Note: Descriptions are shown in the official language in which they were submitted.
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PLANT GROWTH IMPROVEMENT FOR MODULAR PLANT SYSTEMS
This is a continuation-in-part of Serial No. 08/468,713 filed in the U.S.
Patent
and Trademark Office on June 6, 1995.
FIELD OF THE INVENTION
This invention is directed to improvements in transportable plant growing
units. Aeration of modular growing pans and plant growing medium contained
therein is
provided.
BACKGROUND OF INVENTION
Turf and other plant growing systems are known wherein growing pans
cooperate to form a natural plant surface for diverse environments, such as
sports stadia.
Maintenance and growth requires sufficient drainage and aeration techniques.
Drainage
techniques are disclosed in Ripley, et al. Re. No. 35,006 ofU.S. Pat. No.
5,187,894, wherein
integral pans comprise bottom areas with drainage orifices internally formed
or drilled
separately for adequate drainage of water under the surface. While these
drainage orifices
allow for some exchange of gas, they are insufficient to provide adequate
aeration needed to
control root and zone temperature which allows for the retardation of snow and
ice
accumulation and to keep plants from going dormant.
In all-weather envirorunents, freezing water may deform the growing pans
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upon expansion. Ripley et al. in Re. No. 35,006 of U.S. Pat. No. 5,187,894
disclose a
lightweight expandable polymer growing medium in which freezing water deforms
the
polymers rather than the growing pans containing them. Sterrett et al. in U.S.
Patent No.
4,067,716 disclose a growing medium comprising combusted bark particles with
improved
wetting characteristics.
Plant growing media often require surface aeration. Conventional means of
aeration for plants include surface aeration with hollow tines or coring for
maintaining healthy
root systems, and carefully selected artificial growing media which are less
prone to dense
packing than ordinary soil. These methods may be inadequate for aeration when
heavy use
can densely pack even expanded polymers. Moreover, surface aeration methods
require
manual labor and often produce unsightly plant and soil litter.
There is a need to provide plant growing pans with a universal modification
that will provide for improved aeration techniques which will thereby improve
soil properties
and promote healthier plants for use in nearly any type of plant growing
medium, including
ordinary soil.
OBJECT OF THE INVENTION
One object of this invention is to provide subsurface aeration of plant growth
media in modular growing pans to promote the growth and maintenance of plants
under select
optimum conditions.
A further object is to provide improved growing pans for plants which may
eliminate the need for surface aeration and carefully selected growing media
while attracting
roots deeply into the soil, providing air circulation to remove potentially
harmful gases, and
providing adequate water drainage.
A further object is to provide means to easily transport and install modified
growing pans for use in the provision of plant surfaces in stadia, gardening,
landscaping, and
the like.
These and other objectives will become apparent from a review of the instant
specification and attendant claims.
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SUMMARY OF THE INVENTION
In accordance with the present invention, growing pans are provided for
improved ventilation of plant growing media and plants. Transportable growing
units each
comprise a growing pan adapted for containing plant growing medium together
with plants,
the growing pan comprising a bottom having a network of air channels defined
therein, a
plurality of sidewalk extending upwardly from the perimeter of the bottom and
having a top
edge, and a plurality of uniformly spaced aeration orifices comprising at
least about 0.3% of
the surface area of the bottom, the aeration orifices being in fluid
communication with the air
channels to allow for sufficient gas exchange. In another embodiment the
orifices account
for at least about 0.4% of the surface area of the bottom. In a preferred
embodiment, the
aeration orifices account for about 0.5% to about 4% of the surface area of
the bottom, with
0.5% being most preferred.
In other embodiments of the present invention methods are disclosed for
improving the growth of plants comprising providing a growing pan adapted for
containing
plant growing medium together with plants. The growing pan has a network of
air channels
in fluid communication with a plurality of uniformly spaced aeration orifices
through which
pressurized gas is forced to aerate the growing medium and plants. In order to
provide
sufficient aeration means are provided for cooperating with the orifices for
forcing gas through
the growing medium and plants.
The growing pan is capable of transportation and modular installation in
accordance with previously described systems for modular plant growing, i. e.,
Ripley et al.;
U.S. Pats. No. 5,187,894; Re. No. 35,006 and 5,467,555, each ofwhich is
incorporated herein
by reference. The growing pans cooperate with eachother to provide plant
surfaces in stadia,
gardening, landscaping or the like. Although the pans may interlock, this is
not a necessary
feature.
Modification of plant growing pans may be at either a remote site of plant
growth and maintenance or at the primary location of plant use, depending on
frequency of
rotation between the two locations, degree of soil settling that may occur
from activity on
plant or turf surface, and ease of modifying growing pans at the site.
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BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 depicts a growing pan with aeration and drainage orifices and air
channels for aeration. An embodiment is shown having stretchers which raise
the pan from
the underlying surface.
Figure 2 depicts a cross section of growing pan containing growing medium
and plants with orifices for aeration and water drainage.
Figure 3 depicts, in perspective, a partial array of growing units showing air
channels and an end piece for closing off the network of air channels at a
periphery of the
assembly or array.
Figure 4 depicts a top view of a growing pan.
PREFERRED EMBODIMENTS
It has been determined that soil aeration is critical for healthy plant growth
and
maintenance. This is especially true for modular turf and other plant units
which risk
suffering dense soil packing from high-impact use.
In accordance with the present invention, it is now possible to allow gaseous
mixtures, such as those containing harmful gases, to flow out of the growing
medium through
the bottom of a plant growing pan and to introduce advantageous air evenly
throughout the
growing medium. In the present invention a growing pan for containing plant
growing
medium is provided comprising a bottom having a network of air channels
defined therein,
a plurality of sidewalk extending upwardly from the perimeter of the bottom
and having a top
edge, and a plurality of uniformly spaced aeration orifices comprising at
least about 0.3% of
the surface area of the bottom, the aeration orifices being in fluid
communication with the air
channels. In other embodiments, the aeration orifices comprise at least about
0.4% of the
surface area of the bottom. In preferred embodiments the aeration orifices
comprise from
about 0.5% to about 4% of the surface area of the bottom, with 0.5% being most
preferred.
In some embodiments, the present invention provides methods for improving
the growth of plants whereby growing pans adapted for containing plant growing
medium
together with plants are provided. The growing pans have defined therein a
network of air
channels in fluid communication with a plurality of uniformly spaced aeration
orifices.
Pressurized gas is forced through the orifices to aerate the growing medium
and plants.
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Referring to the drawings, a network of air channels in 10 and between 18
growing pans 24 is in fluid communication with aeration orifices 22 at the
bottom of the
growing pans. Drainage holes 30 are also shown. The bottom of the growing pan
may also
have stretchers 20 which raise the turf unit from an underlying surface to
permit improved
water drainage and allow for improved aeration of the entire growing medium
14. The
stretchers also provide assistance in the transportation of the units and can
be modified to level
an entire modular plant growing surface with uneven subsurfaces.
Figure 3 shows one end piece 26 which cooperates with the geometry of the
growing pans 24 to effectively block the air channels at a periphery of an
assemblage of pans.
This maintains pressure in the air channels 10, 18. As will be apparent, it is
preferred to block
the entire periphery in order to improve gas throughput through the growing
pans.
Where it is desirable to force positively or negatively pressurized air
through
the growing medium, it is necessary to provide a suitable fitting for
introducing the
pressurized gas into the network of air channels. Such fittings, such as screw
fittings, nipples,
friction fittings and the like are commonplace, and well known to those
skilled in the art. The
means for supplying pressurized air or other gas can be any conventional
source such as a
vacuum pump, compressor, blower, fan or other means. It is also conventional
to add
components to a gas mixture, e.g., air, to increase the percentage of the
composition
attributable to particular gasses, e.g., carbon dioxide or oxygen.
The growing pans may preferably comprise a gas-permeable mesh or other
liner to preclude soil seepage through water drainage orifices, while allowing
removal of
carbon dioxide, methane, hydrogen sulfide, and other potentially harmful
gasses from the
plant's environment. This helps to further attract roots down into the soil to
make the
turfgrass or other plants more resistant to disease, wear, drought damage and
saturation
damage.
In one embodiment of the invention, growing pans are provided with means
of aeration at a remote location analogous to a green house specially adapted
for their growth
and maintenance. Plants benefit from the particularized conditions optimum for
plant
development for the maximum period of time prior to being exposed to activity
conditions.
Additionally, varying plant or plant units may be substituted in order to
maintain the actual
primary use location in optimum condition. Alternatively, modular plant
growing pans at the
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primary use location are aerated to eliminate the need for frequent
replacement by plant units
from the remote location.
Gaseous mixtures forced through the soil rise to the environment around the
stem and leaves of the plant, where photosynthesis and respiration primarily
occur. The
mixtures may be optimized for nurturing modular plant units. For example, when
plants are
exposed to light, photosynthesis generally exceeds respiration. Plants consume
more carbon
dioxide than they release and release more oxygen than they consume during
this period.
Gaseous mixtures introduced when plants are exposed to light may, preferably,
be enhanced
in carbon dioxide and depleted in oxygen relative to air in order to promote
photosynthesis.
For example, when plants are exposed to light, said gas comprise:
from about 15 to 20% by volume oxygen;
from about 80 to 85% nitrogen;
from about 0.03 to .1 % carbon dioxide.
Similarly, respiration predominates while plants are in darkness, and plants
can
benefit from gaseous mixtures enhanced in oxygen and depleted in carbon
dioxide to drive
this process. While plants are in darkness, the gas may preferably comprise:
from about 20 to 30% by volume oxygen;
from about 70 to 80% nitrogen;
from about 0 to 0.03% carbon dioxide.
In urban areas, where plants are generally exposed to higher levels of carbon
dioxide and other potentially harmful gases, it is preferred to deplete the
gaseous mixture of
carbon dioxide relative to the background air plants normally are exposed to.
It will be appreciated that when pluralities of growing units are assembled
together, a relatively large surface is formed. The air channels in and among
the units
preferably cooperate to form a network of such channels. In some embodiments,
the channels
are provided with a source of a pressurized air mixture such as provided by
blowers or the
like, or with a source for introducing negative pressure, such as vacuum pump.
The periphery
of an assemblage of growing pans may be closed off in any consistent manner to
cause the air
to be forced into the pans and through the growing medium therein. Such
closures may be
through application of a wall, film or other barner at such periphery or in
any other convenient
way.
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The pressure, frequency, and duration of subsurface aeration are optimized for
the type of plant, growing medium and degree of soil packing which may occur
from use.
Growing media with a high degree of expandable polymers will require less
aeration than
ordinary soil. Plant roots may strengthen in response to frequent aeration and
the resulting
disturbance of growing medium. The force and duration of aeration should be
adjusted
according to the degree of beneficial response for each plant. For example, in
some
embodiments this invention claims a range of net gas aeration pressures to be
forced through
the growing medium of from about 1 to 100 psi. Gas may be forced through the
growing
medium continuously, for one hour beginning every other hour, for one hour
during each
period of plant exposure to light or darkness, or as adjusted for the most
beneficial plant
response.
As is apparent, turf surfaces, e.g. for athletic events and gardens may be
built
from a plurality of growing pans connected together along with preferred soil
pieces such that
the network of air channels can be pressurized with gas. Improved growth
results.
1 S It is preferred that plant growing media comprise an artificial soil
having a
relatively light weight for transportation. The soil may include an expanded
polymer with an
extremely light specific gravity selected to be substantially inert with
respect to plant growth
chemistry. It is also preferred to provide modular, transportable plant units
designed to
cooperate with each other to facilitate the elaboration of substantially
continuous plant
surfaces for athletics, decoration and other uses.
Those skilled in the art will appreciate that numerous changes and
modifications can be made to the preferred embodiments of the invention and
that such
changes and modifications can be made without departing from the spirit of the
invention.
It is therefore intended that the appended claims cover all such equivalent
variations as fall
within the true spirit and scope of the invention.
