- Author: Drew Lyon
- Posted by: Gale Perez
In my previous position as the Extension Dryland Cropping Systems Specialist with the University of Nebraska Panhandle Research and Extension Center in Scottsbluff, I focused my research efforts on intensifying and diversifying the winter wheat-fallow cropping system. The addition of summer crops into the rotation was a first step. Inserting summer crops such as proso millet, sunflower, or corn reduced the frequency of summer fallow from every other year to once every three years. Summer crops also helped in the management of winter annual grass weeds such as downy brome, jointed goatgrass, and feral rye. As I looked for ways to eliminate summer fallow from the rotation, my attention turned to forage crops.
Forage crops are typically harvested at about 50% heading (grass crops) or flowering (broadleaf crops). This is often six or more weeks earlier than if the crops were harvested for grain. This earlier harvest provides a couple of benefits. First, it decreases soil water depletion. Water use by crops is typically greatest from the boot or flower bud stage through early grain fill. By harvesting the crop shortly after the start of this heavy water use time, valuable soil water is conserved for the following grain crop, which in western Nebraska, was often winter wheat. The earlier harvest also prevented seed production in many weeds growing in the forage crop. Taken together, these two benefits made forage crops a good alternative for summer fallow. However, there were obstacles to the use of forage crops such as a lack of forage harvesting and handling equipment and limited local markets.
When I arrived in Pullman, WA in 2012, the focus of my program shifted to weed management in wheat production systems. One of the first new weed species I learned about was Italian ryegrass. Italian ryegrass biotypes have developed resistance to eight different herbicide modes of action, which makes managing Italian ryegrass with herbicides very difficult. Some growers have turned to forage crops to help them manage Italian ryegrass.
At a Washing State University (WSU) Weed Science Field Day a few years back, we had a grower tell us that one of his approaches for managing Italian ryegrass was to plant forage barley and harvest the forage barley and Italian ryegrass before they headed and sell it in small bales to horse owners. Italian ryegrass is an excellent forage, and the bales fetched a good price. I thought that was an excellent out-of-the-box approach for managing this very troublesome weed. I could see a similar approach working for feral rye or wild oat management.
I have also noticed that some growers with Italian ryegrass issues have planted alfalfa to manage the problem. Here, Roundup Ready alfalfa could help in the establishment year, but after that, the simple act of harvesting the alfalfa before Italian ryegrass sets seed is all that would be needed. A perennial crop like alfalfa also brings other crop rotation benefits for weed control. Once established, alfalfa competes strongly with annual weeds. The seed of most annual grasses do not survive long in the soil, so keeping alfalfa in for just three or four years will significantly decrease the soil seedbank of annual grass weeds and allow a return to annual cropping with much lower grass weed pressure.
Despite the obstacles to the adoption of forage crops in our dryland cropping systems, forage crops do offer several benefits for weed management. As herbicide resistance becomes more problematic throughout the region, non-chemical approaches to weed management will become more important. I would love to hear how you have used forage crops in your rotation to manage weeds. Please leave a comment so that others can learn from your experience.
Thanks!
Dr. Drew Lyon
Endowed Chair Small Grains Extension and Research, Weed Science
Washington State University
(drew.lyon@wsu.edu)
Original source: Weeders of the West blog | April 25, 2024
- Author: Mike Hsu
Study at Desert Research and Extension Center highlights agriculture's sustainability role
Under the blistering sun of Southern California's Imperial Valley, it's not surprising that subsurface drip irrigation is more effective and efficient than furrow (or flood) irrigation, a practice in which up to 50% of water is lost to evaporation.
But a recent study also concludes that drip irrigation can dramatically reduce greenhouse gas emissions from soil – which contribute to climate change and unhealthy air quality in the region – without sacrificing yields of forage crops alfalfa and sudangrass.
“It was really exciting to see,” said lead author Holly Andrews, a National Science Foundation postdoctoral fellow at the University of Arizona. “The crop yield was at least maintained and in some cases increased, but the water use and gaseous emissions were especially decreased under drip irrigation.”
Desert REC crucial to collecting data
Andrews and her colleagues gathered data from field studies at University of California Agriculture and Natural Resources' Desert Research and Extension Center, a crucial hub of desert agriculture research for more than 100 years. Studies in that context are increasingly important, as much of California and the Southwest becomes hotter and drier.
“We already have this history of looking at drip irrigation at this site, so our study was trying to build on that,” said Andrews, who lauded Desert REC's facilities and staff.
In their study published in Agriculture, Ecosystems & Environment, researchers found that – in comparison to furrow irrigation – drip irrigation in alfalfa slashed per-yield soil carbon dioxide emissions by 59%, nitrous oxide by 38% and nitric oxide by 20%.
Nitrous oxide is a greenhouse gas with nearly 300 times more warming potential as carbon dioxide, and nitric oxide is a precursor to ozone and major contributor to air pollution.
While drip irrigation only decreased water demand 1% in alfalfa, the practice led to a substantial 49% decrease in irrigation for sudangrass. For more fertilizer-intensive sudangrass, drip irrigation also reduced soil emissions of nitrous oxide by 59% and nitric oxide by 49% – the result of drip irrigation making those fertilizers more efficient.
Water management can help mitigate climate change
Studying alfalfa and sudangrass – forage crops with very different fertilizer requirements – was a strategic choice by the researchers. They are number one and number three on the list of most widely grown crops by acreage in the Imperial Valley (Bermudagrass, another forage crop, is number two).
With so much land dedicated to producing these crops, the adoption of drip irrigation at scale could deliver significant benefits to residents' health and quality of life.
“The thought that saving water can increase yields while lowering the emission of trace gases that affect regional air quality and Earth's climate is quite encouraging,” said Pete Homyak, an assistant professor of environmental sciences at UC Riverside who contributed to the study. “This is especially true for the Imperial Valley, an arid region where water is a limited resource and where residents are exposed to bad air quality.”
Homyak, who is affiliated with UC ANR through UC Riverside's Agricultural Experiment Station, said that this study illustrates how changes in water management can substantially mitigate agricultural impacts on the environment.
The study findings should encourage growers to replace furrow irrigation systems with drip irrigation infrastructure – especially in combination with financial incentives from the state, such as cap-and-trade and carbon credit programs, that can help defray high installation costs.
“It really is worthwhile if you're thinking sustainability and environmental activism in how agriculture can actually support climate change mitigation,” Andrews explained. “These practices might be a way that we can start to change that picture a little bit – and make agriculture more sustainable by tailoring irrigation management to local climate conditions.”
In addition to Andrews and Homyak, the other study authors are Patty Oikawa, California State University, East Bay; Jun Wang, University of Iowa; and Darrel Jenerette, UC Riverside.
/h3>/h3>/h2>- Author: Nicholas Clark
This year's Alfalfa and Forage Field Day held on September 19, 2018 at the Kearney Agricultural Research and Extension Center in Parlier, CA, was another success.
The presentations and handouts from that day are now available on the University of CA Alfalfa and Forages website. Click here to reach the page where you can download individual presentation slides and handouts.
ABOUT THE EVENT
Industry sponsorship of this event reached an outstanding level, and the meeting will be funded for another year without the need to reach out to potential sponsors in 2019. Thank you again to our sponsors BASF, Bayer CropScience, Gar Tootelian, Innovative Ag Services, Netafim, Simplot, and Verdegaal Brothers.
PCA's and CCA's earned 1.5 "Other" DPR CEU's and/or 4.0 CCA CEU's in five areas.
This year, non-UC employee guest speaker Tim Hays, PCA with Buttonwillow Warehouse, gave a great presentation about the industry perspective on the state of alfalfa insect IPM.
Of note, we saw about 65 students from Avenal High School attend as part of a work study program sponsored by Wonderful Company in which the students are tracked through all four years of high school, taking college courses and participating in ag professional continuing education. Each successful student will graduate high school with a diploma in addition to an AS degree in an ag field.
AFTER THE MEETING, LOOKING TO 2019
Participants will receive a kind reminder request in their email inbox to fill out an evaluation survey letting us know how we did and what we can improve/provide next time. This meeting is for growers, consultants, allied industry, and agency staff interested in forage production in the San Joaquin Valley, and we need your input to make it worth your while.
- Author: Nicholas Clark
The agenda for the annual Kearney Alfalfa and Forage Field Day is set.
Where: Kearney Agricultural Research and Extension Center; 9240 S. Riverbend Ave.; Parlier, CA 93648
When: Wednesday, September 19, 2018 @ 7:30 AM - 12:15 PM
What: A half day of field tours, hands on demonstrations, and classroom presentations from UC Farm Advisors and Specialists as well as industry professionals. Refreshments and lunch are provided.
Cost: $0.00
1.5 "Other" DPR units have been applied for. 0.5 NM, 1.0 SWM, 1.5 IPM, 0.5 CM, & 0.5 MM CCA credits have been approved.
This meeting is industry sponsored. We thank our sponsors: BASF, Bayer, Gar Tootelian, Innovative Ag Services, Netafim, Simplot, & Verdegaal Brothers.
See the attached agenda for more details
- Author: Vonny M. Barlow
- Author: Daniel Putnam
2015 Western Alfalfa & Forage Symposium will be held in Reno, Nevada on December 2-4 at the Silver Legacy Hotel, with a focus on water, irrigation, pest management and economics.
This is a great opportunity to learn more about alfalfa and other forage crops, and to visit with farmers, scientists, experts in various fields. Eleven Western States have joined forces this year to plan the Symposium. The event will be managed by the California Alfalfa & Forage Association (Sacramento, CA). Typically between 500 and 700 people attend.
Highlights:
- One-Day Alfalfa Irrigation Training Workshop (December 2)
- Economic Trends
- Pest Management Methodologies
- Environmental/Water Issues
- Alternative Forage Crops in a Drought Year
- Forage Quality and Utilization
- Harvesting Technology
PCA and CCA continuing education credits will be offered.
Sponsorship opportunities are available
Exhibits are encouraged (generally 60-70 exhibitors host booths)
For an idea about the previous symposia, visit the 2014 California Alfalfa and Grains Symposium web page (videos and written proceedings).
See the symposium website: http://calhay.org/symposium/ for registration and program information.