Some Wisdom from the 1960’s
“I am convinced that the recommendations for the best use of commercial fertilizers might better be classified as propaganda to sell fertilizer.”
The above is a quote from page 21 of More Food From Soil Science, perhaps the magnum opus for lay readers by the creator of the Growers Program and one of the founders of Growers Mineral, Corp., Dr. Victor A. Tiedjens. He did not see fault so much with the idea of commercial fertilization, or even with the products themselves, but rather with those who pushed them as both the savior of modern agriculture and the best way to increase yield and, therefore, profitability. In his research, he found that rarely could significant and cost-effective yield increases be attributed to commercial fertilizer, but more often to favorable weather, healthy soil (read: calcium limestone), and better varieties that could withstand common crop ailments.
In his research both before and after helping form the company. Dr. Tiedjens routinely observed that increasing the amount of commercial fertilizer applied did not give corresponding increases to the yield. In spite of this, agricultural authorities of his day (and those today as well) continued to beat the drum of fertilizer=yield. In his research, he found that having adequate exchangeable calcium in both the top- and subsoil gave far greater corresponding yield results.
Much of his early research occurred on the eastern seaboard of the U.S., where most of the soils he was working with were sandy, had not developed from a limestone base, and had an undifferentiated profile (there were few distinct layers in the soil profile). In these soils, he found a quick response to relatively lower amounts of applied calcium, and greater responses as it was applied deeper into the profile. Armed with this information, he reasoned that the soils in the west (namely Ohio), which do have a limestone base and a differentiated profile, would not need the limestone mixed as deeply, or would not need it at all.
He quickly realized how wrong he was. It is not as important how much total calcium is in a soil profile, but rather how much of it is exchangeable, or chemically active. He found that, because of decades of commercial fertilizer application high in potassium, ammonia, and sodium, and no calcium application, both the top- and subsoils were exchangeable calcium deficient. In this condition, his research showed that no amount of commercial fertilizer could ever substantially increase yield without first addressing the calcium deficiency, because the above nutrients were available in toxic amounts to the plant. Applying adequate calcium would cause the negative effects of these nutrients to be neutralized. You can think of it this way: commercial fertilizer can, indeed, help to increase yields, but only when the calcium needs of the soil and plant have first been met.
Circling back to the quote from the beginning of this article, Dr. Tiedjens' research showed him that the amounts of commercial fertilizer being recommended in his day, let alone the even higher amounts often recommended now, were only adding value to the salesman's bottom line, and were in fact hurting the farmer. As we at Growers still say to this day, get your soil in order with high-calcium limestone, and then consider what the fertility needs of your crop may be.
This is an excerpt from the Early Fall Growers Solution (2024) written by Zach Smith, Product and Training Specialist.
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