Posts Tagged: cover crops
Ventura County Research Symposium
Sustainability Through Soil Health
February 27, 2020
Please join us for a morning of research updates and
speakers highlighting industry trends including:
- Soil Health Assessment and Management:
- Lessons from the Arid and Semiarid Southwest
- Dr. John Idowu, Extension Agronomist & Associate Professor at New Mexico State University
- Messages from Soil Health Research
- in San Joaquin Valley
- Dr. Jeffrey P. Mitchell, CE Cropping Systems Specialist at Kearney Agricultural Research & Extension Center
citrus cover crop
KQED reporter Mark Schapiro discovered a "center of insurrection" at the UC West Side Research and Extension Center in Five Points, where UC Cooperative Extension cropping systems specialist Jeff Mitchell has been building soil on a research plot for 20 years.
Schapiro's story was part of a series titled "Reckoning in the Central Valley," a collaboration between Bay Nature magazine and KQED Science examining how climate change is exposing the vulnerabilities of California agriculture.
In the Central Valley, climate change is disrupting the predictability that is key to maintaining a profitable industrial agriculture system. Mitchell believes that employing practices that build soil - such as reducing or eliminating tillage and planting cover crops - will help farmers ride the wave of climate change.
It's that cover-cropped field “that is the real disruptor here," Mitchell said.
The soil in test plots where cover crops were grown are loaded with far more organic matter than soil in fields where cover crops were not grown. The organic matter improves water absorption, making the land more resilient to drier conditions. Fields with cover crops also sequester carbon and produce crops that may be more nutritious.
“What you see in Five Points,” said Daphne Miller, a physician who studies the links between the health of the foods we eat and the soil in which they're grown, “is that the plots with the greatest diversity of cover crops had the most diverse microbiome in the soil.”
WESTMINSTER, Colorado - An article in the most recent edition of the journal Weed Science shows that cover crops can play an important role in slowing the development of herbicide resistant weeds.
Researchers conducted field experiments in Pennsylvania to explore how cover cropping tactics influenced the management of horseweed in no-till grain crops. Seven cover-cropping treatments were used over two subsequent growing seasons.
There were several significant findings. In comparison to fallow control plots, cover crop treatments reduced horseweed density at the time of a pre-plant, burndown herbicide application by 52% in the first year and 86% in the next. This reduced the herbicide "workload" and lowered the selection pressure for resistant weeds. Cereal rye alone or in combination with forage radish was found to provide the most consistent horseweed suppression.
Importantly, winter hardy cover crops also reduced horseweed size inequality - meaning fewer large horseweed plants were found at the time of herbicide application. Researchers say this reduces the chance of a size-dependent fitness advantage for horseweed biotypes that develop herbicide resistance.
"Our hope is that understanding the complementary relationship between cover crops and herbicides can lead to new weed control strategies that slow the development of herbicide resistance," says John M. Wallace, Ph.D., of Pennsylvania State University.
Full text of the article "Cover crop effects on horseweed (Erigeron canadensis) density and size inequality at the time of herbicide exposure" is now available in Weed Science Volume 67, Issue 3.
Interesting farm call this morning. A strawberry grower near Watsonville reported a large group of worms (caterpillars) migrating north out of the mixed cover crop including barley and mustard.
These worms were identified by our new UCCE entomologist Alejandro del Pozo as being a species of armyworm, for which this sort of behavior is not unusual. One distinct characteristic to ID these worms is the ‘Y' shaped suture on their forehead. For instance, the beet armyworm,Spodoptera exigua, could be a problem in strawberries when high infestations are left unmanaged. You could read more about the beet armyworm as pest of strawberries on the UCIPM guidelines at http://ipm.ucanr.edu/PMG/r734300611.html
Knowing that these creatures do feed on strawberries, the advice to the grower is to mow and disk the cover crop to destroy the majority of these worms. Yes, the grower is forfeiting some of the benefit of the cover crop he expected to keep going until the end of August, but the risk to his strawberry crop of this large population of armyworms is greater.
Armyworm on strawberry
Armyworm egg cluster. Note that it occurs as a mass.
So you're a rural landowner thinking about planting cover crops in your fields or orchards. And/or,...
Larva of lady beetle munching on an aphid. (Photo by Kathy Keeatley Garvey)
A multi-colored Asian beetles snags an aphid. (Photo by Kathy Keatley Garvey)
These are lady beetle eggs. (Photo by Kathy Keatley Garvey)