From GENE LOGSDON
My wife’s mother followed an annual ritual of going to the woods and bringing back a bushel of dirt to use for potting soil. Carol, as a little girl, went with her to help carry the heavy basket back. Others tell me of similar memories, the woods soil being used not just for potting but to add to raised beds of city gardens to increase fertility. Folklore if not fact has always believed that virgin soil has almost magical qualities of fertility. I have a hunch that readers of this blog know of this custom or maybe still follow similar practices.
There are plenty of specific agronomic studies comparing virgin vs. farmed soils, almost all indicating more biological life in virgin soils. But the studies are couched in the impenetrable language of soil science— words five miles long— and do not come up with the kind of firm or even tentative conclusions I am looking for— whether or not virgin soils have superior nutritional or productive characteristics over soil cultivated for a long time but kept fertile with modern farming practices. I presume that scientific farming interests aren’t particularly eager to do research that might show that soils suffer from being cultivated, even with all our scientific knowhow.
In my research, I was lucky enough to stumble across Ronald Amundson, Professor and Chair of the Department of Environmental Science, Policy, and Management at the University of California, Berkeley, and also a Fellow of the Soil Science Society of America. He speaks in a language I can understand (probably because he grew up on a South Dakota farm and has worked the soil himself). Like me, he is much intrigued by our remaining virgin soils. “I suspect that the biology of virgin soils has more diversity and abundance compared to farmland, but I do not know yet of any microbiologists who have really studied the issue,” he says in an email. “I have been trying to get funding for such a study but times are tight now.” Then he added, most significantly in my opinion: “Our soils have been forming for over 10,000 years. We highly value 5000 year old trees but think little about completely changing something much older.”
Farm science seems to think that it can remake in a few years or sooner soil as good as those that took 10,000 years to form. I wonder. Some years ago I was walking with a friend across his farm when he asked me if I could see anything peculiar about his wheat field. Part of it was a little greener and taller than the other part, as if they were different varieties, or planted on different days or with different amounts of fertilizer. No, he replied, the only difference is that one side of the field was cleared 40 years ago and the other 80 years ago. This was particularly significant, I think, because he has always treated his land gently, always keeping it in long rotations with green manure crops as well as using careful applications of commercial fertilizers.
On my own little farm, I have about four acres of woods— old growth forest underlain with virgin soil. I have often noticed how much more vigorously plants seem to grow there even in the partial shade of the trees than they do in my fields that have been farmed for 150 years. Peach trees especially— a story I’ve told here a few years ago. Burdock leaves grow so big that one of them would be enough to wrap a baby in. Giant ragweeds really become giants, to 15 feet tall. Lambsquarter grows above the chicken coop roof. Needless to say, all three of these weeds have nutritional or commercial value. (Have you ever tried stir-fried burdock roots?)
There are records of 200 bushel corn grown on new land in the Midwest in the late 1800s even with low-producing open pollinated varieties, but average yields went down to 40 bushels per acre or less until hybrid corn came along. Wouldn’t it be interesting to know what would happen if today’s highest yielding corn varieties were planted in soil never touched by the plow? I intend to try it next year. I’ve even found an old account of how pioneers planted corn between stumps on newly cleared ground— with a dibble stick. I’d appreciate any thoughts you readers have about this. Or results from similar experiments. I am wondering if we shouldn’t be paying more attention to what’s left of our virgin soils.