724 



CLOVER CROP. 



Plots Nos. 15 to 21 had the season before grown barley. Each 

 plot was sown with 12 Ibs. of red clover seeds in the autumn. The 

 following are the results : 



Each of the crops was grown under similar circumstances as 

 far as the date of sowing, composition of the soil, the amount of 

 rainfall, sunshine, etc., were concerned. All the experiments were 

 performed in duplicate with almost identical results. The con- 

 clusions that Griffiths draws from these experiments are : 



1. That nitrate of soda is a good manure for cereals, root an< 

 leguminous crops generally, increasing the yield over other nitro- 

 genous manures. 



2. That it is better to use the nitrate of soda in fractions as a 

 top dressing, as the crops progress in growth, rather than at one 

 time, for a larger yield is obtained in each case. This appears to 

 be directly due to the manurial value of the nitrogen contained in 

 the nitrate of soda, and indirectly due to its action on the dormant 

 nitrogenous constituents of the soil, for there is an increase in the 

 nitrogen of the crops over that applied in the form of nitrate of 

 soda. It is probable that nitrates favor nitrification. 



3. It was found that in those crops grown with nitrate of soda 

 the albuminoids are increased, and, generally speaking, the soluble 

 carbo-hydrates are also increased. Hence their higher value as 

 feeding stuffs. 



4. The amount of chlorophyll (green coloring matter) an 

 starch grains in the leaves of those crops grown with nitrate o 

 soda, are increased more than in the others. 



5. That nitrate of soda is a better manure for potatoes than 

 potassium nitrate, although potash manures are generally used for 

 these crops. 



6. When nitrate of soda is used, the harvest of all crops is fully 

 two weeks earlier than by other nitrogenous manures. 



7. Crops grown with nitrate of soda resisted the attacks of 

 micro-parasitic organisms, while the use of potash manures en- 

 couraged the attacks of these organisms. The resistance to the 

 germinating power of the spores of parasitic fungi on the part of 

 the crops grown with nitrate of soda is due to the rapid develop- 

 ment of the chlorophyll in the leaves, and so places the plants be- 

 yond the destructive influence of parasitic fungi. 



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