432 



Field-Experiments on Permanent Pasture. 



minor degree, diminished the produce. On the other hand, the 

 mixture of superphosphate and potash salts gave the largest 

 increase, and all the remaining manuies had a markedly bene- 

 ficial effect upon the grass crops. 



In the next place, I have to report the results of experiments 

 with the same dressings which were employed in the preceding 

 trials, in a field of permanent pasture of great age, on Crook's 

 Farm, Coldstream, Berwickshire, in the occupation of Mr. 

 George P. Smith. A part of the field was laid out in ten 

 experimental plots of one-tenth of an acre each. The manures 

 were spread on the plots early in spring, and the produce of the 

 several plots was cut and weighed on July 29th, 1871, when 

 the results contained in the following tabular statement were 

 obtained : — 



Plots. 



1 



2 

 3 

 4 



5 



G 



7 

 8 



9 



10 



Description 'of Mantre. 



Quicklime 



Quicklime 



and 

 Common salt 



Fine bone-dust . . 



Mineral superphosphate 



and 

 Crude i^otash salts 



No manure 



Common salt 



Peruvian guano .. 



Crude potash salts 



Mineral superphosphate 



and 

 Peruvian guano ' . . 



No manure 



4 



The average produce of the two unmanured plots was 3 tons 

 8 cwts. and 7 stones, and the difference in the weight of the cut 

 grass of these plots amounted to 1 ton 3 cwts. and 2 stones. 



The pasture thus appears to have been less uniform in its 

 productive powers than is desirable for experimental purposes. 

 Probably the want of uniformity of the field will explain the 

 anomalous results which were obtained on Plots 4 and 8. It 

 will be noticed that whilst 5 cwts. of crude potash salts per acre 

 produced an increase of 1 ton 15 cwts. and 1 stone, the mixture 



