Future Irrigation Research Articles

Potential genotype-based climate change adaptation strategies for sustaining cotton production in the Texas High Plains: A simulation study

• Future seed cotton yield showed mixed response across the Texas High Plains due to differences in baseline temperature. • Yield and growth benefits from CO 2 fertilization were suppressed by increased temperature and water stress. • Future irrigation water use would likely increase due to drier and warmer conditions. • High yielding ideotype showed substantial yield gains under irrigated conditions with marginal increase in water use. • For dryland conditions, the long maturity ideotype simulation resulted in maximum yield gains. The Texas High Plains (THP) is a major cotton-producing region in the United States. Sustaining cotton production under declining groundwater availability in the underlying Ogallala Aquifer and changing climate remains a key challenge for stakeholders in this region. The objectives of this study were to assess climate change impacts on cotton yield and irrigation water use, and evaluate six ideotypes for adaptation. In this study, we used the DSSAT-CSM-CROPGRO-Cotton model for simulating cotton production under 18 projected future climate scenarios and with six potential adaptation ideotypes at Bushland, Halfway and Lamesa in the northern, central, and southern parts of the THP region, respectively. Seed cotton yield and irrigation water use between baseline (1976–2005) and future periods (mid-century:2036–2065 and late-century: 2066–2095) were compared. The irrigated seed cotton yield is expected to increase by 12–21 % at cooler northern sites, and decrease by 2% at the warmer southern site, in the mid-century compared to the baseline. For the same period, seasonal irrigation water use is expected to increase by 6–11 % and dryland seed cotton yield is expected to change by +6 % to −11 % across the locations. The increases in irrigated seed cotton yield were attributed to increased vegetative growth under elevated CO 2 , while the decline in dryland seed cotton yield was due to poor boll retention at high growing season temperatures. Six potential climate change adaptive ideotypes with greater drought and heat tolerances, higher yield potential, and longer maturity were designed and compared to the reference cultivar. For irrigated conditions, increasing area of full leaf and enhancing partitioning of assimilates to reproductive growth (high yield potential) were preferred, because these characteristics increased seed cotton yield substantially (by 3–9 %) with a marginal change in irrigation water use (by −1 to 3 %). For dryland production, a long maturity ideotype with longer boll filling duration was the most effective ideotype with a substantial increase in seed cotton yield by 11–45 %. The results from this study will be useful to THP cotton producers and water managers in making appropriate decisions for adapting cotton production to projected changes in future climate and groundwater availability.

Assessment of Future Climate Change Impact on an Agricultural Reservoir in South Korea

Drought has been frequently occurring in South Korea due to climate change. Analyzing the water supply capacity of the water resource system provides essential information for water resource management. This study evaluates the future water supply capacity of the Gwanghye (GH) agricultural reservoir based on the representative concentration pathways 4.5 and 8.5 climate change scenarios. We performed a reservoir simulation by reflecting the full water level of the reservoir before and after reservoir heightening. Climate change is expected to decrease the GH reservoir’s future available water resources due to the overall reduction in the reservoir’s runoff. After the reservoir-heightening project, an overall improvement was observed in the stability of the future irrigation water supply. Moreover, the remaining water after the supply of the irrigation water could supply 0.6–7.2 × 103 m3 of daily instream water. Thus, flexible reservoir operations are necessary according to climate change scenarios and the reservoir operation period. The use of climate change information should be expanded to establish reasonable water management policies for future climate change scenarios.

Analysing the water and land system impacts of Germany's future energy system

While it is generally accepted that our fossil fuel-dominated energy systems must undergo a sustainable transition, researchers have often neglected the potential impacts of this on water and land systems. However, if unintended environmental impacts from this process are to be avoided, understanding its implications for land use and water demand is of crucial importance. Moreover, developed countries may induce environmental stress beyond their own borders, for instance through extensive imports of bioenergy. In this paper, Germany serves as an example of a developed country with ambitious energy transformation targets. Results show that in particular, the politically-driven aspiration for more organic farming in Germany results in a higher import quota of biomass, especially biofuels. These imports translate into land demand, which will exceed the area available in Germany for bioenergy by a factor of 3–6.5 by 2050. As this will likely bring about land stress in the respective exporting countries, this effect of the German energy transformation ought to be limited as much as possible. In contrast, domestic water demand for the German energy system is expected to decrease by over 80% through 2050 due to declining numbers of fossil-fuelled power plants. However, possible future irrigation needs for bioenergy may reduce or even counterbalance this decreasing effect. In addition, energy policy targets specific to the transport sector show a high sensitivity to biomass imports. In particular, the sector-specific target for greenhouse gas reductions will seemingly promote biomass imports, leading to the above-described challenges in the pursuit of sustainability.

Smart Soil Irrigation System Based on A Digital Camera and Graphic User Interface

Irrigation consumes 70% of the water quantity used worldwide. In a context of rising food demand and declining in water resources, the development of advanced irrigation technologies based on modern techniques in agriculture is a significant demand to keep this resource safe. To achieve this target, the management of water resources in agriculture needs to be specified and controlled. This study aims to propose an automatic, non-contact and cost-effective soil irrigation system based on analysing the changes in loam soil colour captured by a digital camera at different illumination levels. A graphic user interface (GUI) attached to the Arduino Uno microcontroller was used to drive the water pump and determine whether the loam soil requires irrigation or not. The experimental results illustrate the effectiveness of the proposed irrigation system to determine soil state and provide an accurate decision for soil irrigating, thus making this system a promising approach in future irrigation technologies.

Impacts of Climate Change on Irrigation Water Management in the Babai River Basin, Nepal

The diminishing spring discharge in the Middle Mountain Zone (MMZ) in Nepal is a matter of concern because it directly affects the livelihoods of low-income farmers in the region. Therefore, understanding the impacts of changes in climate and land-use patterns on water demand and availability is crucial. We investigated the impact of climate change on streamflow and environmental flow, and the demand for spring-fed river water for irrigation using the limited meteorological data available for the Babai River Basin, Nepal. SWAT and CROPWAT8.0 were used to respectively calculate present and future streamflow and irrigation water demand. Three general circulation models under two representative concentration pathways (RCPs 4.5 and 8.5) for the periods of 2020–2044, 2045–2069, and 2070–2099 were used to investigate the impact of climate change. Results indicate that the catchment is likely to experience an increase in rainfall and temperature in the future. The impact of the increment in rainfall and rise in temperature are replicated in the annual river flow that is anticipated to increase by 24–37%, to the historical data of 1991–2014. Despite this increase, projections show that the Babai River Basin will remain a water deficit basin from January to May in future decades.

Paddy rice adaptation strategies to climate change: Transplanting date shift and BMP applications

Due to climate change, food security and water use associated with paddy rice cultivation in Korea are facing great challenges, and practical measures are needed to compensate for the negative impacts of climate change. Transplanting date shift (TDS) has been considered as an adaptation strategy to climate change, however, its impact on water use, water quality, and rice production is still unclear. This study was designed to assess not only TDS but also drainage outlet raising (DOR) as a practical adaptation strategy to climate change. We analyzed the impacts of climate change on water use, water quality, and water productivity in 12 combination scenarios of TDS and DOR using a well-proven APEX-Paddy model according to 10 General Circulation Models (GCMs). We found that the future runoff and total nitrogen (T-N) load appeared differently in each decade, and the future runoff and T-N load increased more than the irrigation water and rice yield over the observed period of time due to the effects of the rainfall amount and rainfall intensity rather than the effects of the increased temperature. The future rice yield declined continuously as the temperature increased due to the rising CO2; however, a significantly amount of irrigation water was saved due to the TDS. According to the DOR implementation, the future runoff, T-N load, and irrigation water requirement were significantly reduced, while the rice yield increased slightly. The RM5 scenario, which includes both the DOR and 40-day delayed TDS, was ranked as the most effective best management practices (BMPs) with the highest water productivity in all of the scenarios. The results of this study indicated that an adequate combination of TDS and DOR taking into account the weather conditions would mitigate the negative impacts of climate change.

Investigation of Effective Irrigation Strategies for High-Density Apple Orchards in Pennsylvania

Irrigation helps grow agricultural crops in dry areas and during periods of inadequate rainfall. Proper irrigation could improve both crop productivity and produce quality. For high density apple orchards, water relations are even more important. Most irrigation in tree fruit orchards is applied based on grower’s experience or simple observations, which may lead to over- or under-irrigation. To investigate an effective irrigation strategy in high-density apple orchard, three irrigation methods were tested including soil moisture-based, evapotranspiration (ET)-based and conventional methods. In soil moisture-based irrigation, soil water content and soil water potential sensors were measured side by side. In ET-based irrigation, daily ET (ETc) and accumulated water deficit were calculated. Conventional method was based on the experience of the operator. The experiment was conducted from early June through middle of October (one growing season). Lastly, water consumption, fruit yield and fruit quality were analyzed for these irrigation strategies. Results indicated that the soil moisture-based irrigation used least water, with 10.8% and 4.8% less than ET-based and conventional methods, respectively. The yield from the rows with the soil moisture-based irrigation was slightly higher than the other two, while the fruit quality was similar. The outcome from this study proved the effectiveness of using soil moisture sensors for irrigation scheduling and could be an important step for future automatic irrigation system.

Irrigation management in Nigeria: Lessons from the Kano River irrigation scheme*

AbstractNigeria has, in the past, tried various rural development strategies to achieve agricultural development and national food security. Among these has been the setting up of farm settlement schemes, marketing boards, the Agricultural Credit Guarantee Scheme, Operation Feed the Nation, the Land Use Decree, etc. These could not achieve much because of various political, economic and social characteristics of the Nigerian population. As a further step, river basin development authorities (RBDAs) were established. The objectives of the RBDAs and their geographical coverage brought the confidence and the possibility of finally achieving the goal of rural transformation. However, like other schemes, the RBDAs are beset with problems which are also inherent in the present economic set‐up of the country, and which would require double the energy spent in the past, to have the RBDAs perform the wonders, which the other strategies have failed to achieve.In redoubling efforts towards improved rural transformation, participatory irrigation management (PIM) began to occupy the irrigation space of the RBDAs, especially in the northern part of the country in the mid‐1990s. These efforts were then met with challenges that threatened the PIM initiatives a few years after inception.This paper examines these challenges and the current efforts by government in addressing the challenges, with a view to refocusing future public irrigation development and management in Nigeria.

Estimation of future irrigation performance with times series analysis: a case study of Andırın, Kahramanmaraş, Turkey

Estimation of future irrigation performance with times series analysis: a case study of Andırın, Kahramanmaraş, Turkey

Modeling climate change impacts on crop water demand, middle Awash River basin, case study of Berehet woreda

Abstract Climate change mainly affects crops via impacting evapotranspiration. This study quantifies climate change impacts on evapotranspiration, crop water requirement, and irrigation water demand. Seventeen GCMs from the MarkSim-GCM were used for RCP 4.5 and 8.5 scenarios for future projection. A soil sample was collected from 15 points from the maize production area. Based on USDA soil textural classification, the soil is classified as silt loam (higher class), clay loam (middle class), and clay loam (lower class). The crop growing season onset and offset were determined using the Markov chain model and compared with the farmer's indigenous experience. The main rainy season (Kiremt) starts during the 1st meteorological decade of June for baseline period and 2nd decade to 3rd decade of June for both RCP 4.5 and RCP 8.5 of near (2020s) and mid (2050s) future period. The offset date is in the range of 270 (base period), RCP 4.5 (278, 284), and RCP 8.5 (281, 274) DOY for baseline, near, and mid future. The rainfall and temperature change show an increasing pattern from the base period under both scenarios. Furthermore, the reference evapotranspiration (ETo) estimating model was developed using multiple variable regression and used for a future period in this study. In the base period, ETo increases from 33.4 mm/dec in the 1st decade of July to the peak value of 52.1 mm/dec in the 3rd decade of May. Under RCP8 .5, the 2nd decade of August ETO is minimal (44.3 mm/dec), while in 1st decade of April ETO was maximum (75.3 mm/dec) and raise from 44.3 mm/dec in the 2nd decade of August to the peak value of 75.3 mm/dec in the 1st decade of April. Under RCP 4.5, ETO raises from 33 mm/dec in the 1st decade of Dec to the peak value of 48 mm/dec in the 3rd decade of May. ETo shows an increasing trend from the base period under both scenarios. During the base period, a maize variety with a growing period of 110 days required 403.2 mm depth of water, while 67 mm is required as supplementary irrigation. Crop water and irrigation requirements of the maize variety with a growing period of 110 days are predicted to be 436.1 and 445.1 mm water during the 2020 and 2050 s for RCP 4.5, while 101.8 to 63.7 mm depth of water as supplementary irrigation respectively and 441.3 and 447.3 mm of water during 2020 and 2050 s of the future period for RCP 8.5, while 142.9 to 134.0 mm required as supplementary irrigation for both periods of RCP 8.5 scenarios. Crop water need will increase by 8.16 and 10.39% for RCP 4.5 and by 9.45 and 10.94% for RCP 8.5 of the 2020 and 2050 s respectively. In this study, a new ETO model is developed using a multiple variable linear regression model and its degree of the fitting is statistically tested and Kc is adjusted for the local climate, and hence, can be used in future irrigation and related studies. Generally, decision-makers, farmers, Irrigation engineers, and other stakeholders can use the results of this study in irrigation design, monitoring, scheduling, and other related activities.

Use of multispectral and thermal satellite imagery to determine crop water requirements using SEBAL, METRIC, and SWAP models in hot and hyper-arid Oman

Hyper-arid regions, such as the Sultanate of Oman, require precise information regarding actual water application to develop efficient irrigation management. Remote sensing techniques with imagery models can be used as practical tools in irrigation practices by estimating the actual evapotranspiration (ETa) at local and regional scales. In this study, spatial and temporal changes in the ETa were evaluated by investigating the performance of three different models, including two surface energy balance models: surface energy balance algorithm for land (SEBAL) and mapping evapotranspiration at high-resolution internalized calibration (METRIC), as well as an agro-hydrological model: soil, water, atmosphere, and plant (SWAP), for the hyper-arid conditions of Oman. This study is unique in its field application, as very few studies have conducted ETa estimations using satellite imagery in the hot and hyper-arid regions of Oman. In situ meteorological data were integrated with Landsat-8 operational land multispectral imagery and thermal infrared sensor satellite images. Further, a sensitivity analysis comparing the three models' estimated ETa with in situ sap flow field measurements (SFM) and the Penman-Monteith (PM) model. The results showed that the SEBAL model overestimated the sensible heat flux compared with the METRIC model. Although the PM model showed a higher correlation (R2 = 0.87) with the SFM, the METRIC model, among all the investigated models, showed the highest correlation of R2 = 0.83. Further, the SEBAL and METRIC models overestimated the ETa, especially in the summer. Conversely, SWAP underestimated the ETa, as compared with the SFM. These results show that the METRIC model estimates the ETa with high spatial and temporal accuracy. Meanwhile, the SWAP model was the least suitable model for estimating the ETa under the hyper-arid condition of Oman. These findings will act as a reference for accurate water requirements, thereby linking water resource management and future irrigation scheduling in local hot and hyper-arid conditions.

Future Irrigation Water Requirements of the Main Crops Cultivated in the Niger River Basin

Precise agricultural predictions of climate change effects on crop water productivity are essential to ensure food security and alleviate water scarcity. In this regard, the present study provides an overview of the future impacts of climate change on the irrigation of agricultural products such as rice, millet, maize, cassava, sorghum, and sugar cane. These crops are some of the most-consumed foodstuffs in countries of the Niger River basin. This study is realized throughout 2020 to 2080, and three Global Climate Models (GCMs) (CSIRO, MIROC5, and ECHAM. MPI-ESM-LR) have been used. The GCMs data have been provided by the IPCC5 database. The irrigation water requirement for each crop was calculated using Smith’s CROPWAT approach. The Penman–Monteith equation recommended by the FAO was used to calculate the potential evapotranspiration. The inter-annual results of the IWR, according to the set of models selected, illustrate that the largest quantities of water used for irrigation are generally observed between January and March, and the lowest quantities are the most often seen between July and September. The majority of models also illustrate a peak in the IWR between March and April. Sorghum and millet are the crops consuming the least amount of water for irrigation; followed by cassava, then rice and corn, and finally sugar cane. The most significant IWRs, which have been predicted, will be between 16.3 mm/day (MIROC5 model, RCP 4.5) and 45.9 mm/day (CSIRO model, RCP 4.5), particularly in Mali, Niger, Algeria, and rarely in Burkina-Faso (CSIRO model, RCP4.5 and 8.5). The lowest IWRs predicted by the models will be from 1.29 mm/day (MIROC5 model, RCP 4.5) to 33.4 mm/day (CSIRO model, RCP 4.5); they will be observed according to the models in Guinea, southern Mali, Ivory Coast, center and southern Nigeria, and Cameroon. However, models predict sugarcane to be the plant with the highest IWR, between 0.25 mm/day (Benin in 2020–2040) and 25.66 mm/day (Chad in 2060–2080). According to the models’ predictions, millet is the crop with the most IWR, between 0.20 mm/day (Benin from 2020 to 2060) and 19.37 mm/day (Chad in 2060–2080). With the results of this study, the countries belonging to the Niger River basin can put in place robust policies in the water resources and agriculture sectors, thus ensuring food security and high-quality production of staple crops, and avoiding water scarcity while facing the negative impacts of climate change.

The role of perceptions, goals and characteristics of wine growers on irrigation adoption in the context of climate change

Among the multiple adaptations that exist to face climate change, irrigation is one straightforward option for wine growing. Yet, widespread development of irrigation may strengthen water scarcity and further increase farmers’ vulnerability to water stress. In this context, understanding the conditions of the adoption of irrigation is of outmost importance to characterize the process, the risks and the policy implications of climate change adaptation. This paper presents an empirical approach for understanding the factors driving current and envisioned irrigation at farm level, by combining Internet-survey data and terroir data (precipitation, temperature, and soil water holding capacity) characterizing wine growers and farms in southeastern France (Languedoc-Roussillon). Survey data include current and future practices, the perceptions of past changes, and wine growers' main objectives. The sample gathers 28% of growers that are already irrigating their vines, 39% that are considering this option for the future. Results of different econometric models show that both terroir and socio-economic factors such as perceptions and objectives play significant roles in the adoption of irrigation. Specifically, perceptions of water scarcity seem to drive future irrigation projects much more than real water scarcity. These results carry important policy implications for water-demand forecasting and water-supply planning.

The Water Needs of Grapevines in Central Poland

Climate warming increases the water needs of plants. The aim of this study was to estimate the water needs of grapevines in central Poland. Water needs were calculated using the crop coefficients method. Reference evapotranspiration was assessed by the Blaney–Criddle’s equation, modified for climate conditions in Poland. Crop coefficients were assumed according to the Doorenbos and Pruitt method. Water needs were calculated using the data from four meteorological stations. Rainfall deficit with the probability occurrence of normal years, medium dry years, and very dry years was determined by the Ostromęcki’s method. Water needs of grapevines during the average growing season were estimated at 438 mm. Upward time trend in the water needs both in the period of May–October and June–August was estimated. Temporal variability in the water needs was significant for all of the provinces. These changes were mainly impacted by a significant increasing tendency in mean air temperature and less by precipitation totals that did not show a clear changing tendency. Due to climate change, vineyards will require irrigation in the near future. The use of resource-efficient irrigation requires a precise estimate of the grapevines’ water needs. The study identified the water requirements for grapevines in central Poland.

Study of the Wet Bulb in Stratified Soils (Sand-Covered Soil) in Intensive Greenhouse Agriculture under Drip Irrigation by Calibrating the Hydrus-3D Model

The development of the wet bulb under drip irrigation in sand-covered soils presents a different behavior compared to the one observed in homogeneous soils. Moreover, the presence of a very active crop imposes a series of variations that have not been fully characterized. The aim of this work is to present the data acquisition methodology to calibrate and validate the Hydrus-3D model in order to safely define the evolution of moisture in wet bulbs generated in stratified “sanded” soils characteristic of greenhouses with intensive pepper crop under drip irrigation. The procedure for collecting and processing moisture data in stratified soils has been defined. Soil permeability; retention curve, texture, and bulk density have been measured experimentally for each material. It has been found that the inclusion of a previous day in the simulation improves model predictions of soil moisture distribution. In soils with less gravel, a lower average stress and a more homogeneous moisture distribution were observed. It has been proved that the Hydrus-3D model can reproduce the behavior of sand covered soils under intensive greenhouse growing conditions, and it has been possible to verify that the predictions are adequate to what has been observed in the field. In view of the results, the Hydrus-3D model could be used to establish future irrigation strategies or to locate the optimal placement point of tensiometers that control irrigation in sandy soils for intensive agriculture.

Requirements for Sustainable Irrigated Agriculture

The aim of this review is to present a holistic view on irrigation with respect to local environmental and social conditions. Future irrigation development is addressed with a focus on sustainable development. However, technical irrigation aspects are included and references are provided for further reading and completeness. An irrigation intervention is always a combination of feasible technical, social and environmental aspects. This review provides an overview of the various fields of expertise involved in irrigation interventions and contributes to cross-discipline discussions and understanding. The selected cases demonstrate the bias of human developments and they serve to raise awareness of the impact of human interventions. The practical examples refer mainly to the authors’ project experiences and were selected so as to support pathways for sustainable irrigation development. Placing modern irrigation in relation to sustainable development goals needs a sophisticated holistic approach.

A comparative study of irrigation techniques for energy flow and greenhouse gas (GHG) emissions in wheat agroecosystems under contrasting environments in south of Iran

The agriculture sector in general and irrigation, in particular, can be a major emitter of greenhouse gases and can contribute to global climate change. Most studies dealing with the evaluation of irrigation planning worldwide have not taken this aspect of irrigation into account, while it is of paramount importance to attach environmental assessment of irrigation programs, in particular their impacts on greenhouse gas (GHG) emissions, to any policy-making and development efforts for planning irrigation strategies. The present study aims at describing the energy flow and GHG emissions in wheat agroecosystems under different irrigation systems in Southern Iran. Three irrigation systems, including furrow irrigation (FI), sprinkler irrigation (SI) and drip irrigation (DI) were studied in two contrasting environments with regard to pedo-climatic conditions. The results indicated that environment and irrigation system remarkably affected energy input, energy output and GHG emissions. The highest energy input was observed in DI (75.59 GJ ha−1) followed by FI (62.67 GJ ha−1) and SI systems (49.81 GJ ha−1). In DI system, the main energy consumption item belonged to polyethylene (PE) pipelines (about one-third of total input energy), while in other two irrigation systems diesel fuel consumption was the main component of energy consumption (32.77% and 36.2% in FI and SI systems, respectively). Changing the irrigation method from furrow to sprinkler and drip reduced water requirement by 43.7% and 39.6% and electricity consumption by 36.5% and 25.2%, respectively. The highest output energy (averaged over both environments) was observed in DI system (154.52 GJ ha−1), although it was not considerably different from SI system (151.41 GJ ha−1). The environment that had more suitable environmental condition and longer growing season for wheat growth showed higher output energy (167.87 GJ ha−1) compared to a less favorable environment (125.57 GJ ha−1). Pressurized irrigation systems had priority over traditional irrigation practices in terms of energy efficiencies and global warming potential (GWP) and were more environment-friendly. SI system had the highest net energy and energy use efficiency (3.02 and 0.111 kg MJ−1, respectively). Averaged over both environments, the highest direct energy, indirect energy, renewable energy and non-renewable energy consumptions were observed in FI (34.47 GJ ha−1), DI (49.26 GJ ha−1), FI (8.91 GJ ha−1) and DI (68.48 GJ ha−1) systems, respectively. Our results indicated that the total GWP on a hectare basis could be decreased by changing the irrigation system from FI (10886.1 kg CO2eq ha−1) to pressurized irrigation systems (8945.7 kg CO2eq ha−1 and 8049.7 kg CO2eq ha−1 for DI and SI system, respectively). In contrast to previous studies (which have mainly focused on methods of irrigation other than sprinkler), sprinkler irrigation was superior in these regards when compared to drip irrigation. The present study helps decision-makers to grasp a better understanding of the linkage between various methods of irrigation and the subsequent impact on GHG emissions, which is a prerequisite to any planning effort for future irrigation strategies at national and international levels.

The Water Requirements of Grapevines (Vitis vinifera L.) Under Climatic Conditions of Central Poland

The purpose of this study was to estimate the water needs of grapevines in central Poland in 1981-2010. Water needs were calculated by the plant coefficients, which were assumed according to the Doorenbos and Pruitt method. Reference evapotranspiration was assessed by the Blaney-Criddle’s equation, modified for Polish conditions. Rainfall deficit with the occurrence probability of normal, medium dry and very dry years was determined by the Ostromęcki’s method. Water needs of grapevines during the growing season was 434 mm. Upward time trend in the water needs both in the periods May-October and June-August was estimated. Temporal variability in the water needs was significant for most of the provinces. The rainfall deficit was recorded with the occurrence probability of normal as well as medium or very dry years in the entire study area. Due to climate changes, vineyards will require irrigation in the near future. This research significantly broadens and refines the knowledge about the water needs of grapevines in central Poland, which will allow the design of resource-efficient irrigation programs for grapevines in the studied region of Poland.

Design, Implementation, and Empirical Validation of an IoT Smart Irrigation System for Fog Computing Applications Based on LoRa and LoRaWAN Sensor Nodes.

Climate change is driving new solutions to manage water more efficiently. Such solutions involve the development of smart irrigation systems where Internet of Things (IoT) nodes are deployed throughout large areas. In addition, in the mentioned areas, wireless communications can be difficult due to the presence of obstacles and metallic objects that block electromagnetic wave propagation totally or partially. This article details the development of a smart irrigation system able to cover large urban areas thanks to the use of Low-Power Wide-Area Network (LPWAN) sensor nodes based on LoRa and LoRaWAN. IoT nodes collect soil temperature/moisture and air temperature data, and control water supply autonomously, either by making use of fog computing gateways or by relying on remote commands sent from a cloud. Since the selection of IoT node and gateway locations is essential to have good connectivity and to reduce energy consumption, this article uses an in-house 3D-ray launching radio-planning tool to determine the best locations in real scenarios. Specifically, this paper provides details on the modeling of a university campus, which includes elements like buildings, roads, green areas, or vehicles. In such a scenario, simulations and empirical measurements were performed for two different testbeds: a LoRaWAN testbed that operates at 868 MHz and a testbed based on LoRa with 433 MHz transceivers. All the measurements agree with the simulation results, showing the impact of shadowing effects and material features (e.g., permittivity, conductivity) in the electromagnetic propagation of near-ground and underground LoRaWAN communications. Higher RF power levels are observed for 433 MHz due to the higher transmitted power level and the lower radio propagation losses, and even in the worst gateway location, the received power level is higher than the sensitivity threshold (−148 dBm). Regarding water consumption, the provided estimations indicate that the proposed smart irrigation system is able to reduce roughly 23% of the amount of used water just by considering weather forecasts. The obtained results provide useful guidelines for future smart irrigation developers and show the radio planning tool accuracy, which allows for optimizing the sensor network topology and the overall performance of the network in terms of coverage, cost, and energy consumption.

Utilizing homogenized observation records and reconstructed time series data to estimate recent trends in Mid-Atlantic soil moisture scarcity

The Mid-Atlantic region of the USA has experienced increasing annual precipitation amounts in recent decades, along with more frequent extreme events of greater magnitude. Unlike many US regions that have suffered increasing drought conditions from higher evapotranspiration demand, positive trends in the Mid-Atlantic accumulated precipitation are greater than the recent increases in reference evapotranspiration. The temporal correlation between precipitation events and soil moisture capacity is essential for determining how the nature of drought has changed in the region. This analysis has shown that soil moisture scarcity has declined in nine of ten subregions of the Mid-Atlantic that were analyzed from 1985 to 2019. Two algorithms were deployed to draw this conclusion: Climatol enabled the use of the FAO-56 Penman-Monteith equation on daily observation station data for which complete records were unavailable, and the second algorithm calculated soil moisture levels on a daily basis, more accurately capturing drought conditions than common methods using weekly or monthly summaries. Although the declining drought trends were not statistically significant, a result of more extreme events and higher evapotranspiration rates, the inclusion of direct data from an expanded set of locations provides greater clarity from the trends, allowing policymakers and landowners to anticipate changes in future Mid-Atlantic irrigation water demand.