938 EXPERIMENT STATION RECORD. 



nitrogen lias been applied each year in the form of nitrate of soda, 

 phosphoric acid in form of dissolved boneblack, and potash in form of 

 muriate of potash, with and without the addition of lime. During the 

 earlier years the crop experimented with was corn. Subsequently a 

 large variety of other crops were used. In 1897 the plants grown 

 were crimson clover, common white beans, sunflower, summer squash, 

 and corn. The results are reported in detail and summarized as follows : 



"The first year's experiment with maize indicated a probable need of potash. 

 Experiments for 3 successive years with the same crop showed in a most decisive 

 manner that phosphoric acid was more deficient in the soil than nitrogen or potash. 



"Most of our agricultural plants gave indications that their individual require- 

 ments for phosphoric acid on our soil were determinable in a soil test as well by 

 maize as by the use of each of them. 



"Sunflowers, by virtue of greater requirements for potash or of less ability to 

 extract it from the soil, are probably not well calculated for use in determining 

 phosphoric acid deficiencies for most other plants. White beans, summer squashes, 

 and crimson clover seem also less desirable for such a use than the cereals. 



"Liming, an unusual amount of water, or possibly both factors, seem capable of 

 rendering assimilable some of the otherwise inert phosphates already existing in 

 the soil." 



On the substitution of soda for and its value in connection 

 with potash, H. J. Wheeler and J. A. Tillinghast (Rhode Island 

 Sta. Rpt. 1897, pp. 326-240, pis. 4). — The experiments here reported were 

 a continuation of those of previous years (E. S. R., 9, p. 933). The fol- 

 lowing is a summary of the results thus far obtained: 



"It may be stated at this time that with each succeeding year soda, when used 

 without potash, has steadily deteriorated in its action when compared with the 

 results from plats manured with potash, but without soda. 



" Where soda has been added in increasing quantities to a full potash ration, 

 little or no benefit from its use has been apparent. On the other hand, the addi- 

 tion of increasing quantities of potash to a full soda ration, has, especially in the 

 last 2 years, been attended with most marked gains. 



"In the instances where potash and soda have both been employed in varying 

 amounts, marked evidence of benefit from soda is noticeable in the results for 18SI7, 

 particularly where the potash ration was reduced to one-fourth of the maximum 

 amount. 



"There seems to be some doubt if it would prove an economical practice to reduce 

 the supply of potash sufficiently to gain the greatest benefit from the soda, for by so 

 doing the total crop seems to be seriously reduced. It may be possible that certain 

 plants may be able to make use of soda without the danger just mentioned. This 

 point can only be determined by further experimentation. 



" It is not known at present, and can not be until the analytical data are all avail- 

 able, whether the soda has probably acted as a direct plant food, or indirectly by 

 virtue of its having liberated some potash or other manurial ingredients. It is 

 hoped that something in this connection will be ready for publication in the near 

 future." 



A study of the needs of certain Rhode Island soils, H. J. 

 Wheeler, 0. O. Flagg, and G. E. Adams (Rhode Island Sta. Bpt. 

 1897, pp. 185-201, pis. 7). — This is an account of cooperative experi- 

 ments during 1897 in continuation of those of previous years (E. S. R., 



