Soil Analysis
Categories:
THE NEED OF COMMERCIAL FERTILIZERS
There is wide misconception regarding the value of
chemical analysis of the soil as an aid in making choice of a
fertilizer. Analysis has shown that some soil types are relatively
richer in plant-constituents than are others, and it has shown abnormal
deficiency in some types of limited area. It has given us more
knowledge of soils, but as a guide to fertilization in particular
instances it usually has no value. The sa
ples used by an analyst are
so small that the inaccuracy in his determination may easily be greater
than the total amount of plant-food in a very heavy application of
commercial fertilizer. A field that has been reduced to temporarily low
productive power by heavy cropping or bad farming methods may show a
greater content of plant-food than another field that is in a highly
productive condition. This is a fact difficult of acceptance by some
who want the aid of science, but such are the present limitations. The
weight of a fertilizer application is so small in comparison with the
weight of the surface part of an acre of land that the use of a ton of
fertilizer may not be detected in the analyst's determinations, and
moreover his determinations of actual availability in the soil's
supplies are not serviceable in the selection of a fertilizer for any
particular field and crop.