Show STUDY BEST USE OF DIVERS fertilizers small field plats for purpose have been established special tests conducted to determine amount of potash needed to meet requirements of tobacco plant prepared by the united states department of agriculture the enormous fertilizer consumption in the united states slate amounting to more than a dundr hundred ed million dollars prior to the war viar has undergone la in the last few years a decided change not so much in volume as in the composition of the fertilizing materials this lias has forced a careful study ot of ratios of essential plant food constituents on prominent and essential crops accordingly email small field plats tor for the study of fertilizer fertilizers have been established by the united states department part ment of agriculture on different soils and under different agricultural conditions the test fields now in operation are at presque isle me state college pa ra norf norfolk olk va florence S C pecan city ga putney ga thomas ille ga mon ti cello celio ala 1 orlando ha ila ashland WIs and scottsburg Scotts burg ind special field tests s have been con conducted to determine the smalle 41 quantities of potash which will the requirements of the tobacco more especially on the lighter soils of the flue cured district marked rei re have been obtained math w ath only 24 pounds and even enen as low as aj U pounds of potash per acre these applications hive have sufficed leed to prevent the appearance of the characteristic in symptoms of potash deficiency elency which the plant shows when no potash Is supplied in the fertilizer it has been possible also to establish an ampre i ceable difference between the sulphate and the of potash in their action on the plant the unusual fertilizer situation has brought forth numerous fertilizer substitutes utes of more or less doubtful merit for alch which extravagant claims arc aro made companies are organizing to exploit fertilizer materials concern in ing the value of which littek Is known and a considerable increase in such test work nork seems necessary several such products have been investigated and tested by the department some of them are practically morth worthless less and others have value entirely out of proportion to prices charged |