February, 1921 



BETTER FRUIT 



Soil Analysis and the Fertilizing of Orchards 



By Major E. P. Newsom, Lecturer on Chemistry of Soils Fertilizing 



UNDER normal mechanical condi- 

 tions of soil and water supply, the 

 chemical nature of the soil is reflected 

 in the life, appearance, behavior and 

 fruitage of the tree. Soil analysis is 

 not the angle from which to attack the 

 problem of fertilization. It is an out- 

 worn theory and should be thrown into 

 the discard along with that other passe 

 theory, so much in vogue a few years 

 ago, "clean cultivation." 



Let us admit that in the Yakima and 

 Wenatchee Valleys we have rock phos- 

 phate and potash sufficient for a great 

 number of years, does it follow that 

 we should fertilize with nitrogen and 

 a cover crop alone? By no means. 

 Tell that to the expert horticulturist of 

 the East or Europe, and he will laugh 

 in your face. 



Sources of Potash. 



The chief sources of potash in the 

 soil are from feldspar, granite, horn- 

 blend, etc., in which rocks it occurs 

 with alumninum in the form of a 

 double silicate. Mud pumped up from 

 the sea to form new land around our 

 city harbors is impregnated with salt, 

 and for the space of two years not even 

 grass will grow on it. But the rain 

 falling upon this newly made land 

 causes the salt to leach down deeply 

 in the soil, and after the space of two 

 years any kind of vegetation will grow 

 upon it. Now, if the rock phosphate 

 and potash were soluble, the same thing 

 would happen — these plant foods would 

 leach down in the soil so deeply within 

 two years, that a farmer could not 

 sprout cow peas on his land. 



The double silicate of aluminum and 

 potash is absolutely insoluble in water. 

 The erroneous impression prevails that 

 the use of superphosphate releases the 

 potash. Phosphoric acid acting upon 

 the double silicate of aluminum and 

 potassium gives the double phosphate 

 of aluminum and potash, which is just 

 as insoluble as the double silicate. Car- 

 bonic acid, however, being a very weak 

 acid, does not attack the aluminum sili- 

 cate, but having great affinity for the 

 potassium, does attack the latter, form- 

 ing carbonate of potash which is sol- 

 uble. 



Some College Experiments. 



That phosphoric acid used alone does 

 not release any appreciable amount of 

 potash is clearly shown by the experi- 

 ments of the Pennsylvania State Col- 

 lege, covering a period of 35 years. The 

 analysis of the soil plats showed the 

 presence of 20 pounds of potash for 

 every one of nitrogen, and 25 pounds of 

 potash for every one of phosphoric 

 acid. One would naturally suppose, if 

 the soil analysis theory were of any 

 value, that if any plant food additional 

 were needed it would not be potash, 

 but rather nitrogen and phosphoric 

 acid, especially so, if the phosphoric 

 acid acted to release and render soluble 

 the superabundance of potash. The re- 

 sults, however, showed that in a rota- 

 tion of clover, corn, wheat and oats, 



covering a period of 35 years, the high- 

 est net return on this soil came from 

 plats on which phosphoric acid and 

 potash were applied at the rate of one 

 pound of the former to 2.08 pounds of 

 the latter. Again, these long continued 

 experiments further showed that when 

 either potash or phosphoric acid were 

 used alone, or even nitrogen used alone, 

 the net results were always lessened. 



Now, a cover crop of the nitrogen 

 gathering legume is most excellent 



Page 35 



since it furnishes nitrogen to the tree 

 from the air and since it fosters through 

 its humus the bacterial life. This bac- 

 terial life in functioning generates car- 

 bon dioxide and this when absorbed by 

 water furnishes a mild acid, carbonic 

 acid, which is a solvent for calcium 

 carbonate (limestone), rock phosphate 

 and potash. But the bacteria work 

 slowly. One year there is a good crop 

 of fruit, the next year is a "skip" crop, 

 and the third year, perhaps, another 

 good crop. Now, if the soil analysis 

 theory were of any value and we should 

 not use potash and phosphoric acid in 

 our fertilizer, why this "skip" crop? 



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Clear More of This Land 

 in 1921 



"DEOPLE in this state are rapidly joining the 

 •^ "Clear-More-Land" movement. Last year 

 was one of the largest land-clearing years in this 

 section. During 1921 an even greater acreage will 

 be cleared and cultivated largely thru the use of 

 explosives. Every one is out to get bigger crops. 

 Most people use 



or Repauno Stumping Powders 



because they are generally recognized as quick, 

 efficient and economical means of clearing cut- 

 over land. 



Join your neighbors. Clear more acres each 

 year. Every acre put under cultivation will 

 return a handsome profit to you. 



Your local dealer can supply you with Du Pont 

 or Repauno Stumping Powders and Blasting 

 Accessories. See him and write for FREE book 

 "Developing Logged-off Lands" describing the 

 use of explosives for land-clearing, tree-planting 

 and ditching. 



E. I. du Pont de Nemours & Co., Inc. 



Seattle, Washington 

 Portland, Oregon Spokane, Washington 



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ISF.RS UBNTXON BETTER FRUIT 



