Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!agate!shelby!polya!Polya.Stanford.EDU
From: ray@Polya.Stanford.EDU (Ray Baxter)
Newsgroups: sci.bio
Subject: Re: Is Mowing your Lawn bad for the Environment?
Keywords: lawns fertility
Message-ID: <9773@polya.Stanford.EDU>
Date: 7 Jun 89 04:41:40 GMT
References: <24792@agate.BERKELEY.EDU> <20388@uflorida.cis.ufl.EDU> <2876@cuuxb.ATT.COM> <1277@lafcol.UUCP>
Sender: Ray Baxter <ray@polya.Stanford.EDU>
Reply-To: ray@Polya.Stanford.EDU (Ray Baxter)
Distribution: usa
Organization: Biological Sciences, Stanford University
Lines: 12
In-reply-to: logant@lafcol.UUCP (Tracy Logan)

In article <1277@lafcol.UUCP>, logant@lafcol (Tracy Logan) writes:
>The worries about clippings and nitrogen puzzle me.

Don't be puzzled.  These claims are simply wrong.  There is no
way that returning grass clippings to your lawn will reduce the
availible soil nitrogen, as compared to say bagging the grass and
carting it off.  The original poster seemed to believe that because
only legumes (such as clover) fixed nitrogen from atmospheric N2, the 
nitrogen present in non-legumes was not returned to the soil.
While it is true that only legumes can cause a net increase in soil
nitrogen, there will be more nitrogen in soils where the grass clipping
are returned.