Consumptive Water Use Research Articles

Responses of the Leaf Water Physiology and Yield of Grapevine via Different Irrigation Strategies in Extremely Arid Areas

The contradiction between water supply and demand has become increasingly prominent due to the large agricultural water consumption and low irrigation water use efficiency (IWUE) in the extremely arid area of Xinjiang, which needs to be solved by efficient irrigation. In this study, the effects of different irrigation levels (the lower and upper limits of irrigation (LULI) were 50–80%, 60–90%, and 70–100% of the field capacity (FC), respectively) under two irrigation methods (root zone irrigation (RZI) and furrow irrigation (FI)) on the photosynthetic physiology and yield of grape were analyzed to explore suitable irrigation schemes in extremely arid areas. The results show that the diurnal variation curve of the net photosynthetic rate (Pn) of grape leaves in the extreme arid region was not sensitive to the response of irrigation methods. However, RZI could improve the apparent quantum efficiency and maximum photosynthetic rate by 60.00% and 31.25%, respectively, reduce the light compensation point by 17.91%, and alleviate the photosynthetic lunch break phenomenon. Under FI, the physiological indexes of leaves increased with the increase in the LULI, while the Pn and SPAD values were the largest under RZI when the LULI was 60–90% of FC. The daily average Pn value of T2 in 2021 and 2022 ranged from 12.93 to 17.77 μmol·m−2·s−1. Compared with FI, RZI significantly improved the leaf water potential, Pn, and SPAD values by increasing the soil water content (SWC) of the 40–80 cm soil layer by 5.04–8.80%, which increased the yield by 6.86–18.67%. The results show that the yield and water use efficiency reached the peak when the LULI was 60–90% of FC under RZI, which could provide theoretical support for efficient irrigation of vineyards in extremely arid areas.

How far are groundwater resource assessments in India reliable?

AbstractThe article critically reviews the methodology adopted by the Central Ground Water Board (CGWB) for the assessment of groundwater resources in India. The authors developed a water balance equation that simulates the changes in annual and seasonal groundwater storages of an agricultural region, using a water accounting framework; they solved the developed equation using the data of annual and seasonal water level fluctuations for a wet year for Ludhiana district of Punjab to estimate different components of the water balance. The estimated values are used to test the robustness of the CGWB methodology for monsoon recharge. The annual groundwater storage change obtained from solving the water balance equation was compared with the observed change in annual groundwater storage and was found to closely tally. As per the water balance equation, the CGWB estimates of rainfall recharge conform to the annual water level fluctuations recorded by the agency and therefore are not reliable. Hence, we could infer that our methodology is superior to that of CGWB for estimating monsoon recharge. The validated equation was also used to estimate the recharge from rainfall during a dry year. Using these outputs in a simple groundwater balance equation, irrigation return flows were estimated for the wet and dry years. The equation was then extended to the Ahmednagar district of Maharashtra, a hard rock area, for estimating the surface water import during a wet year, the key unknown in the region's water balance. Hence, our methodology can be employed to estimate rainfall recharge for dry years using annual changes in groundwater storage and estimated consumptive uses of water, when the “WLF approach,” used by CGWB, fails, owing to the presence of an additional variable, that is, monsoon draft. For wet years, it can be used to arrive at the consumptive use of water for various purposes.

Evaluation of personal water footprint components in Turkey: factors associated with obesity and food consumption

ABSTRACT This study aimed to evaluate the personal water footprint individuals, and was conducted with 3431 individuals İbetween 18–95 years. A questionnaire form included questions about demographic characteristics, anthropometric measurements, and food consumption was applied. The “Extended Water Footprint Calculator” was used to evaluate the personal water footprint, and various questions were asked to determine the components of food consumption, domestic water, and industrial water use. The average age of the participants was 34.6 ± 13.93 years. The total water footprint of the male was significantly higher than the female. The total water footprint of individuals between the ages of 41–64 was higher than other age groups, and also obese individuals had the highest total water footprint (p < 0.05). Meat and meat products contributed the most to the total water footprint. Having a normal body weight and adopting more sustainable dietary patterns should be emphasized because of their impacts on the environment and health.

ВОДОПОТРЕБЛЕНИЕ КУЛЬТУР ЗЕРНОТРАВЯНЫХ СЕВООБОРОТОВ ПРИ ЭНЕРГОНАКОПИТЕЛЬНОЙ СИСТЕМЕ СОДЕРЖАНИЯ ПОЧВЫ В ЗАПАДНОМ ПРИКАСПИИ

The study was carried out on the meadow-chestnut soils of farm “OOO Vympel-2002” located in Khasavyurt district of the Republic of Dagestan. The purpose of the research was to examine the effect of varying saturation levels of cereal-grain crop rotations by alfalfa and winter wheat + crop residue natural phytocenosis on the total consumptive water use and the water-use ratio in the Western Caspian region. The main criterion for sustainable yields of winter wheat at 3–4-year repeated sowing is the crop residue natural phytocenosis formed in the second half of summer after harvesting the crop and plowing its biomass for green manure. The study has found that in the cereal-grass crop rotations, alfalfa consumes the largest amount of water for its yield during four years of use. The crop rotation that employs 75 % alfalfa and 25 % of winter wheat+the crop residue natural phytocenosis demonstrates the maximum total consumptive water use of 5000 m3 per 1 ha of rotation area. A larger share of winter wheat + the crop residue natural phytocenosis is crucial for more economical use of water in the crop rotation. The water-use ratio for alfalfa used in monoculture systems was 2660.7; the ratio was 3.7 times lower for winter wheat + the crop residue natural phytocenosis. Crop rotations that used from 75, 50 and 25 % of alfalfa had lower ratios than the monoculture systems (by 38.3, 55.7 and 65.9 %, respectively). The data indicate that the combination of winter wheat + the crop residue natural phytocenosis used for green manure reduce the water needed to obtain yields. The study results should be applied for designing cereal-grass and other types of crop rotations in the region.

Production maximization of rainy season rice (Oryza sativa) through effective use of water and solar radiation under modified system of rice intensification in Assam

A field experiment was conducted in a farmers’ field at Nepalikhuti, Golaghat, Assam during the rainy (kharif) season of 2016 and 2017, to find out the effect of different transplanting dates and hill densities of rice (Oryza sativa L.) under system of rice intensification (SRI) which was compared with conventional rice cultivation (CRC). The experiment was designed in factorial split-plot with 2 crop-establishment methods (SRI and CRC) and 3 transplanting dates (26 June, 10 and 25 July) in the main plot; and 4 different hill densities (20 cm × 10 cm, 20 cm × 20 cm, 25 cm × 20 cm and 25 cm × 25 cm) in the subplots and replicated thrice. With an increased grain yield of 5.71 t/ha, SRI-establishment showed a significant yield advantage of 0.83 t/ha coupled with 2.64% more consumptively used water and 1.29 kg/ha-mm more water-use efficiency over CRC. Results showed strong positive correlation (0.95**) between water-use efficiency (WUE) and yield attributes primarily the effective tillers/m2. Regression analysis revealed that irrespective of establishment methods, the consumptive use (CU) of water, accumulated incident photosynthetically active radiation (AIPAR), radiation-use efficiency (RUE) and heat-use efficiency (HUE) greatly influenced the grain yield. However, in SRI, WUE appeared to be an additional key determinant of grain yield. Between 2 establishment methods, SRI was found to be more competent in utilizing water and solar radiation owing to its ideal canopy environment.

Impact Assessment of climate change on water resources of the Amu Darya River basin

Water consumption and water use have been continuously increasing, and the impact of economic activities on the hydrological regime of water flow, especially in irrigation, population and industry, has increased significantly. In particular, it is significantly increasing in the countries of Central Asia, including the Republic of Uzbekistan. Today's global problem is the severity, scale and unusualness of anthropogenic climate change, especially in developing countries, creates the need for action with an urgent scientific approach. Undoubtedly, the assessment of the observed climate change and the current state of water resources will require many years of in-depth scientific research. One of the factors limiting the development of the countries of the Amu Darya basin is the lack of water resources. The world is experiencing intensive climate warming, which leads to the melting of glaciers, which are the main sources of fresh water for the river basins that make up the water resources of the countries of Central Asia. The article gives an assessment of regional and local climate change and gives recommendations for reducing water shortages in the countries of the province

Consumo hídrico e eficiência do uso da água da pimenta ‘Biquinho’ em cultivo hidropônico com água salobra

ABSTRACT: The knowledge of water consumption and the efficiency of water use by crops is extremely important in the elaboration of agronomic and hydraulic projects of hydroponic systems. Thus, the present study determined the water consumption and water use efficiency of ‘Biquinho’ pepper cultivated in the hydroponic system using seven levels of electrical conductivity of the nutrient solution (ECsol) of 2.70, 3.64, 4.58, 5.28, 6.09, 6.90, and 7.77 dS m-1 and six replicates in randomized blocks. The hydroponic system used was the Nutrient Film Technique (NFT). The water consumption per plant was determined at an interval of ten days in the crop cycle (120 days after transplanting). The maximum mean daily water consumption was equal to 5.88 L plant-1 during the period 111-120 DAT, for ECsol of 4.58 dS m-1. The maximum water consumption for the crop cycle (120 DAT) was 275.66 L per plant for an estimated ECsol = 4.11 dS m-1. The highest water use efficiency (WUE), based on the total production of fruit fresh mass (ripe and unripe fruits) of ‘Biquinho’ pepper was 10.84 kg m-3 up to an estimated ECsol of 5.18 dS m-1, with an exponential reduction thereafter. The salinity of the nutrient solution, biomass production, and evapotranspiration are factors that influence the most water consumption of ‘Biquinho’ pepper.

A sustainable network design of a hybrid biomass supply chain by considering the water–energy–carbon nexus

AbstractNowadays, with population growth, rising global energy demand, increasing water consumption, carbon emissions, and excessive use of fossil fuels, the world faces a major challenge. Biomass is one of the most attractive sources of energy production, with positive effects on the economy, environment, and society, which can decrease the world's reliance on fossil fuels and deal with this universal challenge. Consequently, the biomass supply chain network design has received more attention in recent decades. Since energy and water are two significant sources for society's sustainable development and carbon emissions are essential for environmental health, the study of the water–energy–carbon (WEC) nexus is essential. In this study, a multiobjective multiperiod model for designing a sustainable supply chain network based on hybrid second‐generation (i.e., Jatropha, agricultural waste, and animal waste) and third‐generation (i.e., microalgae) biomasses is presented. The proposed multiobjective model consists of five objective functions that maximize the total energy produced and the number of jobs created and minimize the total water consumed, carbon emitted, and total costs. Case study results demonstrate the performance of the model utilizing the MINMAX goal programming approach. Based on the results, energy production from Jatropha is more appropriate in comparison with energy production from microalgae, agriculture waste, and animal waste. The findings also show that the proposed model in this research considering the WEC nexus performs significantly better than the classical model without considering the WEC nexus.

Evaluation of Partitioned Evaporation and Transpiration Estimates within the DisALEXI Modeling Framework over Irrigated Crops in California

Accurate characterization of evapotranspiration (ET) is imperative in water-limited cropping systems such as California vineyards and almond orchards. Satellite-based ET modeling techniques, including the atmosphere–land exchange inverse model (ALEXI) and associated flux disaggregation technique (DisALEXI), have proven reliable in determining field scale ET. However, validation efforts typically focus on ET and omit an evaluation of partitioned evaporation (E) and transpiration (T). ALEXI/DisALEXI is based on the two-source energy balance (TSEB) model, making it uniquely qualified to derive E and T individually. The current study evaluated E and T estimates derived using two formulations of DisALEXI; one based on Priestley-Taylor (DisALEXI-PT) and the other on Penman-Monteith (DisALEXI-PM). The modeled values were validated against partitioned fluxes derived from the conditional eddy covariance (CEC) approach using EC flux towers in three wine grape vineyards and three almond orchards for the year 2021. Modeled estimates were derived using Landsat 8 Collection 2 thermal infrared and surface reflectance imagery as well as Harmonized Landsat and Sentinel-2 surface reflectance datasets as input into DisALEXI. The results indicated that the modeled total ET fluxes were similar between the two methods, but the partitioned values diverged, with DisALEXI-PT overestimating E and slightly underestimating T when compared to CEC estimates. Conversely, DisALEXI-PM agreed better with CEC-derived E and overestimated T estimates under non-advective conditions. Compared to one another, DisALEXI-PM estimated canopy temperatures ~5 °C cooler and soil temperatures ~5 °C warmer than DisALEXI-PT, causing differences in E and T of −2.6 mm day−1 and +2.6 mm day−1, respectively. The evaluation of the iterative process required for DisALEXI indicates DisALEXI-PM ET values converge on ALEXI ET with proportionate adjustments to E and T, while DisALEXI-PT convergence is driven by adjustments to E. The analysis presented here can potentially drive improvements in the modeling framework to provide specific soil and canopy consumptive water use information in unique canopy structures, allowing for improved irrigation and water use efficiencies in these water-limited systems.

Deficit mulched drip irrigation improves yield, quality, and water use efficiency of watermelon in a desert oasis region

In the context of global warming, drought is a crucial factor affecting agricultural production, especially for the oasis farming areas of northwestern China, where water resources are extremely scarce. To reveal the response of watermelon water consumption (WC), yield, quality, and water use efficiency (WUE) to water deficit (WD) and to determine the optimal mode of irrigation in the desert oasis areas of Hexi, we applied different WD treatments on a field oasis watermelon in 2020 and 2021. The experiments employed two gradients of light (l) and moderate (m) WD treatments during the seedling (S), vine (V), expansion (E), and maturity (M) stages except for flowering and fruiting (F) stage, with full irrigation during the entire growth period as the control (CK). The results showed that the WC of oasis watermelon at each growth stage was in the order: E > V > S > M > F, in which WC by E stage accounted for 33.15–40.33%. Compared with the CK, WD had an obvious effect on water saving, and WD during the V or E stages inhibited the growth of vine leaves to a certain extent. The Sl treatment (light WD during S stage) had the highest yield and WUE, with significant increases of 5.23–5.38% and 7.10–7.37% (p < 0.05), respectively, in the two years, while the Mm treatment (moderate WD during the M stage) resulted in the best overall nutritional quality of watermelon, with soluble solids, soluble sugars, vitamin C, and soluble protein contents increasing by 11.31%, 33.43%, 24.03%, and 10.31% (p < 0.05), respectively. However, an integrated evaluation that coupled grey relation analysis (GRA) with a technique for determining order preference by its similarity to an ideal solution (TOPSIS) model, considering growth, yield, quality, and efficiency indicators, concluded that the Ml treatment (light WD during the M stage) achieved the highest comprehensive score, followed by the Sl treatment. Therefore, it is recommended that the optimal deficit irrigation mode for oasis watermelon is the Ml treatment, which can balance water savings, yields, and quality improvements, while the Sl treatment can be considered as a backup mode. This study provides theoretical and technical support for achieving efficient water-saving cultivation and scale development of watermelon production in desert oasis areas.

Development of an inexact simulation-evaluation model for the joint analysis of water pricing and groundwater allocation policies

A critical step in water management policy development is the analysis of its socio-economic and environmental implications. However, few methods could proactively and reliably predict and assess the impacts of policies while handling the inherent uncertainty. To fill such a gap, an inexact simulation-evaluation method was developed for analyzing the impacts of multiple water management policies under uncertainty. The interval positive mathematical programming (IPMP) method was proposed as the simulation tool by coupling interval programming with positive mathematical programming (PMP). The evaluation tool was developed by combining the interval TOPSIS method and the interval maximum deviation method. This simulation-evaluation method can directly communicate a policy's simulation outcomes into the evaluation process while addressing the uncertainties in both simulation and evaluation. The proposed method can also reproduce the actual situation with a calibration process, which enables accurate and smooth responses to policy changes. This approach was used for agricultural water management in arid north-west China. Seventy-five policy alternatives generated from three groundwater allocation limits and twenty-five differential water pricing levels were investigated. The impacts of these alternatives on farmer income, farmer employment, water consumption, planting areas, and fertilizer use were simulated using IPMP. Twenty-four non-inferior alternatives were selected and further evaluated with multi-dimensional criteria. The final results showed that, the water price for grain crops with traditional irrigation methods should rise by 60%, those for cash crops with drip irrigation should decrease by 60%, and the groundwater quota should be reduced by 20%. Compared with traditional models, IPMP can increase simulation accuracy by reproducing observed situations, enhance robustness by reflecting input uncertainty, and improve flexibility in decision-making by providing interval solutions. The inexact simulation-evaluation model can also be widely used to analyze other policies.

Comparative life cycle assessment for the manufacture of bio-detergents

The increasing consumption of cleaning products deteriorates water resources due to harmful components such as phosphorus (P) and nitrogen (N) compounds, oils, bleach, and acids, typical compounds in traditional detergents. The use of biodegradable detergents as an environmentally friendly alternative has been proposed in different regions. In Colombia, resolution 1770/2018 sets a minimum biodegradability rate of 60% for the surfactants present in liquid detergents, which would reduce to a similar extent the impacts on water after their use. However, the environmental impacts of the supply chain of these detergents and their raw materials have not been evaluated so far. This study presents an environmental life cycle assessment of petroleum-based liquid detergents and a comparison to traditional solid detergents, based on the ISO 14040 standard and the ReCiPe-2016 impacts assessment method. A novel bio-detergent containing anionic plant-based surfactants was proposed in this analysis. The impacts of packaging and the distribution of the product to consumers were also considered. Raw materials contributed to 91% of the total of 314 g of CO2 eq generated per liter of liquid detergent, where the production of fatty alcohol sulfate and PET packaging shared 78.8% and 12.2% of the total impact, respectively. It was also determined that 5.4 L of water are consumed and 0.09 g of P eq and 0.1 g of N eq are emitted per liter of detergent. This liquid detergent presented better environmental performance than traditional detergents in all the impact categories, except for the fossil resource scarcity category. The evaluated detergent would significantly mitigate the generation of negative effects on ecosystems. Moreover, the substitution of PET for HDPE packaging could reduce the impacts on freshwater eutrophication by 10%, although the carbon footprint can slightly increase, which could be compensated due to its higher recyclability rate. In contrast, the proposed bio-detergent would not have significant benefits and would negatively affect water consumption and land use in its supply chain.

Effect of different surface irrigation systems and organic fertilization on water productivity of maize yield.

This study aimed to assess the performance and the effects of different surface irrigation systems, growth, and yield of maize crops in the irrigation district of Babil Iraq. Field experiments were conducted in the autumn of 2020 to manage five surfaces irrigation systems Besides, two irrigation intervals (5 and 8 days) and two levels of organic fertilizers (humic acid) (0 OM0 and 20 OM1 kg ha-1). The experiment was a Split Split Block Design with three replications. The results indicated that the actual water consumption use (ETa) varied with irrigation systems. ETa reached 688, 673 mm season-1 for BSI treatment and decreased to 293, 275 mm season-1 for APFIRB under irrigation intervals 5 days and OM0, OM1 treatments respectively. Organic fertilizer reduced the amount of ETa by 4 and 2.5% compared to control in 5 and 8 days irrigation intervals, respectively. The mean grain yield reached 7149.9 kg ha-1 for OM1, while organic humic acid application improved the grain yield by 7.95% compared to OM0. Meanwhile that the no significant differences in corn grain yield with irrigation systems.

The environmental impact of the Dutch health-care sector beyond climate change: an input–output analysis

Studies suggest that the Dutch health-care sector is responsible for 4-8% of the national carbon footprint, but the environmental footprint of this sector beyond climate change is not well understood. Therefore, we aimed to estimate the environmental footprint of the Dutch health-care sector for a range of environmental impact categories. In this input-output analysis, we used Exiobase (version 3), which contains data on global trade flows and their associated environmental impact, in combination with health-care expenditure data from Statistics Netherlands. We covered the impact categories: climate change, blue water consumption, abiotic material extraction, land use, and total waste generation. The calculated sectoral footprint was the sum of all impacts associated with the operational phase (direct impact) and impacts occurring in the value chain of purchased goods and services (indirect impact) given an expenditure vector. The expenditure vector was the sum of three elements of health-care expenditure: health-care services; pharmaceuticals and chemical products; and medical appliances. We calculated the impact share of health care on the total Dutch consumption footprint. We evaluated the contribution to the impact categories from the categories that composed the expenditure vector. We did a hotspot analysis in which the indirect impact was split according to where (sector, geography, or both) the impact physically occurred. These top-down results were complemented with bottom-up data on emissions from pressurised metered-dose inhalers, anaesthetic gases, and private travel. The health-care sector's share of the national footprint was highest for material extraction (13·0%), followed by blue water consumption (7·5%), climate change (7·3%), land use (7·2%), and waste generation (4·2%). Pharmaceuticals and other chemical products were the biggest contributors to all impacts. The sectors contributing to climate change were more evenly distributed than the sectors contributing to the other impact categories. The mining sector mostly contributed to material extraction and the agricultural sector contributed largely to blue water consumption and land use. The mining sector and the agricultural sector were the main contributors to waste generation. Climate change occurred mainly in the Netherlands, whereas the other impacts mainly occurred abroad. The Dutch health-care sector contributes to a broad set of environmental impact categories beyond climate change. Our results will help stakeholders involved in the health-care sector to pinpoint topics that need to be prioritised and to prevent trade-offs by addressing multiple environmental issues simultaneously. Dutch Ministry of Health, Welfare and Sport.

Adaptabilities of Water Production Function Models for Rice in Cold and Black Soil Region of China

Crop water production function models (WPFMs) are required methods to study the relationships between yield and water consumption under regulated deficit irrigation (RDI). In this study, a pot experiment was established to study the effect of water deficit during both individual growth stages and across two consecutive growth stages of rice on yield, water consumption, and water use efficiency (WUE) in 2017 and 2018. Light, medium, and severe water deficits were set as 80~90%, 70~80%, and 60~70% of saturated soil moisture content, respectively. The accuracies of five WPFMs were tested based on the experimental results. The results showed that yields and WUE of a light water deficit were higher than those of medium and severe water deficits at each growth stage. The yields and WUE of light drought stress treatments in the flowering and milky stages were higher than the saturated soil moisture control by 4~7.4% and 5.3~20.6%, respectively. Water consumption decreased with increasing water deficit across two consecutive growth stages. The Minhas model had the highest simulation accuracy of the five WPFMs, with relatively lower AE, RMSE, Cv, CRM, and higher R2, which were 0.0002, 0.0634, 6.9965, 0.0002, and 0.9951 in 2017 and 0.0110, 0.0760, 8.9882, 0.0131, and 0.9923 in 2018, respectively. The sensitivity indices for the Minhas model more accurately reflected the sensitivity of rice yield to water deficit at different growth stages in 2017 and 2018, compared with the Jensen model, Stewart model, Blank model, and Singh model. Rice yield was most sensitive to water deficit at the jointing and booting stage. The results indicate that the Minhas model is the most suitable WPFM for guiding rice irrigation practices in cold and black soil regions of China.

Evaluation of the temporal reconstruction methods for MODIS-based continuous daily actual evapotranspiration estimation

Monitoring continuous daily actual evapotranspiration (ET) is very useful for managing regional water resources and understanding vegetation water consumption and water use efficiency. However, the research on remote sensing-based temporal reconstruction methods for mapping continuous daily ET is still limited, lacking comparative evaluations and mechanism discussions. In the study, four reconstruction methods, including two interpolation methods (the reference evaporative fraction (ETrF) and evaporative fraction (EF) method) and two calibration methods (the advection-aridity (AA) and modified Katerji-Perrier (KP) method), were systematically evaluated to reconstruct continuous daily ET from discrete daily ET based on MODIS products and atmospheric data. Meanwhile, an additional test using in situ measurements as a perfect proxy for the retrievals on satellite overpass dates was added as a baseline case that is independent of remotely sensed ET error. The internal coupling mechanism between each model’s simulations and the underlying surface physical and atmospheric driving factors were also analyzed using the sensitivity and uncertainty analysis methods. The results demonstrated that the interpolation methods performed better and had a higher potential for improvement as the quality of remote sensing ET inputs improved. Although the underestimation errors in the remote sensing-based ET estimates propagated to subsequent reconstructions and caused underestimation to a certain extent, the four methods could still effectively simulate continuous daily ET. Among them, the EF method with a simple calculation process, which used reference quantity directly related to solar radiation, had the best performance based on in situ with an R2 of 0.8233 and an NRMSE of 0.0889. Given remote sensing estimates, the AA method was the best due to the compensation effects, with an R2 of 0.7267 and an NRMSE of 0.1442. As all methods showed high sensitivity to ET of satellite overpass days, its accuracy should be a top priority for continuous daily ET reconstruction work.

Production and morphophysiological responses of Panicum maximum cv. BRS Zuri to water availability

Due to the increasing intensification of livestock farming and agricultural systems, there is demand for highly productive forage species. Panicum maximum cv. BRS Zuri is forage that has good productivity, vigor and promotes good animal performance. The objective of this study was to evaluate the morphophysiological and production characteristics of Panicum maximum cv. BRS Zuri subjected to water availability in Fluvic Neosol (Entisol). A potted-plant experiment was conducted in a greenhouse at the Federal University of Rondonópolis, Brazil. The experimental design was completely randomized, with five levels of water availability, corresponding to 25, 50, 75, 100 and 125 % of the maximum soil water holding capacity, and six replicates, in three successive cuts. The variables analyzed were: soil pH, SPAD index, plant height, leaf area, shoot dry mass, root dry mass, root volume, water consumption and water use efficiency. Water availability influenced the development of Panicum maximum cv. BRS Zuri, with the highest results between 67 % and 111 % of the maximum soil water holding capacity. The results show that the production and morphological responses were negatively influenced by water availability levels of 25 % and 125 %. These results makes it possible to affirm that, under the studied conditions, the cultivar BRS Zuri showed moderate adaptation to 125% water availability (excess water).

Environmental impacts of eco-nutrition swine feeding programs in spatially explicit geographic regions of the United States.

This study was conducted to determine greenhouse gas (GHG) emissions, water consumption, land use, as well as nitrogen (N), phosphorus (P), and carbon (C) balance of five diet formulation strategies and feeding programs for growing-finishing pigs (25-130 kg body weight) in the three spatially explicit geographic regions where the majority of U.S. pork production occurs. Feeding programs evaluated consisted of 1) standard corn-soybean meal (CSBM) diets, 2) CSBM containing 15% corn distillers dried grains with solubles (DDGS), 3) CSBM with 8.6% thermally processed supermarket food waste (FW), 4) low crude protein CSBM diets supplemented with synthetic amino acids (SAA), and 5) CSBM with phytase enzyme (PHY) added at 600 FTU (phytase units)/kg of diet. An attributional Life Cycle Assessment approach using a highly specialized, spatially explicit Food System Supply-Chain Sustainability (FoodS3) model was used to quantify GHG emissions, water consumption, and land use of corn, soybean meal, and DDGS based on county level sourcing. The DDGS, FW, and SAA feeding programs had less estimated N and P intake and excretion than CSBM, and the PHY feeding program provided the greatest reduction in P excretion. The FW feeding program had the least overall GHG emissions (319.9 vs. 324.6 to 354.1 kg CO2 equiv./market hog), land use (331.5 vs. 346.5 to 385.2 m2/market hog), and water consumption (7.64 vs. 7.70 to 8.30 m3/market hog) among the alternatives. The DDGS feeding program had the greatest GHG emissions (354.1 kg CO2 equiv./market hog) among all programs but had less impacts on water consumption (7.70 m3) and land use (346.5 m2) per market hog than CSBM and PHY. The SAA feeding program provided a 6.5-7.4% reduction in land use impacts compared with CSBM and PHY, respectively. Regardless of feeding program, the Midwest had the least contributions to GHG emissions and land use attributed to feed and manure among regions. Water consumption per market hog associated with feeding programs was much greater in the Southwest (59.66-63.58 m3) than in the Midwest (4.45-4.88 m3) and Mid-Atlantic (1.85-2.14 m3) regions. Results show that diet composition and U.S. geographic region significantly affect GHG emissions, water consumption, and land use of pork production systems, and the potential use of thermally processed supermarket food waste at relatively low diet inclusion rates (<10%) can reduce environmental impacts compared with other common feeding strategies.

Mangroves provide blue carbon ecological value at a low freshwater cost

“Blue carbon” wetland vegetation has a limited freshwater requirement. One type, mangroves, utilizes less freshwater during transpiration than adjacent terrestrial ecoregions, equating to only 43% (average) to 57% (potential) of evapotranspiration (ET). Here, we demonstrate that comparative consumptive water use by mangrove vegetation is as much as 2905 kL H2O ha−1 year−1 less than adjacent ecoregions with {E}_{c}-to-ET ratios of 47–70%. Lower porewater salinity would, however, increase mangrove {E}_{c}-to-ET ratios by affecting leaf-, tree-, and stand-level eco-physiological controls on transpiration. Restricted water use is also additive to other ecosystem services provided by mangroves, such as high carbon sequestration, coastal protection and support of biodiversity within estuarine and marine environments. Low freshwater demand enables mangroves to sustain ecological values of connected estuarine ecosystems with future reductions in freshwater while not competing with the freshwater needs of humans. Conservative water use may also be a characteristic of other emergent blue carbon wetlands.

Straw mulching for enhanced water use efficiency and economic returns from soybean fields in the Loess Plateau China

Water shortages threaten agricultural sustainability in the semi-arid areas of the Loess Plateau. Judicious mulching management can improve water conservation practices to alleviate this issue while increasing crop productivity. We investigated the effect of straw strip mulching and film mulching on soil water consumption, temperature, growth, grain yield, and economic income of soybean [Glycine max(Linn.) Merr.] from 2017 to 2018 in Qingyang on the semi-arid Loess Plateau in China using four treatments: (a) alternating ridges and furrows with ridges mulched with white polyethylene film (PMP), (b) alternating flat and bare land with only the plat mulched by white polyethylene film (PMF), (c) alternating strips mulched with maize (Zea mays L.) straw (SM), and (d) traditional land planting without mulching (CK). The mulching treatments (PMP, PMF, and SM) increased soil water consumption and soil water use efficiency. The SM, PMF, and PMP treatments had 12.3–12.5, 16.8–22.1, and 23.2–24.2 mm higher soil water consumption (0–120 cm depth) than CK, most of which occurred in the 60–120 cm soil layer. Compared with CK, PMP and PMF significantly increased soil temperature by 1.30–1.31 °C and 0.76–1.00 °C, soybean grain yield by 38.6–39.0 % and 38.8–44.2 %, and water use efficiency (WUE) by 27.7–32.8 % and 30.8–37.5 %, respectively, while SM significantly decreased soil temperature by 0.96–1.15 °C, and increased grain yield by 21.8–25.4 % and WUE by 16.9–21.9 %. PMP and PMF did not significantly change soil water consumption, WUE, or grain yield. The SM treatment increased net income by 501.3–691.7 and 1914.5–2244.9 CNY ha−1 relative to PMP and CK, respectively, but PMF and SM did not significantly differ. Therefore, the SM system could help increase grain yields and economic returns in dryland soybean production, avoiding the adverse effects of the increasingly popular plastic mulching approach.