Xref: utzoo sci.bio:2080 sci.environment:1313
Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!att!cuuxb!rbc
From: rbc@cuuxb.ATT.COM (~XT6511100~Rick Clark~C24~H15~6011~)
Newsgroups: sci.bio,sci.environment
Subject: Re: Is Mowing your Lawn bad for the Environment?
Message-ID: <2882@cuuxb.ATT.COM>
Date: 2 Jun 89 17:48:04 GMT
References: <24792@agate.BERKELEY.EDU> <20388@uflorida.cis.ufl.EDU> <1785@spp2.UUCP>
Reply-To: rbc@cuuxb.UUCP (Richard B. Clark)
Followup-To: sci.bio
Distribution: usa
Organization: AT&T, Data Systems Group, Lisle, IL
Lines: 29


In article <1785@spp2.UUCP> ries@spp2.UUCP (Marc Ries) writes:
>In article <20388@uflorida.cis.ufl.EDU> ajw@manatee.cis.ufl.edu (Andy Wilcox) writes:
>> * If possible, blow your grass over your yard, and let it decompose
>>   there.  Raw grass contains a sizeable portion of nitrogen that is
>>   returned to soil by this method.  Leaving grass on the lawn does
>>   not cause thatch, which is most commonly caused by over
>>   fertilization. 
>
>      Unfortunately, raw "grass" clippings actually USE UP
>      available   soil   nitrogen   in   the   process  of
>      decomposition.  It's crops like  CLOVER  (that  turn


Are you sure about that Andy?  I recall from my MSU crop and soil
science courses that straw decomposition is a net consumer of nitrogen
but that hay was a net contributor.  (They didn't specify clover or timothy).
I suspect the fresh clippings are analogous to hay and the thatch is
analogous to straw (clippings with the nitrogen decay products already
leached into soil and air by rain and sun).

If you can compost the clippings or get them into dense shade at roots
of good grass to rot quickly, I think they do return more nitrogen than
they consume from the decay process.  They do NOT return more nitrogen
than they originally took from the soil (like clover can), but it is better
than not returning anything.
-- 
=Richard B. Clark
 Lisle, IL       ...!{att,lll-crg}!cuuxb!rbc  OR cuuxb!rbc@arpa.att.com