[Prev][Next][Index][Thread]
Re: windbreak plants for plasticulture vegetable
Hi Suzanne:
Soil moves by wind in 3 ways, suspension, creep, and saltation. Suspension
is commonly known as dust (particle size less than 0.1 mm diameter). This
is not likely to be an issue for prevention - it does not cause crop
damage. Larger particles (0.5-2 mm diameter) move in a process called
creep - they are rolled along the ground surface. Again these particles
are generally not causing crop damage. The real action you want to prevent
is saltation. Particles of intermediate size (0.05-0.5 mm) literally
bounce along the surface, causing abrasion ("sandblasting") as they
encounter plant tissue.
In general, the distance a particle will move is 10 times the height of
it's bounce (Hudson, 1971, Soil Coservation, pp 252-259). The maximum
height a particle will jump appears to be 1 foot (Davies and Harrod, 1970,
No. 88 Great Britain NAAS Quarterly Review). So, to prevent soil damage due
to particles moving through saltation, it would appear that windbreaks need
to be at least every 10 feet.
However, if you have the sweeping clouds of soil which I have seen in many
open fields, the maximum height a soil particle moves is certainly greater
than 1 foot. In New York, I worked with the onion growers to try and solve
their problem of soil wind erosion damage. The system we developed there
was a soil cover which did not have to be tall, but was dense at the soil
surface. This prevented the soil from being susceptible to movement by
wind. A fall planted cereal, rye, barley or oats, can winter kill, or be
mowed or sprayed in the spring, and the residue left in place. Onions were
then planted in the spring, and at the same time a cereal grain was
broadcast throughout the onion field. The broadcast intercrop acted as a
"nurse crop" - protected the onions from wind, and actually seemed to
prevent the erosion from occurring. However, I did not measure wind
erosion, I measured onion production. And onion production was generally
good in this system. The winter cover crop and spring intercrop system
seemed to give enough soil cover to prevent crop damage. Last time I
heard, more than 90% of the NY onion growers had adopted the system. If
this sounds like a system which may work for you, you may want to check
with Roy Ellerbrock or Ted Boswell at Cornell to see what system the
growers are using now and how easy it is to manage.
The cold winds may be adequately moderated by a cereal windbreak which
creates a microclimate near the soil surface. I am sure there are others
on the list or elsewhere who have much more information on this. I can
certainly dig through my files if you need more.
>I am an extension agent with the University of Florida. Several of the
>commercial vegetable farmers I work with are seeking recommendations for
>plants to use as windbreaks in their plasticulture system. The main
>crops are strawberries followed by eggplant/pepper/tomato or a cucurbit.
>
>Does anyone have information/experience with windbreaks that would fit
>into our system here? Protection needed Oct through May. Must be
>frost-tolerant, but temps will also be up to 90 F. Irrigation is
>provided to crop with drip. Frost
>protection provided overhead with rainbirds. Growers seek protection
>from cold winter winds and blowing sands that damage plants & fruit.
>
>To date, the best recommendations I have are sugarcane and winter rye.
>
>I also want to learn how to determine the necessary spacing for the
>windbreak rows. Space is expensive and the crop is low. I shtere a
>formula for calculating the distance that a windbreak will protect if you
>know its height?
>
>Thanks for your help!
>Suzanne Cady
>Extension Agent - Vegetables
>University of Florida
Carol A. Miles, Ph.D.
Washington State University
Extension Agricultural Systems
360 NW North Street
Chehalis, WA 98532
PHONE 360-740-1295 FAX 360-740-2792
milesc@wsu.edu
Follow-Ups: