HEALTH = Nutrition/Calories = Calcium/Potassium
When we decide how to manage our gardens we can take steps to imitate dryland soils by keeping potassium levels lower while maintaining higher levels of calcium.
Now take another close look at the third chart. Average vegetation from dryland soils contains slightly more potassium than calcium (1.2:1) while average vegetation from wetland soils contains many more times more potassium than calcium (4.5:1). When we import manure or vegetation into our garden or farm soils we are adding large quantities of potassium. Those of us living in rainy climates that were naturally forested have it much worse in this respect than those of us gardening on the prairies or growing irrigated gardens in desert climates because the very vegetation and manure we use to "build up" our gardens contains much more potassium while most of our soils already contain all we need and then some.
It should be clear to you now why some organic gardeners receive the soil tests like the man at my lecture. Even the soil tester, although scientifically trained and university educated, did not appreciate the actual source of the potassium overdose. The tester concluded it must have been wood ashes when actually the potassium came from organic matter itself.
I conclude that organic matter is somewhat dangerous stuff whose use should be limited to the amount needed to maintain basic soil tilth and a healthy, complex soil ecology.
Fertilizing Gardens Organically
Scientists analyzing the connections between soil fertility and the nutritional value of crops have repeatedly remarked that the best crops are grown with compost and fertilizer. Not fertilizer alone and not compost alone. The best place for gardeners to see these data is Werner Schupan's book (listed in the bibliography).
But say the word "fertilizer" to an organic gardener and you'll usually raise their hackles. Actually there is no direct linkage of the words "fertilizer" and "chemical." A fertilizer is any concentrated plant nutrient source that rapidly becomes available in the soil. In my opinion, chemicals are the poorest fertilizers; organic fertilizers are far superior.
The very first fertilizer sold widely in the industrial world was guano. It is the naturally sun-dried droppings of nesting sea birds that accumulates in thick layers on rocky islands off the coast of South America. Guano is a potent nutrient source similar to dried chicken manure, containing large quantities of nitrogen, fair amounts of phosphorus, and smaller quantities of potassium. Guano is more potent than any other manure because sea birds eat ocean fish, a very high protein and highly mineralized food. Other potent organic fertilizers include seed meals; pure, dried chicken manure; slaughterhouse wastes; dried kelp and other seaweeds; and fish meal.
Composition of Organic Fertilizers
Material % Nitrogen % Phos. % Potassium Alfalfa meal 2.5 0.5 2.1 Bone meal (raw) 3.5 21.0 0.2 Bone meal (steamed) 2.0 21.0 0.2 Chicken manure (pure, fresh) 2.6 1.25 0.75 Cottonseed meal 7.0 3.0 2.0 Blood meal 12.0 3.0 -- Fish meal 8.0 7.0 -- Greensand -- 1.5 7.0 Hoof and Horn 12.5 2.0 -- Kelp meal 1.5 0.75 4.9 Peanut meal 3.6 0.7 0.5 Tankage 11.0 5.0 --
