12 



N. H. Agr. Experiment Station 



[Bulletin 306 



Rapid soil tests were carried out on some of the treated series at tlie 

 close of the experiment with the following results : 



Rapid soil tests nv O'Kane plots. 



The soil is aeid. hut not exce.ssively so. The iiigher pll test on the 

 nitrogen plots may he due to lower acidity from the applications of ni- 

 trate of soda. The test for nitrogen is identical for all three series. 

 This may be explained, however, by the fact that the test was not made 

 until after the growing season, which indicates no residue of nitrogen re- 

 maining at this date. 



The interesting facts about the tests have to do with phosphoric acid 

 and potash. Applications of complete fertilizer have raised the test 

 for phosphoric acid from "very low"' to "low plus. "" a level which is 

 apparently satisfactory for the grass hay crop. The potash test at 

 medium for the untreated plots is high enough for good crops of grass 

 hay. Continued treatment with nitrogen alone reduced this test to 

 "low-medium." while the "very high plus" test for potash on the com- 

 plete fertilizei- plots is. of course, above the level at wliich grass hay will 

 give additional response to this nutrient. 



The recovery of nitrogen in this test follows the same general pattern 

 as in the one previously discussed, running 30% for nitrogen alone. 

 36.49^ for nitrate of potash. 46.8% for Ammo Phos A. fi.l.G'r for ni- 

 trate of soda and superphosphate, and 62.8% for tiie complete fertilizer. 



On anotlier section of the O'Kane field previou.sly described, a test 

 was run to determine the relative response of fall and spring applica- 

 tions of top-dressing fertilizers. 



One such test was with nitrate of soda applied in niid-Siptcmher, too 

 late to get much growth stimulation in the fall l)ut early enough for ni- 

 trate absorption and root storage. This was compared with the same 

 amount of niti-ate of soda applied April 13-20. depending upon weatlu^r 

 conditions. Two hundred and fifty pounds of nitrate of soda per acre 

 was the application rate. 



Table VIII. Spring uud full applications of nitrate of soda o» O'Kane 



f<ir))i i>lots. 



