Agricultural Chemistry — Turnips. 513 



The effects of ammoniacal salts, as they have been before 

 described, depending upon a proper combination with other 

 constituents, are further exhibited in the results of this second 

 year. The variations in the number of plants and weight of bulbs, 

 in Nos. 4, 5, and 6, and also in the results of these numbers as 

 compared with those of Nos. 11 and 20 here given, may be 

 adduced in illustration of this fact. 



Selected Results. 



■ Plot 

 Nos. 



Description of Manures. 



Average 

 Wei-ht 



of Bulbs 

 in lbs. 



Number 

 of Plants 

 per Acre. 



4 



4 cwts. superphosphate lime, \ cwt. phosphate ammonia . 



0-92 



16,768 



5 



4 cwt. sulphate 



0-87 



14,256 



6 



3 , , , , > > 15 lbs. phosphate , , 



0-65 



21,632 



11 



4 cwts. superphosphate lime, 15 lbs. phosphate ammonia, 













10,320 



20 



2 cwt. superphosphate lime, \ cwt. sulphate ammonia, 









4 cwt. rape-cake 



0-7S 



6,832 



Thus there is a slight superiority in No. 4 over No. 5, both in 

 development and number of plants ; phosphate of ammonia 

 being used in the former, and sulphate in the latter. In No. 6, 

 as compared with the two preceding, the amount of phosphoric 

 acid is diminished, but in a greater degree. That of ammonia, 

 to which body may be attributed an injurious effect upon the 

 health of the plant when in excess, or not sufficiently incorporated 

 with the soil, and a beneficial one after not only necessary 

 diffusion has taken place, but the plants themselves have attained 

 some strength and vigour. As might be expected, then the 

 number of plants is greater, though the average weight of bulbs 

 is less in No. 6 than in 4 and 5. 



Comparing with each other Nos. 6 and 11, in which the 

 amount of ammoniacal salts supplied by manure was identical, 

 we find that an increase of superphosphate of lime by 1 cwt., 

 and the addition of 4 cwt. of rape-cake (No. 1 1), whilst they 

 reduced the number of plants from 14,256 to 10,320 (an effect 

 certainly not due to the superphosphate of lime), at the same 

 time raised the average weight of bulb from 0*65 to 1*29; 

 showing the benefit of the supply of organic matter in those cases 

 where it had not proved injurious or destructive to the plants, 

 and the other conditions were such as to favour their healthy 

 growth. Again, in No. 20, as compared with No. 11, the 

 amount of supply by rape-cake is equal ; that of ammoniacal 



