Posts Tagged soil fertility
March 10, 2008 at 8:32 pm · Filed under Notes ·Tagged farming, organic farming, soil fertility, soil health, soil organic matter, sustainable agriculture, william albrecht
Today I actually found the time to read. Gardening for Profit is buried somewhere in the moving boxes, but I did manage to bring along my copy of The Biological Farmer. I’ll finish posting notes for Gardening for Profit when I get back to Oregon, but now seems like a good time to start sharing what I’m learning from Gary Zimmer.
This author runs a sustainable agriculture consulting firm in the upper Midwest and this book was originally intended to be a primer for consultants-in-training. He also owns and operates a 500-acre organic crop and dairy farm, and manages a 240-acre livestock and crop demonstration farm. It sounds like he’s heavily influenced by Albrecht, so I’m using this book as an introduction to soil-focused agriculture.
Some of the information isn’t new to me, since I studied environmental science and ecology in school. My eyes didn’t perk up till chapter 2, when he described 6 rules essential to biological farming. By “biological” farming, he means farming to maximize productivity and profits over time by understanding and working with biological processes (whereas conventional practices focus on maximum productivity and profits ASAP, and don’t give a @#$% about biological processes). He goes a step further and describes his criteria for sustainable agriculture, which can be achieved by practicing biological agriculture properly and in the long run: zero soil loss, nutrient balance, and 25 earthworms per cubic foot of soil.
So here are the 6 basic rules essential to biological farming: Read the rest of this entry »
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February 4, 2008 at 10:01 pm · Filed under Notes ·Tagged compost, composting, guano, manure, soil fertility, soil preparation
Notes based on Gardening for Profit (Chapter 7) by Peter Henderson.
Back then when horses did all the work, there was lots of horse manure to be had. So Henderson took advantage of it and really piled it on.
At least six months before applying it, the manure was dumped in a natural depression. If there wasn’t one, they dug one out 18-24″ deep. They put up a 6′ fence around it. The wagons were pulled up next to the fence and fresh manure was tossed in, spread out evenly throughout the depression. Pigs were kept in the enclosure to break things up, and they were fed weeds and unsold vegetables from the field.
- I wonder how large this manure pit needed to be. I guess it depends on how much manure he needed, which depends on how much land he was preparing (he’d spread 50 to 100 tons per acre).
- Also, how many pigs? Two? Ten? That’s probably a function of field size and manure quantity, as well.
Henderson was a big fan of horse manure, and not just because it was plentiful. He considered it 1/3 more valuable than that of cattle and pigs, in terms of weight (i.e. 100 lbs of horse manure would work just as well as 130 lbs of cattle or pig manure). He also cites horse manure as being extra beneficial as a pulverizer on stiff soils. Read the rest of this entry »
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January 28, 2008 at 2:30 pm · Filed under Notes ·Tagged manure, plowing, soil fertility, soil preparation, tilling
Notes based on Gardening for Profit (Chapter 6) by Peter Henderson.
Henderson describes the soils he works with. His general guideline is to look for a dark-colored loam soil (neither sandy nor clayey) that’s at least 12″ deep, preferably with a yellowish sandy loam underneath (good for drainage). Soils to look for, in order of preference:
1. alluvial saline deposit – usually within a mile from the tide mark; dark heavy loam containing decomposing shells; 10-30″ deep; overlaying subsoil of yellow sandy loam
2. lighter soil, both in color and specific gravity – 8-15″ deep; similar subsoil to above
3. still lighter soil, in color and specific gravity – sand predominates over loam; subsoil is pure sand; good for melons, cucumbers, sweet potatoes, radishes, and tomatoes; not good for onions, cabbages, celery
4. clayey loam – 10″ deep; over thick stratum of stiff bluish clay; found on highest points; not good for early vegetables; favorable for a late crop like celery
Note to self: Look further into soil classification. I’m having trouble visualizing these distinctions because I’ve never closely analyzed soils. Read the rest of this entry »
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January 3, 2008 at 11:02 pm · Filed under To do ·Tagged compost, farming, soil fertility, soil health, soil organic matter, sustainable agriculture
OK, back to business. My plan had been to borrow a copy of The Biological Farmer by Gary Zimmer from the local university library. I’d been told it’s an excellent primer, and I’ve been looking for a source to provide me with a balanced context so I don’t get lost in the details. But before I could get my hands on a library copy, my schedule went to hell and now my “inside source” at the university has graduated. So then I was going to actually buy a copy, but tonight I came across another highly recommended book that’s available through the soil and health library nurtured by Steve Solomon (bless his heart). The book is Gardening for Profit by Peter Henderson and–get this–it was written and published in 1867! For a book to still be relevant and helpful over 200 years later [edit: 100 years later–math class, anyone?]…this I’ve got to read.
That library, by the way, it’s dangerous. There are so many goodies in there that I could easily blow a month’s paycheck in one sitting–I was so tempted to print out at least five books at once, but I practiced moderation and decided to print only one title, Gardening for Profit, at my local Fedex Kinko’s for $16. You can upload the PDF to their website and complete your order so that all you have to do is pick it up when it’s ready. I had my copy bound nicely so that it lasts a long, long time. I also paid the voluntary $15 to become a lifetime member of the soil and health library. Small price to pay for such a goldmine of knowledge!
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December 29, 2007 at 9:00 pm · Filed under Notes ·Tagged albrecht, drought, farming, soil fertility, soil health
Everything is still on hold because of the aforementioned medical emergency. The holidays are keeping me busy, too. But the good news is that I’ve gotten a small piece published in Culinate, an online food magazine based out of Portland, Oregon. It’s a news piece based on one of my first entries here, The Drought Myth. While it’s quite brief, it brings Albrecht’s point closer to the mainstream. Check it out:
The fertile plain, Culinate.com
[Edit: 1/30/08]
Some readers commented that Albrecht wasn’t condoning the use of chemical fertilizers, which is was the piece implied by connecting his article to the NYT article about Malawi. That’s not what I was getting at, but I can see how that implication could be drawn.
The comments further implied that the Malawi government is doing more harm than good by turning to chemical fertilizers. I wonder, though, if we look beyond the “evils” of chemical fertilizer, if using them for a few years can possibly lead to a win/win situation. Here’s the comment I posted:
I completely agree that raw materials are the most effective way to encourage soil health in the long run. But, I’m not sure it would be economical or feasible for Malawi’s government to fund a more sustainable approach to soil fertility, at least not at first.
If raw materials are not affordable, then the next best thing would be for Malawi to jump-start their agricultural economy with chemical fertilizers (which are cheaper, more accessible, and more convenient) and use the excess income to fund more sustainable (usually more expensive) methods ASAP.
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November 29, 2007 at 11:27 pm · Filed under Notes ·Tagged compost, farming, soil fertility, soil health, soil organic matter, sustainable agriculture
Found an abstract which might explain how excess N messes with soil carbon sequestration:
“The added NO3- suppressed mineralization of C from SOM and stimulated mineralization of C from stover. Adjustment of rates of stover decomposition to temperature regimes normally encountered in Iowa fields after harvest showed that stover decomposition would not be complete within 1 yr and that increases in NO3- availability decreased the amount of stover C remaining in the soil. This effect of NO3- could explain how additions of unneeded N could decrease concentrations of SOM in long-term studies in which residues and NO3- are added in annual cycles. These observations suggest that practices that reduce unnecessary fertilization could help conserve SOM and reduce net amounts of CO2 released to the atmosphere.”
Next: My pathetic attempt to translate this into understandable terms after reading the whole study, if I can get my hands on it.
Update: No luck finding the full study after searching two state university library systems. Here’s the citation for this article in case anyone’s interested:
Title: NITROGEN EFFECTS ON CONSERVATION OF CARBON DURING CORN RESIDUE DECOMPOSITION IN SOIL
Author(s): GREEN CJ, BLACKMER AM, HORTON R
Source: SOIL SCIENCE SOCIETY OF AMERICA JOURNAL 59 (2): 453-459 MAR-APR 1995
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November 28, 2007 at 11:58 pm · Filed under Notes ·Tagged compost, farming, soil fertility, soil health, soil organic matter, sustainable agriculture
Now that I’ve read the compost study, Albrecht’s article on soil restoration, and the nitrogen myth article, I’m still left wondering how nitrogen directly impacts the formation of organic matter. Albrecht insists that there must be adequate nitrogen present in the soil or else carbon is lost (presumably as carbon dioxide). The compost study results back this up – more nitrogen resulted in more soil carbon. But then the nitrogen myth article implies that excess nitrogen (and I mean extreme, as in 60-190% net addition of N) also results in the loss of carbon from the soil. How does this work?
C + Excess N = CO2
C + Too little N = CO2
C + Just the right amount of N = Soil carbon
I think I need to get my hands on a soil science/microbiology textbook. Maybe I’ll peruse eBay and find a cheap copy that some college student spilled their beer on.
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November 24, 2007 at 10:35 pm · Filed under Notes ·Tagged compost, farming, permaculture, soil fertility, soil health, soil studies, sustainable agriculture, william albrecht
My Albrecht studies continue with an article titled Loss of Soil Organic Matter and Its Restoration. Like The Drought Myth, it was packed with insights and information. The metaphors were especially striking. He referred to the soil as a breathing, working entity, like a factory where organic matter is fuel, bacteria is fire, and nitrogen is the building material of choice. It uses the equivalent of 1 horsepower per acre to burn organic matter, “exhaling” more than 25 times as much carbon dioxide per day as an adult man at work.
The organic matter (its supply of fuel) has been building up gradually for 25,000 years in North America, since a glacier receded and left minerals in its wake. Then came the pioneers who tilled the soil, and a steep decline in soil organic matter (SOM) began. With the loss of SOM came a proportionate decline in agricultural productivity, and the trend continues to this day (compensated for by chemical inputs, of course). In this article, Albrecht outlines ways in which this trend can be halted or even reversed. Read the rest of this entry »
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