Chemical Analysis Alone not a Sure Guide The Farmer Can Learn Much by Observation Previous Work on Florida Soils A Deficiency of Plant Food Indicated Lessons from the Pineapple Fertilizer Experiment Loss of Phosphoric Acid and Potash Rapidity of Absorption and Solution Importance of the Absorptive Power of the Soil Pineapple 'Soils Lacking in Absorptive Power Value of Slowly Available Materials for Such Soils Page SOIL STUDIES I.a (A Preliminary Report.) By A. W. BLAIR. INTRODUCTION. Within comparatively recent years a vast amount of work has been done along the line of studying the chemical and physical properties of the soils of the United States, and classifying and mapping them according to certain physical properties and productive capacities. While much of this has been of an experimental nature, and may not always have produced visible results, still we have been accumulating during this time, a wealth of knowledge in regard to the soil that is of inestimable value. We have learned that within it dwell myriads of organisms, which are constantly producing wonderful chemical changes, and that the success of the crop may depend upon the presence of these organisms. We have learned much in regard to the importance of thorough and frequent cultivation, and the bearing this has upon the moisture content of the soil. We have learned that certain types. are adapted to particular crops and that an effort to grow some other crop on this type means failure; that certain conditions of texture, moisture content and fertilizer application will produce a maximum crop, while the failure to maintain these conditions may mean partial or total loss of crop. CHEMICAL ANALYSIS ALONE NOT A SURE GUIDE. ALONE It is generally admitted that the productiveness of a soil cannot be determined by a mere chemical analysis alone. True, the analysis will show what elements are present and in what quantities, but it does not show what is absolutely avail a A part of the material in this bulletin was presented in a paper read before the annual meeting of the State Horticultural Society held in Jacksonville, May, 1906. able for the immediate use of the plant. Of two soils showing great similarity in chemical composition, the one may be highly productive and the other very unproductive. The reasons for this may possibly be found in different moisture conditions, or a difference in physical texture, or in the difference in the amount of available plant food, or in a combination of all these differences. The chemical analysis may, however, be of value in showing what the possibilities of the soil are under the proper treatment. This subject has been studied by the agricultural chemist, the soil physicist, and the practical farmer, and all have contributed to the fund of knowledge. THE FARMER CAN LEARN MUCH BY OBSERVATION. The practical farmer, however, if he be thoughtful and inquisitive of nature, possesses certain advantages over the others, in that he is brought constantly in direct contact with the problems that he is trying to solve. He learns to judge from the texture and general appearance of the soil, what crop it is best fitted to produce. He can tell you perhaps, that this soil is adapted to orange growing and that to vegetables, though he may not be able to explain to you how he makes this distinction. He can tell you something about the treatment that should be pursued in the production of the desired crop, but here it is that all of his wisdom and knowledge gained through years of close observation are called into play, for conditions are constantly changing, and the treatment which gave good results at one time may at another time produce failure. On this account he should be constantly on his guard, watching, as a physician watches his patient, for indications good or otherwise, of the methods he has employed and the treatment he has applied. The experienced florist can tell from the development and appearance of the plant whether it has received the proper treatment; so with the farmer and fruit grower; each must watch the appearance and development of the plant or tree, note its vitality, the diseases or insect ravages to which it is subject, and the texture and quality of the fruit, for all of these may have a bearing on the condition of the soil or the treatment it has received, and it is from these symptoms that we must judge of the cause of the trouble. THE GEOLOGY OF FLORIDA SOILS. A recent publication of the Bureau of Soils of the U. S. Department of Agriculture makes the following brief reference to the Geology of Florida: "The land surface of the peninsula of Florida, as it stands today, owes its position to successive upheavals and depressions and to the accumulations of beds of limestone, sand, and clay during the period of submergence below the sea. The primary uplift was in Eocene times, and the deposits that make up the backbone of the central part of the State are of Vicksburg age. These are limestones, containing the disklike fossil remains of the Orbitoides Mantelli, which may be found a short distance below the surface in any part of the area. Later formations were deposited over this Vicksburg limestone, and during the last submergence to which the region was subjected a heavy stratum of sand was laid down over the entire peninsula. The breaking up of the land surface into its present condition has been brought about by the removal of this mantle of sand by stream action and by the dissolution of the limestone bed by the chemical and mechanical action of subterranean waters. These agencies have resulted in an eroded region, ranging in height from 50 to 200 feet above sea level, in which are sharply cut valleys and a few areas of plateau-like appearance, where the original sand cap has not undergone much change. In the eroded areas the soils vary as the limestone is approached, and in some places in proportion as the limestone itself has weathered." PREVIOUS WORK ON FLORIDA SOILS. In 1897 the Florida Experiment Station issued a bulletinb giving the results of an extensive chemical study of the soils a Advance Sheets.-Field Operations of the Bureau of Soils, 1904. b A chemical study of Some Typical Florida Soils by A. A. Persons. Bulletin No. 43. of the State, including analyses of nearly all the different types found in the State. In 1898 the U. S. Department of Agriculture issued a preliminary report on The Soils of Florida. This report describes several different types of soils, and the vegetation characteristic of each, and compares them as to texture, chemical composition, soluble salt and moisture content. In bulletin No. 68 of this Station will be found an exhaustive study of the pineapple soils of the State. More recently the Bureau of Soils of the United States Department of Agriculture has made surveys of three small areas known respectively as the Soil Survey of Gadsen County, Soil Survey of the Gainesville Area and the Soil Survey of Leon Countyb. The results of these surveys are published in map form showing the relative amounts of the different types of soils found in each area, together with a brief history of settlement and agricultural development, brief remarks on climate, physiography and geology, descriptions of the types of soils and agricultural methods and conditions. A DEFICIENCY OF PLANT FOOD INDICATED. This work, and especially the chemical side of it, together with much practical experience, has demonstrated the fact that most of the Florida soils are very deficient in plant food, when compared with the average type of arable soils. Assuming that the sandy soils of Florida will weigh 4,000,000 pounds per acre to a depth of one foot, Whitneyc has shown that there would be about 6,000 pounds of potash, phosphoric acid and lime per acre, while the amount of these plant foods present, on the average, in the soils of the humid regions of the United States is 26,000 pounds per acre. He has further shown that in no case does the amount of soluble salts present in the soil moisture reach 100 pounds per acre a A Preliminary Report on the Soils of Florida by Milton Whitney. Bulletin No. 13, Division of Soils. b Field Operations of the Bureau of Soils, 1903, 1904 and 1905 respectively. c Bulletin No. 13, Division of Soils, pp. 21 and 22. |