 |
 |
<!--
function MM_swapImgRestore() { //v3.0
var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}
function MM_preloadImages() { //v3.0
var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length;
i++) if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}
function MM_swapImage() { //v3.0
var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src;
x.src=a[i+2];} }
//-->
 |
|
|
|
REUSING
TURFGRASS CLIPPINGS TO IMPROVE
TURFGRASS HEALTH AND PERFORMANCE
|
|
Janet
Hartin, UC Cooperative Extension, San Bernardino and Los
Angeles Counties
J. Michael Henry, UC Cooperative Extension, Riverside
and Orange Counties
|
Introduction
California's Integrated Waste Management
Act, enacted from Assembly Bill 939 legislation, mandates
a 50 percent diversion of landfill wastes that each county
and city generates by the end of the year 2,000, based on
1990 levels. Grasscycling, composting and mulching offer
valuable alternatives to depositing grass clippings in landfills,
and promote the growth of healthy landscape plants. Studies
indicate that an average California lawn generates 300 to
400 pounds of grass clippings per 1,000 square feet annually,
which equates to as much as eight tons per acre each year.
Grass clippings historically have comprised half of the
yard trimmings deposited in California landfills, and yard
trimmings make up the largest single component of California's
municipal waste.
Grasscycling
In grasscycling, clippings are simply
left on the turf area as it is mowed to decompose, rather
than bagged. Grasscycling is an excellent method of recycling
a valuable organic resource in lawns and large public and
commercial turfgrass plantings such as parks, cemeteries,
school grounds and portions of golf courses. In situations
where prolonged wet weather, mechanical breakdown of mowers,
or infrequent mowing result in large amounts of clippings,
the cut turfgrass should be bagged and composted or dried
for use as mulch. Besides diverting organic matter from
landfills, grasscycling supplies valuable organic material
and nutrients to the soil. Grass clippings decompose quickly.
They typically contain about 4 percent nitrogen, 0.5 percent
phosphorus, and 2 percent potassium, which reduce fertilizer
requirements by approximately 20 percent. Grasscycling also
reduces mowing time and disposal costs. Golf
course putting greens, sod farms, and major league sports
fields are not as adapted to grasscycling due to their requirements
for exceptionally uniform playing surfaces.
Mowing
It is often usually necessary to mow
at least weekly during the active growing season when grasscycling
to avoid a build-up of excess clippings. Turfgrass that
is not cut frequently enough when grasscycling may produce
a "hay-like" look that can be unsightly. Maintaining turfgrass
at the recommended mowing height is also important. Follow
the 1/3 rule; mow often enough so that no more than 1/3
of the length of the grass blade needs to be removed during
any single mowing. This allows short clippings to work their
way through the canopy to decompose, without covering the
surface. It is important to use sharp mower blades and mow
when the surface is dry. Table 1 lists recommended mowing
heights for several species of turfgrass. Studies have shown
that there are benefits to maintaining a relatively high
mowing height to encourage the development of deeper roots,
which can improve drought resistance and reduce stress.
|
|
|
|
|
