1900.] PUBLIC DOCUMENT — No. 33. 13 



It may be remembered that in each of the three previous 5'^ears 

 in which this field has produced corn tlie muriate of potash has, 

 whether singly or in combination, proved much more useful than 

 either of the other fertilizers used. There is much evidence in the 

 behavior of the crops this year, during the growing season, and in 

 the results, that this salt is proving injurious in its chemical effect 

 upon the soil. I believe this effect to be a loss of lime in the form 

 of chloride by leaching, but cannot regard this as yet proven. I 

 will present the facts apparently bearing upon the case, and leave 

 full discussion to a later report. 



1. During the early part of the growing season the corn upon 

 all the plots which had received muriate of potash was distinctly 

 behind tliat upon other plots. 



2. As the season advanced, the corn upon these plots gradu- 

 ally lost its sickly appearance, gained upon that in the other plots, 

 eventually excelling, in the case of the plot receiving nitrogen, 

 phosphoric acid and potash, that in all other plots except the 

 manure plot. 



3. This unhealthy appearance of the corn early in the season, 

 followed by great improvement later, is analogous to effects noticed 

 in other experiments,* where chlorides have been used, and where 

 liming the land has remedied the faulty condition. 



4. On that plot receiving dissolved bone-black as well as muri- 

 ate of potash, the crop was in the end a good one. As is well 

 known, the dissolved bone-black contains a large amount of sul- 

 fate of lime. It is believed that this may take the place of the 

 lime leached from the soil as a consequence of the use of muriate 

 of potash, or at least that it corrects in some way the faulty con- 

 dition consequent upon the use of this salt. It may here be pointed 

 out that a similar corrective influence is evident in the results ob- 

 tained both in 1897 and 1898 upon our other soil test acre, which 

 will immediately be discussed. 



It is of interest, further, to point out that the crop this year upon 

 the lime plot was not quite equal to the average of the nothing 

 plots, while that of the plaster plot (sulfate of lime) was about 

 double that of the lime plot. In the earlier j^ears of this soil test 

 the yield of neither the lime nor the plaster plot ever exceeded that 

 of the nothings, but for the past three years the plaster plot has 

 been relatively gaining. The explanation of this difference between 

 the effect of plaster and lime is not apparent. It will be made the 

 subject of future study. . . . 



The problems suggested by the results of the year must be 



* For example, Plot 6, Field A. See report State Experiment Station for 1896. 



