In its quest for higher yields per acre, modern agriculture seems unaware or unconcerned with any nutritional changes that its methods of production may be producing in crops. Soil fertility and crop selection, the same two factors that influence the yield, also influence the nutritional value of the crop being produced.
Dr. William A. Albrecht, PhD, Professor of Soils and Chairman of the Department of Soils at the University of Missouri College of Agriculture, has left us evidence in his papers of this link between the nutritional value of the crop and these two agricultural factors–soil fertility and crop selection.
We select nutrition based on the food we are going to eat. When given the chance to choose, cows select their nutrition based on soil fertility rather than on the crop growing there.
Dr. Albrecht provides an example of this behavior from a farmer’s observations of beef cattle on the Poirot Farms near Golden City, Missouri.1 A herd of over 100 cattle was expected to graze on a virgin prairie field growing mainly bluegrass and white clover. This field had never had any soil treatment. The farmer noticed, however, that the cattle were crossing this field and going through an open gate into a corn field that had been abandoned because of a shortage of labor.
This well-fertilized field was taken over by a variety of weeds, all of which the cattle ate and kept down to a short growth during the season, while the bluegrass and white clover grew longer and longer, ignored by the cattle. The cows were forced to cross this unfertilized prairie field daily for access to water. Clearly the cows selected the weeds over the white clover and bluegrass because of the difference in the soil fertility of the two fields. A farmer might be expected to harvest the white clover and bluegrass as hay while destroying the crop of weeds. In learning from this demonstration, we might better nourish cattle as well as ourselves.
CALCIUM AND POTASSIUM
On a bag of N P K fertilizer, N refers to nitrogen, P refers to phosphorus and K refers to the element potassium. As the calcium to potassium ratio varies in the soil, so does the protein content and the mineral content of the crop. In a paper first published in 1947 in The Journal of the American Academy of Applied Nutrition, Dr. Albrecht reports on an experiment with soybeans grown with increasing amounts of potassium in the soil.2
With the calcium being held constant, the potassium was used in three different amounts while all other soil treatments remained the same. The soil receiving the largest amount of potassium produced a 25 percent larger crop than the soil receiving the smallest amount of potassium. While this result would please the farmer and the agricultural industry, a chemical analysis might produce a different reaction from a consumer of the food produced. The nitrogen contents in the crop for the three different amounts of potassium were 2.8 percent in the smallest crop, 2.5 percent in the intermediate crop, and 2.19 percent in the largest crop. The nitrogen content is directly related to the protein content. The phosphorus concentration was .25 percent in the smallest crop, .18 percent in the intermediate, and .14 percent in the largest crop. The calcium content was approximately .75 percent of the dry weight in the smallest crop and only .27 percent or about one-third of the dry weight in the largest crop.
Although the largest amount of potassium in this trial produced the largest bulk yield of the crop, it also produced the lowest total yields with respect to the nitrogen, phosphorus and calcium. In order to get the same amount of protein, phosphorus or calcium provided by the crop from the field with the lowest yield, a consumer of the crop from the field with the highest yield would need to eat more, thus consuming more carbohydrate.
A diet that forces the animal or human to eat more carbohydrate to obtain the required protein and minerals is a fattening diet. In this example, it isn’t the type of food that is the fattening factor, but rather the soil fertility for the crop that is the fattening factor. We may worry about what fattening foods we eat, but we never worry about the fact that the same food may be more or less fattening depending on the soil fertility and the fertilizers used in the crop’s production.
Albrecht was not necessarily opposed to the use of NPK fertilizer, but to the large amounts of N and K they contained. As Albrecht explains, early NPK formulations contained a lot of phosphorus and smaller amounts of nitrogen and potassium. When agricultural scientists discovered that increasing the amount of N and K increased yields, the ratios of the three elements were changed to take advantage of this increased production. So both nitrogen and potassium fertilizers are not themselves the problem, but rather overuse of both for increasing crop yields is the problem as the resulting crop ends up being deficient from a nutritional point of view.
SOIL FERTILITY AND RAINFALL
Judging the nutritional value of food based on whether or not it is produced in “natural” soil does not guarantee high nutrition in the food. Soil fertility in natural conditions may be under construction or under destruction from the naturally occurring amount of rainfall.
In the same previously mentioned paper from 1947, Dr. Albrecht discussed how this variation in soil fertility with respect to annual rainfall is demonstrated across the prairie state of Kansas.3 Annual rainfall varies from 17 inches in western Kansas to 37 inches in eastern Kansas and the crop yields per acre are higher in the east than in the west. In naturally occurring conditions, buffalo grazed in western Kansas but not in eastern Kansas where the yields of prairie grasses were larger per acre. These grazing patterns indicate soil fertility varies from western Kansas to eastern Kansas. Lime (or calcium) is found one foot down in the soil for a further depth of one foot in western Kansas. Moving east this layer of lime-containing soil gradually becomes less until it is gone in eastern Kansas. Wheat grown in Kansas in 1940 varied from 18 percent protein content in western Kansas to 10 percent protein content in eastern Kansas.
One can see that the buffalo, like the cattle in the earlier example, choose their feed based on the soil fertility rather than on yield per acre, choosing to graze on the soil with the greater reserve of calcium, in spite of the lower amount of grass per acre.
The declining amount of calcium in the soil profile is linked to the increased annual rainfall. While, at first, rainfall is necessary to construct soil fertility by gradually breaking calcium out of rock and making it available for plant nutrition, over long periods of time the rainfall also gradually leaches the calcium from the soil and the subsoil, eventually carrying it to the sea. Under conditions of higher annual rainfall, this process takes place more quickly than when the annual rainfall is lower. When there is no longer any source of parent rock containing calcium for the rainfall to draw from to add calcium to the soil, the soil fertility gradually declines and the soil loses its ability to produce crops of high nutritional value. The surprising conclusion: letting nature take care of the soil fertility is no way to assure production of nutrient dense crops.
SHOULD WE TAKE SUPPLEMENTS?
In an attempt to make up for foods considered deficient in nutrients, people may take supplements, believing that these make up for the lack of nutrition caused by the low soil fertility. Albrecht cites an experiment that caused him to question this thinking.4 Test rabbits were fed one of two lespedeza [bush clover] hays, one of which received a lime or calcium treatment and one which received no treatment. The hay from the lime-treated soil produced better growth in the rabbits. Surprisingly, the hay from the untreated soil was the better digested. The urine of the test animals was analysed for both phosphorus and calcium contents. The animals eating the hay from untreated soil excreted twice as much phosphorus and calcium in their urine as the animals eating the hay from the calcium-treated soil.
In order for these minerals to come out in the urine of the test animals, they must have been both digested and absorbed. Yet something must have been missing in the hay from the untreated soil that was necessary to allow the animal to make full use of these minerals. Lacking enough of this essential factor would cause some of the minerals to simply pass through the body without being used, wasting the effort made by the body to digest and absorb them. Thus, the mineral content of food obtained by ash analysis, or the digestible and absorbable mineral content of a supplement may not be good ways to judge their actual nutritional value.
Farmers may use different tactics to deal with insects when the underlying problem is the soil fertility and the insects are the symptom of the low soil fertility. Dr. Albrecht illustrated this relationship by describing what happened when uninvited insects arrived during an experiment in which he was looking at the effects of changes in carefully controlled soil fertility on the nutritional values in spinach.5
Albrecht grew spinach in soil with varying amounts of nitrogen and varying amounts of calcium to study the change in nutritional value as nitrogen and calcium amounts increased or decreased. All other nutrient elements were uniformly added to all the pots, which each contained two spinach plants. Both calcium and nitrogen were each added in four different amounts.
During the growth of the plants, insect thrips attacked some of the spinach. Interestingly the percentage damage to the leaf surface was related to the soil fertility. Going from the lowest application to the highest application of nitrogen, the surface damage to the spinach leaves was 38.6 percent, 39.5 percent, 6.9 percent and 3.6 percent respectively. In the soils with lower amounts of nitrogen, increasing the amounts of calcium reduced the insect damage. Thus, while the farmer may view insects as pests that destroy his crop and thereby cost him income, the consumer of food may view insects differently. Those interested in the nutritional value of the food may see the insects as their allies who point out which foods contain low nutritional value and which should not be consumed.
Nitrogen had a definite effect on yield. The spinach yield ranged from 121.3 grams for 10 plants in the pots with the lowest amount of nitrogen to 418.8 for 10 plants in the pots with the highest amount of nitrogen. Levels of oxalate acid–a naturally occurring component of many plants that acts as an anti-nutrient, blocking mineral absorption–dropped from 8.17 percent of dry matter for the pots with the lowest nitrogen to 6.02 percent of dry matter for the pots with the highest application of nitrogen in this test.
This study underscored the importance of nitrogen in the soil and showed that nitrogen can be used to increase both yield and nutritional value of crops. However, at a certain point, additional application of nitrogen to increase yield will lower the nutritional value of the crop.
A SURPRISE ABOUT VITAMIN C
Albrecht came up with unexpected results when he tested the spinach for vitamin C. The highest level of vitamin C, 28.7 milligrams per 100 grams, came from spinach in the pots with the lowest amount of nitrogen, declining to a value of 20.9 milligrams per 100 grams for the spinach grown in the highest amount of nitrogen. The experiment was replicated ten times and the insect attacks remained the same in all the trials, that is, the attacks were concentrated on the plants with the highest nitrogen levels, the highest yield but with the lowest level of vitamin C.
These results led Albrecht to question our understanding of the nutritional contribution made by vitamin C. Albrecht stated that the decreasing quantity with healthier plants demonstrated vitamin C was not directly contributing to healthier growth. He described vitamin C as a catalyst or whip driving the metabolism of the plant faster by its presence in greater quantity to help overcome the deficiencies in other nutrients. Albrecht asks the obvious question: do higher levels of vitamin C indicate a more nutritious or less nutritious crop for our consumption? Thus, to say that a food is better for you because it has more vitamin C may be the exact opposite of the truth. And as with plants, it may be that people with weaker immune systems may require a larger daily dose of vitamin C than people with healthier, stronger immune systems. The concept of a recommended daily dose of vitamin C for everyone is therefore nonsense.
As soil fertility declines, it becomes harder for the farmer to produce a crop in what once was a productive soil. The industry came up with the answer to enable the farmer to maintain or even increase his yield as soil fertility declined. Their answer was hybrid crops. Hybrid crops are known for their vigor and increased insect and disease resistance. Since a farmer can’t save seeds from a hybrid crop to grow the same crop the next year, there had to be some benefit in hybrid seeds to persuade the farmer to purchase new seeds each year.
Obviously high yield along with insect and disease resistance is good for the farmer’s income. Nobody seems to have asked whether this meant anything in the way of nutritional value for the consumer. In order to maintain yields as soil fertility declines, it becomes necessary to grow crops that place less demand on the soil fertility for their growth. Crops that require less nutrition from the soil will thrive while crops that require higher nutrition from the soil will fail.
The first way farmers accomplished this was to switch from legume crops to non-legume crops. The introduction of hybrids has provided the farmer with a new means to maintain his yield while growing the same crop.
Dr. Albrecht explained how the hybridization of corn fits the pattern of increased bulk yield at the cost of reduced protein content.6 Hybrid corn can grow where old fashioned open pollinated corn fails because the hybrid requires less nutrition in the way of minerals from the soil to survive. This attribute has been accomplished by cross breeding to alter the genetics, reducing the protein output of the corn while increasing the carbohydrate output. While the hybrid demands less from the soil to survive, it also produces less protein and more carbohydrate. This is effectively no different from growing the crop with more potassium to increase yield per acre at the expense of total nutritional value per acre. If a crop demands less from the soil fertility, it produces less nutrition.
When crops grown for high production produce less nutrition, it would be logical to think that animals bred for high production would also produce less nutrition. Chickens bred solely for meat or egg production and cattle bred for dairy or meat production are likely not producing the same levels of nutrition as the dual purpose breeds. Feeding high production crops to high production animals would be combining the worst of both worlds when it comes to nutritional output. The high production dairy cow, the Holstein, may be fed organically grown corn and may be pastured on high yielding organically grown hybrid grasses. The organic milk produced by this system might even be consumed raw. But do you think there is any chance that the milk produced in this way would have anywhere the same nutritional value as the raw milk that Price used in his experiments in the 1930s?
Farmers are currently paid based on the yield they produce. If we want farmers to produce food for nutritional value instead of yield–by spending money to improve soil fertility while at the same time choosing animal or vegetable crops that decrease their yield–we must be prepared to pay for it. If you think you can’t afford more money for food, think about the fact that you need to eat less of a more nutritious food.
Actually, eating more of a less nutritious food may not even be the equivalent of eating less of a more nutritious food. Even if total mineral intake is the same, it makes a big difference how much of the minerals are simply excreted, as in the case of the lower nutrition food. When you eat smaller amounts of more nutritious food, your total food bill may even go down, while at the same time your health improves.
William Albrecht, The Father of Soil Fertility Research
Dr. William Albrecht was born on a farm in central Illinois. His four academic degrees including his PhD were earned at the University of Illinois. As Chairman of the Department of Soils at the University of Missouri College of Agriculture, Albrecht pioneered the study of soil fertility and its effect on plant and animal health. He retired from the university in 1959, but before his death in 1974 at age 85, he left his collection of published papers to Acres, USA, now published as four volumes. Over thirty pages in the first volume are required to list these papers in which Albrecht presents evidence to substantiate his observation that declining soil fertility and unbalanced soil fertility were the underlying causes for poor crops and for pathological conditions in animals fed these crops.
His contribution to the field of soil fertility mirrors the contribution of Dr. Weston A. Price to the field of nutrition. Dr. Albrecht wrote a foreword to the supplement in the 1970 edition of Nutrition and Physical Degeneration and also served as a member of the Board of Directors of the Price-Pottenger Nutrition Foundation.
References from The Albrecht Papers
- Volume I, “Weeds, as the cows classify them,” from the chapter titled, “It’s the Soil that Feeds Us.”
- Volume I, “Crop Bulk as Criterion of Soil Productivity Invites Deficiencies,” from Chapter 25, “Soil Fertility as a Pattern of Possible Deficiencies.”
- Volume I, “Soil Construction Favours Proteinaceous, Soil Destruction Carbonaceous Quality of Vegetation,” also from Chapter 25.
- Volume IV, Chapter 5, “Pastures.”
- Volume IV, Chapter 4, “The Anatomy of Soil Fertility.”
- Volume II, Chapter 4, “Nutritious Feeds via Soil Fertility and Not Plant Pedigrees.”
This article appeared in Wise Traditions in Food, Farming and the Healing Arts, the quarterly magazine of the Weston A. Price Foundation, Winter 2004.