Soil Fertilizers
RATES OF FEEDING
A great deal of fuss is made about the feeding value of various fertilizer formulae. I have seen amateur rose growers, for example, all but come to blows in arguing whether a 6-10-7 was a better rose fertilizer than a 5-10-5 or a 4-12-4. Advocates of all three were vehement in their protests that only their ratios and rates of feeding would produce perfect roses.

I wish I could be that dogmatic with any degree of confidence in my recommendations. Where I can be dogmatic is in saying that there is no perfect general formula. Within reason, any complete fertilizer will produce good roses and other plants if the grower uses enough, without going overboard. Soil is an amazing buffering agent and will accept many times the amount of fertilizer usually recom­mended-without injury to the plants. I recall a vegetable garden I made early in World War II. As a member and officer of the Illinois State Victory Garden committee, I was on the go night after night and had little time to do my own work. Yet I felt that I should set a good example and make a home vegetable garden. The only answer was to have the soil preparation and fertilizing done for me. The handy man I hired was not too good at figures (particularly decimals) and skipped a place in his calculations, which resulted in the application of ten times as much 10-6-4 fertilizer as I had intended.

Fortunately, this was a complete fertilizer, not only in the big three of N, P, and K, but in the minor elements as well. To show how selective and discriminating plants are in their food uptake, I saw not one instance of over-feeding of any one element. True, the weed growth was phenomenal (this was the first time in my life I ever had to cut ragweed with an axe) but everything else grew on the same phenomenal scale. So long as food elements are in balance and are supplied in amounts sufficient for good growth, with no one ingre­dient lacking, plants can be depended upon to take what they need and leave the surplus unused.

This does not mean that the point cannot be reached where the soil will be saturated with excess soluble salts which will damage or kill the plants. It does mean that the soil, particularly when it is liberally supplied with organic matter, is capable of buffering tre­mendous overdoses, so that, within reason, an accidental overdose need not be a calamity.




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