Water Availability Conditions Research Articles

Cowpea response to different irrigation depths in the Submedium São Francisco River Valley, in Juazeiro, BA, Brazil

Different cowpea genotypes respond differently to water regimes and to different climatic conditions. The aim of this study was to evaluate the response of cowpea to different irrigation depths in the Submedium São Francisco River Valley, Brazil. The experiment was conducted at the experimental field of DTCS/UNEB, in Juazeiro, BA, Brazil, from November/2016 to January/2017, in a 2 x 5 factorial scheme randomized block design (cowpea genotypes x irrigation depths), with three replicates. The genotypes used were BRS Acauã and Canapu and irrigation depths, obtained based on 50, 75, 100, 125, and 150% of ETo. Physiological characteristics, production components and water use efficiency were analyzed. Increased irrigation depths only caused a significant effect on mass of one 100 grains. With water availability and climatic conditions observed during the experiment, BRS Acauã outperformed Canapu, with a better yield performance. BRS Acauã genotype had a better response in water use efficiency for grain yield, exceeding Canapu by 47.21%.

Water productivity monitoring by using geotechnological tools in contrasting social and environmental conditions: Applications in the São Francisco River basin, Brazil

We used the SAFER (Simple Algorithm for Evapotranspiration Retrieving) algorithm together with the Monteith's RUE (Radiation Use Efficiency) model, for large-scale water productivity assessments in different social and environmental conditions of the São Francisco River sub basins, Brazil, by coupling remote sensing parameters from MODIS images and a net of agrometeorological stations, during the year 2016. Variations on actual evapotranspiration (ET) and biomass production (BIO) among ecosystems and sub basins were strongly detected, affecting the water productivity based on ET (WP = BIO/ET). The mean ET daily rates were 2.1 mm d−1 for both, Forest Zone (FZ) and Savanna (SV), and 1.3 mm d−1 for Caatinga (CA), while regarding BIO they were 67, 68 e 33 kg ha−1 d−1, for FZ, SV, and CA, respectively resulting in corresponding average WP values of 2.6; 2.5, and 1.7 kg m−3. The modelling by using the MODIS reflectance product together with gridded weather data presented operational applicability for monitoring water and vegetation dynamics at a 16-day period and at a 250 m spatial resolution along the year, under conditions of distinct water availability. The satisfactory results highlighted the suitability of geotechnological tools to subsidize the rational natural resources management on large scales in societies with different environmental vulnerabilities.

Estimating and understanding crop yields with explainable deep learning in the Indian Wheat Belt

Forecasting crop yields is becoming increasingly important under the current context in which food security needs to be ensured despite the challenges brought by climate change, an expanding world population accompanied by rising incomes, increasing soil erosion, and decreasing water resources. Temperature, radiation, water availability and other environmental conditions influence crop growth, development, and final grain yield in a complex nonlinear manner. Machine learning (ML) techniques, and deep learning (DL) methods in particular, can account for such nonlinear relations between yield and its covariates. However, they typically lack transparency and interpretability, since the way the predictions are derived is not directly evident. Yet, in the context of yield forecasting, understanding which are the underlying factors behind both a predicted loss or gain is of great relevance. Here, we explore how to benefit from the increased predictive performance of DL methods while maintaining the ability to interpret how the models achieve their results. To do so, we applied a deep neural network to multivariate time series of vegetation and meteorological data to estimate the wheat yield in the Indian Wheat Belt. Then, we visualized and analyzed the features and yield drivers learned by the model with the use of regression activation maps. The DL model outperformed other tested models (ridge regression and random forest) and facilitated the interpretation of variables and processes that lead to yield variability. The learned features were mostly related to the length of the growing season, and temperature and light conditions during this time. For example, our results showed that high yields in 2012 were associated with low temperatures accompanied by sunny conditions during the growing period. The proposed methodology can be used for other crops and regions in order to facilitate application of DL models in agriculture.

Clinal variation in drought resistance shapes past population declines and future management of a threatened plant

AbstractPredicting vegetation responses to increased future drought is challenging, owing to the complex interaction of multiple factors influencing both plant drought resistance and local climatic conditions, each of which may be subject to spatial and temporal heterogeneity. We conducted a detailed study of potential mechanisms underlying an elevational gradient in mortality that has characterized recent population declines of a threatened alpine plant, the Haleakalā silversword (Argyroxiphium sandwicense subsp. macrocephalum). We used a pair of greenhouse experiments staged at high and low elevations to test the influences of plasticity (to contrasting soil water availability and atmospheric conditions) and heredity (different seed source elevations) on the development of functional traits associated with drought resistance and on performance in a terminal drought. We then out‐planted a subset of plants into three common‐garden plots near the bottom, middle, and top of the silversword elevational range, and tracked growth and survival over 3.5 yr. A range of morphological traits (root and leaf mass fractions, specific leaf area, leaf area ratio, and root length per shoot mass) exhibited either heritable variation or plasticity or both. Among physiological traits measured, only water use efficiency exhibited a plastic treatment response. Survival of out‐plants was influenced during the first year by a home site advantage, and by the water treatment imposed in the greenhouses, with high water plants dying more often than low water plants. These effects subsequently dissipated, being replaced over the final 1.5 yr by a strengthening out‐plant site effect: survival was positively associated with site elevation, matching the pattern of mortality observed in the wild population. The balance of information suggests this pattern stems from lower elevation plants being less drought resistant than higher elevation plants, owing principally to plasticity, and thus suffering greater mortality during recent dry seasons. The pattern may be enhanced by stronger deviations from typical climatic conditions at lower elevations. Our findings suggest that future management should focus on climatically suitable habitat rather than advantageous genetic ecotypes. More broadly, they provide evidence that clinal variation can be important to consider when modeling future vegetation responses to climate change.

Gallesia integrifolia (Spreng.) Harms. Growth Under Different Shade and Water Availability Conditions

Our study sought to evaluate parameters of mycorrhizal growth and colonization of Gallesia integrifolia under different light and water availability conditions. The experiment was conducted in a greenhouse, with the following treatments: three light levels (0%, 50% and 80% shading), and two water regimes (watering daily and twice a week), in a completely randomized experimental design. The results showed that the plants kept under 50% shading and the ones kept under full light, both watered daily, had the best performance. Mycorrhizal association was observed in all treatments, which favored the establishment of seedlings even in environments with less water availability. G. integrifolia showed acclimation to higher levels of shading and lower availability of water, which may be related to the species plasticity and its wide distribution.

New information about the mechanism of oil displacement from productive reservoirs using flow control technologies

The article is devoted to improving the efficiency of methods application to increase oil recovery of deposits that are at the final stage of development. This stage is characterized by a high degree of waterlogging of reservoirs and extracted products. From a wide range of chemical methods for increasing oil recovery in Russian oil deposits, flow-regulating (flow-deflecting) technologies have become widespread. The article analyzes the results of purposeful use of thickened water for the completion of reserves of already flooded sandstone layers. Experimental studies were performed on two specially created five-point elements in the experimental sections of the Romashkinskoye deposit. To monitor the process of low-viscosity and high-viscosity oil displacement the following methods were used: a) intake, monitoring and production wells, in which the interval of productive horizons are lined with fiberglass pipes; b) method of high-frequency resistivity (technology of "VNIIneftepromgeophysics" Institute). The studies performed in the monitoring mode showed that, along with the increase in reservoir coverage by flooding at the macro level, there is also a displacement of part of the capillary-trapped oil in the already flooded layers’ intervals, that is, at the level of micro-uniformity of the porous medium. The paper concludes on the effectiveness of using flow-regulating technologies in conditions of high water availability of development objects.

Crop water requirement and water use efficiency of cauliflower under mulching and drip irrigation in eastern Plateau hills region of Jharkhand

Water scarcity puts a big adverse impact on food production and its related activities. Under the scarce water availability conditions it becomes a tedious proposition to raise crops, in absence of appropriate management, for ensuring food security. In order to get rid of this constraint, an efficient irrigation system with the use of appropriate mulching and irrigation level would be the most suitable option, which can save water and increase productivity of cauliflower. The present investigation was carried out to determine water requirement and water use efficiency of cauliflower (Brassica oleracea var. botrytis) under various growing condition (t1- Surface irrigation, t2- Drip irrigation ( 100%Et), t3- Drip irrigation( 80%Et), t4- Drip irrigation( 100%Et) with Black plastic Mulch, T5- Drip irrigation ( 80%ET) with Black plastic Mulch. This experiment was conducted in the field of the department of agricultural engineering, Birsa Agricultural University, Kanke, ranchi during 2017-18. Drip irrigation based on crop water requirement significantly increased crop yield of cauliflower and improved WUE due to consumption of less water. The findings of this research work revealed that use of 80 per cent of crop water requirement through drip irrigation with black plastic mulch(25 micron) system besides giving a saving of 69% water resulted in 3.2 times higher yield of cauliflower as compared to surface irrigation. Drip irrigation in combination with plastic mulch was found to be more appropriate and profitable method in improving WUE and increasing crop yield of cauliflower. Estimation of crop water requirement from crop evapotranspiration equation by measuring microclimates directly is an appropriate method for effective management of scarce water resources under climatic condition of Jharkhand.

Organic cultivation of yellow passion fruit using tall seedlings with long root systems

Studies related to adaptation to the environment and different conditions of water availability contribute to decision-making regarding the management of any crop to be implanted. Accordingly, this work aimed to evaluate the yield and quality of organic yellow passion fruit cultivated in a long root system in dryland conditions. The experimental design was in randomized blocks, with five treatments and four replications with four plants each. The treatments consisted of the alteration of the length of the root system, namely: T1 = 25 cm; T2 = 50 cm; T3 = 75 cm; T4 = 100 cm; and T5 = 125 cm. At 120 days after emergence (DAE), the seedlings were transplanted to the field and the following variables were evaluated: plant height (cm) and base diameter (mm) at 120 DAE; total titratable acidity (TTA), total soluble solids (TSS), Ratio (TSS/TTA); and fruit yield. The cultivation of tall seedlings with a long root system provides the maintenance of production during the dry season. The TTA, TSS, and the ratio do not change when modifying the length of the root system, although they do change with the harvest season. The cultivation of passion fruit in an organic system using plants with a long root system with an estimated length of 114 cm provides a higher fruit yield (7,472 kg ha-1) in 22 months of cultivation.

Sustainability Perspectives of Vigna unguiculata L. Walp. Cultivation under No Tillage and Water Stress Conditions.

Nowadays, agriculture is facing the great challenge of climate change which puts the productivity of the crops in peril due to unpredictable rain patterns and water shortages, especially in the developing world. Besides productivity, nutritional values of the yields of these crops may also be affected, especially under low mechanization and the low water availability conditions of the developing world. Conservation agriculture (CA) is a topic of emerging interest due to the provision of adequate yields and reduced environmental impact, such as greenhouse gas emissions, by being based on three main principles: minimum soil disturbance (reduced or no tillage), cover crop maintenance, and crop rotation. The aim of this study was to assess the impact of CA management on the growth performance and the nutritional profile of cowpea (Vigna unguiculata L. Walp), a pulse of African origin, commonly known as black eye bean under field conditions. A field experiment was designed to assess the effect of conventional tillage (CT) and no-tillage (NT) combined with the usage of a set of cover crops, coupled to normal and deficient water regimes. Cowpea was revealed to be able to grow and yield comparably at each level of the treatment tested, with a better ability to face water exhaustion under CA management. After a faster initial growth phase in CT plots, the level of adaptability of this legume to NT was such that growth performances improved significantly with respect to CT plots. The flowering rate was higher and earlier in CT conditions, while in NT it was slower but longer-lasting. The leafy photosynthetic rate and the nutritional profile of beans were slightly influenced by tillage management: only total starch content was negatively affected in NT and watered plots while proteins and aminoacids did not show any significant variation. Furthermore, significantly higher carbon and nitrogen concentration occurred in NT soils especially at the topmost (0–5 cm) soil horizon. These findings confirm the capability of CA to enrich soil superficial horizons and highlight that cowpea is a suitable crop to be grown under sustainable CA management. This practice could be pivotal to preserve soils and to save agronomical costs without losing a panel of nutrients that are important to the human diet. Due to its great protein and aminoacidic composition, V. unguiculata is a good candidate for further cultivation in regions of the word facing deficiencies in the intake of such nutrients, such as the Mediterranean basins and Sub-Saharan countries.

Lab tests on semi-aerobic landfilling of MSW under varying conditions of water availability and putrescible waste content

Semi-aerobic landfilling is applied increasingly as a sustainable technology worldwide, although frequently controversial results are achieved. The authors suggest that differences in water availability (climate, moisture content, etc.) and putrescible waste content are the key factors involved in controlling performance and efficiencies. The aim of the present study was to investigate the effect of inverse conditions (high/low) of these two factors. Six lab-scale lysimeters were specifically set up to correspond to three different conditions of water availability (wet conditions, dry conditions and artificially controlled watering under dry conditions) and two different waste types (high and low putrescible content). Lysimeters were operated for four months under thermal-insulated conditions and the quality and quantity of emissions monitored regularly. Concentrations of mobile ammonia and total organic carbon (TOC) in landfilled waste were modelled by means of first-order kinetics, and carbon and nitrogen mass balances were calculated. The best performance for the semi-aerobic process was achieved at a water availability of approximately 1.5–2.4 kgH2O/kgTS using the following two combinations: a) Waste with high putrescible content and no addition of external water due to the presence of sufficient endogenous water in the waste (moisture) to promote biological stabilisation of waste (Respiration index in 4 days, RI4 = 12.87 mgO2/gTS, BOD/COD < 0.05); b) Waste with low putrescible content and controlled watering (RI4 = 12.25 mgO2/gTS, BOD/COD < 0.04). The study highlighted how semi-aerobic landfilling operations should be carefully adjusted case by case according to waste quality and climate conditions.

Root and shoot competition lead to contrasting competitive outcomes under water stress: Asystematic review and meta-analysis.

BackgroundCompetition is a critical process that shapes plant communities and interacts with environmental constraints. There are surprising knowledge gaps related to mechanisms that belie competitive processes, though important to natural communities and agricultural systems: the contribution of different plant parts on competitive outcomes and the effect of environmental constraints on these outcomes.ObjectiveStudies that partition competition into root-only and shoot-only interactions assess whether plant parts impose different competitive intensities using physical partitions and serve as an important way to fill knowledge gaps. Given predicted drought escalation due to climate change, we focused a systematic review–including a meta-analysis on the effects of water supply and competitive outcomes.MethodsWe searched ISI Web of Science for peer-reviewed studies and found 2042 results. From which eleven suitable studies, five of which had extractable information of 80 effect sizes on 10 species to test these effects. We used a meta-analysis to compare the log response ratios (lnRR) on biomass for responses to competition between roots, shoots, and full plants at two water levels.ResultsWater availability treatment and competition treatment (root-only, shoot-only, and full plant competition) significantly interacted to affect plant growth responses (p < 0.0001). Root-only and full plant competition are more intense in low water availability (-1.2 and -0.9 mean lnRR, respectively) conditions than shoot-only competition (-0.2 mean lnRR). However, shoot-only competition in high water availability was the most intense (— 0.78 mean lnRR) compared to root-only and full competition (-0.5 and 0.61 mean lnRR, respectively) showing the opposite pattern to low water availability. These results also show that the intensity of full competition is similar to root-only competition and that low water availability intensifies root competition while weakening shoot competition.ConclusionsThe outcome that competition is most intense between roots at low water availability emphasizes the importance of root competition and these patterns of competition may shift in a changing climate, creating further urgency for further studies to fil knowledge gaps addressing issues of drought on plant interactions and communities.

Climate and water availability impacts on early growth and growth efficiency of Eucalyptus genotypes: The importance of GxE interactions

Predicting Eucalyptus plantation productivity in the face of climate change is a key challenge for intensively managed forest plantations around the world. Forest industry tree improvement and advanced silvicultural programs are charged with maximizing forest production but face challenging selection choices where Eucalyptus genotypes may be sensitive to genetic × environment interactions (GxE). Our study investigated the importance of GXE interactions by measuring the early (establishment to 2.6 years old) cumulative growth response of 30 selected genotypes of Eucalyptus globulus, E. nitens, E. badjensis, E. smithii, E. nitens × globulus and E. camaldulensis × globulus hybrid seedlings established across contrasting water availability conditions (High vs Low Irrigation). We compared the same genotypes at a low vapor pressure deficit (VPD) and clayey soil (North site) and a high VPD sandy soil (South site) in order to evaluate the stability of these genotypes across environmental gradients and thus evaluate the importance of genetic versus environmental impacts on growth. Stand growth was evaluated at 2.6 years when leaf area index (LAI) reached canopy closure in order to estimate a growth efficiency relationship (GE) with current annual increment (CAI). As expected, irrigation increased cumulative growth and LAI for all taxas, except for E. smithii at the North site. Genotypes showed large significant differences of performance within and across sites under each irrigation treatment. However, a strong relationship between North and South cumulative volume at age 2.6 years was observed for irrigated genotypes but not for non-irrigated genotypes. This suggests that a large GxE interaction may be expected under low water resource availability conditions associated with strong effects in ranking change of evaluated taxas and genotypes. Comparing taxas with at least two genotypes or more in our experiment, GE increased under High Irrigation for all taxas across sites. However, E. nitens × globulus hybrids showed small differences between High vs Low Irrigation treatments GE relationships compared to E. nitens and E. globulus genotypes. Our results suggest the need for strategic allocation of genotypes to contrasting drought risk environments and the need to assess our understanding of how particular genotypes interact with water stress conditions.

Modeling Stem Water Potential by Separating the Effects of Soil Water Availability and Climatic Conditions on Water Status in Grapevine (Vitis vinifera L.).

Measuring seasonal plant water status is critical in choosing appropriate management strategies to ensure yields and quality of agricultural products, particularly in a context of climate change. Water status of grapevines is known to be a key factor for yield, grape composition, and wine quality. Predawn leaf water potential (PLWP) and stem water potential (SWP) proved to be simple and precise indicators for assessing grapevine water status and subsequent same-day spatial comparisons. A drawback of SWP is that it does not allow for temporal comparisons, because the measured value is impacted both by soil water availability and climatic conditions on the day of measurement. The objectives of this study are i) to provide a model that separates the effect of soil water content from the effect of climatic conditions on the SWP value and ii) to standardize the SWP value to a value under predefined reference climatic conditions in order to compare SWP values collected under different climatic conditions. SWP and PLWP were temporally assessed on three soil types in Saint-Émilion (Bordeaux, France) in 2015 and on five soil types in Margaux (Bordeaux, France) in 2018 using a pressure chamber. SWP measurements on two consecutive days with contrasting climatic conditions allowed to assess the impact of these conditions on SWP values. A large portion of the variability in SWP values was explained by PLWP. Model selection further showed that the addition of maximum air temperature and seasonality explained a significant amount of the remaining variability in SWP values. SWP values could be successfully standardized to a theoretical value under reference climatic conditions, which allows for temporal comparisons of SWP values. A plant-based measurement, such as the water potential, can be considered as the most straightforward indicator of plant water status as it integrates the effects of soil, plant, and atmospheric conditions. More precise interpretation of SWP values provides winegrowers with a tool to more adequately implement short- and long-term management strategies to adapt to drought in order to ensure yield and grape quality.

Contrasting leaf porometer and infra-red gas analyser methodologies: an old paradigm about the stomatal conductance measurement

Here we compare the stomatal conductance (gs) values obtained with leaf porometer and infra-red gas analyzer (IRGA) in different species subjected to different water availability and evaluated in two different environmental conditions. Sunflower, maize, bean, and grapevine were subjected to two treatments of water availability: well-watered and progressive water stress for 3 days and evaluated in two different times with contrasting environmental conditions. The gs was determined both on the abaxial and adaxial side of leaves using a leaf porometer and an IRGA. The measured gs strongly differed between IRGA and porometer, in a way that depended on the species, as well as water availability and environmental conditions. Under maximum water stress, gs measured with leaf porometer was higher than those measured with IRGA in the four species studied. The present results question the use of usual methodologies for the estimation of gs, suggesting that gs would not only depend on the environmental conditions and the water status of the plants, but also on the method used to measure it.

Effects of temperature and water activity change on ecophysiology of ochratoxigenic Aspergillus carbonarius in field-simulating conditions

Ochratoxin A (OTA) is the primary mycotoxin threat in wine and dried vine fruits. Its presence in grape and wine is strongly related to climatic conditions and the expected climate change could represent a risk of increasing fungal colonization and OTA contamination in grapes. In this regard, the interacting effect of i) different conditions of water availability (0.93 and 0.99aw) and ii) different 10 h/14 h dark/light alternating temperature conditions simulating a nowadays (18/31 °C) and climate change scenario (20/37 °C) in high OTA risk areas of Apulia region, were studied. Lag phases prior to growth, mycelial growth rate, the expression of biosynthesis, transcription factors and regulatory genes of OTA cluster and OTA production were analysed in Aspergillus carbonarius ITEM 5010 under the combined effect of different climatic factors. At 18/31 °C and under water stress conditions (0.93 aw) the growth rate was slower than at 0.99 aw; on the contrary, at 20/37 °C a higher growth rate was observed at 0.93 aw. An over-expression of OTA genes and genes belonging to the global regulator Velvet complex was observed at 18/31 °C and 0.99 aw, with the specific OTA pathway transcription factor bZIP showing the highest expression level. The up-regulated transcription profile of the genes positively correlated with OTA production higher at 18/31 °C than at 20/37 °C and 0.99 aw; while no OTA production was detected at 0.93 aw at each of the temperature conditions tested. These findings provide preliminary evidence that the possible increase of the temperature, likely to happen in some areas of the Apulia region, may results in a reduction of both A. carbonarius spoilage and OTA production in grapes.

The modern state of the ecosystem in the Volga River delta ecotone and dynamics of the changes in water availability conditions

We prove that an abrupt amount of water-soluble salts in soils occurs due to rapid increase in heat provision under decrease in precipitation amount for the period with the temperatures above 10°C (under the integrated index of territories aridity, the G.T. Selyaninov coefficient is up to 0.3 or less). Based on the results of investigations from 137 model sites at the Volga River delta in the years with water availability contrast conditions (2014 and 2015 are years with little water and 2016 and 2017 are water-abundant years), we indicate a decrease in the volume of river runoff according to the landscape-ecological complex of soil-plant cover. We also show the toxicity level due to the increase in toxic Cl-, Na+ and Mg2+ under simultaneous decrease in the content of SO42- and Ca2+ ions. Moreover, there is a change in soil salinization type from chloride-sulphatic to sulphatic-chloride, which directly affects plant cover: total biomass and foliage cover decrease on all deltoid landscapes of high levels, the participation of sedge and herbs decreases, and role of forbs increases. These processes are blocked due to the rise of the subsequent conditions of abrupt water availability and move back. The greatest and the most rapid changes are observed within particularly extended alluvial natural boundaries of low level in the vegetation classes Phragmitetea R. Tx. Et Preising 1942 and Bolboschoenetea maritime Vicherek et R. Tx. 1969 ex R. Tx. et Hulb. 1971 at the level of associations and types.

Gas Exchange of Mimosa tenuiflora (Willd.) Poiret Under Water Deficit and Rewatering

This research aimed to evaluate the physiological responses of Mimosa tenuiflora plants submitted to variable water availability conditions during the nursery stage. Twelve-month-old plants kept in plastic pots containing 5 kg of the substrate composed of the subsoil soil mixture and bovine manure (2:1) were submitted to two treatments: irrigated (control) and water stress, which was imposed through the suspension of irrigation, rewatering after seven days of stress. The relative water content (RWC) and stomatal parameters were evaluated. The M. tenuiflora plants responded quickly to the irrigation suspension, promoting the closure of the stomata, occurring reduction in stomatal conductance, transpiration rate and photosynthesis. The instantaneous efficiency in water use of plants under water deficit remained high only until the middle of the period when irrigation was suspended, and then declined until the last day of the water deficit. After rehydration, the plants showed recovery in all evaluated parameters, indicating that the level of stress imposed did not cause irreversible damages in the cells and tissues.

Higher temporal evapotranspiration estimation with improved SEBS model from geostationary meteorological satellite data

Evapotranspiration (ET) is a key variable in hydrologic cycle that directly affects the redistribution of precipitation and surface balance. ET measurements with high temporal resolution are required for coupling with models of highly dynamic processes, e.g., hydrological and land surface processes. The Haihe River Basin is the focus of China’s industrial base and it is one of the three major grain-producing regions within the country. However, this area is facing serious water resource shortages and water pollution problems. The present study used geostationary satellite remote sensing data, in situ meteorological observations, and the surface energy balance system (SEBS) model with a new kB−1 parameterization to estimate 3-hourly and daily energy and water fluxes in the Haihe River Basin. The results of the SEBS model were validated with point-scale data from five observation flux towers. Validation showed that 3-hourly and daily ET derived from the SEBS model performed well (R2 = 0.67, mean bias = 0.027 mm/h, RMSE = 0.1 mm/h). Moreover, factors influencing ET were also identified based on the results of this study. ET varies with land cover type and physical and chemical properties of the underlying surface. Furthermore, ET is also controlled by water availability, radiation, and other atmospheric conditions. It was found that ET had strong correlation with the normalized difference vegetation index (NDVI). Specifically, daily ET fluctuated with the NDVI when the NDVI was <0.29, and ET increased rapidly as the NDVI increased from 0.29 to 0.81. For NDVI values >0.81, indicating a state of saturation, the rate of increase of ET slowed. This research produced reliable information that could assist in sustainable management of the water resources and in improved understanding of the hydrologic cycle of the Haihe River Basin.

Physiological analysis and gene expression analysis of ZmDBP3, ZmALDH9, ZmAN13, and ZmDREB2A in maize lines

The objective of this study was to evaluate gene expression related to water deficit tolerance in maize lines. For this, lines previously classified as tolerant (91-T and 32-T) and non-tolerant (24-NT and 57-NT) to water deficit were used. The seeds of the four lines were evaluated for emergence and emergence speed index, and the seedlings were evaluated for root and shoot length under two conditions of water availability (70 and 10% substrate water retention capacity). In transcript analysis, the expression of several genes associated with water deficit tolerance, ZmDBP3, ZmALDH9, ZmAN13, and ZmDREB2A, was evaluated by qRT-PCR for the 91-T and 57-NT lines. It can be concluded that soil water deficiency did not reduce root development. However, the shoot length was significantly lower under dry conditions. Through transcript analysis, the genes ZmDBP3 and ZmAN13 were identified as potential markers for the early selection of maize lines tolerant to water deficit.

Spatial probability modelling of forest productivity indicator in Italy

• Geostatistics and GIS connected topo-climatic factors and forest productivity. • Spatial patterns showed the environmental control on forest productivity. • Probability maps differentiated high and low wood productivity rates. The prediction of forest productivity is essential for sustainable forest management, particularly in countries, like Italy, where forest is an important part of many protected areas. A spatial predictive probability model for forest productivity rates in Italy was developed over the period 1961–1990, based on 135 annually-resolved records of site productivity and auxiliary variables measured at 219 stations. Our analysis shows that the probability of finding high (>7.3 m 3 ha −1 yr −1 ) and low (<5.8 m 3 ha −1 yr −1 ) productivity rates changes across different regions of Italy. The generated spatial patterns contribute to a better understanding of the factors structuring the distribution of forest productivity in Italy because they reflect the dependence of temperature and water availability conditions on the latitudinal and altitudinal location of the study areas. We observed that the temperature control dominates forest productivity at high elevations and latitudes, whereas low-elevation sites in central and southern Italy are more sensitive to water availability. The proposed spatial probability modelling should be further assessed for its possible incorporation into forest management plans.