DETERMINING THE CONSUMPTIVE WATER USE OF CROPS IN COLORADO FOR EFFICIENT IRRIGATION

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1019719
• Project Start Date: Jul 1, 2019
• Project End Date: Jun 30, 2024
• Program Code: [(N/A)]- (N/A)

Recipient Organization
COLORADO STATE UNIVERSITY
(N/A)
FORT COLLINS,CO 80523

Performing Department
Soil and Crop Science

Non Technical Summary
Water transfers from agriculture to growing municipalities, well shutdowns, tighter regulations for compact compliance in major river basins, and droughts have reduced the availability of water for irrigation. Among the Western states, Colorado is one of the hardest hit. These pressures on irrigation water supplies require increased efficiency of irrigation. The application of correct amounts of irrigation water, based on knowledge of local crop consumptive water use or evapotranspiration (ETc), is essential for increasing irrigation application efficiency. This project aims to improve the estimation of ETc for common irrigated crops in Colorado using daily weather data and simple models of crop development and irrigation water requirements (IWR). The improved ETc and IWR calculations will be incorporated and tested in the Water Irrigation Scheduler for Efficient Application (WISE) online tool that was developed for Colorado. The use of WISE for day-to-day irrigation scheduling will be demonstrated to irrigators, crop consultants, water managers, and water conservationists in Colorado. Increased adoption of WISE for ETc - based irrigation scheduling is expected to reduce over-irrigation and nutrient losses while improving crop yields.

Animal Health Component

100%

Research Effort Categories

Basic

(N/A)

Applied

100%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
111	0210	2050	100%

Knowledge Area
111 - Conservation and Efficient Use of Water;

Subject Of Investigation
0210 - Water resources;

Field Of Science
2050 - Hydrology;

Keywords

evapotranspiration

irrigation

scheduling

efficiency

Goals / Objectives
Develop local crop coefficient (Kc) curves for estimating crop evapotranspiration (ETc) from alfalfa reference crop ET values (ETr) calculated using the American Society of Civil Engineers (ASCE) standardized reference ET equation.Incorporate and test newly developed Kc curves in the Water Irrigation Scheduler for Efficient Application (WISE) online tool that was developed for Colorado.Demonstrate the use of WISE for tactical irrigation scheduling at Extension events across Colorado.

Project Methods
Development of local Kcr curvesThe two precision weighing lysimeters at AVRC will be the primary sources of actual ETc data for this project (Andales et al., 2018; Berrada et al., 2008). Hourly measured ETc from the lysimeters will be aggregated to daily values. Hourly weather data from an automatic weather station adjacent to the lysimeter fields will be used in the hourly version of the ASCE standardized reference ET equation to calculate alfalfa (tall) reference ETr (Allen et al., 2005). Hourly ETr will be aggregated to daily values. The daily Kcr will be calculated as Kcr = ETc / ETr. Daily Kcr values will be plotted against growing degree days (°C·days) or days after planting or green up to develop crop-specific Kcr curves (e.g., Andales et al., 2018). Grass hay and dry beans will be the crops grown on the lysimeters in 2019. Subsequent crops on the lysimeters will be selected in coordination with CDWR.In addition to lysimeter data, actual ETc estimated by water balance or eddy correlation at other irrigated sites will be used to develop Kcr curves for other crops. Additional sites will include the Limited Irrigation Research Farm (LIRF), Greeley, CO (managed by USDA-Agricultural Research Service) and several Colorado Agricultural Experiment Station (CAES) sites (e.g., ARDEC, Fort Collins, CO; SLVRC, Center, CO; Fruita Research Station, Fruita, CO).Incorporation and testing of new Kcr curves in WISENewly developed Kcr curves from the lysimeter project at AVRC and from other sites will be incorporated in the WISE tool, as they become available. The new Kcr curves will be used with ETr values calculated from local weather data to estimate daily ETc values. The daily ETc values will then be used in the soil water balance equation to estimate irrigation water requirements (Andales et al., 2014). Priority crops to be tested will include dominant irrigated crops such as grass hay (eastern Colorado and West Slope), potatoes and barley (San Luis Valley), and dry beans (eastern Colorado).Field tests of the new Kcr curves in WISE will primarily be done at the sites mentioned in the previous section, in close collaboration with researchers or Water Resource Specialists already working at those sites. Each field test will involve root zone soil water content monitoring, recording of crop developmental stages, leaf area index or canopy cover measurements, and field measurements of actual ETc by water balance, eddy covariance, or remote sensing techniques. The ETc estimated from the product of daily ASCE standardized ETr and corresponding Kcr values will be compared to field measurements of ETc. Reduced ETc estimated by WISE using the soil water stress coefficient (KS; Allen et al., 2007; Andales et al., 2014) will also be evaluated using deficit irrigation data sets. Adjustments to the Kcr curves will be made to improve agreement between calculated and field-measured ETc or soil water deficit values.Demonstration of WISEThe project team has previously demonstrated WISE to various stakeholders and organizations such as irrigating farmers, Colorado Corn Growers Association, Rocky Mountain Agribusiness Association, Western Sugar Cooperative, USDA-Natural Resources Conservation Service, Northern Water, Pioneer, Budweiser (Fort Collins Plant), MillerCoors, Coca Cola, and several Water Conservancy Districts. The project team will continue to work with the CSU Extension Water Resources Team to promote the adoption of WISE across the State. Live demonstrations of the tool will be given at annual Extension Crops Clinics and special Irrigation Water Management workshops as well as regional outreach conferences such as the Central Plains Irrigation Conference (https://www.ksre.k-state.edu/sdi/revents/cpia.html). Results from field tests and publications from this project will be uploaded to the WISE website (http://wise.colostate.edu/).

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:This project benefits crop irrigators, water managers, crop consultants, and water conservationists in Colorado. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Twenty-three (23) producers in the Republican River basin of Colorado were provided basic theoretical background on evapotranspiration (ET) estimation from weather data and its use in water balance-based irrigation scheduling tools such as WISE. The basin has rapidly declining groundwater because of irrigation pumping rates that exceed groundwater recharge from precipitation. Irrigation scheduling based on water balance was demonstrated as a viable tool to conserve water and reduce groundwater pumping. The producers were also introduced to concepts of short-term ET and rainfall forecasts and how they are incorporated in irrigation scheduling. The information was shared to producers on February 17, 2020 as part of the Colorado Master Irrigator Program (http://www.comasterirrigator.org/). Program participants in 2020 are involved in managing more than 20,000 irrigated acres located within/across all 8 Republican River Basin counties in northeastern CO; this is more than 1/20th of the Basin's irrigated acres. How have the results been disseminated to communities of interest?Four peer-reviewed articles were published to disseminate results to water scientists and engineers. Two conference presentations were also given to an international or state-wide audience. A workshop demonstrating the use of the WISE online tool for tactical irrigation scheduling was also presented to 23 participants in the Colorado Master Irrigator Program. The WISE tool is freely available online at http://wise.colostate.edu/. What do you plan to do during the next reporting period to accomplish the goals?The ETc and crop growth data for corn and grass hay that were collected in the 2020 growing season will be processed and quality checked. These data will be used to improve the seasonal Kc curves for corn and grass hay under southeast Colorado conditions. The improved seasonal Kc curves will be incorporated into the WISE tool and shared with the Colorado Division of Water Resources for their use in consumptive use modeling in the Arkansas River Basin (southeast Colorado). WISE will be demonstrated and validated for more crops and locations across Colorado. Dry beans will be planted on one lysimeter to collect a second growing season of dry bean ETc data (to augment 2019 data), while the existing grass hay mixture on the other lysimeter will be maintained at Rocky Ford, CO for the 2021 growing season.

Impacts
What was accomplished under these goals? A crop coefficient (Kc) curve for sugar beets adapted for growing conditions in the High Plains (including northeast Colorado) was developed, incorporated into WISE, and published in the journal Applied Engineering in Agriculture. The WISE online tool with the sugar beet Kc curve has been made available to over 850 growers belonging to the Western Sugar Cooperative that operates in Colorado, Nebraska, Wyoming, and Montana. Hourly and daily ETc data were collected for one season of corn under sprinkler irrigation and a second season of grass hay under furrow irrigation from two precision weighing lysimeters during 2020. Evapotranspiration data were processed for grass hay and dry beans (pinto beans) from the 2019 growing season. Use of the WISE tool for tactical irrigation scheduling was demonstrated at one producer-focused workshop and two conferences.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Andales, A.A., Bartlett, A.C., Bauder, T.A., Wardle, E.M. 2020. Adapting a cloud-based irrigation scheduler for sugar beets in the High Plains. Applied Engineering in Agriculture 36(4):479-488. doi: 10.13031/aea.13902
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Taghvaeian, S., Andales, A., Allen, N., Kisekka, I., O'Shaughnessy, S., Porter, D., Sui, R., Irmak, S., Fulton, A., Aguilar, J. 2020. Irrigation scheduling for agriculture in the United States: The progress made and the path forward. Transactions of the ASABE 63(5)1603-1618. doi: 10.13031/trans.14110
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Jones, A.S., Andales, A.A., Ch�vez, J.L., McGovern, C.L., Smith, G.E.B., David, O., Fletcher, S.J. 2020. Use of Predictive Weather Uncertainties in an Irrigation Scheduling Tool - Part I: A Review of Metrics and Adjoint Methods. Journal of the American Water Resources Association 56(2):187-200. https://doi.org/10.1111/1752-1688.12810.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Jones, A.S., Andales, A.A., Ch�vez, J.L., McGovern, C.L., Smith, G.E.B., David, O., Fletcher, S.J. 2019. Use of Predictive Weather Uncertainties in an Irrigation Scheduling Tool - Part II: An Application of Metrics and Adjoints. Journal of the American Water Resources Association 56(2):201-211. https://doi.org/10.1111/1752-1688.12806.

Progress 07/01/19 to 09/30/19

Outputs
Target Audience:This project benefits crop irrigators, water managers, crop consultants, and water conservationists in Colorado. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?One PhD student was trained on how to use WISE for subsurface drip irrigation scheduling of alfalfa hay during the 2019 growing season. How have the results been disseminated to communities of interest?Information about dry bean ETc measurements using a precision weighing lysimeter in southeast Colorado were shared with 13 individuals affiliated with the dry bean industry in eastern Colorado. What do you plan to do during the next reporting period to accomplish the goals?The ETc and crop growth data for dry beans and grass hay that were collected in the 2019 growing season will be processed and quality-checked. These data will be used to develop seasonal Kc curves for dry bean and grass hay under southeast Colorado conditions. The seasonal Kc curves will be incorporated into the WISE tool. WISE will be demonstrated and validated for more crops and locations across Colorado. Grain corn will be planted on one lysimeter, while the existing grass hay mixture on the other lysimeter will be maintained at Rocky Ford, CO for the 2020 growing season.

Impacts
What was accomplished under these goals? Hourly and daily ETc data were collected for one season of dry beans and a second season of grass hay during 2019. Evapotranspiration data were processed for grass hay from the 2018 growing season.

Publications