LOUISIANA
Louisiana's goal is to work with agencies at all levels to address all
categories of nonpoint source pollution through statewide education and
targeted watershed projects. The state uses a committee made up of some 18
state and federal agencies to implement both statewide and watershed projects
to reduce nonpoint source pollution and improve water quality.
BMPs Replace Mudding-In for Growing Rice
In the Mermentau River Basin, most of the land is used for agriculture, and
rice is the major crop produced there. When Louisiana discovered that 75
percent of the waters draining into the Mermentau River Basin did not meet
their designated uses, the state decided to act on the water quality problems
caused by rice production. According to the 1992 water quality inventory, 12 of
the 16 water quality management subsegments were either not meeting or only
partially meeting their designated uses. These problems stemmed from rice
production, a major agricultural commodity in the state. Data showed that
levels of organic carbon, nutrients, and sediment all increased during the
spring rice planting season, while dissolved oxygen declined to levels as low
as 0.2 to 0.5 mg/L.
Section 319 cooperative agreements in FY 1988 and 1989 and again in FY 1990
and 1992 allowed the Louisiana Department of Environmental Quality (LDEQ) to
address these water quality problems by establishing a rice demonstration
project to evaluate four alternative best management practices.
LDEQ contracted with Louisiana State University (LSU) Agricultural Center
to evaluate alternatives to the - traditional practice of "mudding-in."
Mudding-in is a cultural practice that has been used in southwest Louisiana for
generations to control red rice. This rapidly spreading, non-harvestable weed
chokes out desirable rice plants. In mudding-in, also called dragging or muddy
water planting, farmers plow the flooded fields and release the water
immediately. This practice takes along sediment and other undesirable
materials.
The alternative BMPs are:
- Water planting in previous crop residue;
- Retention of flood water in a closed levee system during and after soil
disturbing activities;
- Clear water planting into a prepared seedbed; and
- Mudding-in with the use of vegetated filter strips.
LSU found that using alternative BMPs over two years decreased sediment
loading from 20 to 63 percent and organic carbon by as much as 92 percent.
Working cooperatively with the SCS and ASCS, LDEQ began educational programs
and technical assistance to encourage rice farmers to adopt the new management
practices. The LSU Agricultural Center reviewed the BMPs and will put more
emphasis on solving water quality problems associated with rice production in
Louisiana. By 1994 a total of 39,779 acres of rice had been planted with the
new BMPs. One of the latest project components, funded with FY 1991 section 319
monies, is to correlate results from BMP implementation with in-stream and
edge-of-field water quality data to estimate how load reductions translate into
water quality improvement.
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