Sufficient Soil Moisture Research Articles

РОЛЬ КРОЮЩИХ ТРИХОМ В БИОХИМИЧЕСКОЙ АДАПТАЦИИ И ИНДИКАЦИИ ЭКОЛОГИЧЕСКИХ УСЛОВИЙ МЕСТООБИТАНИЙ РАСТЕНИЙ

Covering trichomes serve the functions of physical protection of plants (reduction of transpiration, protection against overheating, etc.). In connection with the weak knowledge of their participation in other mechanisms for the formation of stress-tolerance, the purpose of the study was to clarify the role of the leaf-ups on the example of the type of the Boraginaceae family ( Echium Vulossum Officinale, Symphytum Caucasicum, S. Asperum ) in biochemical adaptation in biochemical adaptation Indication of environmental growing conditions. The collection of plant material was produced in two experimental sites in the foothill and steppe zones of the Kabardino-Balkarian Republic, which are related respectively to the environmental optimum (moderate air temperature, sufficient soil moisture) and stress (elevated temperature, lack of moisture). The density of the tricho governing on both surfaces of the leaf plate E. vulgare and C. Officinale in the environmental optimum exceeds the similar indicator of S. asperum and S. caucasicum leaves by 1.3-4.2 times. With a decrease in the favorableness of the growing conditions, the density of the trichium protruding increases in E. vulgare and C. Officinale in 1.2-1.4, in S. Asperum and S. caucasicum -2.0-4.4 times. In favorable conditions, the specific weight of the Trich with peroxidase changes from 20-45 % ( Symphytum) to 67-71 % ( E. Vulgare and C. Officinale ). The activity of peroxidase in plant leaves decreases among: E. vulgare> C. Officinale> S. asperum> S. caucasicum . In favorable conditions of growth, a high correlation was noted between the activity of peroxidase, the content of the tannins and the number of tricho protruding, showing peroxidate activity; With the deterioration of thermal and water regimes, the correlation is moderate. The results obtained indicate an important role of the leaves protruding in biochemical adaptation, the indication of the environmental conditions of growth and the diagnosis of stability of the types of the Boraginaceae family to stress conditions according to the variability of peroxidious activity and the content of the tannins.

Root Zone Water Management Effects on Soil Hydrothermal Properties and Sweet Potato Yield.

Sufficient soil moisture is required to ensure the successful transplantation of sweet potato seedlings. Thus, reasonable water management is essential for achieving high quality and yield in sweet potato production. We conducted field experiments in northern China, planted on 18 May and harvested on 18 October 2021, at the Nancun Experimental Base of Qingdao Agricultural University. Three water management treatments were tested for sweet potato seedlings after transplanting: hole irrigation (W1), optimized drip irrigation (W2), and traditional drip irrigation (W3). The variation characteristics of soil volumetric water content, soil temperature, and soil CO2 concentration in the root zone were monitored in situ for 0-50 days. The agronomy, root morphology, photosynthetic parameters, 13C accumulation, yield, and yield components of sweet potato were determined. The results showed that soil VWC was maintained at 22-25% and 27-32% in the hole irrigation and combined drip irrigation treatments, respectively, from 0 to 30 days after transplanting. However, there was no significant difference between the traditional (W3) and optimized (W2) drip irrigation systems. From 30 to 50 days after transplanting, the VWC decreased significantly in all treatments, with significant differences among all treatments. Soil CO2 concentrations were positively correlated with VWC from 0 to 30 days after transplanting but gradually increased from 30 to 50 days, with significant differences among treatments. Soil temperature varied with fluctuations in air temperature, with no significant differences among treatments. Sweet potato survival rates were significantly lower in the hole irrigation treatments than in the drip irrigation treatments, with no significant difference between W2 and W3. The aboveground biomass, photosynthetic parameters, and leaf area index were significantly higher under drip irrigation than under hole irrigation, and values were higher in W3 than in W2. However, the total root length, root volume, and 13C partitioning rate were higher in W2 than in W3. These findings suggest that excessive drip irrigation can lead to an imbalance in sweet potato reservoir sources. Compared with W1, the W2 and W3 treatments exhibited significant yield increases of 42.98% and 36.49%, respectively. The W2 treatment had the lowest sweet potato deformity rate.

The dominant pests (Coleoptera) of cereal crops, and population forecast for this

Goal. Create a forecast of the development of harmful organisms in cereal crops, to determine the economic feasibility of applying plant protection measures.
 Methods. Analysis of the phytosanitary state of cereal crops in Ukraine, where the main attention is paid to the dominant pest species. Analysis of the areas of distribution of these pests, population dynamics, their phenology and the state of populations in the context of natural and climatic zones (Steppe, Forest-steppe and Polissya). To assess the phytosanitary state of crops, and its dynamic changes, the following are used: — the results of phytosanitary monitoring of crops (according to generally accepted methods), which were carried out directly by the staff of the forecast laboratory of the Institute of Plant Protection of NAAS; — current reports of researchers from other laboratories of the Institute of Plant Protection of NAAS from the places of business trips; — materials of decadal reports of regional plant protection stations, as well as signaling and forecasting points; — information on the phytosanitary situation from regional state research stations and institutes of NAAS.
 Results. A study of the phytosanitary state of cereal crops on the territory of Ukraine was carried out, the dominant species of pests were identified, materials were prepared regarding the peculiarities of the phytosanitary state in the conditions of the year, and a long-term (annual) forecast of the development of pests for the next year was drawn up, based on the appropriate analysis of the data obtained.
 Conclusions. In recent years, climate change in Ukraine has manifested itself through an increase in the average annual temperature, and an increase in the sum of effective temperatures. A decrease in the zone of sufficient soil moisture was noted, its line shifted to the north. Under the influence of abiotic factors, pests constantly change the boundaries of their habitat and zones of damage, therefore reliable protection of crops is impossible without constant monitoring, constant clarification of the species composition of phytophages, and phytosanitary forecast. Improved methodological approaches for assessing the phytosanitary state of acrocyanoses and the promptness of obtaining relevant data will allow agricultural producers to make timely decisions on the economic feasibility of using certain plant protection products.

Monitoring Drought Events and Vegetation Conditions in Pakistan: Implications for Drought Management and Food Security

Drought is an environmental and humanitarian concern, affecting various regions and landscapes with detrimental impacts on the natural environment and human lives. It is crucial to have access to accurate and timely information on vegetation conditions to mitigate its effects, which is possible through remote sensing techniques. The Google Earth Engine (GEE) platform offers powerful tools and a vast collection of geospatial data that can improve drought monitoring efforts. In Pakistan, a country prone to droughts and natural disasters, this study employs GEE to monitor drought events over croplands and determine their severity using indices such as Vegetation Health Index (VHI), Vegetation Condition Index (VCI), and Temperature Condition Index (TCI). Additionally, the study generates mean yearly and monthly VHI maps, allowing for the observation of trends in drought occurrences over time. Analysis of yearly and monthly mean VHI maps reveals that in 2001 and 2002, the Pakistan cropland experienced severe to moderate drought. From 2011 to 2021, overall drought occurrences were relatively low, and the annual VHI reflected healthy vegetation conditions. The study emphasizes the adequacy of vegetation in 2019, 2020, and 2021. Notably, agricultural areas in Punjab demonstrate sufficient soil moisture and healthy vegetation, while in Sindh, cropland is predominantly affected by severe to moderate drought, characterized by a continuous deficiency of soil moisture. Temporal variations highlight an increasing trend in VHI, indicating a promising outlook for healthy vegetation in Pakistan's cropland. This study provides valuable information for drought management, planning, water resource management, food production, and food security.

Carbon Dioxide and Heat Fluxes during Reforestation in the North Caucasus

Human impact on natural ecosystems has significantly increased in recent decades. As a result, the structure and functioning of ecosystems are seriously altered. This in turn affects regional weather and climate conditions through changes in the radiation, water, and carbon balance of ecosystems. Investigating the process of natural ecosystem restoration after disturbances is an important issue in the context of climate change. During monitoring observations of greenhouse gas (GHG) fluxes in a reforestation area in the Chechen Republic, new experimental data on their seasonal variability were obtained, and their sensitivity to changes in environmental conditions was assessed. Forest restoration and land reclamation are essential components of the low-carbon development and decarbonization strategy of the world economy. Observations of GHG fluxes were conducted in the reclaimed area, which was planted with tree seedlings. One year of eddy covariance flux measurements (May 2022–June 2023) demonstrated that CO2 uptake by the reforestation area in a humid continental climate with hot summers and cold winters is determined by the moisture conditions of the growing season. The cumulative net ecosystem exchange (NEE) for the entire measurement period at the carbon farm was 613.7 gC·m−2. The uptake of CO2 by the reforestation area was observed only due to active seedling growth during periods of sufficient soil moisture (May 2023). During this time, total NEE uptake was 48.7 gC·m−2. Sensible and latent heat fluxes were also dependent on weather conditions, primarily on incoming solar radiation and moisture conditions. For the successful implementation of climate projects aimed at the creation of artificial forest ecosystems with high CO2 uptake capacity, it is essential to develop appropriate hydro-meliorative measures that ensure a sufficient amount of available soil moisture.

Effect of sufficient and deficit irrigation with different salt inputs on the yield of cucumber

Soil salinisation is considered one of the major environmental hazards threatening agricultural productivity and can be accentuated by climate change as well as the use of low-quality water in irrigation. This is the case in our study area which is affected by secondary salinisation due to the use of saline irrigation water for horticultural production. Deficit irrigation technique is implemented especially in arid and semiarid regions due to its potential to optimise water productivity while maintaining or increasing crop yield. The main objective of this study was to compare the effect of irrigation with sufficient (SD) and deficit (DD) doses. This research was carried out in Karcag in 2020. Cucumber was grown on a meadow chernozem soil and was irrigated with SD and DD of two irrigation water qualities. Soil moisture was monitored and crop yields were recorded. Despite the differences in quality and quantity of water, the application of less water by DD maintained the same yield as SD. We found a non-significant difference between the average soil moisture contents under the treatments (15.5 v/v% for SD and 13.5 v/v% for DD). Deficit irrigation can be an efficient technique due to its potential for improving water use efficiency, maintaining sufficient soil moisture content favourable for proper crop development and yield.

Climate and soil-based constraints to rainfed cotton yield in the Northern Territory, Australia – A modelling approach using APSIM-OZCOT

Cotton production in Australia is expanding to the northern semi-arid tropical regions as a means to droughtproof the industry. The majority of expansion is expected to come from rainfed farming systems. However, little is known on tropical rainfed cotton, particularly on climate and soil-based constraints that determine cotton production. Using the Northern Territory (NT) as case study, we investigated the effects of between and intra seasonal rainfall variability and key soil types on soil moisture dynamics,timely operations, lint yield, and industry viability. We examined several regions with greatest potential for rainfed agriculture in the NT, including sites in the Daly Basin, Mataranka and Larrimah. To this purpose we applied a locally calibrated and validated cotton growth model (APSIM-OZCOT) using weather files sourced from the SILO database of Australian climate data, and soil profile parameters for three red Kandosols: Blain, Oolloo and Tippera. Our study shows that simulated median lint yields ranged from 570 to 996 kg ha−1, with larger yields achieved on soils that hold more moisture (Blain > Oolloo > Tippera), and at locations that received greater amounts of seasonal rainfall. Planting window largely governed soil-moisture availability and thus sowing opportunities. An early planting (1–15 December) increased yields (greater available soil-moisture) but reduced planting opportunities due to insufficient mulch cover at planting. A late planting (15 Jan to 1 Feb) reduced cotton yields due to less seasonal rainfall, but increased the number of sowing opportunities in the drier regions since more time was allowed to establish sufficient cover crop. Availability of deep soil-moisture was important, particularly in the later crop phases when the roots reach deeper layers, and sufficient soil moisture is required to grow and finish bolls. Our assessment further highlights the potential impact of excessively wet conditions on cotton production. Short periods of intense rainfall (known as “burst” events); a typical characteristic of the monsoon, reduce cotton yield through waterlogging. Scaling our simulated yields to the potential area of suitable soils in the NT shows considerable benefits to the regional economy and should be considered when planning industry development, including the establishment of cotton gins. The insights gained from this study are relevant to industry developments in similar environments, such as in parts of Brazil, India, and Sahelian Africa

The Response of Daily Carbon Dioxide and Water Vapor Fluxes to Temperature and Precipitation Extremes in Temperate and Boreal Forests

Forest ecosystems in the mid-latitudes of the Northern Hemisphere are significantly affected by frequent extreme weather events. How different forest ecosystems respond to these changes is a major challenge. This study aims to assess differences in the response of daily net ecosystem exchange (NEE) of CO2 and latent heat flux (LE) between different boreal and temperate ecosystems and the atmosphere to extreme weather events (e.g., anomalous temperature and precipitation). In order to achieve the main objective of our study, we used available reanalysis data and existing information on turbulent atmospheric fluxes and meteorological parameters from the global and regional FLUXNET databases. The analysis of NEE and LE responses to high/low temperature and precipitation revealed a large diversity of flux responses in temperate and boreal forests, mainly related to forest type, geographic location, regional climate conditions, and plant species composition. During the warm and cold seasons, the extremely high temperatures usually lead to increased CO2 release in all forest types, with the largest response in coniferous forests. The decreasing air temperatures that occur during the warm season mostly lead to higher CO2 uptake, indicating more favorable conditions for photosynthesis at relatively low summer temperatures. The extremely low temperatures in the cold season are not accompanied by significant NEE anomalies. The response of LE to temperature variations does not change significantly throughout the year, with higher temperatures leading to LE increases and lower temperatures leading to LE reductions. The immediate response to heavy precipitation is an increase in CO2 release and a decrease in evaporation. The cumulative effect of heavy precipitations is opposite to the immediate effect in the warm season and results in increased CO2 uptake due to intensified photosynthesis in living plants under sufficient soil moisture conditions.

Differential responses of CO2 and latent heat fluxes to climatic anomalies on two alpine grasslands on the northeastern Qinghai–Tibetan Plateau

Discrete extreme heat events, deluges, and droughts will become more frequent and disproportionately affect the processes and functions of grassland ecosystems. Here, we compared the responses of CO2 and heat fluxes to natural extreme events in 2016 in a lower alpine meadow and neighboring upper shrubland on the northeastern Qinghai–Tibetan Plateau. Unlike insensitive sensible heat flux, latent heat flux (LE) increased by 21.8 % in the meadow and by 56.4 % in the shrubland during a dry period and subsequent compound hot-dry period in August. Changes (Δ, data for 2016 minus the corresponding means from other years) in the heat flux at both sites were determined by changes in solar radiation (ΔSwin), as sufficient soil moisture was available. ΔLE was more sensitive to ΔSwin in the open-canopy shrubland, reflecting its greater capacity for evaporative cooling to buffer climate anomalies. CO2 fluxes responded weakly to extreme wet or dry events but strongly when those events were accompanied by exceptional heat. During single or compound hot events, the mean changes in total ecosystem respiration (ΔTER) increased by about 30 % in both grasslands, although ΔTER was more sensitive to changes in the topsoil temperature in the more productive meadow than in the shrubland. The mean changes in gross primary productivity (ΔGPP) fluctuated by <10 % in the warmer meadow but increased by 29.3 % in the cooler shrubland relative to the respective baseline, probably because of the differences in canopy structure and root depth and the consequent high-temperature stress on vegetation photosynthesis. The changes in net ecosystem CO2 exchange (ΔNEE) were significantly related to ΔTER in the meadow and increased by 55.8 %, whereas ΔNEE was controlled mainly by ΔGPP in the shrubland and decreased by 22.4 %. Overall, both alpine grasslands were resistant to rainfall anomalies but susceptible to exceptional warmth, with the differential responses being ascribed to canopy structure and root depth. Our results provide helpful insights based on which the carbon sequestration and water-holding functions of alpine grasslands during future climate change can be predicted.

The Distribution of Surface Soil Moisture over Space and Time in Eastern Taylor Valley, Antarctica

Available soil moisture is thought to be the limiting factor for most ecosystem processes in the cold polar desert of the McMurdo Dry Valleys (MDVs) of Antarctica. Previous studies have shown that microfauna throughout the MDVs are capable of biological activity when sufficient soil moisture is available (~2–10% gravimetric water content), but few studies have attempted to quantify the distribution, abundance, and frequency of soil moisture on scales beyond that of traditional field work or local field investigations. In this study, we present our work to quantify the soil moisture content of soils throughout the Fryxell basin using multispectral satellite remote sensing techniques. Our efforts demonstrate that ecologically relevant abundances of liquid water are common across the landscape throughout the austral summer. On average, the Fryxell basin of Taylor Valley is modeled as containing 1.5 ± 0.5% gravimetric water content (GWC) across its non-fluvial landscape with ~23% of the landscape experiencing an average GWC &gt; 2% throughout the study period, which is the observed limit of soil nematode activity. These results indicate that liquid water in the soils of the MDVs may be more abundant than previously thought, and that the distribution and availability of liquid water is dependent on both soil properties and the distribution of water sources. These results can also help to identify ecological hotspots in the harsh polar Antarctic environment and serve as a baseline for detecting future changes in the soil hydrological regime.

Emerging Weed Problems under Changing Climatic Condition: A Review

Climate is a major force in earth’s environmental system, and even minor changes in climate can have complex and serious effects on the environment. Atmospheric CO2, temperature and precipitation are major important abiotic variables that directly affect weed physiology and growth. Weeds are more genetically diverse than crops, hence show enhanced growth and reproductive stability than crops. Among the C3 and C4 weeds in cropped field, C3 weeds have more response in photosynthesis to increased CO2 level in atmosphere. The elevated CO2 under sufficient soil moisture condition will leads the higher C3 weed competitiveness in C4 crops. So weed growth is favoured as CO2 is increased. Temperature changes resulted in an expansion of weeds, and shifting of weeds. Based on the differences in temperature, the C4 spp. able to tolerate high temperature than C3 spp. Therefore, C4 weeds benefit more than the C3 crops from temperature increases that accompany elevated CO2 levels. Due to global warming, weeds expand their range into new areas. Precipitation is also one of the important climate variable that influences the growth and distribution of weeds growth. Even though CO2 concentration level and temperature rise in future are predictable, amount, distribution, and intensity of rainfall patterns remains much more uncertain. Moisture is a key factor required for weed seed germination, growth and development. Climate change can affect the frequency and intensity of rainfall and result in occurrences of extreme events such as floods and droughts; consequently, weeds adapted to these conditions will have a higher competitive advantage.

ПРОДУКТИВНОСТЬ РАЗЛИЧНЫХ ВИДОВ ЯРОВОЙ ПШЕНИЦЫ В ЗАВИСИМОСТИ ОТ ФОНА ПИТАНИЯ ПРИ РАЗЛИЧНЫХ НОРМАХ ВЫСЕВА В УСЛОВИЯХ ПРЕДКАМСКОЙ ЗОНЫ РЕСПУБЛИКИ ТАТАРСТАН

The article presents experimental material on the study of the seeding rate for various nutrition backgrounds on the development of spring soft wheat and spelt wheat, the nature of stem formation, which has an important effect on the formation of grain yield. The purpose of this work is to study the reaction of spring wheat species to the level of application of mineral fertilizers at different seeding rates in the conditions of gray forest soil of the Republic of Tatarstan. Field studies were carried out on the territory of Agrobiotechnopark LLC of the Kazan State Agrarian University. The material for research is spring soft wheat (Triticum aestivum) varieties Ulyanovsk 105 and Tulaykovskaya Nadezhda and spelt wheat (Triticum dicoccum) varieties Srednevolzhskaya and Fleece. In 2022, meterological conditions during the growing season of spring wheat were characterized by sufficient soil moisture and temperature conditions. During the entire growing season of spring wheat, 158.9 precipitation fell (GTK-1.35). The formation of the agrocenosis of spring wheat species is mainly determined by seeding rates, as well as field germination and biological resistance of plants during the growing season. At both nutrition levels, as the seeding rate increases from 4 to 7 million germinating seeds per 1 ha, the number of seedlings of both soft and spelt wheat increases. On control (natural background) soft wheat varieties Ulyanovsk 105 from 347 to 539 pcs / m2, fertilized version 344-534 pcs / m2, Tulaykovskaya Nadezhda 340-528 pcs / m2 and 336-522 pcs / m2, respectively, fertilization increased the yield of both types of wheat at all seeding rates: soft wheat varieties Ulyanovsk 105 at 4 million 0.93 tons, 5 million - 1.15 tons, 6 million - 1.17 tons and 7 million - 1.16 tons per ha. Varieties Tulaykovskaya Nadezhda 1.08; 1.1, 1.1; and 1.15 t/ha, respectively. Spelt wheat of the Srednevolzhskaya variety has 0.14; 0.34; 0.45 and 0.3 t/ha per ha. Fleece 0.37; 0.23; 0.22 and 0.35 t / ha, respectively. The highest yield of both types of spring wheat for the studied varieties in the growing season of 2022 was formed both on the control and on the fertilized version of the experiment when sowing 5 million. germinating seeds per 1 hectare.

AISG: IOT-DRIVEN IRRIGATION FOR AUGMENTED PLANT GROWTH

Information technology has become so pervasive in today's highly technological culture that it affects every aspect of human existence. The advent of information technology has proven beneficial to many different industries, including horticulture, both on a domestic and commercial. Gardeners frequently face difficulties in maintaining their gardens during vacations or periods of neglect, leading to plant withering, and these challenges arise due to environmental stressors like light, soil moisture, and water. This research introduces AISG that represent Automat-ed Irrigation Smart Gardening. It provides a solution by integrating an IoT system with a responsive web-based application to monitor a plant's development in real time, including access to relevant data and the ability to adjust settings as needed. This approach will assist the gardeners in managing their plants and irrigate appropriately depending on the specific needs of the plants. Besides, it may reduce water consumption and allow plants to be tended. the moisture sensor measures soil dryness at two distinct locations in the field and transmits the data to the Arduino system, which considers information from both devices to deter-mine the required amount of water. The system continues collecting sensor data until it detects sufficient soil moisture, at which point it automatically turn off the pump. Another benefit of this approach is the gardeners can control the irrigation system that watering their plants from their phone. The sensor's collected information is automatically updated on an hourly basis. In conclusion, the expected outcome of this implementation system enables a more organized and systematic approach to tending plants at home, resulting in improved care and maintenance.

Growth of Stipa breviflora does not respond to nitrogen addition because of its conservative nitrogen utilization

Enhanced atmospheric nitrogen (N) deposition is threating species diversity in the desert steppe ecoregions. Needlegrass (Stipa breviflora) is the dominant specie in the desert steppe grasslands of China and southern Mongolia, and the response of S. brevifolia to N deposition is not well known. In this study, we conducted an experiment to determine the growth and N uptake of S. breviflora in response to several N addition rates. The results showed that N addition did not change plant growth, emergence rate, plant height, or biomass of S. breviflora, even at a N addition rate of 50 kg N ha−1 yr.−1 with sufficient soil moisture during a 120-day growth period. The absence of a N effect was due to the fact that N uptake in S. breviflora was not improved by N addition. These results indicated that S. breviflora is very conservative with respect to N utilization, which could possibly help it resist enhanced atmospheric N deposition. Moreover, conservative N utilization also enables S. breviflora to survive in N-limiting soils.

Effects of frequency of the stale seedbed after autumn or spring ploughing on weed density and composition in sown lemon balm

AbstractWeed management in organic farming needs to integrate a wide range of preventive tools. Here we tested the stale seed bed technique in field experiments with organic lemon balm. In a two‐factorial trial, four intensities of stale seedbed after either autumn or spring ploughing were tested in 2019/2020 and 2020/2021 on alluvial loams of the research farm Wiesengut in the Rhineland, Germany. Increasing the number of stale seedbed passes did not promote weed emergence before sowing in 2020 due to serious spring drought; in 2021 only the two last stale seedbed passes in later spring caused extra weed flushes, while cold weather conditions in early spring prevented weed response to the earlier passes. Despite the differences in the number of germinating weeds in 2021 before sowing, intensification of the stale seedbed had no decreasing effect on weed density in lemon balm after sowing. However, weed species‐specific periods were identified in which the stale seedbed selectively promoted emergence. Autumn ploughing followed by a superficial incorporation of the catch crop in spring resulted in a lower weed emergence than complete residue incorporation by spring ploughing. Seedbank size differed greatly between fields, probably due to crop rotation. The overall weed reducing effect of the tested tillage treatments was low, probably due to high weed pressure on the organic farm. To increase the efficacy of the stale seed bed technique, sufficient soil moisture as well as temperature requirements of the dominating weed flora need to be considered.

Drought Tolerance in Mung Bean is Associated with the Genotypic Divergence, Regulation of Proline, Photosynthetic Pigment and Water Relation

Drought is one of the critical conditions for the growth and productivity of many crops including mung bean (Vigna radiata L. Wilczek). Screening of genotypes for variations is one of the suitable strategies for evaluating crop adaptability and global food security. In this context, the study investigated the physiological and biochemical responses of four drought tolerant (BARI Mung-8, BMX-08010-2, BMX-010015, BMX-08009-7), and four drought sensitive (BARI Mung-1, BARI Mung-3, BU Mung-4, BMX-05001) mung bean genotypes under wellwatered (WW) and water deficit (WD) conditions. The WW treatment maintained sufficient soil moisture (22% ± 0.5%, i.e., 30% deficit of available water) by regularly supplying water. Whereas, the WD treatment was maintained throughout the growing period, and water was applied when the wilting symptom appeared. The drought tolerant (DT) genotypes BARI Mung-8, BMX-08010-2, BMX-010015, BMX-08009-7 showed a high level of proline accumulation (2.52–5.99 mg g−1 FW), photosynthetic pigment (total chlorophyll 2.96–3.27 mg g−1 FW at flowering stage, and 1.62–2.38 mg g−1 FW at pod developing stage), plant water relation attributes including relative water content (RWC) (82%–84%), water retention capacity (WRC) (12–14) as well as lower water saturation deficit (WSD) (19%–23%), and water uptake capacity (WUC) (2.58–2.89) under WD condition, which provided consequently higher relative seed yield. These indicate that the tolerant genotypes gained better physiobiochemical attributes and adaptability in response to drought conditions. Furthermore, the genotype BMX- 08010-2 showed superiority in terms of those physio-biochemical traits, susceptibility index (SSI) and stress tolerance index (STI) to other genotypes. Based on the physiological and biochemical responses, the BMX-08010-2 was found to be a suitable genotype for sustaining yield under drought stress, and subsequently, it could be recommended for crop improvement through hybridization programs. In addition, the identified traits can be used as markers to identify tolerant genotypes for drought-prone areas.

Disentangling temperature and water stress contributions to trends in isoprene emissions using satellite observations of formaldehyde, 2005–2016

Isoprene, produced by plants in response to multiple drivers, affects climate and air quality when released into the atmosphere. In turn, climate change may influence isoprene emissions through variations in occurrence and intensity of types of stress that affect plant functions. We test the effects of multiple drivers (temperature, precipitation, soil moisture, drought index, biomass, aerosols, burned fraction) on space retrievals of formaldehyde (HCHO) column concentrations, as a proxy for isoprene emissions, at global and regional scales over the period 2005–2016. We find declines in HCHO column concentrations over the study period across Europe, the Amazon Basin, southern Africa, and southern Australia, and increases across India, China, and mainland Southeast Asia. Temporal effects and the interactions among drivers are analyzed using generalized linear mixed-effects models to explain trends in HCHO column concentrations. Results show that HCHO column concentrations increase with temperature at the global scale and across the Amazon Basin and India–China regions, even under low levels of precipitation, provided that sufficient soil moisture can maintain vegetation functions and the associated isoprene emissions. Water availability sustains isoprene emissions in dry regions such as Australia, where HCHO column concentrations are positively associated with mean precipitation, with this relation intensifying at low levels of soil moisture. In contrast, isoprene emissions increase under water stress across the Amazon Basin and Europe, where HCHO column concentrations are negatively associated with levels of soil moisture and drought as calculated by the Standardized Precipitation–Evapotranspiration Index (SPEI). This study confirms the key role of temperature in modulating global and regional isoprene emissions and highlights contrasting regional effects of water stress on these emissions.

The sensitivity of maize evapotranspiration to vapor pressure deficit and soil moisture with lagged effects under extreme drought in Southwest China

Evapotranspiration (ET) is regulated by vapor pressure deficit (VPD) and soil moisture (SM) which are expected to change in global climate change. Understanding the impacts of VPD and SM on maize ET is essential for global food security and water cycle. Here, we estimate the actual maize ET in Southwest China during 2001–2011 based on Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) model using remote-sensing data and reanalysis data. Then, we define the extreme drought events in 2009–2011 using the smoothed standardized anomaly of the three-month Standardized Precipitation Evapotranspiration Index (SPEI) to investigate the responses of maize ET to VPD and SM during extreme drought events in Southwest China. We detected the lag times of maize ET responses to VPD and SM, and then analyzed the sensitivity of maize ET to VPD and SM with lagged effects. We found pervasive lagged responses of maize ET with a shorter lag time of VPD (1.12 ±0.006 months, P < 0.05) than SM (1.28±0.006 months, P < 0.05). We analyzed the lag times of maize ET in relation to elevation, temperature, and precipitation to investigate the abiotic impacts on the lagged responses and found the lagged responses were more prevalent in areas at higher altitudes with lower temperatures but there was less variation across precipitation gradients. Maize ET was more sensitive to VPD than SM with lagged effects. High VPD enhanced maize ET under sufficient SM but during an extreme drought event, maize ET might be dramatically reduced due to SM depletion in spite of high VPD. The study highlights the significance of atmospheric water demand for crop water consumption under extreme climate events.

Atmospheric dryness impacts on crop yields are buffered in soils with higher available water capacity

Atmospheric dryness has been recognized as a dominant driver for agroecosystem functioning due to its limiting controls on stomatal behavior, even under sufficient soil moisture. Due to its relative importance in influencing carbon and water fluxes, atmospheric dryness has emerged as an important element of global change, jeopardizing food security and agricultural profitability via negative impacts on crop yields. Although negative impacts of atmospheric dryness are well recognized at various scales, it is unknown how heterogeneity in soils’ ability to retain water for plant uptake affects crop yields’ response to increasing atmospheric dryness. To address this, we analyzed how soil available water capacity (AWC) affects the response of crop yields to space and time variation in summer (June-July-August) vapor pressure deficit (VPDJJA) across the conterminous U.S. (CONUS) during 1980–2020 using 77,701 and 51,190 county-year records for maize and soybean, respectively. A distinct co-distribution of VPDJJA and AWC regimes is experienced by maize and soybean acreage and is subject to significant yield variation. Accounting for entire AWC heterogeneity in CONUS, both crops showed a positive yield response to increasing VPDJJA until 0.8 kPa, thereafter showing a gradually increasing negative response to VPDJJA increase. Upon soil-specific investigation of yield response to VPD, the yield sensitivity parameter to VPDJJA became less negative as soil AWC increased, implying buffering of dryness impacts on yields as the ability of soils to retain water increased. For VPDJJA increase between 1.0 kPa and 1.4 kPa, mean VPDJJA impacts on maize yields in soils with 10 %<AWC < 12.5 % were buffered by one-half (50.6 %) as compared with 7.5 %<AWC < 10 % soils. Increasing AWC from 10 to 12.5 % class to 12.5–15 % class further buffered VPDJJA impacts on maize yields by 26.2 %. VPDJJA impacts on soybean yields in soils with 15 %<AWC < 17.5 % were buffered by 40 % as compared with 12.5 %<AWC < 15 % soils. Further increase in AWC (17.5–20 %) resulted in additional 15.5 % buffering of VPDJJA impacts on soybean as compared to impacts recorded for 15 %<AWC < 17.5 % soils. The greatest buffering of negative impacts from VPDJJA were found when AWC is>10 % and 15 % for maize and soybean, respectively. Possible physical mechanisms responsible for this buffering are improved plant physiological function and fulfilment of evaporative demand due to additional soil water resulting from higher AWC, given sufficient water supply. This empirical large-scale evidence of mediating role of AWC for crop yield impacts from a dryer atmosphere underscores the critical nature of soils to support climate-smart agricultural practices via building soil organic matter as well as providing co-benefits for improved crop performance to meet current and future population’s food and fiber needs.

КАЧЕСТВО ЗЕРНА СОРТОВ ЯРОВОЙ ПШЕНИЦЫ В СВЯЗИ С ПРИМЕНЕНИЕМ МИНЕРАЛЬНЫХ УДОБРЕНИЙ И ЗАЩИТЫ РАСТЕНИЙ В УСЛОВИЯХ ПРЕДВОЛЖЬЯ РЕСПУБЛИКИ ТАТАРСТАН

Studies to study the grain quality of the main varieties of spring wheat included in the state register in the 7th region were carried out in 2020-2021. under the conditions of Avangard LLC, Buinsky municipal district of the Republic of Tatarstan, on chernozem soils typical for this zone with agrochemical characteristics: humus content - 7.0-8.5%, mobile forms of phosphorus - 182-255 mg / kg, potassium - 159-193 mg / kg and pH salt – 5,5-5,8. Agrochemical analyzes of soils were carried out at the Federal State Budgetary Institution CAS "Tatarsky" by generally accepted methods: GOST 26213-91 (humus content), GOST 26484-85 (pHsal.), GOST 26207-91 (mobile forms of phosphorus and potassium). The meteorological conditions of 2020 were characterized by sufficient soil moisture and moderate temperature conditions during the growing season of spring wheat (STC-1.28) and had a positive impact on the future yield and grain quality. Meteorological indicators for the growing season of the research object in 2021 were extremely unfavorable for the formation of the crop. May and June were extremely dry, HTC-0,17-0,27. In the Pre-Volga zone of the Republic of Tatarstan, under conditions of unstable moisture, the effect of fertilizers on the yield is very variable. In a dry year, the effectiveness of mineral fertilizers is insignificant: only such varieties as Ekada 109, Yoldyz and Burlak gave a significant increase in yield by 10.6-11.9%. Conducted observations, records and analyzes in 2020 and 2021 showed that fertilizers in combination with a plant protection unit provided a sustainable increase in grain quality indicators. On average, over 2 years, in the Yoldyz variety, compared with the control and the standard variety Simbirtsit, the amount of mass fraction of gluten increased by 3.5%, and in the Ekada 109 and Burlak varieties by 4,1 and 4,3%.