advantages, as well as emulsifying and foaming properties. PRACTICAL APPLICATION: This study introduces a sustainable protein isolate derived from yeast cells. YPI exhibited considerable promise as a protein source. Nutritionally, YPI notably surpassed plant-based protein isolates in EAA and BCAA contents. Functionally, YPI demonstrated superior water-holding and oil-holding capacities, as well as an effective emulsion and foam stabilizer.