The effects of climate change on water availability affect the performance of surface irrigation,... more The effects of climate change on water availability affect the performance of surface irrigation, which is the oldest and most common method of water application to row crops worldwide. A paradigm shift towards strategies aimed at increasing exibility of irrigation scheduling and improving the design and management of eld layouts and irrigation practices should be explored to promote water savings at the farm scale. In this study, we investigate how adopting a more exible irrigation scheduling and optimizing irrigation management variables and eld layout it is possible to increase the e ciency of border irrigation and thus achieve water savings and improve quality of crop production. The analysis of the actual performance of border irrigation was carried out on two maize elds located in the Padana Plain (Northern Italy) in two years characterized by different rainfall patterns (i.e. 2021 and 2022). Based on this information, continuous monitoring of soil moisture status combined with the AquaCrop-OS agrohydrological model was used to manage exible irrigation scheduling over the experimental elds. While the optimization of irrigation management (owrate per unit width and cutoff time) and eld geometries (border width and slope) was studied using WinSRFR 5.1 USDA software, which was properly calibrated by measures of waterfront advance and recession. The results show that with exible irrigation scheduling and proper irrigation management and eld layout, signi cant water savings can be achieved. Speci cally, in the case study, seasonal water savings of about 10% were obtained just by scheduling irrigation based on actual crop water needs in a very dry agricultural season, while water savings reached up to 60% in a wetter season. On average, an additional 7% of water savings was achieved over the agricultural season when the irrigation duration was correctly applied to each border of the experimental plots, while approximately 20% of water was saved when the border width was correctly designed based on in ow availability. These results provide useful information for improving the management of border irrigation in practice, both under current conditions and in the face of increasing freshwater scarcity in the future.
Comparing different FAO approaches for assessing irrigation needs and scheduling: application on a maize field in Mediterranean area
<p>Selecting the best irrigation management is required for improved use of... more <p>Selecting the best irrigation management is required for improved use of water resources and for achieving sustainable crop productions. That selection implies accurate predictions of crop water requirement in response to meteorological variables and phenological stages. A plethora of irrigation models are reported to date in literature, many of which are based on three different approaches proposed by the FAO organization, the single and double crop coefficient methods and, the canopy-cover curve determination included in the AquaCrop model.</p><p>The objective of this study is to compare irrigation needs and scheduling obtained by the three aforementioned approaches in the agricultural context of the Po River Plain (northern Italy). The first and the second approaches were simulated respectively by Sim1Kc and IdrAgra models, which implemented the algorithms and crop parameterizations reported in FAO paper 56 for a crop water requirement estimation. While the third approach was simulated by the open source version of AquaCrop software.</p><p>Models were tested on a maize plot located in the lower-east part of Lombardy Po River Plain characterized by a humid sub-tropical climate, according Köppen classification. A single sandy-loam layer profile of medium-textured soil 1 m deep was considered for the simulation. Crop parameters values in Sim1Kc and AcquaCrop models were mutuated from the IdrAgra model, which is routinely applied in the region as the reference model for the assessment of crop water requirements.</p><p>Actual evapotranspiration and irrigation needs were evaluated respectively in rainfed and irrigated simulations. These latter were performed replacing soil moisture at the field capacity when 70% of TAW was reached. Results achieved in three agrarian seasons characterized by low, medium and high rainfall volumes (from June to September) were compared (respectively the years 2009, 2002 and 2014 with about 41 mm, 116 mm and 152 mm of rainfall).</p><p>The results show that in rainfed conditions, for each year, actual evapotranspiration simulated by the models were consistent with each other, with an average RMSE, calculated comparing the models in pairs, of about 1 mm over the season. Differences among the models were mainly observed in the first part of the season (respectively before the thirtieth day after the sowing) and for each year, probably caused by a still limited crop and root development, which highlights the differences in simulating water fluxes exchanges in soil-vegetation domain proposed by three modeling approaches.</p><p>Concerning irrigations, IdrAgra and AquaCrop appear very consistent with each other in volumes and frequency, especially during mid-crop stages and in all years with a total irrigation volume of about 400, 300 and 180 mm and with 10, 12 and 8 irrigation interventions respectively in the years 2009, 2002 and 2014. Results of Sim1Kc were consistent with those obtained by the other models only in mid and end crop season, whereas no irrigations were suggested in the first part of the season.</p>
The effects of climate change on water availability affect the performance of surface irrigation,... more The effects of climate change on water availability affect the performance of surface irrigation, which is the oldest and most common method of water application to row crops worldwide. A paradigm shift towards strategies aimed at increasing flexibility of irrigation scheduling and improving the design and management of field layouts and irrigation practices should be explored to promote water conservation at the farm scale. In this study, we investigate how by adopting a more flexible irrigation scheduling and optimizing irrigation management variables and field layout it is possible to increase the efficiency of border irrigation and thus achieve water conservations and improve quality of crop production. The analysis of the actual performance of border irrigation was carried out on two maize fields located in the Padana Plain (Northern Italy) in 2 years characterized by different rainfall patterns (i.e. 2021 and 2022). Based on this information, continuous monitoring of soil mois...
The effects of climate change on water availability affect the performance of surface irrigation,... more The effects of climate change on water availability affect the performance of surface irrigation, which is the oldest and most common method of water application to row crops worldwide. A paradigm shift towards strategies aimed at increasing flexibility of irrigation scheduling and improving the design and management of field layouts and irrigation practices should be explored to promote water savings at the farm scale. In this study, we investigate how adopting a more flexible irrigation scheduling and optimizing irrigation management variables and field layout it is possible to increase the efficiency of border irrigation and thus achieve water savings and improve quality of crop production. The analysis of the actual performance of border irrigation was carried out on two maize fields located in the Padana Plain (Northern Italy) in two years characterized by different rainfall patterns (i.e. 2021 and 2022). Based on this information, continuous monitoring of soil moisture status ...
Evaluating the performance of border irrigation through a glimpse at what happens in northern Italy
<p>Achieving a good irrigation performance is not straightforward in border irrigat... more <p>Achieving a good irrigation performance is not straightforward in border irrigation practices. This is almost always due to a lack of balance between natural factors (i.e. soil texture, infiltration characteristics), geometrical features (filed length, slope and border strip width) and management elements (flow rate and cut-off time). Such lack of balance makes it difficult to reach an optimal water depth across the field and a uniform intake opportunity time to satisfy crop water requirements at every point. In light of these concerns, studies investigating the current irrigation performance of border irrigated fields, and the potential improvements in irrigation managements are needed in order to better understand how we can keep this ancient but still crucial irrigation method alive.</p> <p>In this work, the results of an intensive monitoring campaign of more than ten border strip irrigation events carried out between the years 2021 and 2022 over two maize fields located in the Padana Plain (North Italy), are analyzed to understand the current performance level of this practice. Specifically, observed variables at the experimental sites included the actual flow rate, cut-off time and distance, advance and recession trajectories and water distribution uniformity, were investigated and their spatio-temporal variability discussed. Then, the IrriSurf2D model which is constituted by an integrated 2D hydrodynamic modelling framework intended to describe the dynamics of surface irrigation, was used for reproducing waterfront propagation under new irrigation management practices, i.e. different irrigation durations, flow rates and border layouts (slopes and border widths).</p> <p>Results show that microtopography, border width and antecedent moisture conditions before the irrigation intervention, plays a key role in the advancement of the waterfront along the longitudinal direction of the field and in the spatial variability of the water depth. A significant variability in time of advance and recession trajectories was observed over the experimental fields, whereas the distribution uniformity was generally consistent with literature standards. Additionally, the fields could be irrigated in considerably less time if the cut-off time is adjusted in according with the real flow rate and border layout. In general, the study has demonstrated a great potential to significantly improve irrigation performance by applying alternative field designs and operation strategies. These findings pave the way to define suitable guidelines for practical field irrigations with positive impacts in terms of water distribution uniformity and water saving. </p>
ArduHydro is a low-cost device for water level measurement and monitoring designed for a short an... more ArduHydro is a low-cost device for water level measurement and monitoring designed for a short and long-term employment in controlled and outdoor environments. It measures water level through an ultrasonic sensor and elaborates the signals through an Arduino micro controller. The small size of this device, the low energy required for its operation, its robustness and accuracy make ArduHydro properly versatile for different applications in the eld for water control and management. This article describes the design, the components, the costs, and the performance of ArduHydro. Performance was assessed with a laboratory test inside a hydraulic circuit constituted by an open channel ume and comparing ArduHydro measurements with those obtained with a traditional ultrasonic sensor. An example of ArduHydro application for detecting the wavefront evolution during a surface irrigation is presented as well. The results revealed that ArduHydro measurements were on average very consistent with those obtained by the traditional ultrasonic sensor in all different ow conditions (i.e. different owrate and water depth) demonstrating its reliability and accuracy in the measuring water level. The application of ArduHydro during a surface watering of an agricultural eld allowed to obtain important spatio-temporal information about the water depth along the longitudinal direction of the eld, paying the way for a real comprehension of the dynamics of wavefront evolution in a real-world case study. potential in the root zone, Ravazzani (2017) developed a portable probe for the quanti cation of the soil moisture, while Chiaradia et al. (2015) realized a multisensory system for the continuous monitoring of water dynamic in rice elds. One of the most important hydraulic parameters to control is water level, which can be useful for several applications, such as water ow monitoring and management, prediction of ood and drought and smart
ArduHydro is a low-cost device for water level measurement and monitoring designed for a short an... more ArduHydro is a low-cost device for water level measurement and monitoring designed for a short and long-term employment in controlled and outdoor environments. It measures water level through an ultrasonic sensor and elaborates the signals through an Arduino micro controller. The small size of this device, the low energy required for its operation, its robustness and accuracy make ArduHydro properly versatile for different applications in the field for water control and management. This article describes the design, the components, the costs, and the performance of ArduHydro. Performance was assessed with a laboratory test inside a hydraulic circuit constituted by an open channel flume and comparing ArduHydro measurements with those obtained with a traditional ultrasonic sensor. An example of ArduHydro application for detecting the wavefront evolution during a surface irrigation is presented as well. The results revealed that ArduHydro measurements were on average very consistent wi...
Topographic depressions in Digital Elevation Models (DEMs) have been traditionally seen as a feat... more Topographic depressions in Digital Elevation Models (DEMs) have been traditionally seen as a feature to be removed as no outward flow direction is available to route and accumulate flows. Therefore, to simplify hydrologic analysis for practical purposes, the common approach treated all depressions in DEMs as artefacts and completely removed them in DEMs’ data preprocessing prior to modelling. However, the effects of depression filling on both the geomorphic structure of the river network and surface runoff is still not clear. The use of two-dimensional (2D) hydrodynamic modeling to track inundation patterns has the potential to provide novel point of views on this issue. Specifically, there is no need to remove topographic depression from DEM, as performed in the use of traditional methods for the automatic extraction of river networks, so that their effects can be directly taken into account in simulated drainage patterns and in the associated hydrologic response. The novelty intro...
Hydraulic Characterization of River Networks Based on Flow Patterns Simulated by 2‐D Shallow Water Modeling: Scaling Properties, Multifractal Interpretation, and Perspectives for Channel Heads Detection
Comparing different FAO approaches for assessing irrigation needs and scheduling: application on a maize field in Mediterranean area
<p>Selecting the best irrigation management is required for improved use of water r... more <p>Selecting the best irrigation management is required for improved use of water resources and for achieving sustainable crop productions. That selection implies accurate predictions of crop water requirement in response to meteorological variables and phenological stages. A plethora of irrigation models are reported to date in literature, many of which are based on three different approaches proposed by the FAO organization, the single and double crop coefficient methods and, the canopy-cover curve determination included in the AquaCrop model.</p><p>The objective of this study is to compare irrigation needs and scheduling obtained by the three aforementioned approaches in the agricultural context of the Po River Plain (northern Italy). The first and the second approaches were simulated respectively by Sim1Kc and IdrAgra models, which implemented the algorithms and crop parameterizations reported in FAO paper 56 for a crop water requirement estimation. While the third approach was simulated by the open source version of AquaCrop software.</p><p>Models were tested on a maize plot located in the lower-east part of Lombardy Po River Plain characterized by a humid sub-tropical climate, according Köppen classification. A single sandy-loam layer profile of medium-textured soil 1 m deep was considered for the simulation. Crop parameters values in Sim1Kc and AcquaCrop models were mutuated from the IdrAgra model, which is routinely applied in the region as the reference model for the assessment of crop water requirements.</p><p>Actual evapotranspiration and irrigation needs were evaluated respectively in rainfed and irrigated simulations. These latter were performed replacing soil moisture at the field capacity when 70% of TAW was reached. Results achieved in three agrarian seasons characterized by low, medium and high rainfall volumes (from June to September) were compared (respectively the years 2009, 2002 and 2014 with about 41 mm, 116 mm and 152 mm of rainfall).</p><p>The results show that in rainfed conditions, for each year, actual evapotranspiration simulated by the models were consistent with each other, with an average RMSE, calculated comparing the models in pairs, of about 1 mm over the season. Differences among the models were mainly observed in the first part of the season (respectively before the thirtieth day after the sowing) and for each year, probably caused by a still limited crop and root development, which highlights the differences in simulating water fluxes exchanges in soil-vegetation domain proposed by three modeling approaches.</p><p>Concerning irrigations, IdrAgra and AquaCrop appear very consistent with each other in volumes and frequency, especially during mid-crop stages and in all years with a total irrigation volume of about 400, 300 and 180 mm and with 10, 12 and 8 irrigation interventions respectively in the years 2009, 2002 and 2014. Results of Sim1Kc were consistent with those obtained by the other models only in mid and end crop season, whereas no irrigations were suggested in the first part of the season.</p>
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Papers by Fabiola Gangi