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NEW JERSEY
While agriculture certainly contributes to water quality degradation,
intense development has forced New Jersey to turn its attention to both urban
and suburban sources of nonpoint pollution. To address this nonpoint source
problem, the New Jersey Department of Environmental Protection has shifted its
emphasis from structural abatement of runoff from a single development site to
a more holistic approach that integrates all phases of site development. This
watershed approach considers the natural and human interaction throughout the
entire drainage area. New Jersey is also emphasizing prevention because it is
cost effective and does not rely on regulations. However, because even
well-planned land disturbances increase runoff, New Jersey must still rely on
structures that reduce nonpoint source pollution. Wildflower Blooms Buffer
Runoff Effects More and more observers are appreciating the beauty and grace of
wildflowers, but few have ever considered using a meadow to control water
pollution. That is, until New Jersey decided to compare the effectiveness of
seeding - detention basins with wildflowers rather than traditional turf grass.
This new approach has New Jersey developers and municipalities sitting up and
taking notice. Not only does a wildflower meadow produce a diverse habitat for
wildlife and an appearance more interesting than that of a manicured golf
course, but developers have also discovered that a meadow significantly reduces
maintenance costs.
In New Jersey, detention basins are the most commonly used stormwater
management structures. Turf grass--which provides a quick, effective way to
control erosion and reduce other pollutants--is generally planted early to
stabilize the bottom and sides of the basin and provide long-term ground
cover.
However, methods used to maintain turf grass--applying fertilizers and
pesticides and mowing frequently (as much as 10 times during the growing
season)--can negate any benefits gained in water quality and cost
effectiveness. Excess soluble pesticides and fertilizers can mix with
stormwater runoff and be carried into receiving waters. Excess chemicals can
leach into underground aquifers. Finally, frequent mowing and disposing of
grass clippings is expensive --even with a reliable volunteer program. New
Jersey, aware of the problems of turf grass, was anxious to participate when
the Mercer County Soil Conservation District (MCSCD) proposed studying the
effectiveness of using wildflower meadows instead. In 1990, the New Jersey
Department of Environmental Protection (NJDEP) provided a $8,500 grant through
section 319.
The study looked at various wildflower mixtures and application methods and
identified environmental factors needed for success. In selecting test sites,
MCSCD looked for construction projects that needed to comply with soil erosion
and sediment control regulations--and several developers volunteered for the
project. MCSCD used various mixes, methods, and rates of seed and fertilizer on
10 detention basins. Site preparation was similar, using mulch and tackifier.
MCSCD did not apply herbicides since the study's focus was to avoid nonpoint
source - pollution.
For several months, MCSCD collected data daily on numerous
elements--weather conditions; soil moisture and temperature; and germination,
flowering, and establishment times. The final site evaluations were based on
several criteria--percent of wildflower cover, weeds, and total cover;
maintenance, including mowing required to suppress weeds; and appearance,
considering stand density and height.
Soil moisture proved to be the most important success factor. Moderate
moisture produced the best results; low moisture encouraged weeds; and long
periods of heavy moisture was detrimental. Given the proper conditions, most
seed mixtures were effective, suggesting that any native wildflower seed or
mixture adapted to a particular region will thrive with the right conditions
and proper maintenance.
Although weeds were a significant problem, mowing twice during the first
year as well as other precautions provided effective controls. After the first
year, MCSCD recommends mowing in late fall to disperse seeds and prevent woody
growth. Also, overseeding perennial species in fall and annuals in spring helps
maintain density, promote diversity, and coordinate flowering schedules. These
simple, low-maintenance practices are an appealing alternative to using
nutrients and pesticides on traditional turf grass ground cover.
The study showed that establishing wildflower meadows may be more
expensive--approximately 1 cent per square foot more than traditional turf
seeding. However, maintenance costs have proven to be considerably lower--$50
per year per acre for wildflower meadows, as compared to $500 per year per acre
to maintain turf.
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