ON THE ESSENTIAL CONSTITUENTS OF MANURES. 



43 



The following Table gives the yield in corn and straw of each experimental 

 plot, the manures employed, and the produce calculated per acre. 

 Each plot measured 1 of an acre. 



Manures employed and sown, 

 March 22, 1859. 



Peruvian guano, 2\ cwt. ; cost 

 £1 \2s.6d. (guano, £13 per 

 ton). 



Plot 1 



Plot 2. Nitrate of soda, 1 '- cwt. ; cost 



Plot 3. 



Plot 4. 

 Plot 5. 



£1 12s. 6d. (nitrate of soda, j 



£18 10s. per ton). 

 Nitrate of soda, 180 lbs., and^ 



chloride of sodium, 1^ cwt.; 



cost of manure per acre,£l 12s. 



6d. (cost of salt, 30s. per ton; 



of nitrate, £18 10s. per ton). 

 Wheat-manure, 4 cwt. per acre; 



cost £1 12s. 6d. (price of 



wheat-manure, £8 per ton). 

 Wheat-manure, 6 cwt. per acre ; 



cost £2 8s. (price of wheat- 

 manure, £8 per ton). 



Plot 6. Unmanured. 

 Plot 7. Chalk-marl, 1 ton. 



Produce thrashed out, 

 August 24, 1859. 



Grain, 2406 lbs. or 4<0 T V bushels ; 



weight per bushel, 60 to 60^ lbs. 



Straw, 1 ton 3 cwt. 

 Grain, 2280 lbs. or 38 bushels; 



weight per bushel, 60 lbs. Straw, 



1 ton 4 cwt. 8 lbs. 



Grain, 2436 lbs. or 40^ bushels ; 

 )- weight per bushel, 60f lbs. 

 Straw, 1 ton 4 cwt. 48 lbs. 



Grain, 2370 lbs. or 39^ bushels; 

 weight per bushel,60 lbs. Straw, 



1 ton 3 cwt. 92 lbs. 

 Grain, 2652 lbs. or 44 bushels 12 



lbs.; weight per bushel, 60 lbs. 



Straw, 1 ton 7 cwt. 8 lbs. 

 Grain, 1620 lbs. or 27 bushels; 



weight per bushel, 60 lbs. Straw, 



17 cwt. 80 lbs. 

 Grain, 1618 lbs. or 27 bushels less 



2 lbs.; weight per bushel, 60| lbs. 

 Straw, 16 cwt. 80 lbs. 



A comparison of the different quantities of corn and straw reaped on each 

 experimental plot will show, — 



1. That the plot manured with chalk-marl furnished as nearly as possible 

 the same amount of corn and straw as the unmanured plot. 



The produce in the one amounted to 1620 lbs. of corn, and in the other 

 to 1618 lbs.; or each gave within 2 lbs. 27 bushels of corn. 



In some parts of England chalk-marl is used with considerable benefit for 

 the wheat-crop ; but as the soil on the experimental field is full of limestone 

 rubble, it could not be expected that a marl which owes its fertilizing pro- 

 perties almost entirely to the carbonate of lime and to a little phosphate of 

 lime which it contains, should produce any marked effect upon the wheat- 

 crop. 



Indeed I did not expect any increase by the application of this marl, and 

 merely used it to ascertain the extent of variation in the produce of two sepa- 

 rate plots. The result plainly shows that the experimental field was very 

 uniform in its character and productiveness. 



2. The application of only li cwt. of nitrate of soda raised the produce in 

 corn to 38 bushels, and that of straw to 1 ton 4 cwt. 8 lbs. 



We have thus here an increase of 1 1 bushels of corn and 61 cwt. of straw. 



3. By mixing nitrate of soda with common salt, the produce in corn was 

 raised to 40 bushels, thus showing the advantage of a mixture of nitrate of 

 soda with common salt. 



4. Almost the same produce as by nitrate of soda and salt was obtained by 

 the application of guano, and by the small quantity of wheat-manure. 



By the latter 39^ bushels of corn, and by guano 40^ bushels were obtained, 



