SOrLS FERTILIZERS. 



825 



Ajrrionltnral Acadoniy during the year. The following invostigations call for 

 brief mention : 



On the after effectx of different kinds of iiliositluitic fertilizers. — These trials 

 were oonimenced ivi 1901 and the results of the first 4 years' work have been 

 summarized (B. S. R., 17, p. 1052). The trials during the fifth year (lixr)) 

 were made with Ligowa oats under conditions similar to those of earlier years. 

 The table given below shows the total yields obtained with the different phos- 

 phatic fertilizers experimented with, these being applied with and without lime. 



Yields of oats grown in vegetation pots, 1905 and 1001-190'). 



No phosphoric acid 



Supprpliosphate 



Diciilciuui phosphate__. 

 Tricalcium phosphate.- 

 Prwipitated phosphate. 

 Bone meal 



Without lime. 



1905. 1901-1905. 



Oramfi. 

 13.3 

 37.1 

 26.2 

 23.9 

 31.5 

 27.9 



Orams. 

 87.7 

 388.8 

 367.4 

 253.6 

 353.8 

 273.2 



With lime. 

 1905. 1901-1905. 



Grams. 

 14.0 

 34.fi 

 28.2 

 5.8 

 39.0 

 14.7 



Grams. 

 115.2 

 .389.1 

 394.2 

 132.9 

 374.9 

 142.6 



The fertilizer effect of superphosphate was decidedly superior to that of bone 

 meal even during the fifth year. The bone meal during the entire i)eriod of five 

 years produced a total increase in yield over that of the unfertilized pots 

 amounting to only 70 jter cent of that obtained during the same period by fertil- 

 ization with superphosphate. 



Vuiture trials with new nitrogenous fertilizers. — Trials with calcium 

 cyauamid and calcium nitrate commenced in li)04 and previously reported 

 (E. S. It., 17, p. 447), were continued during the year, and a new series with 

 "nitrogen lime" (Polzenius' process) was commenced. The experimental 

 crops were oats, carrots, and potatoes, the crops being gi'owu in vegetation 

 boxes, and, in the case of potatoes, in zinc boxes placed in the ground (O.o sq. 

 meter surface). The calcium nitrate in 5 cases out of 9 produced higher yields 

 of oats than did sodium nitrate, but the difference in no case exceeded 11 per 

 cent. ?so appreciable difference in the fertilizer effect of the two kinds of 

 nitrates was found either in the trials with oats or with root crops. The cal- 

 cium cyanamid nearly equaled sodium nitrate in its effect on the crop yields 

 without producing quite as high results. The nitrogen lime produced lower 

 results tliau the two other nitrogenous fertilizers with oats and carrots, viz., 

 between 64 and 87 per cent of the effect of the sodium nitrate, while with 

 jiotatoes a 16 per cent higher yield was obtained with this fertilizer than with 

 sodium nitrate. In the case of the highest application of nitrogen lime (1.50 kg. 

 ipcr hectare), a slight poisoning eff"ect was observed in the young oat plants, 

 from which, however, they soon recovered. 



On the inflKcnee of nitrites on the decelopnient and yield of erops. — The first 

 year's trials (1904) in this series have already been reported (E. S. K., 17, p. 

 447). The trials during the two following years given here include pot experi- 

 ments with oats and potatoes. Xo poisonous effect of the nitrite was to be ob- 

 served in any case, although from 1 to 20 parts of nitrite per 100 parts of 

 sodium nitrate (with 4 molecules of water of crystallization) was adde<l in dif- 

 ferent trials. The highest yields of oats were in all cases obtained in the pots 

 to which nitrite had been added, the increase in yield over that obtained with 

 pure sodium nitrafe ranging from 6 (20 per cent nitrite. 190.5) to 18..5 per cent 

 (10 per cent nitrite. 1904). With potatoes a beneficial effect of nitrites was 

 also observed, viz. mm increase in yield of 19.3 per cent when the nitrate was 



39256— No. 9—08 3 



