962 



Manukes in January. 



[Jan., 



A similar long series of experiments carried out at Ohio under 

 Director C. E. Thorne has been summarised. The results for 

 the 16 years 1903-18 are as follows : — 



Nitrate of 

 Potash. 

 Plot 22. 

 1,131 

 25-15 

 3,987 



^86.61 



Crop. 



Tobacco 



Wheat 



Clover 



(bush.) 

 (lb.) . 



JS urate oj 

 Soda. 

 Plot 8. 

 1,227 

 26-63 

 4,416 



Sulphate of 

 Ammonia. 

 UnUmed Laoid. 

 1,095 

 25-82 

 4,149 



Tayihage. 



Plot 18. 

 960 

 26-16 

 4,360 



Annual Values^^ 



$93.82 



$85.79 



$79.97 







Plot 26. 



Limed, Land. 

 Plot 28. 



Plot 29. 



Tobacco 



Wheat 



Clover 



(lb.) 

 (bush.) 

 (lb.) 



1,069 

 27-78 

 4,139 



1,082 

 28-05 

 4,193 



959 

 23-96 

 2,054 



Annual Val 



ues 



$85.77 



$86.78 



$77.44 



Again, nitrate of soda proves superior on the unlimed land, 

 hut the superiority disappears when the land is limed. Artificials 

 prove more effective than the organic manures. 



Manuring in Glass Houses. — It is not the purpose of this 

 section to deal with glass houses, but two important principles 

 brought out may be mentioned. Nitrogenous manures encou- 

 rage development of the leaf and stem, but not always of the 

 fruit. At the Experimental Station at Cheshunt it was found 

 that there was more fruit when nitrogen fertilisers were omitted 

 than when they were supplied. The soil in this case is not far 

 removed from a virgin loam and is still rich in nitrogen, but 

 the general lesson of the experiment is that nitrogen fertilisers, 

 while they caused increase in growth, did not increase, but 

 actually decreased, the fruit. With tomatoes of the Comet 

 variety the results were : — 





Lb. per Plant. 



Tons per Acre. 



Relative 

 Weights. 

 Average 

 1916-19. 



Complete artificials 

 No nitrogen 



1916. 



1917. 



1918. 



1919. 



1916. 



1917. 



1918. 



1919. 



■ 109 

 111 



4- 9 



5- 7 



5-11 

 5-60 



3-32 

 3-62 



5-57 

 5-98 



38-7 

 45-0 



35-8 

 39-2 



25-8 

 28-2 



42-2 

 47-4 



The second important point is that potassium compounds 

 increase the vigour of the plants and enable them more readily 

 to resist disease ; this is generally known to many growers. Flax 

 growers in the North of Ireland have found that potassic ferti- 



Rating tobacco at 15 cents per lb. ; wheat at $2.00 per bush. ; and hay 

 at $20.00 per ton. 



