What we need is a more holistic approach to our food systems. We need to be sure that high yields and maximum profits for producers don’t come with hidden price tags to consumers in terms of nutritional decline or environmental damage. This approach isn’t anything new to organic farmers — they’ve been working their farms as holistic systems all along, and the result is a production system that is better for us, domestic animals and the environment.
Certified organic growers are not allowed to use chemical nitrogen fertilizers, ever. Instead they build soil fertility using cover crops, compost and slow-release natural fertilizers. Because they aren’t grown with chemical nitrogen, organic fruits and vegetables tend to be smaller, and yields seem lower compared to non-organic crops. But as mentioned above, studies have shown that organic crops often contain less water, so in terms of actual nutrient value (and flavor) per bite of food, organic often is a better buy than non-organic produce.
The higher dry matter/lower water content of organic produce also impacts the levels of health-promoting antioxidants such as polyphenols and flavonoids. In a review of the scientific literature, Benbrook discovered that smaller fruits had up to five times more of these antioxidants per unit of calories.
There’s more research that must be done before we can know to what extent the overall quality of our food is declining, and whether the rapidly expanding organic industry will be able to consistently produce more nutritious food than chemical-based agribusiness.
But Benbrook says the public health implications are considerable: “When you think about the diseases and long-term health problems that are caused by poor nutrition — heart disease, diabetes, cancer — the value to society of producing more nutritious crops is enormous.”
Indeed, a 1992 USDA report estimated the following potential health benefits if everyone in the United States could be convinced to eat a diet containing the recommended daily amounts of primary nutrients shown in the table:
• 20 percent reduction in cancer
• 25 percent reduction in heart and vascular conditions
• 50 percent reduction in arthritis
• 20 percent reduction in respiratory and infectious diseases
• 50 percent reduction in infant and maternal deaths
So, it seems to us that the government should be doing more to monitor the nutrient content of our food, especially organic and pasture-based products. Currently, the USDA’s National Nutrient Database, which is widely used as the “official” source for nutrient levels, includes more than 6,600 food products, including meat; fresh, frozen and canned produce; and processed foods. They even include candy bars, gumdrops, TV dinners and hundreds of fast food items in the database. But the agency has not included a single organic item, nor any entries for products from pasture-based meat or dairy systems. If they use our tax dollars to report the nutrients in candy bars, isn’t it time they started including data on these healthier “alternatives,” too?
If you agree that the government needs to do more to enhance the quality of our food supply, write your congressional representatives and let them know. After all, as one USDA secretary whispered while giving us the mandated brush off, “It’s up to the public. If they really want to know, they have to press Congress to appropriate the funds.” You also can send a message every time you shop for your groceries: When you choose organic or grass-fed products, you are helping support farmers and ranchers who are offering high-quality foods from sustainable production systems.
Why Organic is Better: Flavor and Nutrition
[Adapted from Is Agribusiness Making Food Less Nutritious? by Cheryl Long and Lynn Keiley, Mother Earth News June/July 2004]
Growing evidence indicates that today's fruits, vegetables, meat and dairy products have less vitamins and nutrients than in the past.
American agribusiness is producing more food than ever before, but the evidence is building that the vitamins and minerals in that food are declining. For example, eggs from free-range hens contain up to 30 percent more vitamin E, 50 percent more folic acid and 30 percent more vitamin B-12 than factory eggs. And the bright orange color of their yolks show higher levels of antioxidant carotenes. (Many factory-farm eggs are so pale that producers feed the hens expensive marigold flowers to make the yolks brighter in color.)
Once upon a time, most of us ate eggs from free-range chickens kept by small, local producers. But today, agri-culture has become dominated by agri-business. Most of our food now comes from large-scale producers who rely on chemical fertilizers, pesticides and animal drugs, and inhumane confinement animal production. In agribusiness, the main emphasis is on getting the highest possible yields and profits; nutrient content (and flavor) are, at best, second thoughts.
This shift in production methods is clearly giving us less nutritious eggs and meat. Beef from cattle raised in feedlots on growth hormones and high-grain diets has lower levels of vitamins E, A, D and betacarotene, and twice as much fat, as grass-fed beef. Health writer Jo Robinson has done groundbreaking work on this subject, collecting the evidence on her Web site, http://www.eatwild.com, and in her book Pasture Perfect.
Similar nutrient declines can be documented in milk, butter and cheese. As one researcher writing in the Journal of Dairy Research explained, “It follows that continuing breeding and management systems that focus solely on increasing milk yield will result in a steady dilution of vitamins and antioxidants.” (Today’s “super-cows” are bred and fed to produce 20 times more milk than a cow needs to sustain a healthy calf.)
How much, and why, the nutrients in vegetables and fruits may be declining is less clear. Comparisons of 2004 data from the USDA’s National Nutrient Database, with numbers from 1975, show declines in nutrients in a number of foods.
WHAT THE EXPERTS SAY
Many things can impact the nutrient content of a vegetable or fruit. Variety type, soil quality, fertilizers, crop rotations, maturity at harvest time and the distance from farm to table all play a role in determining the vitamins and minerals in our food. We asked sustainable agriculture expert Charles Benbrook, Ph.D., if reliance on chemical fertilizers and emphasis on high yields might reduce the nutrients in fruits and vegetables. Benbrook has been studying the pros and cons of conventional and organic agriculture for more than 15 years. He explained factors that make organic foods rich in nutrients:
Fertilizers. Non-organic farmers use highly soluble nitrogen fertilizers, and keeping this nutrient in their soils is difficult. To be sure they get high yields, they often apply more nitrogen than the crops actually need.
This dependence upon chemical nitrogen fertilizers means we’re getting less for our money, says Benbrook. Numerous studies have demonstrated that high levels of nitrogen stimulate quick growth and increase crop yields because the fruits and vegetables take up more water. In effect, this means consumers pay more for produce diluted with water. “High nitrogen levels make plants grow fast and bulk up with carbohydrates and water. While the fruits these plants produce may be big, they suffer in nutritional quality,” Benbrook says, “whereas organic production systems [which use slow-release forms of nitrogen] produce foods that usually yield denser concentrations of nutrients and deliver consumers a better nutritional bargain per calorie consumed.”
Benbrook says the USDA has a tacit policy to avoid discussions of differences in food quality and safety that may be a function of how food is grown and processed. “The Department made a political decision when they finalized the national organic rule; they declared that ‘organic’ food was not nutritionally superior or safer than conventional food, even though there is solid evidence suggesting otherwise.” This would certainly explain the response we got from Johnson’s office.
What it all comes down to, Benbrook says, is that you can’t buy soil quality in a bag any more than you can buy good nutrition in a pill. Organic farmers work to support the complex natural relationships between crop roots, soil microbes and minerals, but “scientists only understand a few of those relationships. Unless we understand much more fully what the critical balances are, it’s very difficult to import them to the farm in a bag or a bottle.”
Vitamin C. High nitrogen levels reduce the concentrations of vitamin C in crops such as lettuce, beets, endive, kale and Brussels sprouts. Similar effects have been detected on fruits such as apples, oranges, lemons and cantaloupe. Swiss studies have shown similar impacts on potatoes and tomatoes, as well as citrus fruits — which are major sources of this important vitamin.
Harvesting and storage. The fact that the average supermarket apple travels 1,500 miles from farm to table only adds to the problem. “Most fruits reach best eating quality and peak nutrition when fully ripened on the tree or plant,” explains Julio Loaiza, Ph.D., a research scientist at Texas A&M University’s Vegetable and Fruit Improvement Center. “However, fully ripened fruit may not withstand the harsh handling typically involved for travel to distant markets, which leads to a compromise in optimum maturity and nutritional quality.”
Breeding for high yields. Plant breeders could maintain and even increase the nutrient content of most crops, if they were asked to do so. But this goal usually takes a back seat to economic issues: “Large-scale growers want size and fast growth so they can harvest early. These factors feed into sacrifices in nutritional quality,” Benbrook says.
WHY ORGANIC FOOD IS THE WINNER
Little doubt remains that when we choose organic food, we are helping to protect the environment. It’s also clear that organic food contains much lower levels of pesticide residues than non-organic crops. Scientists have been slow to fully study claims that organic food is richer in nutrients, since research agendas and funding are so often driven by dominant non-organic commercial interests. Here’s what we know so far, though, thanks to a comprehensive review of more than 400 scientific papers that compared the quality of organic and non-organic foods. The review, published in 2001 by the non-profit Soil Association of Great Britain, is titled “Organic Farming, Food Quality and Human Health: A Review of the Evidence.”
Higher dry matter? Dry matter represents the non-water component of food — a lower dry matter content indicates a higher water content, which is undesirable for consumers in terms of the dilution of nutrients and flavor, and the price per pound. Ten studies have demonstrated a trend toward higher dry matter contents in organically grown crops, averaging 20 percent higher. One study showed slightly higher dry matter content in a non-organic crop (bananas), and eight studies found inconsistent or non-significant differences.
Higher mineral content? Out of eight studies, seven demonstrated a trend toward higher mineral content in organic crops; one showed a trend toward higher minerals in non-organic crops that also used crop rotations and manure for fertilizer.
Higher vitamin C? Seven studies comparing vitamin C content in fruits and vegetables showed a trend toward higher vitamin C (from 6 percent to as much as 100 percent more) in organic crops. No studies have found higher levels in non-organic crops, and six studies found inconsistent or non-significant results.
SIGNS OF NUTRIENT DECLINE
Here’s a summary of the evidence that nutrients in non-organic factory-farm foods are declining:
• Many vegetables appear to contain lower levels of vitamins and minerals today than they did in 1975, according to official USDA nutrient data reviewed by health writer Alex Jack. Jack has reported that a random sample of USDA data on a dozen vegetables showed that calcium has fallen an average of 26.5 percent, vitamins A and C have dropped 21.4 percent and 29.9 percent, and iron has plummeted by an average of 36.5 percent.
• The concentrations of eight essential minerals in 20 fruits and 20 vegetables in Great Britain has declined, and water content has increased in fruits over the last 50 years, according to a paper by Anne-Marie Mayer in the British Food Journal (1997, Vol. 99, No. 6). She found that average calcium content had dropped 19 percent, iron was down 22 percent and potassium declined 14 percent for the 20 vegetables studied.
• Fruits and vegetables grown using synthetic chemical nitrogen may contain an average of 20 percent less dry matter and more water compared to organic crops fertilized with slower-release natural sources of nitrogen. Higher water content means lower nutrient concentrations per pound of produce (and weaker flavors).
• Meat and dairy products from animals raised in feedlots or cages on high-grain diets contain lower levels of nutrients than meat from animals that are raised on their natural diet of grass, or, in the case of poultry, grass and grain.
• According to the USDA’s Nutrient Database, factory-farm eggs contain 20 percent less iron and 59 percent less vitamin A than they did in 1975. The USDA data also show that today’s eggs contain 3 percent more water than in 1975. (See MOTHER's Chicken and Egg Page.)
• These factory-farm eggs contain significantly less health-enhancing carotenes than eggs from pasture-raised chickens. This difference is easy to see because the more carotenes, the more orange in color the yolks are. Factory-farm eggs also are lower in vitamin E, vitamin B-12, vitamin A, folic acid and omega-3 fatty acids, according to a remarkable collection of studies assembled by journalist Jo Robinson on her Web site, http://www.eatwild.com. Robinson also documents that not only do factory-farm eggs contain less vitamins, they have more fat and cholesterol than eggs from pastured poultry.
• And last but certainly not least, there is this: Because of the last few centuries of human industrialization across the globe, today’s atmosphere contains 30 percent more carbon dioxide than it did during the millions of years that plants, animals and humans have been evolving together. And the CO2 levels are predicted to increase even more unless/until we reduce our CO2 emissions. CO2 is the basic building block for photosynthesis; when plants are exposed to higher levels of CO2, they produce a higher proportion of carbohydrates than normal and this may lead to reduced levels of other nutrients, per calorie. A startling literature review published in Trends in Ecology and Evolution (2002, Vol 17, No. 10), reported initial studies have found that the concentration of every measured element except potassium declined when wheat was grown at high levels of CO2, and four out of five elements in brown rice declined. Global CO2 levels are predicted to continue to increase, and this could be yet another factor that is damaging the quality of our food.
Why Organic is Better: Health Safety
[Adapted from Mad Cow Disease Hits Home by Lindsey Hodel, Mother Earth News February/March 2004]
Fifteen years after Great Britain began destroying 3.7 million cattle because of an epidemic of mad cow disease, the first U.S. case of mad cow was confirmed in December in Washington state. The infected cow already had been slaughtered, and its meat dispersed into the human food supply.
Initially, the USDA reported the cow was a “downer” — an animal too sick to walk, which is a possible sign of mad cow infection — but subsequent eyewitness reports have disputed that claim. Determining the animal’s status is important because downers are targeted in the USDA’s mad cow surveillance plan.
Mad cow (also called BSE or bovine spongiform encephalopathy) is a fatal cattle disease that causes spongelike holes in the brain, making the infected animal stagger — thus the descriptive term “mad” cow. Scientists think animals develop the disease by eating feed containing brains, spinal cords or central nervous system tissues of other infected animals. (Yes, our industrial food system has been feeding cattle parts back to cattle!)
The human form of this disease is called variant Creutzfeldt-Jakob Disease (vCJD), and relatively few people are thought to have been infected by eating nervous-system tissue from diseased cattle. Mad cow and vCJD are caused by prions, infectious protein particles that cannot be destroyed by cooking.
According to the USDA, the risk of humans contracting the disease by eating U.S. beef is extremely low, but consumer groups say the agency is not doing enough to protect the public. The Centers for Disease Control and Prevention so far confirm 153 cases of vCJD worldwide, with 143 of those in the United Kingdom.
Since the outbreak of mad cow disease in the 1980s in Europe, consumer groups have urged the USDA to adopt stringent testing and tracking rules for beef. But, the beef industry resisted. A week after the U.S. mad cow case was confirmed, the USDA finally announced it would implement a national identification system to track meat, and ban downer cattle and mechanically separated meat from the human food supply. Beef producers also must follow new, more-stringent guidelines when using Advanced Meat Recovery (AMR) systems. AMR systems strip meat close to the spinal cord and increase the odds that BSE-infected central-nervous tissue could enter the human food supply.
Three-quarters of processing plants that use AMR systems produce meat containing spinal-cord tissue, a 2002 USDA study estimates. Ground-beef products such as hot dogs and hamburger (including pizza toppings and taco fillings) are most likely to contain stripped meat. Marrow in the bones of muscle cuts could contain spinal cord tissue, too. Milk and milk products are not thought to be at risk of contamination.
Dr. Michael Greger, a physician with the Organic Consumers Association, says the new regulations still aren't enough to protect consumers, and the most glaring omission is the lack of adequate BSE testing of live cattle. During the last 14 years, he says, the USDA tested only about 57,000 cattle (every year, 36 million cattle are slaughtered in this country). “We’re barely testing even the highest-risk animals,” he says.
Greger also says the USDA needs to eliminate the use of beef remnants in all livestock and pet feeds. In 1997, the FDA banned the practice in cattle feed, but Greger says the law is too loosely enforced and does not include other animal feeds.
Marion Nestle, author of Safe Food and Food Politics, and professor of nutrition and food studies at New York University, recommends boycotting beef as a political statement. “It’s the only way to send a message to these powerful forces,” she says. “[The USDA] knew what needed to be done and didn’t do it. Consumers need to start demanding food safety in this country.”
If you do opt to eat beef, certified organic is your safest option — federal organic standards prohibit the use of animal byproducts in organic feeds.
Organic Gardening: Preparing the Soil
[Adapted from Soil Building Basics by MOTHER’s Staff, Mother Earth News November/December 1982 and Preparing The Soil by Walker Abel and MOTHER's staff, Mother Earth News May/June 1985]
The health of the soil is undoubtedly the single most important factor influencing the vigor and productivity of crops.
Loosening soil can be likened to an inhalation: The soil has fluffed and expanded as a chest does when the lungs are filled. But just as our lungs are not simply inert balloons but are alive with blood that moves and uses this air, so the life in the soil responds to the increased air flow, leading to fertility.
And the organisms that make up a living soil must be carefully nurtured. They form an intricate system that is by no means completely understood. According to one estimate, a single teaspoonful of fertile soil contains 4,000,000,000 bacteria, 40 to 100 meters of mold filament, 144,000,000 actinomycetes, and large quantities of algae and other microorganisms. All of these, along with the organic matter that sustains them, transform inert, mineral dirt into healthy, living soil..
Such life-forms are important for a number of reasons. Like some intestinal bacteria in animals, they digest nutrients and change them into a form that higher organisms (in this case, plants) are able to use. Also, by tying up nutrients in their bodies as they grow and then dying and releasing them, these organisms regulate the flow of food to the plants and create a sustained fertility. In addition, their excretions, sometimes called soil glue, bind earthen particles into small aggregates, helping to build a loose, friable soil.
These beneficial microorganisms will not live in a soil that is fertilized only with chemicals. They rely, instead, upon a steady supply of actively decomposing organic matter for their food and energy. (Note the word steady: Organic matter needs to be supplied on an on-going basis.)
And important as its role of supporting microorganisms is, organic matter does even more. It helps aerate the soil (aha, more texture building!), retains water through dry periods, holds nutrients that would otherwise be leached out by rains, and—unlike chemical fertilizers—releases these nutrients slowly as its decomposition proceeds.
At the Eco-Village, we spread one inch of fresh compost over the surface of every just dug bed and then work this material in with a fork so that it's dispersed through the upper four to six inches of the soil. That is our fundamental fertilization program. The compost will nurture the crop throughout the season and leave some residue for long-term soil improvement. (We do occasionally work in some bonemeal to provide extra phosphorus, and hardwood ashes for potash.)
When our compost production is high, we're able to add as much as two or three inches of the homemade amendment per bed to help build up the organic matter in the soil. Ideally, a garden will eventually have a standing ratio of at least 5% organic matter. (This can be difficult to achieve in sandy soils or in regions with very hot summers.)
There are, of course, other sources of organic matter for your soil. In many areas, you can gather leaf mold from municipal leaf dumps. This is an excellent, long-lasting source of organic "fiber." (Use only well-decomposed mold, not fresh leaves.) Well-aged manure is also effective. (If you can only get hold of fresh, "hot" manure, compost it a few months so it won't burn your plants.)
And you can raise your own organic matter by growing cover crops like rye, hairy vetch, or buckwheat and then composting or turning them under. (Remember to wait a month before planting after turning under green matter.)
Building up the life and organic matter in your soil is an ongoing, never-ending garden task. You'll want to work each year at "growing" good soil, just as you'll work at growing good crops. Eventually, you should be able to maintain your soil's health and fertility by doing little more than proper composting, crop rotation, and cover cropping.
Preparing the Soil: Soil Testing
Experienced farmers of old could look at the relative quantities of various weeds or the way crops were growing and diagnose their soils. (The late Peter Escher, a biodynamic agricultural consultant, once outlined a program for improving the soil at Eco-Village after simply tasting one of our carrots!) Such "living soil analyses" can be extremely accurate, since they reveal how the soil is actually functioning in relation to plant growth.
Of course, very few people today have such observational skills. Most of us must rely on chemical soil tests to gain some sense of our plots' strengths and weaknesses. You can buy a kit at a garden supply store or get a test done through your county extension service. Don't rely completely on any test results—the accuracy of soil testing is a subject of much controversy—but do use them to identify glaring deficiencies you should address.
The first thing you should test for is pH, that indicator of acidity or alkalinity. Balancing your garden's pH is important, because a soil that's too acidic (a pH of 6.0 or lower) or too alkaline (a pH of 8.0 or higher) will tie up essential minerals in the earth, making them unavailable to your vegetables.
Check out MOTHER's Soil Testing Labs Directory.
Preparing the Soil: Amendments
SOWING COVER CROPS
Every fall, Kerry and Barbara Sullivan sow rye grain—or a combination (which is predominantly rye) of the grain and hairy vetch—over any garden bed that they don't intend to plant in vegetables early the following spring. Both winter-hardy ground covers—which should be available at local seed and feed supply stores—serve to help loosen up the soil and control erosion. In addition, each of the two plants has its own unique advantages.
The rye grain, also called winter rye (don't confuse it with rye grass), is an amazingly quick grower that—while it may get off to a slow start in the chilly weather of fall—bursts into green in the early days of spring. And, in doing so, it provides a great deal of bulk organic matter for the compost pile.
Hairy vetch (also called winter vetch), on the other hand, doesn't grow as rapidly as does rye … however, it's a hardy nitrogen-fixing plant which actually adds a good bit of that vital—but quickly used up—nutrient to the soil. Our gardeners thus use the vetch primarily on beds that will later grow such nitrogen lovers as spinach.
Before sowing their cover crops, Kerry and Barbara prepare the beds by loosening the soil with a garden fork. They do this by simply swinging the tool laterally into surface clods . . a technique called tilthing (developed by Alan Chadwick, founder of the biodynamic/French intensive gardening method). They then fork up, and shatter, any dirt balls existing in the top 8 to 12 inches of soil. The gardeners work compost into the growing area and treat any hairy vetch seeds with a special inoculant to increase the legume's nitrogen-fixing ability. Finally, they sow the seed by hand and lightly rake over the soil surface.
When it comes time to harvest their cover crops, the gardeners sharpen flat-edged spades and skim the greenery, by chopping it off—just near the soil line—right under the plants' crowns. They then pitchfork the cuttings into a wheelbarrow and use them to make compost.
Now you may wonder why the two growers don't just turn the crop under and there-by save themselves the trouble of harvesting and processing the material. Well, the Sullivans' response to that query is that green matter takes four to six weeks to decompose in the ground, and actually ties up some of the soil's nitrogen while it's degenerating. So it would be necessary to wait more than a month after turning under a cover crop before getting any use out of the nitrogen it could offer! However, since the gardeners skim off their "green manure", they can plant vegetables in the same growing spaces right away.
When Barbara and Kerry have a cover-cropped bed that's going to remain unused for a long period in the spring, they just trim back the greenery with a sickle every time it starts to head, and use those clippings for compost. That practice prevents the plants from getting hard and dry—as they do when seed heads form—and can give the gardeners two, or even three, harvests of good compost fodder from a single plot.
Our master growers also often employ a summer cover crop, buckwheat. This warm-weather plant (which, by the way, provides excellent honeybee forage) grows so rapidly and lushly that the Sullivans try to sow it whenever a bed will lie idle for as long as a month or during hot weather. Once again, they use the foliage for compost material. However, Barbara and Kerry point out that many home gardeners could achieve pretty much the same result by simply letting their weeds grow for a month and skimming those plants off before they go to seed. In fact, such indigenous ground covers might reach down and loosen soil more deeply than buckwheat would, anyway.
ACID AND ALKALINE SOILS
If your soil is too acidic, you'll need to add limestone or hardwood ashes to your gardenon the day you break ground—to increase the pH. Be sure, though, to use only agricultural-grade (not hydrated, or slaked) lime . . . and if you have a choice, opt for dolomitic limestone rather than calcic limestone, because of the former's more favorable magnesium content. To raise your soil's pH one full point, you'll need at least 3 pounds of finely ground limestone per 100 square feet . . . and the denser your soil is, the more limestone you'll have to add. (Very heavy clays sometimes need as much as 8 pounds per 100 square feet.) Alternatively, hardwood ashes—which are fasteracting—can be applied at roughly the same rate as lime. Actually, you might be wise to use a combination of ashes and limestone, to give your garden both an immediate and a sustained boost.
On the other hand, your garden may be alkaline—particularly if you live in the Southwest—in which case you'll need to reduce the pH. A one-inch layer of peat moss, worked into the earth when you till or dig your plot, should lower the rating a point. You can also use agricultural gypsum, at a rate of 2 pounds per 100 square feet, for the same purpose.
After checking your soil's pH, you'll next be interested in its nutritional balance. Of the 216 elements that most affect plant growth, all but three must come from the soil. (The exceptions are carbon, hydrogen, and oxygen, which are derived mainly from water and air.) And among the most important of those remaining, nitrogen, phosphorus, and potassium—the famous N, P, and K of commercial fertilizer formulas—are generally classified as major nutrients, while ten others are labeled minor, or trace, elements.
As most gardeners know, nitrogen is essential to plant growth and vigor. It's often considered the nutrient that most promotes leaf development. (How're your spinach crops?) An ongoing supply of good compost and other organic matter should take care of the nitrogen needs of a healthy garden. To supplement the nitrogen of a soil that already tests out very high in that element, Jeavons—again, in his eminently useful book How to Grow More Vegetables—recommends either .75 pound of blood meal (14% N) . . . 1 pound of fish meal (10% N) . . . 2 pounds of cottonseed meal (8% N) . . . or .75 pound of hoof and horn meal (14% N) per 100 square feet of garden. For a garden rated medium in nitrogen, he triples this dosage. And he roughly quintuples the proportions for a plot ranked very low in the element. In case you'd like to try working out some substitutions of your own, feather meal contains 10 to 13% nitrogen, processed municipal sludge 4 to 5%, poultry manure 4 to 6%, and most animal manures 2 to 4%.
Phosphorus promotes cell division, root development, and—most notably—fruit growth. If your soil tests show a very low phosphorus content, or if last year your green crops exhibited a reddish purple coloration in their stems and leaf veins, or if your fruiting crops were leafy but unproductive (never did get any tomatoes, you say?), you may need to add this element to your soil. For soils already rated very high in phosphorus, Jeavons recommends either 1 pound of bonemeal (24 to 28% P) or 2 pounds finely ground phosphate rock (30% P, but slow-releasing). He doubles the dose for ground rated medium and triples it for plots rated very low. Colloidal phosphate (20% P) and single superphosphate (20% P) are other good—and relatively fast-acting—sources.
Also known as potash, potassium is vital for cell division and growth, helps plants form strong stems and fight off disease, and promotes root growth. (Have a problem with your root crops last year? Notice a lot of yellow-streaked leaves and spindly plants?) For plots with a very high potassium rating, Jeavons recommends 1 pound of kelp meal (3% K) . . . 2 pounds of greensand (7% K) . . . or 3 pounds of crushed granite (4% K). For soil rated medium in potash, he suggests 1 pound of kelp plus 1.33 pounds of greensand (or 2 pounds of crushed granite) . . . 3.33 pounds of greensand . . . or 5 pounds of crushed granite. And for very low-rated soil, he doubles all of the "medium" numbers except the kelp. (Because kelp meal contains some growth hormones, Jeavons feels you should never add more than a pound of it per 100 square feet per year.) Some other organic sources of potash are feldspar dust (5-15%0), wood ashes (8% and sulphate of potash-magnesia—or Sul-po-mag—(22%).
These micronutrients—boron, calcium, chlorine, copper, iron, magnesium, manganese, molybdenum, sulfur, and zinc—are necessary in smaller amounts than nitrogen, phosphorus, or potassium, but, like the spices in a good recipe, are no less important to the end result.
Not only are trace elements valuable as direct nutrients, but they also work as catalysts to prompt chemical reactions that dissolve other soilborne minerals, making them available to plants. Many of the ten micronutrients, in fact, work best only when present in proper proportion with others.
Good composting and other soil-building practices should provide a balanced meal of trace elements in the long run. If you want to give your plot a trace-element boost now—or periodically—seaweed (kelp) is an excellent source. Apply a pound of seaweed meal (or 3 pounds of raw seaweed) per 100 square feet of soil area. Another good, commercially available source is FTE (fritted trace elements).
Preparing the Soil: Cultivation Methods
It wasn't that long ago that farmers were called sodbusters—a term derogatory to people who worked with the soil. Today, however, more and more men and women seem to be eager to get out and bust some very special bits of sod—their home gardens.
Usually, we think of garden cultivation in terms of plowing, tilling, digging, or hoeing—that is, simply turning and loosening the soil. This is accurate as far as it goes, but there's much more implied by the word cul tivation, and no doubt the farmers of old intended for these additional meanings to be understood when they chose this term to describe their practices.
If a teacher stands before a class and says, "In this school, we cultivate the characters of young men and women," that person is stating his or her intent to nurture, refine, and improve the students' basic natures. These meanings are equally applicable in the garden. The full intention of soil cultivation is to nurture and improve the ground so that crops will grow better. And just as the teacher who cultivates character must know what attributes he or she wants the students to gain, so must the gardener have a clear image of what he or she hopes to achieve by working the soil.
For the organic grower, that image has two central aspects: The soil should be loose, friable, and evenly textured . . . and the life it contains should be fully encouraged and nurtured.
It's said that the early Greeks began their transition to agriculture when they observed that plants grew particularly well in the loosened soil of a landslide. That was the example in nature that they tried to imitate with their digging and planting. (Nature also texturizes soil through the action of glaciers, frost, wind, earthworms, gophers, moles, the probing of deep-rooted plants, and so on.) Whatever model you follow with your own ground-disturbing activities, you'll be striving to loosen the soil to a good depth and create an even texture in its upper inches. Such cultivation—in the narrow sense of the word—performs several important functions:
It provides aeration. Roots need oxygen in order to carry on cell respiration and thus grow. Indeed, well-aerated soil may be almost half air space!
It provides drainage. Most garden plants don't like soggy soil. And the deeper the soil is dug, the better the drainage.
It provides easy root movement. In compacted soil, the roots must slowly pry their way down. This slows overall growth. In loosened soil, the roots can move freely to get the water and nutrients they need.
And it provides a good seedbed. The fine, even texture of the upper inches allows the soil to snugly cradle each seed and assures reliable germination.
Of course, you aren't likely to achieve such ideally textured soil in your first gardening season, but you can take a giant step toward that goal. Then again, you could also take a giant step backward . . . if you're not careful.
Many enthusiastic beginning gardeners rush outdoors and work their soil before it's ready. It takes some experience to know when the right time has come. The critical factor is soil moisture: If your plot is either too wet or too dry when you start to dig or till, you can cause serious damage that may take years to heal. (This is particularly true of clay soil; sandy soil is more forgiving.) Too wet ground may turn into large, hard clumps that are difficult to break, while overly dry soil may pulverize into such fine dust that it loses all its texture.
Our Eco-Village soil is predominantly clay. Therefore, it's very slow to warm and dry during our typically cool, wet springs. Certain sections, however, have a higher content of silt and sand. Because of the larger particle size of those ingredients, these beds dry more quickly. Hence, we use them for our early spring plantings of peas, fava beans, and spinach.
To tell if all or part of your soil is ready to work, pick up a clump in your hand and lightly roll it into a ball. Then either drop it or prod it with a finger. If the ball breaks easily into smaller sections, your soil is ready. If it's still rubbery or puttylike, wait for drier weather. On the other hand, if the clod is too dry (if it feels hard or crumbles easily into small, brittle fragments), water the ground thoroughly and check it again in another day or two.
You might also want to dig deeply into your garden to get a general sense of its current quality. Dark red or brown coloration is a sign of good drainage, while gray mixed with yellow or red means your plot's drainage is probably poor. Pale ground is subsoil: If that's all you've got, your soil-building work is cut out for you! Mottled soil may indicate that the water table sometimes rises near your plot's surface. And black-ah, black-soil is rich in organic matter.
If your ground's ready to work, first clear and remove the dead weeds and crop residue . . . and scythe or mow down any tall, live vegetation. You can then either rake this growth off and compost it or—while it's still green-turn it under. Note, however, that cellulose—rich plant matter requires nitrogen to break down, so if you till in the plant material, you'll also be temporarily reducing your soil's supply of that important nutrient. Wait a month after turning in green matter before you plant.
You can, of course, choose one of several ways to break the ground. If you have a small plot and a strong back, you can dig the whole area by hand. As another option, you can rent or buy a rotary tiller to work the plot. It may take a large number of passes with the machine's tines set at increasing depths, but eventually you should be able to finely break up the top four to eight inches of soil.
Then again, you may live in an area where you can pay a tractor owner to plow and disk your plot. Although the machine probably won't work the ground any deeper than a tiller would, it will do the job more quickly and easily. In fact, if you're preparing a large first-year garden on a plot with a thick layer of sod, you'll definitely be better off if you let a tractor do that initial ground breaking.
At the Eco-Village, we work our garden primarily with hand tools (although we have employed rotary tillers, a tractor, and even a draft horse in some areas), using a process called double-digging. This method, as many of you know, involves loosening the soil with a spade and garden fork to a depth of as much as 24 inches to better work in organic matter and to promote texture deep in the soil. The process demands a lot of hard work . . . but the results usually justify the effort. In fact, yields from double-dug beds can be four times as great as those from conventionally dug areas! If you want to learn more about the method, we heartily recommend reading John Jeavons' How to Grow More Vegetables.
While a lot of factors can influence your choice of ground-breaking technique, one element crucial to good soil texture is depth. . .1 rotary tiller or tractor will do a fine job of texturizing the top four to eight inches of your plot, but those machines won't touch anything beneath that. In fact, with repeated use they can actually compact that subsoil into hardpan.
Double-digging, obviously, loosens soil to the greatest depth ... but it also takes the greatest amount of labor. For a "middle ground" alternative, divide your tilled garden into pathways and raised beds, and rake the loosened pathway earth onto the beds: That'll help increase the depth of texturized soil for your crops, no matter how you initially break the ground! (Our 1984 Eco-Village minigar-experiment-reported in our last issue showed that crop yields in either a doubledug or rotary-tilled raised-bed garden are superior to those in standard row culture gardens.)
This biodynamic/French intensive technique—which involves removing the top 12 inches from a four-foot-wide strip of soil, loosening the subsoil yet another foot deep with a garden fork, and then replacing the broken-up layer—has been an integral part of our gardeners' success.
Kerry and Barbara are quick to note that double-digging doesn't preclude the use of other gardening techniques, though. ("I'm not against rototillers or anything like that," Mr. Sullivan states.) Yet its distinctive virtues—allowing a person to grow large crops in a small space and to garden completely (and quietly) with hand tools—appeal to a lot of folks. Kerry adds, "There are certain people, like me, who probably wouldn't have any luck gardening if' they didn't double-dig."
The Sullivans maintain over 100 double-dug raised growing beds in the Eco-Village garden. Approximately 30 of these 4' X 30' areas are used for perennial crops, including asparagus, cane fruits, and long-lived flowers. The rest are redug on an annual basis, either in the fall or early spring. As Barbara puts it, "You'll have to decide how often you want to doubledig your beds, but if you really want to improve most soils—especially clay-laden ones—quickly, you'll redig every year. Fortunately, though, it takes only a couple of hours to work up a well-loosened bed, as compared with the six to eight hours required to dig a 4' X 30' plot from scratch."
Of course, the Sullivans can't redig their perennial beds (doing so would disturb the plants). So, to make up for that lack of regular soil loosening, they incorporate compost—a great deal of it—and some bone meal (as a phosphorus supplement) when they first prepare such areas.
Preparing the Soil: Crop Rotation
The Sullivans rotate crops primarily to help balance such nutrients as nitrogen, potassium, and potash in the ground. As Barbara puts it, "The ideal planting sequence would be to start off with a nitrogen-fixing legume ... follow that with a nitrogen-loving leaf crop . . . then raise a root vegetable . . and finally, after dressing the bed really heavily with compost, grow a heavy-feeding fruiting crop." However, they're rarely able to achieve that optimal sequence themselves. Instead, Barb and Kerry often simply divide their plantings into four groups—the root, leaf, legume, and fruiting crops—and avoid planting two of the same type consecutively in the same place.
Furthermore, since crop rotation can also help prevent the spread of soil-carried diseases, our gardeners make an effort not to raise different vegetables from the same family successively in a growing space. They focus this concern mainly on three groups: the cucurbits (squash, cucumbers, and melons) ... the brassicas (broccoli, cauliflower, cabbage, brussels sprouts, turnips, mustards, collards, and kale) ... and the nightshades (potatoes, peppers, tomatoes, and eggplant). The Sullivans also tend to avoid back-to-back plantings of members of the Umbelliferae (carrots, parsley, parsnips, and dill) and the Chenopodiaceae—or goosefoot—family (beets, spinach, chard, and lamb's-quarters).