504 EXPERIMENT STATION RECORD. 



Elovon analysts reported. The results <)})t:iine(l foi- water-soluljle 

 potash were very irregular, showing- a variation oi 0.47 per eent in a 

 total of less than 2 per eent of potash present. In the ease of obtain- 

 ing the theoretieal amount of potash in mixtures of acid phosphates 

 and potash salts the results were more regular, but still showed a" wide 

 variation. The average of the results with the mixture gave 6.12 per 

 eent of potash, while the theoretical amount was 6.'4o per cent. Work 

 along these lines will be continued. 



H. A. Huston suggested that the loss of potasii might have been 

 occasioned b}' continued l)()iling, as reported by the Kentucky Station 

 several years ago. 



Nitrogi^n. — Owing to the continued bad health of the referee, F. S. 

 Shiver, the report on nitrogen was presented by the associate, W. K. 

 Perkins. The work has been limited to a stud}' of methods for deter- 

 mining availaV)ility of organic nitrogen by the neutral permanganate 

 (Street) and pepsin-hydrochloric acid (Jones) methods. While the 

 work of the year has not materially approached the settlement of the 

 question of the value of the two methods, the associate believed that 

 by closely following certain points in manipulation as outlined the 

 permanganate method can be made to give good results. It was 

 suggested that the work on the tw^o methods be continued. 



Some of the work on avaihibility of nitrogen carried on at the Rotli- 

 amstead Experiment Station was discussed ])y Dr. Bernard Dyer. 



A paper by W. A. Withers and G. S. Fraps on the Rate of nitrifi- 

 cation of certain fertilizers was presented by the former. The exper- 

 iments reported showed a very close correspondence ])etween the rate 

 of nitrification during 3 weeks and the availabilit}" as shown ))y chem- 

 ical and vegetation tests, except in the case of sulphate of ammonia. 

 The latter seemed to be nitrified much more slowly than the organic 

 compounds, yet in many of the field experiments it gave results qlosely 

 approximating those given by nitrate of soda. The nitrification of 

 all materials tested, except bone, was facilitated by adding calcium 

 carbonate. This investigation will be contimied. 



C. B. Williams presented a report on Variable ammonia residts in 

 mixed fertilizers. In tests of methods of analysis on fertilizers con- 

 taining fish scrap, blood, tankage, or nitrate of soda, results show^ed 

 that where the samples were put through a 1.25 mm. siev« (No. 20) 

 the differences ranged from 0.27 to 1.96 per cent. When put through 

 sieves of 0.625 mm. (No. 40) the difi'erences ranged from only O.02 to 

 0.14 per cent. In all these determinations the modified Kjeldahl 

 method was used with 0.7 gm. of substance. It is hoped to supplement 

 these results by fui'ther Avork during the coming season. 



After some discussion on the added value of a fertilizer having its 

 nitrogen in the form of nitrates, a motion was adopted expressing the 



