RAW PHOSPHATE ROCK AS A FERTILIZER. During the present season a number of samples of ground phosphate rock have been forwarded from different sections of the State for analysis, and from the number of inquiries which have been addressed to this office it would appear that much of this material has been sold, or offered for sale, during the past few months. Many parties have written to this office for information as to the relative fertilizing value of the raw phosphate, as compared with the acidulated phosphates, and the writer has invariably advised caution in the employment of this particular kind of phosphate. The samples of this material which have reached this laboratory have almost invariably exhibited a poor mechanical condition, the particles being coarse and irregular in size. As the fineness of division of this phosphate has a most important influence upon its availability to the plant, purchasers of this material have been advised to only use the rock which has been pulverized to a state of practical impalpability, the material in this condition being commonly designated by the name of "floats." A typical analysis of the raw phosphate rock sent to this laboratory this season is given herewith: Citrate Soluble Phosphoric Acid 0.68 per cent. It will be noted that nearly all of the phosphoric acid in this phosphate is in an insoluble or acid soluble condition, and there is scarcely a trace of water soluble phosphoric acid to be found in this raw phosphate. With regard to the comparative availability of raw phosphate rock, it might be stated that the Experiment Station at Auburn, has, during the past few years, carried out under its. supervision more than one hundred co-operative soil and crop tests in a great many different localities in the State with a view to determining the comparative efficiency of raw phosphate and acid phosphate for fertilizing purposes. These tests have been carried out upon quite a variety of soils, and upon most soils the raw phosphate has failed to give anything like so good results as the acid phosphate. In experiments conducted at the Experiment Station and elsewhere, it has been found that the raw phosphate gives the best results when applied in the presence of, or along with, large amounts of organic matter, as for example, in the form of a compost obtained by mixing the raw phosphate with stable manure, and. sometimes with cotton seed also, for some time prior to its application. In the case of the acid phosphate, the ready solubility of most of the phosphoric acid contained therein promotes its rapid and thorough distribution through the top layer of the soil, and hence the plant food is so well disseminated that it is brought within easy reach of the root system of the plant, whereas, in the case of the crude insoluble phosphate, the dif fusion and distribution of the phosphoric acid is necessarily slow, and much of the phosphate is left unutilized at the end of the season in which it is applied. For the above reasons, it is deemed inadvisable to employ the crude phosphate to any great extent upon any given soil until comparative tests of the crude rock and acid phosphate have been made upon that soil, and, even under these conditions, it will probably be found necessary to use much larger amounts of phosphate rock than are ordinarily employed to secure a satisfactory return from its application. THE SOIL SURVEY WORK. During the first session of the last Legislature, among the important acts passed of an educational and progressive nature may be classed the Soil Survey Law. The object of this law is to complete a soil survey of the entire State, and a systematic classification and mapping of the soils of the State, and the practical methods of improving the productive capacity of each distinct type of soil. This work is now being conducted on a co-operative basis with the National Department of Agriculture. Under the law passed by the Legislature the State appropriates ten thousand ($10,000) dollars annually, or so much thereof as may be necessary, to carry the law into effect. The National Department of Agriculture is to contribute an equal or a greater amount, and the work is being managed by this Department for the State, and by the Bureau of Soils at Washington. Under the terms of agreement between these two Departments, five soil survey parties have been at work in the State, each party consisting of two men, one an expert man, furnished by the National Government, the other a graduate of the Alabama Polytechnic Institute, and furnished by the State, in the following counties: Lamar, Bibb, Baldwin, Henry and Autauga. An additional man is furnished by the National Department of Agriculture to assist the State Commissioner of Agriculture in inspecting the work of the various soil survey parties, with the view of insuring uniform work. Fourteen counties of the State had been previously soil surveyed by the National Bureau of Soils before this co-operative work began, leaving about 80 per cent of the State yet to be surveyed. At the present rate of progress with the same force it is estimated that four or five years will be required to complete the survey of the State: The soil maps that will be made of each county will be on a scale of one square inch on the map representing one square mile of ground. The roads, houses, streams, land lines, etc., will be shown. The different types of soils will be indicated by means of colors a given color standing for the same kind of soil wherever found in the county. The map will be published with a full report describing each soil, the crop adapta tion of each, and something of the fertilizer requirements and cultural methods necessary to the most profitable management of each type of soil. A chapter will also be given on the history of settlements, agricultural, developments and general agricultural possibilities. So far there have been fifty or more types of soil mapped in the State by the soil survey parties. After this systematic classification and mapping of the soils of the State are finished, then will follow the study of crop adaptation of the various soils and the practical methods of improving the productive capacity of each type of soil. While this work is comparatively new, yet many demands are being made on the Departments here and at Washington for soil surveys, as well as for lecturers to tell something of the nature and progress of the work, and a desire to hear directly from the members of our forces, who are actually engaged in field surveys, and who have practical knowledge of the soils and the adaptability of crops. The soil survey work done so far in Alabama gives a fair idea of the soils of the State, as well as the undoubted extensive agricultural resources, but much more will be shown by the time the soil survey is completed. The idea of crop adaptation is growing rapidly, and the necessity of soil surveys in order to carry the theory into practice, is a recognized necessity by most expert agriculturists. Individual plant selection for each soil, whether cotton, corn, oats, fruits or vegetables, is the key to securing the varieties of each crop, producing the highest yield and disease resisting qualities. When the crop adaptation of a given soil is in this way worked out, a soil map of the counties will be of immense practical value in showing at once the areas adapted to the growing of certain varieties of cotton, corn and other crops. Therefore, it is worth the greatest efforts of the National Government and the States to determine accurately all the facts in the case, and reduce it to a practical basis for the future benefit of our farmers. The safest guide for the farmer at present is to purchase cotton seed which has been developed or bred on land similar or exactly of the same soil type as that of his own land, until such time as the whole State shall have been soil surveyed, and the relationship betwen soil types and varieties of cotton shall have been more fully worked out. It would also be well for each farmer to give attention to the selection of seed from his own crop, from the second picking, and from the most productive individual stalks, ginning this selection separate from his other crop. In the following table it is especially interesting to note the two comparisons in which the King cotton figures. The King cotton, as we will note, when grown on the Piedmont soil, its home soil, produced more cotton than did the Double Header, to the amount of $20.77 per acre, but when it was grown in Eastern-North Carolina, on the Coastal Plain soil, and on which the Cook Improved cotton was at home, it produced less than did the Cook Improved by $19.26 per acre. The soil differences must be regarded as the principle factor in determining differences in yield. Cook Improved vs. Jones Improved (Miss.) loss per --$26 81 18 25 33 30 20 77 Cook Improved vs. Excelsior (Miss.) loss per acre. Average loss per acre. $23 82 In the above table of comparisons the first named variety is presumably better adapted to the soil type than the second, the money value showing the loss per acre by reason of growing the second variety, which evidently was not so well adapted to the soil type on which the comparison was made the planting, cultivation, fertilizing etc., having been the same for both. By multiplying the above loss per acre by the number of acres in the United States given to the growing of cotton, some further realization may be had as to the enormous loss to cotton growers by reason of using varieties of cotton not suited to their soils. |