- Author: Chris M. Webb
Many food producers use mulches for weed, insect, and disease management and for water conservation to improve crop production . Depending on specific production goals, growers use reflective plastic or cover crop mulches.
Most plastic mulch materials are made of either high- or low-density polyethylene. They typically range from 0.3 to 0.79 inches thick (7.7 to 20.2 mm), 5 or 6 feet wide (1.5 to 1.8 m), and 555 to 1,138 yards long (60 to 1223 m). The additional benefits of plastic mulches in vegetable production include: crop earliness, increased yields, improved crop quality, and reduced fertilizer leaching in some cases.
Challenges with this type of mulch include: removal and disposal, higher production costs, specialized management and equipment for installation, and increased susceptibility to frost.
Use of cover crops as mulches is currently being refined and evaluated in a wide range of vegetable production systems. Additional benefits of cover crop mulches in vegetable production include: enhanced nitrogen availability, reduced soil erosion, increased soil organic matter, reduced intercrop tillage, increased soil quality, and offset payment incentives possible through U.S. Farm Bill conservation programs.
Challenges with this type of mulch include: cooler temperatures above and below mulch, slower-maturing crops, cover crop mulch re-growth, specialized management and equipment in some cases, limited in-season weed management options, cost, and allelopathy (plant chemical interference) between cover crop and production crop.
UC ANR’s free Mulches in California Vegetable Crop Production publication is full of information on this subject with suggestions for further reading at the end.
- Author: Chris M. Webb
Today, Ventura County Cooperative Extension's Maren Mochizuki shares with us about
a local research project.
Armillaria mellea is a fungus that causes root rot in citrus, peach, and many other edible tree and landscape species. UCCE Farm Advisors Jim Downer and Ben Faber are investigating the effect of soil disturbance, organic matter, and Trichoderma (another soil fungus) inoculation on survival of peach trees planted in soil infested Armillaria mellea. Preliminary results were presented on Aug. 4 at the ASHS annual conference in Palm Desert, CA.
To view the presentation abstract, please visit: http://ashs.confex.com/ashs/2010/webprogram/Paper4324.html
For more information on symptoms and management of Armillaria mellea, please visit this UC IPM page.
Field shot showing infected tree with bare branches
and yellow leaves caused by Armillaria mellea.
Armillaria mellea
- Author: Chris M. Webb
Looking for an environmentally safe way to control soilborne pests? Solarization is a nonchemical method that can be successfully used to kill weeds, pathogens, nematodes and insects.
This process heats the soil to temperatures that are too high for the undesirable organisms to live. It also has the potential to improve soil structure, increasing the potential for healthy plants. Faster growing plants as well as higher and better quality yields are associated with solarized soil.
Another benefit of this method of soil preparation is that it can be used by home gardeners, landscape professionals, natural resource restoration projects and in production agriculture.
More information can be found in UC ANR’s Soil Solarization for Gardens and Landscapes pest note or for a more in-depth view and closely related subjects, please visit UC’s Solarization Informational Website.
Illustration by W. Suckow showing solarization steps.
- Author: Chris M. Webb
A useful application, available for free on iPhone and Android OS platforms, SoilWeb provides on-demand access to solid survey information anywhere with cell phone coverage in the lower 48 states.
Developed by UC Davis Ph.D. candidate Dylan Beaudette and his advisor Toby O’Geen, SoilWeb uses GPS or cell tower triangulation capabilities of modern smartphones to determine the location of the user. Once the location is determined results from UC Davis Soil Resource Laboratory soil survey information is sent to the user.
Many resources are available through the SoilWeb app and include: soil profile sketches; soil horizons; series names; landscape position; taxonomic classification; depth profiles of soil chemical and physical properties; land classification indices; land-use interpretations and links to a variety of other environmental databases.
An abstract of the project can be found here.
Graphical User Guide to SoilWeb phone application found on UC Davis Soil Resource Laboratory website.
- Author: Chris M. Webb
Today, Maren Mochizuki shares with us preliminary findings from a local research project.
Soil pH along most of the California coast north of Los Angeles ranges between 7.3 and 8, which is generally higher than many edible and ornamental plants prefer. In some cases, availability of micronutrients such as iron is severely limited in soils above pH 8, leading to deficiency symptoms in plants. Other plants such as blueberries, rhododendrons, azaleas, and hydrangeas prefer acidic soil conditions (pH 6 and below).
To investigate potential soil pH reduction over time, UCCE Farm Advisors Jim Downer and Ben Faber and UCCE Staff Research Associate Maren Mochizuki applied coffee grounds, lemon waste, peat moss, pine needles, oak leaves, and municipal yardwaste in addition to elemental sulfur to soil with an unadultered pH of 7.8.
The project is on-going and is in its third year. Preliminary findings indicate that the combination of organic material plus elemental sulfur reduces pH to a greater degree and more quickly than either the amendment or sulfur alone. We have seen the greatest effect thus far with elemental sulfur plus coffee grounds, chipped lemon waste, or peat moss.
Lemon waste from Ventura County packinghouses.
Lemon waste was chipped before application and
incorporation into soil.
Coffee grounds (top) and peat moss applied
to soil prior to incorporation with a rototiller.