84 



GARDENERS' CHRONICLl 



Potash-Marl 



E. N. CLEVELAND 



POTASH-MARL is a natural fertilizer and as its 

 name indicates is a marl containing a high per- 

 centage of potash, as distinguished from Calcar- 

 eous or Lime-Marl. 



The use of marl was fully understood at the beginning 

 of the century. Since the time of the Roman concjuest, 

 and probably before, the marl beds of northern France 

 and southern Belgium have been constantly exploited. 

 Great hollows are found in many of the fields of northern 

 France made by the excavation of marl many centuries 

 ago. The true function of marl, however, was but little 

 understood, and even its chemical composition was prac- 

 tically unknown by those using it. 



Potash-Marl is a consolidated mass of sandy particles 

 of emerald green color composed of potash, iron and 

 phosphoric acid minerals, together with the decomposed 

 and crystallized remains of whales, sharks' teeth, mol- 

 lusks, fishes and other nitrogenous materials. 



The following is an extract from a scientific report 

 made by Dr. Hal Trueman Beans, Ph.D., of Columbia 

 University, New York : 



"Glauconite, the principal mineral constituent of green- 

 sand, is essentially a hydrated silicate of iron and potas- 

 sium, associated with minerals containing aluminum, cal- 

 cium, magnesium and phosphorus. Owing to the fact 

 that it is a hydrated silicate, it is easily decomposed by 

 the most varied chemical reagents, including even weak 

 organic acids. Silicates of this class are to be sharply 

 distinguished from non-hydrated silicates such as the 

 feldspars, which are extremely difficult to decompose. 

 Furthermore, hydrated silicates absorb additional water 

 in large quantity and are, therefore, further distinguished 

 from the feldspars and similar silicates which show no 

 tendency to retain water. 



"The analvsis of Potash-^Iarl gave this result: 



IMo'isture 'i 4.05% 



Loss on Ignition 4.83 



Iron & Aluminum oxides 28.52 



Insoluble IMatter 50.79 



Phosphorus (P,0,) L14 



Calcium Oxide (CaO) 2.14 



Potash (K^O) 6.50 



"In order to determine the relation between the potash 

 and phosphorus in the available form as determined 

 above, and the total potash and phosphorus contained in 

 the greensand, separate determinations of the total quan- 

 tities were made, with the following result : 



Total Phosphorus (P.OJ 1.84% 



Total Pota.sh (K,0) 7.24 



"It thus appears that approximately 90 per cent of 

 the total potash is in a form which will ultimately be 

 available to plant assimilation. It appears therefore from 

 the alxjve analysis and from the well-known chemical 

 characteristics of glauconite, that these samples of green- 

 sand contain in a reasonably readily available condition 

 all of those inorganic mineral substances which are es- 

 sential to plant growth. While it is true that practically 

 none of this material is in a water-soluble condition, 

 nevertheless, glauconite is so easily decomposed that the 

 above figures may properly be taken to represent that 

 portion of the material which will actually become avail- 

 able to the plant." 



Potash-Marl is both a direct and indirect fertilizer, as 

 it improves both the chemical and physical properties 

 of the soil. It acts in conjunction with the elements at 

 all times to assist in unlocking plant food fnmi llic nat- 



ural soil as well as from the life elements contained in 

 itself; correcting acidity and prompting nitrification. 



The New Jersey State Geologist's last report, ending 

 June 30, 1920, just published, makes the following state- 

 ment as to the solubility of Potash in greensand : "In 

 spite of its low solubility, recent experiments show that 

 plants in their early growing stage will assimilate potash 

 from greensands as effectively as from the usual soluble 

 commercial potassium salts." 



The phosphoric acid contained in the Potash-Marl is 

 acted upon the same as the potash, it becomes slowly 

 soluble through chemical action and weathering. The 

 iron and aluminum oxides in Marl produced quantities 

 of nitrogen, although in the analysis of the Marl no 

 credit is given for it producing any nitrogen which is of 

 great value as a fertilizer. Quoting from "Agricultural 

 Chemistry," by Justus Liebig, Ph. D., F. R. S., one of 

 the greatest chemists in the world. Page 103, "The o.xides 

 of iron and aluminum are distinguished from all other 

 metallic oxides by their power of forming solid com- 

 pounds with ammonia. Minerals containing oxide of 

 iron also possess in an eminent degree that remarkable 

 property of attracting ammonia from the atmosphere 

 and retaining it." 



Dr. Edmund Ruffin, of A'irginia, began his experiments 

 with marl in February, 1818. From land thus treated 

 he obtained an increase of 40 per cent over the crop oti 

 similar land untreated. Encouraged by this result, he 

 planned more extensive experiments for future years. 

 Without entering into the details of these trials, the re- 

 sult may be stated as overwhelmingly -in favor of the use 

 of marled fields. The yield was more than twice as great 

 as from the same fields before marling. 



The experiments were continued for a long series of 

 years, accurate records being kept of the history of each 

 plot of ground, frequent comparisons being made be- 

 tween the measured yields of marled and unmarled fields. 

 Marl was tried with and without manure and manure 

 was tried with and without marl. 



The greater the number of experiments and the more 

 numerous the results obtained the greater proof was 

 given that the use of marl was of great advantage. 



The careful manner in which the experiments were 

 carried on show him to rank as one of the most intelli- 

 gent experimenters of his time. He searched the litera- 

 ture of every age for mention of the occurrence of marl 

 and the history of its publication to the purpose of agri- 

 culture. Fie was familiar with foreign publications on 

 the subject. 



United States Government Rejiort, Published in 1910, 

 Page 761 states : "New Jersey Marl has been of incal- 

 culable value to the region in which it is found. It has 

 raised this region from the lowest stage of agricultural 

 exhaustion to a high state of improvement. 



"Lands which in the old style of cultivation had to 

 lie fallow, by the use of marl produce heavy crops of 

 clover and grow rich while resting. Lands which had 

 been worn out and left in common arc now by the use 

 of this fertilizer yielding large crops of the finest quality. 

 Everywhere in the marl district may be seen farms which 

 in former years would not support a family, but which 

 are now making their owners rich through jiroductive- 

 ness. 



Extract from "The Grapes of New York," by Prof. 

 U. P. Hedrick. Subject; Grapes Suffering from 'Yellow 

 (Continued on pai^c 91) 



