I'm not sure to what extent this research is applicable to our circumstances,
but it may be useful ...
http://www.uga.edu/news/newsbureau/releases/2002releases/0206/020626songbirds.html
Wednesday, June 26, 2002
WRITER: Helen Fosgate, 706-542-2079,
CONTACTS: Bob Cooper, 706-542-6066, ; John
Carroll, 706-542-5815, ; Sandy Cederbaum,
706-542-1403,
UGA [University of Georga] RESEARCH SHOWS CLOVER STRIP-CROPPING IN COTTON
PROVIDES CRITICAL HABITAT FOR THREATENED SONGBIRDS
ATHENS, Ga. ? Cotton farming is on the rise across the South, and that spells
trouble for rural songbirds. Conventionally grown cotton relies heavily on
pesticides, herbicides and plowing or disking every three weeks and contributes
to the steady decline of birds like the Eastern meadowlark, bobwhite quail and
grasshopper sparrow.
But new research by wildlife scientists in the University of Georgia?s Warnell
School of Forest Resources shows that alternative farming practices like clover
strip-cropping provide critically important habitat for threatened songbirds.
Clover, interplanted in rows between the cotton, offers the birds ready cover
from predators, insects for food, and just as importantly, enough time to nest
and fledge young between field operations. This is the first study to compare
the effects on birds of conventional and alternative farming practices in
cotton.
"Other studies have looked at alternative farming systems in terms of cost
savings, erosion control and soil fertility," said UGA wildlife researcher Bob
Cooper, "but we?re the first to look at clover strip-cropping and conservation
tillage systems
in cotton with regard to wildlife."
Much of the songbird decline is linked to the loss of rural land, both here and
in South America where many birds migrate for winter. Thousands of rural acres
have been converted to apartment complexes, shopping areas, suburban housing ?
even to pine plantations. In South America, forests are being bulldozed to make
way for non-sustainable forms of agriculture such as cattle farms and sun-grown
coffee. None of these habitats provide the diverse combination of natural
woodlands, open grasslands and shrubby areas the birds need to feed and raise
young.
Researchers, who include Cooper, UGA wildlife biologist John Carroll and
graduate student Sandy Cederbaum, conducted the study with the cooperation of
several farmers in east-central Georgia who are concerned about songbirds. Their
research, presented at the American Ornithologists&Mac226; Union meeting last
August, was funded by grants from the USDA Natural Resource Conservation
Service, Quail Unlimited, Monsanto Co., the National Environmentally Sustainable
Agriculture Lab in Tifton, Georgia and state McIntire-Stennis funds to UGA
through the Warnell School of Forest Resources.
The researchers compared the density of birds and vegetative cover in cotton
fields where farmers used conservation tillage, clover strip-cropping and
finally intensive farming practices. They monitored the fields through winter,
spring migration, and finally through the breeding and summer growing season,
recording the type and number of bird species in each farming scenario. To learn
more about food availability for the birds, they also sampled the insects in
each field type, noting whether they were beneficial or crop pests.
"Our idea wasn?t to try to come up with something new but to look at existing
cropping systems from a wildlife standpoint," said Cederbaum, who monitored the
fields through the seasons. "We were really surprised by the extent to which the
birds responded to the clover fields. Before this, I hadn?t appreciated the
extent to which agriculture could provide beneficial habitat for birds."
Preparation for strip cropping begins in the fall when farmers plant a cover
crop of clover to stabilize the soil and allow beneficial insects to build up
before planting the cotton crop in early May. To prepare the land for cotton,
farmers use a hooded sprayer to kill 20-inch strips of clover with a herbicide,
usually Roundup, and later plant cotton into the brown strip. This leaves a
20-inch strip of living clover between each row of cotton. As the season
progresses, the clover dies back naturally, but still provides enough structure
and cover to sustain beneficial insects, some of which move into the cotton
plants where they help control pest insects. Dr. Alton Walker, an independent
crop consultant in Wrens, Ga., has been fine-tuning the technique for years.
Researchers found that birds flocked to the strip-clover fields, feeding on
plentiful insects amid the blooming clover. The conservation tillage fields also
provided some cover and insects, though not nearly as much as fields with the
living clover. The brown, barren landscape beneath the conventional cotton crop
supported very few insects and offered no cover.
"Many people fail to realize that cotton fields are wildlife habitat," said UGA
wildlife researcher John Carroll. "The key now is understanding how we can
integrate the needs of wildlife into existing crop production systems."
Other studies have shown that clover strip-cropping is also profitable, since
growers cultivate less and use fewer pesticides, herbicides and fertilizers.
Sharad Phatak, horticulture professor at the Coastal Plain Experiment Station in
Tifton, who has been studying alternative cropping systems for more than 30
years, was encouraged by this study.
"I was very impressed with the number of birds in the clover stripped fields,"
he said. "I believe that by changing cotton farming in this direction, we can
support and help songbirds as well as build and protect our soil."
Birding-Aus is on the Web at
www.shc.melb.catholic.edu.au/home/birding/index.html
To unsubscribe from this mailing list, send the message
"unsubscribe birding-aus" (no quotes, no Subject line)
to
|
