Trace Elements in Fertilizer Held in Decomposable Glass
A Lecture Presented to the members of the Middle Atlantic Chapter, A.R.S.
November 11, 1955
Foolproof fertilizers are in the making, according to the technical director of the agricultural division of a large concern who was in Richmond last week for the meeting of the Middle Atlantic Chapter of the American Rhododendron Society.
Robert B. Schaal, of Cleveland, Ohio, has been experimenting with various methods of applying the major trace elements that most plants need in addition to the "big three"-nitrogen, phosphoric acid and potash. These trace elements are iron, manganese, copper, zinc, boron and molybdenum. While they are found to some extent in most soils, they are seldom available in such quantities that the best possible growth and the best possible bloom are produced, Schaal pointed out.
"The biggest problem we have is how to add trace elements to soil, particularly to the very open textured soil that is required by ericaceous plants such as azaleas and rhododendrons. If we apply them as other fertilizers are applied they are available to the plants in great quantity at first, but then with a heavy rain or watering they are leached from the soil."
ELEMENTS IN GLASS
The "feast and famine" problem has been approached in a number of ways, according to the chemist. His own company has now come lip with what they think is the best answer yet, that is, incorporating the trace elements into an easily decomposable form of glass which will gradually weather the soil, releasing them slowly and at a uniform rate. The method has been under extensive experimentation for eight years at the company and at agricultural experiment stations at Clemson, Rutgers and Ohio State. All results point to the conclusion that the FTE-fritted trace elements-do a more acceptable job than trace elements added to the soil in a soluble form.
Although the product is available in limited quantity now, Schaal said, his company is not pushing it because they feel that it is important first to educate the public to accepting the fact that insoluble fertilizers will do a better job in the long run. Experimenters agree the FTE will be most useful when added to commercial fertilizers and they are hopeful that fertilizer manufacturers will soon begin to incorporate the trace elements in their products.
FTE is rather expensive now, however the increased yield per acre on such truck crops as tomatoes will more than offset the additional cost for fertilizers, the chemist noted. And the investment will be worthwhile for those who go in for ericaceous plants because of the tendency of the loose soils to be poor in the needed elements.
One of the greatest problems in developing FTE has been in "timing" it so that the nutrients will last through a season but will not carry over too long and stimulate growth in cold weather which will be Winter killed. Recent experiments have shown that the new fritted fertilizers actually are easier to control in this respect than are soluble fertilizers.
How in the world did anyone ever get the idea to incorporate fertilizers in glass? It seems an imaginative chemist about 10 years ago ground up a beaker and found that it would produce boron toxicity when worked into the soil. Although the first fritted trace element was therefore poisonous to plants, the FTE of today contains boron and the other elements in just the needed amounts-not enough to harm your prize plants but just enough to give them what they are lacking for optimum growth.