408 EXPERIMENT STATION RECORD. 



The fcitiliziiio- ingredients in the hai'vested <;r<)ps are summarized 



l)elow : 



Fertilizin;/ iiKjred'H'nts in oats (jruwn on different aoih. 



In graiu. i In straw. 



Average... 

 Miiximiini. 

 Minimum . 



Nitrogen. ! ^*'^^°"'^i Potash. 



Per cent. 

 1.62 

 2.53 

 1.20 



Percent. Percent. 

 0.73 \.-yJ. 



1.09 j 2. «1 



0.37 0.2b 



Tlie results obtained indicate that 0.07 per cent of i^hosplioric acid 

 in calcareous, sandy, and clayey soils is sufficient to produce oats of 

 satisfactory phosphoric acid content; 0.13 per cent of phosphoric acid 

 proved sufficient in these soils to produce oats of high jthosplioric acid 

 content, and 0.20 per cent always gave crops rich in phosphoric acid. 



One tenth i)er cent of potash seemed a rather low content in the 

 class of soils mentioned for the requirement of oats; 0.11 and 0.12 per 

 cent gave crops containing sometimes a low, sometimes a fair percent- 

 age of potash, while 0.20 per cent of potash was an ample amount. 



Peaty soils were entirely different in behavior from the mineral soils. 

 Even with considerable quantities of potash and phosphoric acid i)res- 

 ent in the former, the crops were often poor in these constituents. The 

 results, therefore, indicate that peaty soils, like those used in this 

 investigation, being relatively poor in lime and free from clay, are in 

 general benetited by applications of phosphates and potash. 



Humus soils differ from mineral soils in the availability of their phos 

 phone acid, while their potash shows a similar solubility to that of 

 mineral soils. Even as high as 0.20 i^er cent phosphoric acid in humus 

 soils does not seem to produce particularly high phosphoric acid con- 

 tents in oats. Their phosphoric acid seems largely combined with the 

 humus 111 a somewhat insoluble form, and is rendered available only 

 through lime and alkali. 



The humus soils examined contained from 11 to 26. .5 per cent of humus ; 

 the lime varied from 0.28 to 1.38 per cent. In soils richer m lime it is 

 presumed that the ])hosphoric acid would be more easily soluble than 

 was the case with these soils. 



Points of special interest brought out by the investigation are the 

 parallelism between the i)h()si)honc acid contents m the calcareous soils 

 and in the corresponding crops of oats, and also between the potash 

 of the humus soils and that of their crops. The low potash contents 

 found 111 numerous sandy soils and m the crops of oats grown on them 

 are further interesting. The same holds true of a number of peaty soils 

 to which potash fertilizers were added, showing the need of increased 

 potassic fertilization on such soils. — f. w. woll. 



Experiments with oats in 1894, (t. E. IMorrow and F. D. (Iard 

 NER {Illinois ISta. Bui. oJ, jjp. 11:3-117). — In 1804 the largest yields 



