Location: Water Management Research
2021 Annual Report
Objectives
1. Develop new tools and strategies for management of alfalfa production in the western U.S. that conserves scarce water resources, maintains water quality, and leads to high quality dairy forage and the delivery of environmental services. (C1: 1A; C3: 3A, 3B)
2. Develop and evaluate tools, technologies and strategies for improved harvesting, storage and handling of alfalfa forage that ensures the delivery of dairy forage of high quality and nutritional value. (C1: 1A; C3: 3B; C4: 4B, 4C)
Approach
Objective 1: The hypothesis for this research is that water use efficiency and water quality can be improved in alfalfa production in the arid and semi-arid western U.S. while maintaining high nutritional value as dairy forage. Plot- and farm- scale experiments will be carried out to quantify water productivity of existing production systems of alfalfa and other forage crops (corn silage, grain forages, etc.) and to test production potential using more efficient irrigation methods such as drip irrigation and reuse of low quality water. Crop yield and quality will be determined and analyzed to assess the effect of new water management strategies on water savings and water quality. If the initial plan with drip irrigation or low quality water is not feasible, current irrigation methods with improved irrigation scheduling strategies such as deployment of cloud-based soil and plant water status sensors or aerial evapotranspiration surveillance with drones will be used as the alternate approach.
Objective 2: The research goal for this study is to develop new tools and technologies to improve the current process involved with the harvesting, storage, and handling of alfalfa as high quality dairy forage. Both laboratory and field experiments will be carried out to evaluate the current practices of harvesting, storage, and handling of alfalfa forage, their effects on forage quality, and determine the potential processes that can be improved for maximizing operation efficiency and preserving forage quality. New tools, technologies, or management strategies will be tested for the improvement of the harvesting, storage, and handling of alfalfa forage for sustainable dairy production. If selected tools and techniques do not meet the industrial needs for dairy production, additional technologies will be added to the study.
Progress Report
This is the final report for project 2034-13210-001-00D, “Improved Management, Quality and Utilization of Alfalfa for Dairies in the Western U.S.,” which has been replaced by new project 2034-13210-002-00D with the same title in June 2021. For additional information, see the new project report.
In support of Objective 1, a sprinkler irrigation system was installed with the capacity to apply water at three different schedules over four replicated field plots. Each sprinkler nozzle head was fitted with a pressure regulator so that uniform water application can be achieved when sufficient water pressure is available at the source. Ten alfalfa non-dormant varieties, representing Roundup and non-Roundup ready, conventional, reduced lignin, were planted. Uniform irrigation was applied to establish the crop until after the first harvest. Differential irrigation and cutting schedule treatments were initiated after the first base line cut. Time domain reflectometry and neutron probe access tubes were installed for measurement of soil water content. One week before harvest, alfalfa leaf photosynthetic rate, stomatal conductance, and leaf area index were measured from selected treatment plots. After the first cut, weekly plant sampling, plant height, and leaf-stem partitioning measurements were initiated in selected treatment plots for determining growth dynamics. Multispectral aerial images of the experimental plots were obtained using a small unmanned aerial vehicle, or drone. A hand-held multispectral radiometer was also used to measure canopy reflectance in the blue, green, red, near-infrared, and thermal infrared wavebands.
In support of Objective 2, research was initiated to evaluate cutting schedule treatments on alfalfa yield and forage quality. Watermark sensors were installed at multiple depths and locations for measurement of soil water content from replicated field plots under the different cutting schedule treatments. Before mechanical plot harvest, plant height and hand plant sampling were taken from each plot for analysis of alfalfa nutritional quality. Alfalfa yield was measured using a plot harvester equipped with an automated weighing mechanism. Harvests were made on 28-day, 35-day, and alternating (between 21- and 35-day) schedules. Multispectral aerial images of the experimental plots were obtained for Normalized Difference Vegetation Index (NDVI) calculations. In a different field trial, a baseline cutting schedule was established on 35-day intervals. Uniform irrigation was applied to the experimental field to meet crop water demands. One week before harvest, alfalfa leaf photosynthetic rate, stomatal conductance, leaf area index were measured from selected treatment plots. After the first baseline cut, weekly plant sampling, plant height, and leaf-stem partitioning measurements were initiated in selected treatment plots for determining growth dynamics. Before mechanical plot harvest, hand plant sampling was also taken from each plot for analysis of alfalfa nutritional quality. Alfalfa plot yield was measured using a small plot harvester equipped with an automated weighing mechanism.
In addition to the progress on the objectives, significant progress was made on establishing the new project and building a new alfalfa research program in the unit. Major advances were achieved with regards to personnel recruitment, initiating field research, establishing research collaborations with university researchers and stakeholders, and writing and completing a project plan.
With respect to alfalfa field research, eight studies were initiated by ARS Parlier alone or in collaboration with university and dairy farmers. They are: (1) Alfalfa cutting schedule field plot study at University of California Kearney Agricultural Center, (2) Alfalfa variety field plot study at ARS Parlier field station, (3) Alfalfa yield, quality and water use efficiency under different sprinkler irrigation and cutting schedule treatments field plot study at ARS Parlier field station, (4) Alfalfa yield, quality, and spatial variability under subsurface drip and flood irrigation under commercial production at Wegis and Young Farming Company, Bakersfield, California, (5) Alfalfa yield and quality under deficit irrigation with subsurface drip and flood irrigation at University of California Kearney Agricultural Center, (6) Effect of intermittent flooding for groundwater recharge on alfalfa growth, yield, and forage quality at University of California Kearney Agricultural Center, (7) Analysis of reduced-lignin and control alfalfa traits and sheep digestibility study at University of California Davis, and (8) Alfalfa production and water use efficiency under subsurface drip irrigation in the U.S. Great Plains area at Kansas State University Northwest research and Extension Center, Colby, Kansas. Thousands of alfalfa samples were collected from these projects for yield and nutrient analysis. Additional data were also collected on alfalfa water use, soil moisture, and aerial images using drones and other sensors.
With respect to establishing research collaborations, research agreements were created with Kansas State University, University of California Kearney Agricultural Research Center, University of California, Davis, and the Wegis and Young Farming Company, Bakersfield, California. Regular communications were made on research updates for these collaborative projects. Communications have also been made with the National Alfalfa and Forage Alliance and its members in the Western United States and California Alfalfa and Forage Association to identify research priorities.
Accomplishments
Review Publications
Begna, S.H., Angadi, S., Mesbah, A., Umesh, M., Stamm, M. 2021. Forage yield and quality of winter canola-pea mixed cropping system. Sustainability. 13(4). Article 2122. https://doi.org/10.3390/su13042122.
Paye, W., Begna, S.H., Ghimire, R., Angadi, S., Singh, P., Umesh, M., Darapuneni, M. 2021. Winter canola yield and nitrogen use efficiency in a semiarid irrigated condition. Agronomy Journal. 113(2):2053-2067. https://doi.org/10.1002/agj2.20611.
