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Abstract
In general, rice planting dates, seeding rates, preferred varieties,
and harvesting methods vary among regions, but they are largely
the same for conventional and organic systems. The state or county
Cooperative Extension Service provides such general information.
This publication focuses on the special considerations relevant
to organic rice production.
Table of Contents
Organic Production
Organic systems avoid the use of synthetic fertilizers, pesticides,
and growth regulators. Instead they rely on crop rotations, crop
residues, animal manures, legumes, green manures, off-farm wastes,
mechanical cultivation, mineral-bearing rocks, and biological pest
control to maintain soil health, supply plant nutrients, and minimize
insects, weeds, and other pests.
While anyone can choose to grow organically, federal regulations
now control the labeling and marketing of all
organic products. If you plan to represent your farm
products as organic, you must be certified. To learn about the steps
toward organic certification, see ATTRA's Organic
Farm Certification & The National Organic Program.
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Weed Suppression
Weed control and soil fertility are the principal challenges associated
with organic rice production. Primary weed-control practices include
crop rotations, land leveling, seedbed preparation, water management,
and rotary hoeing.
To reduce weed pressure, lengthen the standard two-year rice/soybean
rotation to a three-year rotation of rice/soybeans/grain crop (sorghum,
wheat, corn, etc.). The longer rotation allows additional time to
break weed life cycles and reduce the number of weed seeds in the
soil. Other weed-control options center on the use of field flooding
to suppress weeds directly and to give the crop a competitive advantage.
Flooding will be more effective if fields are precision leveled.
Leveling makes the water depth uniform and facilitates rapid flow
onto and from the field (1).
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Case Studies In Weed Control
Organic and reduced-input producers have developed some innovative
means for growing rice without chemicals. Some examples follow:
- An Arkansas organic rice producer rotates his crops in the following
sequence: rice/soybeans/winter wheat/summer fallow. His weed-control
plan includes timely water management, precision-leveled fields
to ensure uniform flooding depth; levees on a 1.0- to 1.5-inch
drop; and a pumping system that floods and drains fields rapidly.
After applying composted barnyard manure and drilling rice seed,
he floods to 4 inches to drown weeds. The water is allowed to
stand for 10 to 12 days. He controls water weevils either by draining
and drying the ground until it firms up or by a fresh water flush.
This producer has been raising organic rice for 18 years. He declined
to serve as a contact person and prefers that we not use his name.
- The Lundbergs of Richvale, California, are large-scale organic
rice producers who use a purple vetch green-manure crop as their
nitrogen source (2). They mow the vetch in
spring to 6 inches and drill rice seed directly into the vetch
mulch (3). Following planting, they flood
the field to kill the vetch and germinate the rice seed. Following
germination, they drain the field and allow it to dry, and then
the field is re-flooded for the season. Weed control is based
primarily on water-level control. Some weediness is tolerated,
reducing yields in some years. Water weevils seldom present a
problem, since the Lundbergs practice dry planting. The Lundbergs
harvest their rice at 17% moisture, disk the straw down, and fallow
the ground for a year. Permanent levees are maintained with a
sickle mower.
- Arkansas grower Steven Rutledge uses a wheat/rice relay intercrop
that reduces his input costs $50 to $70 per acre and requires
no land preparation or herbicides (4). By
applying pre-flood fertilizer with a ground rig, he saves an additional
$4 to $8 per acre over aerial application costs. He plants (by
airplane) between 140 and 180 pounds of seed per acre of a short-season
rice variety, into standing wheat at the milk stage. He then floods
the field to sprout the seed. After germination, he drains the
field to allow the rice to peg down, and to dry the ground for
wheat harvest. Rutledge believes that flooding the wheat in the
milk stage does it no harm. By wheat harvest, the rice is only
a few inches high—too low for damage by the combine header.
After wheat harvest, he applies nitrogen fertilizer by ground
rig—of course, this fertilizer application would not be
allowed in an organic system. A major advantage to his system
is the weed control provided by the wheat straw. Rutledge has
used this system since the late 1970s and has never failed to
get a rice stand.
- Rice growers in Arkansas (5) are capturing
winter rainwater and allowing it to stand in their fields. They
close the levees in early November and don't drain the fields
until early February or March. The benefits of this include more
rapid decomposition of stubble, less soil erosion, increased habitat
for waterfowl, and some control of red rice, a major weed problem.
Other Arkansas growers are trying to suppress red rice by water-seeding
their rice crop into tilled fields that have been flooded. Water-seeding
suppresses red rice germination by keeping the soil anaerobic.
The final seedbed must be prepared immediately prior to flooding
to kill those red rice seeds that have already germinated. The
University of Arkansas recommends using only pre-germinated rice
seed when water-seeding (6). Wintering ducks
are also a major factor in managing red rice. An Arkansas study
showed that duck foraging resulted in a 97% reduction of red and
white rice seed in a winter-flooded field (1).
Ducks and geese also feed on such weeds and seeds as barnyard
grass, smartweed, beggar tick, crabgrass, panicum, and other agronomic
pest species.
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Soil Fertility
Maintaining soil fertility in organic cropping typically involves
some combination of crop rotation with deep-rooted legume crops
or green manure/cover crops, and applying rock minerals, animal
manures, composts, and other approved organic amendments. Leguminous
green-manure crops can supply 30 to 50 percent of the nitrogen needs
of high-yielding rice varieties. The availability of green-manure
nitrogen depends on the quantity, quality, and type of green-manure
crop; the time and method of application; soil fertility; and cropping
method (7).
USDA researcher Dr. Seth Dabney (8) studied
rice production in two Louisiana fields that had been green-manured
with subterranean clover. The sub-clover provided enough nitrogen
to produce high rice yields without additional nitrogen at one location,
but the other required 50 pounds of additional nitrogen per acre
to achieve similar yields. He also demonstrated that the sub-clover
would naturally re-seed itself following no-till-planted rice. The
reseeded sub-clover stands were more productive than those that
were manually seeded. These results verified what other Louisiana
researchers had seen in re-seeded sub-clover stands—higher
re-seeded-stand densities and earlier growth commencement in the
fall. In addition, clover-planting costs were eliminated with the
naturally re-seeded stand.
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Insects And Diseases
Because rice is grown in flooded fields, insect pests are usually
a minor problem. Fall armyworm and chinchbug populations can build
up in the absence of flooding, but are easily controlled by a flush
of water. Rice water weevil and rice stinkbugs are less affected
by flooding. Timely planting, variety selection, and cultural practices
to suppress weeds and encourage dense stands of rice will help control
stinkbugs and water weevils (9).
Rice blast and sheath blight diseases are often controlled by appropriate
variety selection. Excessive nitrogen levels, rarely a problem in
organic production, can encourage sheath blight, kernel smut, and
other diseases.
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Economics
Organic rice is typically sold in niche and specialty markets,
where it commands a price two to three times higher than that of
conventionally grown rice (10). But while it
sells at higher prices, organic rice also costs more to produce
(11). Recent cost information, however, is
difficult to find.
In 1992, the University of California Cooperative Extension Service
calculated the costs of organic rice production in the Sacramento
Valley for both water-seeded and no-till, drill-seeded rice (12,
13). The no-till, drill-seeded organic rice
cost $653.65 per acre to produce, and the water-seeded organic rice
cost $677.94 per acre.
More recently, Missouri grower Andy Turman calculated that organic
rice cost $22 more per acre to produce than conventionally grown
rice in 2000 (14). He attributed the difference
to fertilizer shipping costs, extra tillage, and labor for hand
weeding. (Turman uses furrow irrigation, rather than flood irrigation,
requiring 30% to 50% less water.)
Yields from organic rice production tend to be lower than conventional
yields. Turman calculated his yield to be one-third that of a conventional
rice crop. Similarly, Lowell Farms of Texas estimate their organic
rice yield at 50% to 60% of conventional yields (15).
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Marketing
While marketing organic products presents a challenge, there are
some places to find buyers for your crops. Many "conventional"
farm magazines and websites can be good sources of information on
buyers of organic crops. The ATTRA publication Marketing
Organic Grains
identifies several organic grain buyers.
The Organic Consumers Association is a public-interest organization
dedicated to building a healthy, safe, and sustainable system of
food production and consumption. They act as a global clearinghouse
for information and provide grassroots technical assistance. Their
website includes information on a host of organic issues. Contact:
The Organic Consumers
Association
6101 Cliff Estate Rd.
Little Marais, MN 55614
Tel: 218-226-4164
Fax: 218-226-4157
info@organicconsumers.org
FarmWorld was established
as a worldwide trading site for information on agricultural commodities
and products. The site offers free buy/sell/trade listings in a
variety of categories, including grains.
Sustainable
Farming Connection provides useful information on organic farming,
including links to a number of marketing resources.
agAccess Information
Services offers business, marketing, and strategic planning
services as well as market research. Services are oriented toward
specialty and organic producers. Contact:
agAccess Information
Service
424 Second St., Suite B
Davis, CA 95616
Tel: 530-756-0778
Fax: 530-756-0484
aginfo@ceresgroup.com
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References
- Sullivan, Preston, and Robert
Strader. 1993. Precision-Leveled Fields Prove Excellent Long-Term
Investments. Rice Farming. April. p. 28-29, 32.
- Anon. No date. A Partnership With
Nature: The Rice Farming Techniques of Lundberg Family Farms.
www.lundberg.com/farming/sustainability.shtml.
- Kotzsch, Ronald E. 1988. Close-up
on organic rices. East West. April. p. 14-21.
- Cook, Klink. 1994. Doublecropped
rice/wheat cuts weed control costs. Mid-South Farmer. May. p.
8-9.
- Bennett, David. 1996. Can Waterfowl
Help Rid Your Fields Of Red Rice. Delta Farm Press. February 16.
p. 16-17.
- Bennett, David. 1996. Can Waterfowl
Help Rid Your Fields Of Red Rice. Delta Farm Press. February 16.
p. 16-17.
- Westcott, M.P., and D.S. Mikkelsen.
1988. Effect of green manure on rice fertility in the United States.
p. 257-274. In: Green Manure in Rice Farming: Proceedings of a
Symposium on Sustainable Agriculture. International Rice Research
Institute, Philippines.
- Dabney, S.M., et al. 1989. Subterranean
clover cover crop used to increase rice yield. Agronomy Journal.
Vol. 81, No. 3. p. 483-487.
- Anon. 1989. 1989 Rice Production
Guidelines. Texas Agricultural Extension Publication D-1253. Texas
A&M University. College Station, TX. 72 p.
- McClung, Anna,and Christine
Bergman. No date. Potential for Using Asian Rice Germplasm in
Organic Culture in the U.S. USDA-ARS Rice Research Unit, Beaumont,
TX. http://usda-ars-beaumont.tamu.edu/asian.html.
- Lundberg Family Farms. 1990.
Lundburg Rice Paper. Vol. 6, No. 2. October. p. 1-2.
- Williams, J., et al. 1992. U.S.
Cooperative Extension Sample Costs to Produce Organic Rice in
the Sacramento Valley. Water Seeded. California Extension Service.
23 p. www.sarep.ucdavis.edu/pubs/costs/92/rice.htm
- Williams, J., et al. 1992. U.S.
Cooperative Extension Sample Costs to Produce Organic Rice in
the Sacramento Valley. No-till Drill Seeded. California Extension
Service. 23 p.
- Turman, Andy. No date. Organic
Rice Production Project. http://www.deltanetwork.org/pres/organic%20rice.htm
(web page no longer available)
- Atkinson, Betsy Woods. 1999.
Growing Organic Rice. Acres U.S.A. April. p. 1, 8-9.
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Further Resources
U.C. Cooperative Extension Rice Project
www.agronomy.ucdavis.edu/agronomy/
This website provides many online resources related to rice
production, including diseases and pests, water quality and management,
water fowl, cover crops, and weed management.
University of California
Agriculture & Natural Resources
http://anrcatalog.ucdavis.edu/InOrder/Shop/Shop.asp
This website identifies a number of useful sources of agricultural
information, including several publications on rice.
Organic Rice Production
By Preston Sullivan
NCAT Agriculture Specialist
Paul Williams, Editor
Cole Loeffler, HTML Production
CT 143
Slot 229
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