Message-ID: <KF16+OEfKmA@ssc.msu.edu> Date: Tue, 8 Oct 1996 15:49:52 EDT From: Don Osborn <mailto:don.osborn@SSC.MSU.EDU> Subject: Sustainability & soil mineral depletion To: Multiple recipients of list DEVEL-L <mailto:DEVEL-L@AMERICAN.EDU>
Tom Hodges mentioned an Andean cropping system in operation for 1500 years and Stanley Chin mentioned intensive Chinese agriculture. Soil tilth and fertility are maintained in these systems through cultivation and organic inputs--but what about mineral content?Some people in the US (esp. in the health food industry) are making much of the fact that for instance commercially produced spinach contains much less iron today than it did 50 years ago. Supposedly many foods show similar declines in mineral nutrient value. Is this a function of agricultural practices that destroy topsoil or, more broadly, of continuous cultivation in an area (or instrumental use of data which actually show sonmething else for marketing purposes). Does small scale intensive & "sustainable" agriculture replenish the trace minerals in soil, or do foods in such systems end up showing similar depletions?
Don Osborn mailto:osborndo@pilot.msu.edu don.osborn@ssc.msu.edu