Papers by Jonathan Aguilar
Water
The Ogallala Aquifer underlies 45 million ha, providing water for approximately 1.9 million peopl... more The Ogallala Aquifer underlies 45 million ha, providing water for approximately 1.9 million people and supporting the robust agriculture economy of the US Great Plains region. The Ogallala Aquifer has experienced severe depletion, particularly in the Southern Plains states. This paper presents policy innovations that promote adoption of irrigation technology, and management innovations. Innovation in Kansas water policy has had the dual effects of increasing the authority of the state to regulate water while also providing more flexibility and increasing local input to water management and regulation. Technology innovations have focused on improved timing and placement of water. Management innovations include soil water monitoring, irrigation scheduling, soil health management and drought-tolerant varieties, crops, and cropping systems. The most noted success has been in the collective action which implemented a Local Enhanced Management Area (LEMA), which demonstrated that reduced ...
Water
Soil salinization is one of the significant concerns regarding irrigation with saline waters as a... more Soil salinization is one of the significant concerns regarding irrigation with saline waters as an alternative resource for limited freshwater resources in arid and semi-arid regions. Thus, the investigation of proper management methods to control soil salinity for irrigation with saline waters is inevitable. The HYDRUS-1D model is a well-known numerical model that can facilitate the exploration of management scenarios to mitigate the consequences of irrigation with saline waters, especially soil salinization. However, before using the model as a decision support system, it is crucial to calibrate the model and analyze the model’s parameters and outputs’ uncertainty. Therefore, the generalized likelihood uncertainty estimation (GLUE) algorithm was implemented for the HYDRUS-1D model in the R environment to calibrate the model and assess the uncertainty aspects for simulating soil salinity of corn root zone under saline irrigation with linear move sprinkle irrigation system. The resu...
Agronomy
Utilizing degraded quality waters such as saline water as irrigation water with proper management... more Utilizing degraded quality waters such as saline water as irrigation water with proper management methods such as leaching application is a potential answer to water scarcity in agricultural systems. Leaching application requires understanding the relationship between the amount of irrigation water and its quality with the dynamic of salts in the soil. The HYDRUS-1D model can simulate the dynamic of soil salinity under saline water irrigation conditions. However, these simulations are subject to uncertainty. A study was conducted to assess the uncertainty of the HYDRUS-1D model parameters and outputs to simulate the dynamic of salts under saline water irrigation conditions using the Markov Chain Monte Carlo (MCMC) based Metropolis-Hastings algorithm in the R-Studio environment. Results indicated a low level of uncertainty in parameters related to the advection term (water movement simulation) and water stress reduction function for root water uptake in the solute transport process. ...
Frontiers in Agronomy
Variable rate irrigation (VRI) requires accurate knowledge of crop water demands at the sub-field... more Variable rate irrigation (VRI) requires accurate knowledge of crop water demands at the sub-field level. Existing VRI practices commonly use one or more variables like soil electrical conductivity, historical yields, and topographic maps to delineate variable rate zones. However, these data sets do not quantify within season variability in crop water demands. Crop coefficients are widely used to help estimate evapotranspiration (ET) at different stages of a crop’s growth cycle, and past research has shown how remotely sensed data can identify differences in crop coefficients at regional and field levels. However, the amount of spatial and temporal variation in crop coefficients at the sub-field level (i.e. within a single center pivot system) has not been widely researched. This study aims to compare sub-field ET estimates from two remote sensing platforms and quantify spatial and temporal variations in aggregated sub-field level ET. Vegetation indices and reference ET data were col...
2022 Houston, Texas July 17-20, 2022
2018 Detroit, Michigan July 29 - August 1, 2018, 2018
Recent innovations in the irrigation industry indicate a transition to more water efficient and u... more Recent innovations in the irrigation industry indicate a transition to more water efficient and uniform systems. This transition is necessary to preserve limited aquifer resources used by irrigation systems in the U.S. Great Plains where center pivot irrigation has become the dominant irrigation method. New in-canopy sprinkler packages have allowed these center pivot systems to operate more efficiently and uniformly, however, these in-canopy sprinklers hang low in the canopy and have the potential to become entangled in crop biomass and detach from the center pivot. Detached in-canopy sprinklers can impact the uniformity of the irrigation system resulting in decreased crop yields by disrupting the designed flow and pressure requirements of the sprinkler package. Therefore, it is crucial that producers detect and replace missing in-canopy sprinklers immediately. The current method to detect missing in-canopy sprinklers is manual inspection along the center pivot which uses significant time and labor. A monitoring system to alert the user of any detachments can eliminate unnecessary exploration and direct the user to the specific location of the detached in-canopy sprinkler. A prototype in-canopy sprinkler monitoring system was designed to monitor in-canopy sprinklers on a center pivot irrigation system and alerts the user when and where an in-canopy sprinkler becomes detached from the center pivot span. The system utilizes three major components to accomplish this task: a master controller node, a series of sprinkler nodes, and a digital compass node. The master controller node requests the status of in-canopy sprinklers from each connected sprinkler node, which constantly monitors its connected in-canopy sprinkler, and if a sprinkler is found to be missing alerts the user via an SMS text message sent to their cell phone that the in-canopy sprinkler is missing and can be found at specific geographic coordinates. The master controller node calculates the geographic coordinates of the detached in-canopy sprinkler by requesting the current compass bearing angle of the center pivot span from the digital compass node. This angle, combined with the known coordinates of the pivot point of the center pivot system and radius of the detached in-canopy sprinkler from the pivot point can be used to calculate the coordinates of the detached in-canopy sprinkler. To test the performance of the designed system, it was connected to a demonstration center pivot and several trials were performed. The demonstration center pivot consisted of a rotatable span with eight detachable drop hoses and in-canopy sprinklers. Trials performed were designed to test the system's ability to react to detached in-canopy sprinklers and drop hoses, detect and identify issues that might arise during normal operation, and respond to user's SMS text messages with the proper system information as part of the user interface. The system successfully passed each set of trials ensuring that this prototype will accurately detect when and where an in-canopy sprinkler becomes detached and promptly alert the user. v
Journal of Irrigation and Drainage Engineering, 2021
The preservation of limited aquifer resources in the US Great Plains has driven the innovation an... more The preservation of limited aquifer resources in the US Great Plains has driven the innovation and deployment of more efficient sprinkler packages for center pivot irrigation systems. One of the more efficient sprinkler packages available are in-canopy sprinkler packages, which hang low in the canopy. Although effective, they have the potential to become entangled in crop biomass and detach from the center pivot. Such detachments impact the efficiency and uniformity of the system, resulting in disrupted flow and pressure conditions, ultimately decreasing crop yield. Therefore, it is crucial that producers detect and replace missing in-canopy sprinklers immediately. A novel prototype monitoring system was designed using low-cost, publicly available technologies to monitor in-canopy sprinklers on a center pivot irrigation system and alert the user when and where an in-canopy sprinkler has become detached from the center pivot span. Later design revisions of the monitoring system introduced the ability of the monitoring system to also detect when a sprinkler became clogged. Experimental trials verified that the monitoring system operates efficiently and accurately; however, minor changes need to be made before large-scale implementation is possible.
Overall, SDI systems have been successful in the Great Plains region despite minor technical diff... more Overall, SDI systems have been successful in the Great Plains region despite minor technical difficulties during the adoption process. In a 2005 survey of SDI users, nearly 80% of Kansas producers indicated they were at least satisfied with the performance of their SDI system, and less than 4% indicated they were unsatisfied (Alam & Rogers, 2005). However, even satisfied users indicated a need for additional SDI management information. The most noted concern was rodent damage and subsequent repairs. A few systems had failed or been abandoned after limited use due to inadequate design, inadequate management, or a combination of both.
Freddie R. Lamm Research Irrigation Engineer Northwest Research-Extension Center Colby, Kansas Vo... more Freddie R. Lamm Research Irrigation Engineer Northwest Research-Extension Center Colby, Kansas Voice: 785-462-6281 Fax 785-462-2315 Email: [email protected] Danny H. Rogers Extension Irrigation Engineer Biological and Agricultural Engineering Manhattan, Kansas Voice: 785-532-5813 Fax 785-532-6944 Email: [email protected] Isaya Kisekka Research Agricultural Engineer Southwest Research-Extension Center Garden City, Kansas Voice: 620-275-9164 Email: [email protected] Jonathan Aguilar Extension Irrigation Specialist Southwest Research-Extension Center Garden City, Kansas Voice: 620-275-9164 Email: [email protected]
Kansas Agricultural Experiment Station Research Reports, 2016
There is limited information on forage sorghum and corn silage yield response to full and deficit... more There is limited information on forage sorghum and corn silage yield response to full and deficit irrigation in Kansas. The objective of this study was to generate information on forage sorghum (brown mid-rib hybrids (BMR and non-BMR)) and corn silage yield response to different levels of irrigation as influenced by irrigation capacity in southwest Kansas. Preliminary results indicate the effect of irrigation capacity on forage yield was significant (P = 0.0009) in 2014 but not 2015, probably due to high growing season rainfall received in 2015. Corn silage produced significantly (p < 0.05) higher biomass at all irrigation capacities compared to forage sorghum hybrids in 2015. BMR forage sorghum produced significantly lower biomass compared to non-BMR hybrid in both 2014 and 2015 (P < 0.05). The highest amounts of forage produced for corn silage, BMR, and non-BMR forage sorghum were 24.6, 17.4, and 21.1 tons/a adjusted to 65%, moisture respectively. Water productivity ranged from 1.0 to 1.4 dry matter tons/a/in. More research is needed under normal and dry years to quantify forage sorghum and corn silage yield and forage quality response to full and deficit irrigation.
Kansas Agricultural Experiment Station Research Reports, 2016
Kansas Agricultural Experiment Station Research Reports, 2015
Irrigation scheduling is crucial to effectively manage water resources and optimize profitability... more Irrigation scheduling is crucial to effectively manage water resources and optimize profitability of an irrigated operation. Tools that can be customized to a field's characteristics can greatly facilitate irrigation scheduling decisions. Soil moisture sensors and the evapotranspiration (ET)-based KanSched are two of the tools that could be implemented in an irrigated farm. Focusing on the installation of soil moisture sensors, demonstration setups were established at the Southwest Research-Extension Center plots in Garden City, Kansas, and in a producer's field, each with three types of moisture sensors at different depths. Among others, this project validates the importance of moisture sensors being installed as early as possible in a representative location with good soil-sensor contact. The moisture sensors, at the least, help in determining when irrigation water should be applied or scheduled. Furthermore, in implementing an irrigation schedule, the irrigation manager considers the irrigation system capacity, the amount that can be efficiently applied, the soil intake rate, and other relevant factors.
2015 ASABE / IA Irrigation Symposium: Emerging Technologies for Sustainable Irrigation - A Tribute to the Career of Terry Howell, Sr. Conference Proceedings, 2015
Declining groundwater levels in the Ogallala aquifer due to withdrawals exceeding annual recharge... more Declining groundwater levels in the Ogallala aquifer due to withdrawals exceeding annual recharge result in diminished well capacities that eventually become incapable of meeting full crop water needs. Producers need recommendations for deficit irrigation strategies that can maximize net returns in most years under low well capacities. The objectives of this study were to (1) calibrate and validate the CERES-Maize model in DSSAT-CSM v4.6 under southwest Kansas soils and climatic conditions and (2) apply the calibrated model to assess three factors related to irrigation management: (i) the optimum plant-available water threshold to initiate irrigation for maximizing net returns, (ii) the effect of percentage soil water depletion at planting on yield, seasonal transpiration, water productivity, extractable soil water at maturity, and net returns, and (iii) the effect of late irrigation season termination on extractable soil water at physiological maturity, yield, and net returns. The CERES-Maize model in DSSAT-CSM v4.6 in conjunction with short-term experimental data and 63 years (1950 to 2013) of historical weather data were used in this study. The calibrated model was able to predict end of season grain yield with acceptable accuracy (NSE > 0.9, 0.13 < %RMSE < 0.19), indicating that the model could be used for assessing alternative management strategies for optimizing the use of limited water for irrigating corn in southwest Kansas. Irrigation scheduling based on a 50% plant-available water threshold maximized net returns compared to initiating irrigation at greater
With declining well capacities in the Central High Plains resulting from withdrawals exceeding re... more With declining well capacities in the Central High Plains resulting from withdrawals exceeding recharge in the Ogallala aquifer, producers will need to adopt advanced irrigation scheduling to maintain productivity with limited water. A study was conducted to assess the effect of irrigation scheduling approaches based on plant water stress sensing, soil water sensing, and climate (ET), or a combination of these methods on corn growth, yield, and water productivity of two hybrids (conventional and drought tolerant), seasonal crop water use, and total irrigation applications. The study involved five irrigation scheduling treatments applying 80% of full irrigation and a control (full irrigation) treatment and two corn hybrids arranged in a split-plot design. Results indicate there were no significant differences in yield among irrigation scheduling methods (p-value=0.38). However, there were significant differences in yield between conventional and drought tolerant corn hybrids (p-value...
Kansas Agricultural Experiment Station Research Reports
The farmers within the Ogallala aquifer desire to extend the usable life of this aquifer despite ... more The farmers within the Ogallala aquifer desire to extend the usable life of this aquifer despite experiencing diminishing well capacities, thus the quest for more efficient irrigation application technologies. Mobile drip irrigation (MDI), which integrates drip lines onto a mechanical irrigation system such as a center pivot, has attracted their attention lately. The concept is that by applying water along crop rows, it was hypothesized that MDI could eliminate water losses due to spray droplet evaporation, wind drift, and reduce soil evaporation due to limited surface wetting especially before canopy closure. A study was conducted with the following objectives: 1) compare soil water evaporation under MDI and incanopy spray nozzles (low elevation spray application (LESA)); 2) evaluate soil water redistribution under MDI at 60-inch drip line lateral spacing; and 3) compare corn grain yield, and water productivity under MDI and LESA at two well capacities (300 and 600 gpm). The experimental design was randomized complete block with four replications and two treatments (MDI and LESA). Nozzle performance was evaluated using the Spot-on flow measurement device. Soil water evaporation was measured using 4-inch minilysimeters placed between corn rows. The effect of a 60-inch lateral spacing on soil water redistribution was measured using neutron attenuation to a depth of 8 feet. Corn yield was determined from harvesting two 40-foot corn rows in the center of each plot. Measured and design nozzle flow rates were similar indicating the irrigation system was performing as designed. Results indicate that soil water evaporation was lower under MDI compared to LESA by an average of 35%. Soil water was greatest at the mid-point between two drip line laterals spaced 60 inches apart at a depth of approximately 20-24 inches. These results indicate drip line spacing of 60 inches is adequate for silt loam soils of southwest Kansas. The effect of irrigation application method (MDI versus spray nozzles [LESA]) on yield at high (600 gpm) and low (300 gpm) well capacities was not statistically significant at the 5% level (P > 0.05). The effect of application method on water productivity and irrigation water use efficiency was also not significant. The lack of significant differences in yield could be attributed to the above normal rainfall received during the 2015 growing season (18 inches from May to September). However, it is worth noting that the effect of application method on end-of-season soil water was statistically significant under low well capacity (300 gpm) with mobile drip irrigation having more soil water compared to spray nozzles.
Sustainability
A decrease in water resources, as well as changing environmental conditions, calls for efficient ... more A decrease in water resources, as well as changing environmental conditions, calls for efficient irrigation-water management in cotton-production systems. Cotton (Gossypium sp.) is an important cash crop in many countries, and it is used more than any other fiber in the world. With water shortages occurring more frequently nowadays, researchers have developed many approaches for irrigation-water management to optimize yield and water-use efficiency. This review covers different irrigation methods and their effects on cotton yield. The review first considers the cotton crop coefficient (Kc) and shows that the FAO-56 values are not appropriate for all regions, hence local Kc values need to be determined. Second, cotton water use and evapotranspiration are reviewed. Cotton is sensitive to limited water, especially during the flowering stage, and irrigation scheduling should match the crop evapotranspiration. Water use depends upon location, climatic conditions, and irrigation methods a...
Transactions of the ASABE
HighlightsThe progress made in agricultural irrigation scheduling in the past ten years and the c... more HighlightsThe progress made in agricultural irrigation scheduling in the past ten years and the current challenges are discussed.The main scientific scheduling strategies are based on soil water status, plant characteristics, and crop modeling.Challenges include large time and data requirements and availability of decision support systems.Opportunities include integration of scheduling strategies and demonstrating their effectiveness through local studies.. Irrigation scheduling is the process of determining the appropriate amount and timing of water application to achieve desired crop yield and quality, maximize water conservation, and minimize possible negative effects on the environment, such as nutrient leaching below the crop root zone. Effective irrigation scheduling has been shown to save water, save energy, and help agricultural producers achieve improved yields and quality. However, scientific irrigation scheduling methods generally have remained limited to mostly research ...
Transactions of the ASABE
HIGHLIGHTSUniversity extension has been playing a larger role, serving a larger number of irrigat... more HIGHLIGHTSUniversity extension has been playing a larger role, serving a larger number of irrigated farms.Extension programs in irrigation water management (IWM) have been transitioning away from lectures and field tours as the primary means of knowledge transfer.New IWM programs focus on experiential learning, development of practitioner networks, and industry participation.. Promotion and adoption of irrigation water management (IWM) technology, tools, and best management practices are important as water availability concerns are addressed. Traditional extension programs have relied on lecture presentations, field tours, fact sheets, and on-station demonstrations to promote IWM practices and tools. However, these platforms tend not to provide the experience and opportunity for growers to identify and become comfortable with innovative solutions, such as new technology. To address these challenges and to appeal to an ever-changing client base, innovative and locally relevant extens...
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Papers by Jonathan Aguilar