Water Availability For Agriculture Research Articles

Characterizing streamflow regimes using a distributed model for sustainable resource management in the humid tropics

Estimating streamflow regimes on small tropical islands is challenging due to limited observational data, poor accuracy of remote sensing, and the limitations of coarse-scale climate models, restricting our understanding of hydrological processes and the management of water resources. The inadequacy of data has also affected the development of instream flow standards (i.e., environmental flows, e-flows) needed to protect ecological and cultural values central to island communities. Estimates of water availability for agriculture, hydropower, and drinking water supply are also critical for informed investments in water resource planning. We utilized high-resolution (250 m) gridded daily rainfall data to parameterize the Soil and Water Assessment Tool (SWAT) to characterize streamflow regimes at ungauged locations in a watershed on Kaua‘i Island. The resultant flow statistics were then used to describe the daily, seasonal, and annual availability of surface water to evaluate the implications of potential e-flow scenarios on water available for run-of-river hydropower. Compared to rainfall data derived from a single station within the watershed, the gridded daily rainfall product increased the accuracy of model output from not satisfactory to good. Model techniques using high resolution rainfall data may substitute for long-term hydrological data collection across complex tropical environments and provide data for making sustainable management decisions at ungauged locations.

Analysis of projected climate change in sorghum growing semi-arid rift valley of Ethiopia

Global warming projected to have a significant impact on agricultural water availability for crops in Africa in particularly in Ethiopia. Therefore, the study was conducted to analyze the projected change of temperature and rainfall in sorghum growing semi-arid rift valley of Ethiopia. The weather data for 11 stations were generated using AgiMP5 technique for RCP 4.5 and 8.5 and for the period of 2050s and 2080s. MAKESENS employed for the detection of trend of extreme indices. InStat v3.37 were used for the analysis of start, end, and length of growth season. Under RCP 4.5, the projected mean annual minimum air temperatures in CRV, ERVE and NRVE could increase respectively by 1.9 °C (2050s) and 2.6 °C (2080s), 1.8 °C (2050s) and 2.5 °C (2080s) and 1.88 °C (2050s) and 2.69 °C (2080s). Under RCP 8.5, however, with same location it will projected to increase in both time frames (2050s and 2080s) in all studied sites. The mean annual maximum air temperature, projected under RCP 4.5 in the CRV, ERV and NRVE will increase by 1.59 °C (2050s) and 2.18°C (2080s),1.42 °C (2050s) and 2.08 °C (2080s) and 1.46 °C (2050s) and 2.09 °C (2080s) respectively. However, under the RCP 8.5, at same regions it projected to rise in both periods (2050s and 2080s). This will be convoy with increase of the hot and cold extremes’ indices in regions. The mean percentage change of annual rainfall is projected to decrease insignificantly in (0.6-5.5% and 2.6%) and increase (0.85-12.3% and 22.3%) in half of the stations located in CRV and ERVE, whereas, in NRVE it will projected to increase (6.1-14.6%) under RCP 4.5 in all stations in 2050s. Though the annual projected rainfall under RCP 4.5 in 2080s will decline in range of 2.1-10.1%, 3.12-4.5% and 0.9-4.6% at CRV, ERVE and NRVE respectively. In most of the location in CRV and ERVE stations growing season rainfall will projected to decline from 1.45% to 53.8% and 0.8 to 8.8%, whereas, in NRVE it will projected to increase in 9.2 to 19% under RCP 4.5 in period of 2050. The projected SOS will be changed in mixed pattern, whereas and LGP will prolonged in most locations. The findings indicated that there has been a change of projected climate change in semi-arid RV, which will be alter the agricultural practices in depletion of soil moisture. Therefore, in adjusting planting timing and using early/medium maturation sorghum varieties, may be necessary for farmers in the region. Soil and water management needs attention.

Revitalizing Key Conditions and Integrated Watershed Management to Mitigate Land Degradation and Sustain Water Availability for Agriculture in Semi-Arid Regions: A Case Study of Ethiopia

Land, the source of 97% of global food, remains threatened by progressive soil erosion-induced land degradation, such as, in the semi-arid regions. To address this problem, soil and water conservation interventions have been implemented in watersheds across Ethiopia. Despite witnessing successful and positive impacts in some watersheds, the broader promotion of watershed-based interventions faces obstacles. Soil and water deteriorations persist in many of the watersheds in Ethiopia, leading to water shortages and related challenges in sustaining agriculture. The objectives of this research are thus to i) identify the main challenges and constraints hindering the promotion of watershed-based interventions in Ethiopia, and ii) identify key conditions for revitalizing the Integrated Watershed Management (IWSM) approach to mitigate soil erosion-induced land degradation, rehabilitate and sustainably manage watershed resources. A systematic review of over 60 published articles, extracted from the internet database using various search engines such as Google Scholar, ScienceDirect, Academia.edu, and ResearchGate, was conducted. Additionally, valuable comments from 65 peer-reviewers worldwide were collected through the Qeios platform during a posting period for more than two months, and these comments were utilized to update the first preprint version of this article. Based on the review, identified challenges and limitations include poor institutional support, lack of participation, inadequate planning of soil and water conservation (SWC) technologies, absence of research and development linkages, and insufficient capacity building. To address these challenges and limitations, recommendations for revitalizing the integrated watershed management (IWSM) approach and key conditions are discussed. The identified key conditions for revitalizing watershed-based interventions in Ethiopia include: i) ensuring institutional support and community participation, ii) strengthening the watershed-based intervention, and iii) establishing a watershed-based platform for scientific tools, research-based innovation, and capacity building to sustain water availability for agriculture in Ethiopia, serving as an experience for other semi-arid regions.

Drought Stress Amelioration Attributes of Plant-Associated Microbiome on Agricultural Plants.

The future global food security depends on the availability of water for agriculture. Yet, the ongoing rise in nonagricultural uses for water, such as urban and industrial uses, and growing environmental quality concerns have increased pressure of irrigation water demand and posed danger to food security. Nevertheless, its severity and duration are predicted to rise shortly. Drought pressure causes stunted growth, severe damage to photosynthesis activity, loss in crop yield, reduced seed germination, and reduced nutrient intake by plants. To overcome the effects of a devastating drought on plants, it is essential to think about the causes, mechanisms of action, and long-term agronomy management and genetics. As a result, there is an urgent need for long-term medication to deal with the harmful effects of drought pressure. The review focuses on the adverse impact of drought on the plant, physiological, and biochemical aspects, and management measures to control the severity of drought conditions. This article reviews the role of genome editing (GE) technologies such as CRISPR 9 (CRISPR-Cas9) related spaces and short palindromic relapse between proteins in reducing the effects of phytohormones, osmolytes, external compounds, proteins, microbes (plant growth-promoting microorganism [PGPM]), approach omics, and drought on plants that support plant growth. This research is to examine the potential of using the microbiome associated with plants for drought resistance and sustainable agriculture. Researchers also advocate using a mix of biotechnology, agronomic, and advanced GE technologies to create drought-tolerant plant varieties.

Evapotranspiration and Yield Impact Tools for More Water-Use Efficient Alfalfa Production in Desert Environments

Drought and climate change have decreased water availability for agriculture, especially in the desert of southwestern USA. Efficiency enhancements in irrigation management aimed at conserving water are key to adjust to limits in water supply, improve profitability and sustainability of alfalfa production in arid and semiarid areas. This study intended to conduct a field-scale analysis to develop yield and ET estimation tools for the effective use of irrigation water in a desert alfalfa production system. Extensive data collection and trials were carried out over three years in nine fully irrigated commercial alfalfa fields in the low deserts of California. The seasonal crop water consumption measured using the residual of energy balance method varied from 1381 mm to 1596 mm across the experimental sites and crop seasons. Variable seasonal dry mater (DM) yields ranged from 23.01 Mg ha−1 to 29.90 Mg ha−1. The results indicated that the first five cuttings each year were the most productive cuttings with a mean DM value ranged between 3.29 (cut 1) and 4.21 (cut 4) Mg ha−1 but declined in later cuttings. An average annual water productivity (WP) value of 17.0 kg ha−1 mm−1 was determined across the sites varying from 15.5 to 18.9 kg ha−1 mm−1. The findings suggested that one may lose up to 1.44 Mg ha−1 alfalfa yields with moderate summer deficit irrigation strategies, using 40% less water applied than full irrigation practices over the summer period of July–September. A more severe summer water deficit, with no irrigation event over the summer period of July–September may result in a potential water savings of 0.234–0.246 (ha·m) ha−1 and 19–21% seasonal yield losses in the desert environment. This study describes the seasonal yield pattern, the crop water use-production function, and the crop coefficient values for various harvest cycles over the crop season. These tools may assist farmers to quantify water savings and estimate yield losses for more accurate and effective irrigation management strategies to meet water conservation objectives and for the resiliency of alfalfa production in the desert region.

Impact assessment of watershed approach (Change detection in water bodiesrsquo; area and LULC, NDVI, NDMI) for reducing vulnerability of drinking water and availability of water for agriculture of Dahegaon Cluster watershed in Gangapur block of Aurangabad District- Maharashtra

Impact assessment of watershed approach (Change detection in water bodiesrsquo; area and LULC, NDVI, NDMI) for reducing vulnerability of drinking water and availability of water for agriculture of Dahegaon Cluster watershed in Gangapur block of Aurangabad District- Maharashtra

Climate Change and Food Security in Sub-Saharan Africa

Climate change affects food security directly through temperature levels and water availability in agriculture and indirectly through its impact on disease vectors and pests. This paper investigates the economic impact of climate change on food security in Su-Saharan Africa. Panel data from all Su-Saharan African countries are used to analyze the impact of temperature and precipitation on food security. Their coefficient of variation is used to analyze their impact on food security. The results from the analysis show that the coefficient of variations in both temperature and precipitation affects food security negatively. The climate variables affect food security directly through their impact on food production and indirectly through their impact on other food security indicators. According to the findings, the impact of climate change on food security in the region is damaging. The study recommends ecosystem management and production system improvement. To overcome the impact, the study suggests appropriate land use policy formulation, natural resource conservation, implementing best agronomic practices, and maintaining population growth at an optimum level in the region

Exploring Climate-Driven agricultural water shortages in a Snow-Fed basin using a water allocation model and Machine learning

Water allocation models (WAM) can capture complex feedbacks between water infrastructure, water supply, water demand, and water rights structure. They are an important tool for water managers to reduce conflict and aid in future water resource planning. Future streamflow reductions and shifts in timing are anticipated in snow-dominated watersheds of the western United States due to projected reductions in snow water storage. These basins tend to be water-limited and rely on groundwater to support agricultural demand. Water managers in the snow-fed, agricultural Walker River Basin (WRB) in California and Nevada use a dynamically coupled WAM and physically based groundwater flow model as a decision support tool. Large computation time is required to simulate groundwater dynamics, limiting the number of model scenarios that can feasibly be run to test alternative management scenarios under climate change. Machine learning (ML) techniques have been used to capture complex nonlinear hydrologic dynamics in other contexts, but to our knowledge there have not been efforts to use ML to increase computational efficiency in modeling groundwater responses to agricultural water use. We use extreme gradient boosting to replace the groundwater sub-model for the WRB decision support tool, resulting in accurate estimates of reservoir storage (monthly error almost always < 5% of reservoir capacity), streamflow (total outflow errors from −3% to 20% depending on scenario) and agricultural water shortages (-12% to 18% error in total shortage depending on scenario). For comparison, we found that omitting groundwater modeling from the WAM results in a larger overprediction of outflows (2 to 58%) and underprediction in agricultural water shortages (0 to 41%) across a range of scenarios. We use this validated ML method to explore the sensitivity of agricultural water availability to a range of streamflow volumes and streamflow timings. Results indicate that agricultural water shortages are more sensitive to annual streamflow volume in comparison to shifts in streamflow timing. Our model shows that reservoirs can buffer the impact of altered flow timing on agricultural production, except under extreme conditions in which all precipitation falls as rain (no snow storage) and streamflow peaks in the winter. Future work will explore these thresholds in more detail. While the results here are site-specific, the methodology for coupling a WAM with a ML representation of surface–groundwater interactions can be applied to a wide variety of water resource modeling applications. These results also provide a stark example of the importance of snowpack storage and groundwater management to western US water infrastructure.

Developing an Open-Source IoT Platform for Optimal Irrigation Scheduling and Decision-Making: Implementation at Olive Grove Parcels

Climate change has reduced the availability of good quality water for agriculture, while favoring the proliferation of harmful insects, especially in Mediterranean areas. Deploying IoT-based systems can help optimize water-use efficiency in agriculture and address problems caused by extreme weather events. This work presents an IoT-based monitoring system for obtaining soil moisture, soil electrical conductivity, soil temperature and meteorological data useful in irrigation management and pest control. The proposed system was implemented and evaluated for olive parcels located both at coastal and inland areas of the eastern part of Crete; these areas face severe issues with water availability and saltwater intrusion (coastal region). The system includes the monitoring of soil moisture and atmospheric sensors, with the aim of providing information to farmers for decision-making and at the future implementation of an automated irrigation system, optimizing the use of water resources. Data acquisition was performed through smart sensors connected to a microcontroller. Data were received at a portal and made available on the cloud, being monitored in real-time through an open-source IoT platform. An e-mail alert was sent to the farmers when soil moisture was lower than a threshold value specific to the soil type or when climatic conditions favored the development of the olive fruit fly. One of the main advantages of the proposed decision-making system is a low-cost IoT solution, as it is based on open-source software and the hardware on edge devices consists of widespread economic modules. The reliability of the IoT-based monitoring system has been tested and could be used as a support service tool offering an efficient irrigation and pest control service.

Analysis of Climate Change Impacts on Agricultural Water Availability in Cimanuk Watershed, Indonesia

Climate change has been affecting agricultural water resources dynamics spatially and temporally. This article presents analysis results of climate change impact on agricultural water availability in Cimanuk Watershed, Indonesia. STREAM was utilized to model agricultural water availability through FAO MOSAICC web application. Climate spatial data time-series were generated using 3 Global Climate Model (GCM), i.e.,: CanESM2, CNRM-CM5, and MPI-ESM-MR following two climate change scenarios of RCP4.5 and 8.5. Model inputs were split into three periods of 1981–2010 (historical), 2010–2039 (near-future), and 2040–2069 (far-future). Historical data model validation showed the efficiency coefficient of the observed and simulated discharge data ratio was 0.68. The results showed a decreasing volumetric water availability from all generated climate data and scenarios, identified by comparing the discharge normal distribution of the historical and future data periods. Whereas, trend analysis of RCP4.5 scenario showed increasing maximum discharge of Cimanuk river using CanESM2 and MPI-ESM-MR GCM’s data, with a Mann–Kendall coefficient of 3.23 and 3.57. These results indicate a different agricultural water balance status within the watershed area, particularly a “very critical” water balance in Indramayu and Majalengka, “critical” in Garut, and “close to critical” in Sumedang Regency.

Science for social licence to arrest an ecosystem-transforming invasion.

The primary role for scientific information in addressing complex environmental problems, such as biological invasions, is generally assumed to be as a guide for management decisions. However, scientific information often plays a minor role in decision-making, with practitioners instead relying on professional experience and local knowledge. We explore alternative pathways by which scientific information could help reduce the spread and impacts of invasive species. Our study centred on attempts to understand the main motivations and constraints of three local governance bodies responsible for the management of invasive (wilding) conifer species in the southern South Island of New Zealand in achieving strategic and operational goals. We used a combination of workshop discussions, questionnaire responses and visits to field sites to elicit feedback from study participants. We applied a mixed inductive-deductive thematic analysis approach to derive themes from the feedback received. The three main themes identified were: (1) impacts of wilding conifers and goals for wilding conifer control, (2) barriers to achieving medium- and long-term goals, and (3) science needed to support wilding conifer control. Participants identified reversal and prevention of both instrumental (e.g. reduced water availability for agriculture) and intrinsic (e.g. loss of biodiversity and landscape values) impacts of wilding conifer invasions as primary motivators behind wilding conifer control. Barriers to achieving goals were overwhelmingly social, relating either to unwillingness of landowners to participate or poorly designed regulatory frameworks. Consequently, science needs related primarily to gaining social licence to remove wilding conifers from private land and for more appropriate regulations. Scientific information provided via spread and impacts forecasting models was viewed as a key source of scientific information in gaining social licence. International experience suggests that invasive species control programmes often face significant external social barriers. Thus, for many biological invasions, the primary role of science might be to achieve social licence and regulatory support for the long-term goals of invasive species control programmes and the management interventions required to achieve those goals.

Estimation of Potential Evapotranspiration for Optimizing the Usage of Surface Irrigation in Wajo District

Indonesian government is trying to increase the production of agricultural commodities in order to support the food self-sufficiency program. To support this program, the availability of irrigation facilities is important in supporting the productivity of agricultural field. Climate change and changes in agricultural systems have an impact on changes in the need of irrigation water in crop cultivation. The decreasing availability of water for agriculture encourages us to be able to use water more efficiently, especially for irrigation water. The purpose of this research is to predict the ETp value as a basis for determining plant water requirements, to determine the most suitable ETp model, to validate the prediction results of ETp values ​​using direct measurements in the field, and to obtain information related to climate factors that have the most influence on the ETp rate. The measurement of the ETp value is based on the use of Merra-2 global climate data and climate data from field measurements. ETp models used are Blaney-Criddle, Hargraves, Remanenko, Penman and Penman-Monteith. Research results showed that the ETp rate in Wajo District tended to increase during the July-October period indicating an increase in water demand in crop cultivation. The most influential climate parameter in determining the Penman Monteith ETp rate is solar radiation. The results of the ETp analysis using global data show that the Penman model is the closest model to the Penman Monteith ETp model from field measurements.

Low-cost mitigation strategies for community resilience in the Trans-Himalaya to address food and water scarcity in changing environment.

Food and water scarcity in high altitudes of the Trans-Himalayan landscape are being seen as impacts of climate change, which is characterized by prolonged winters with sub-zero temperatures for a longer period. Average daily temperature from Oct to Mar (2020-21) ranged from - 6.73 ± 1.55 to 6.85 ± 1.93°C; however, fluctuates between - 10.5°C (minimum) and 4.6°C (maximum) on a typical day. With minimal rainfall, agriculture is limited to one season in these cold deserts thus limiting the land productivity. The changing scenario affects water availability for agriculture and otherwise in the villages located at further high altitudes dependent on snowmelt flow in nearby streams. This study explores the potential of extended cultivation during winters using low-cost inputs by comparing different technological options for temperature retention for vegetable cultivation. It further demonstrates the role of peoples' participation in developing zero-energy artificial ice reservoirs (water harvesting technology through capturing and storing water in the form of ice) in winters to make water available in the following growing season. With site-specific modifications, an artificial ice reservoir was created by the villagers in2020-21 which provided additional water for irrigation and was timely available (14days in advance). Using this additional water, a barren area was brought under the plantation to meet futuristic wood and fodder requirements. Confidence building (knowledge gathered, interventions to solve the major problem of water scarcity) through locally adaptable solutions (portable polyhouse, ice reservoir, increased plant productivity) motivated high altitude villagers in Trans-Himalayan to combat threats of climate change.

The Use of GAMLSS Framework for a Non-Stationary Frequency Analysis of Annual Runoff Data over a Mediterranean Area

Climate change affects all the components of the hydrological cycle. Starting from precipitation distribution, climate alterations have direct effects on both surface water and groundwater in terms of their quantity and quality. These effects lead to modifications in water availability for agriculture, ecology and other social uses. Change in rainfall patterns also affects the runoff of natural rivers. For this reason, studying runoff data according to classical hydrological approaches, i.e., statistical inference methods that exploit stationary probability distributions, might result in missing important information relevant to climate change. From this point of view, a new approach has to be found in the study of this type of data that allows for non-stationary analysis. In this study, the statistical framework known as Generalized Additive Models for Location, Scale and Shape (GAMLSS), which can be used to carry out non-stationary statistical analyses, was applied in a non-stationary frequency analysis of runoff data collected by four gauges widely distributed across Sicily (Italy) in the period 1916–1998. A classical stationary frequency analysis of these runoff data was followed by a different non-stationary frequency analysis; while the first was made using annual rainfall as a covariate, with the aim of understanding how certain statistical parameters of runoff distribution vary with changes in rainfall, the second derived information about the temporal variability of runoff frequencies by considering time as a covariate. A comparison between stationary and non-stationary approaches was carried out using the Akaike information criterion as a performance metric. After analyzing four different probability distributions, the non-stationary model with annual rainfall as a covariate was found to be the best among all those examined, and the three-parameter lognormal the most frequently preferred distribution.

Cerrado deforestation threatens regional climate and water availability for agriculture and ecosystems.

The Brazilian Cerrado is one of the most biodiverse savannas in the world, yet 46% of its original cover has been cleared to make way for crops and pastures. These extensive land-use transitions (LUTs) are expected to influence regional climate by reducing evapotranspiration (ET), increasing land surface temperature (LST), and ultimately reducing precipitation. Here, we quantify the impacts of LUTs on ET and LST in the Cerrado by combining MODIS satellite data with annual land use and land cover maps from 2006 to 2019. We performed regression analyses to quantify the effects of six common LUTs on ET and LST across the entire gradient of Cerrado landscapes. Results indicate that clearing forests for cropland or pasture increased average LST by ~3.5°C and reduced mean annual ET by 44% and 39%, respectively. Transitions from woody savannas to cropland or pasture increased average LST by 1.9°C and reduced mean annual ET by 27% and 21%, respectively. Converting native grasslands to cropland or pasture increased average LST by 0.9 and 0.6°C, respectively. Conversely, grassland-to-pasture transitions increased mean annual ET by 15%. To date, land changes have caused a 10% reduction in water recycled to the atmosphere annually and a 0.9°C increase in average LST across the biome, compared to the historic baseline under native vegetation. Global climate changes from increased atmospheric greenhouse gas concentrations will only exacerbate these effects. Considering potential future scenarios, we found that abandoning deforestation control policies or allowing legal deforestation to continue (at least 28.4Mha) would further reduce yearly ET (by -9% and -3%, respectively) and increase average LST (by +0.7 and +0.3°C, respectively) by 2050. In contrast, policies encouraging zero deforestation and restoration of the 5.2Mha of illegally deforested areas would partially offset the warming and drying impacts of land-use change.

Application of Analytical Hierarchy Process and Geophysical Method for Groundwater Potential Mapping in the Tata Basin, Morocco

Ensuring water availability for agriculture and drinking water supply in semi-arid mountainous regions requires control of factors influencing groundwater availability. In most cases, the population draws its water needs from the alluvial aquifers close to villages that are already limited and influenced by current climatic change. In addition, the establishment of deep wells in the hard rock aquifers depletes the aquifer. Hence, understanding the factors influencing water availability is an urgent requirement. The use of geographic information system (GIS), and remote sensing (RS), together with decision-making methods like analytical hierarchy process (AHP) will be of good aid in this regard. In the Tata basin, located in SE Morocco, ten factors were used to explain the groundwater potentiality map (GWPM). Five categories of potential zones were determined: very low (8.67%), low (17.74%), moderate (46.77%), high (19.95%), and very high (6.87%). The efficiency of the AHP model is validated using the ROC curve (receiver operating characteristics) which revealed a good correlation between the high potential groundwater zones and the spatial distribution of high flow wells. Geophysical prospecting, using electrical resistivity profiles, has made it possible to propose new well sites. It corresponds to conductive resistivity zones that coincide with the intersection of hydrogeological lineaments.

Evaluating the Suitability of System of Rice Intensification Practices for Enhancing Rice and Water Productivity in Semi-Arid Environment, Tamil Nadu, India

&#x0D; In the world of rapid change in climate, irregular rainfall pattern tends to pose serious impact on water availability for agriculture. Rice is one of the important food crops to get affected by the low water availability because of its high water requirement. Various techniques were used in the past to mitigate low water availability and increase productivity but most techniques will improve one aspect at the expense of the other. System of Rice Intensification (SRI) is being tried by many countries with several modifications based on their priorities, with the aim of enhancing productivity besides reducing the water demand for rice cultivation. It is essential to have more insight into the individual and compounding effect of multiple components of SRI on yield, and water productivity of rice for identifying the potential and suitable SRI practices. Investigating the influence of different practices of SRI viz., planting of young and single seedlings per hill in wider spacing, water saving irrigation like Alternate Wetting and Drying (AWD), and weed control using cono-weeders on rice using the data obtained from the field experiment carried out during 2021 in Tamil Nadu Agricultural University, Coimbatore, India. Water productivity of rice plants under SRI were compared with conventional practices. The results revealed that plants grown with complete SRI practices had increased water productivity by 0.25 kg grain/m3 of water which is almost twice that of conventional cultivation system. The yield obtained in SRI treatments was higher about 39% than conventional treatments. The total water savings were 20 % higher in AWD treatments than continuous flooding treatments.&#x0D; &#x0D;

Evaluation of soil wetting patterns in drip irrigation

Increasing agricultural water use efficiency is of prime importance owing to the decrease in availability of fresh water for agriculture. In these circumstances, drip irrigation is considered so far as the most efficient irrigation systems and can be utilized correctly with the knowledge of dimension of the soil wetted volume which is the main factors in determining the spacing of drippers. Therefore, the present study was conducted at the Instructional Farm, Faculty of Agricultural Engineering, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal during 2019–20 to examine the vertical (Z) and horizontal (W) water fronts advance within the soil profile at the dripper in a clay loam soil. Same volume of water (50 litre) was applied at the rate of 2.3 and 4.9 lph at each irrigation. By observing the soil on the tips of the auger, the depth of wetting was determined and noted down for different points on the line of the wetted area. It was found that there is little variation in the theoretical width and depth with the actual width and depth of wetting of the soil in case of 4.9 lph discharge rate. For the given discharge rate, the inaccuracy was less for the wetted depth than the wetted diameter. So, the information obtained from this investigation, about soil wetting pattern of drip irrigation system can be helpful to decide emitter, lateral spacing and system pressure for delivering required amount of water to the plant root zone. Thus, this investigation can be instrumental in design and management of drip system, which is slowly becoming a promising agricultural water management practice to tackle the huge food productivity problem and environmental issues of developing and under-developed countries.

Effect of various crop establishment methods on the crop performance and water use efficiency of rice (Oryza sativa)

With decreasing water availability for agriculture and increasing demand for rice, water use in rice production systems has to be reduced and water productivity increased. In this paper we compared the effects of two varieties on crop performance and water use under different methods of crop establishment, in the field experiments at students’ farm, Khalsa College, Amritsar during kharif season of 2016 and 2017. The field was laid out in split plot design with four replications with two cultivars i.e., PR 126 and PR 121 in main plot treatments and six methods of sowing/transplanting i.e., W-DSR (Wet-Direct Seeded Rice) on flat beds, D-DSR (Dry-Direct seeded Rice) on flat beds, PTR (puddle transplanted rice), RSR (Ridge Sown Rice), RTR (Ridge Transplanted Rice), W-DSR (Wet- Direct Seeded Rice) on ridges, D-DSR (Dry- Direct Seeded Rice) on ridges and RTR (Ridge Transplanted Rice) were kept in sub plot treatments. The experiments were conducted in irrigated lowlands where soil texture was sandy loam. The results revealed that grain yields of rice were 72.63 q/ha and 73.54 q/ha under W-DSR on flat beds, 70.07 q/ha and 71.50 q/ha under D-DSR on flat beds, 69.24 q/ha and 73.84 q/ha under PTR, 70.48 q/ha and 73.76 q/ha under W-DSR on ridges, 74.51 q/ha and 71.64 q/ha under D-DSR on ridges and 69.21 q/ha and 73.13 q/ha under RTR in both years. Yield did not significantly differ between DSR and other crop establishment technologies in both years, but water use efficiency was higher under W-DSR on flat beds as well as on ridges than under PTR and RTR in both years. Flat sowing of rice under W-DSR was economical than other treatments. Accordingly, conventional practice of rice planting is no longer able to sustain the productivity of rice cropping systems.

Climate Change Impacts on Agricultural Water Availability in the Middle Rio Grande Basin

AbstractWe present a comprehensive analysis of water availability under plausible future climate conditions in a heavily irrigated agricultural watershed located in the middle section of the Rio Grande Basin in the United States Desert Southwest. Future managed streamflow scenarios (through year 2099) were selected from among 97 scenarios developed based on downscaled, bias‐corrected global climate model outputs to evaluate future inflows to the principal surface water storage reservoirs, possible future reservoir releases, and groundwater pumping to sustain irrigated agriculture. The streamflow projections describe a wide range of dry and wet conditions compared to the average historical flows in the river, indicating significant uncertainty in future water availability in the Rio Grande Basin. We applied the Soil and Water Assessment Tool to illustrate the impact of climate futures on different components of the water budget at a watershed scale. Results indicate declining reliability of reservoir storage to meet the water demand of irrigated agriculture. The impact of declining surface water can be offset by increasing the pressure on the already‐strained groundwater resources. However, the region should be prepared to use slightly saline (total dissolved solids [TDS] &gt; 1,000 mg/L) and moderately saline groundwater (TDS &gt; 3,000 mg/L) as fresh groundwater in the regional aquifer is depleted within the 21st Century under hotter and drier conditions and status quo agricultural land and water management practices.