ISO EFFECTS ON IMPOVERISHED ACID SOILS. 



been applied. The peculiar fitness of this kind of soil for clover 

 after marling, and the supposed cause of the remarkable heavy first 

 crop of clover, will require further remarks, and will be again 

 referred to hereafter. 



CHAPTER XIII. 



THE EFFECTS OF CALCAREOUS MANURES ON ACID SOILS REDUCED 

 BY CULTIVATION. 



PROPOSITION 5 continued. 



My use of marl has been more extensive on impoverished acid 

 soils than on all other kinds, and has never failed there to produce 

 striking improvement. Yet it has unfortunately happened that the 

 two experiments made on such land with most care, and on which 

 I relied mainly for evidence of the durable and increasing benefit 

 from this manure, have had their beneficial effects almost destroyed 

 by the applications having been made too heavy. These experi- 

 ments, like the 4th and 6th, already reported, were designed to re- 

 main without any subsequent alteration, so that the measurement 

 of their products, once in every succeeding course of crops, might 

 exhibit the progress of improvement under all the different circum- 

 stances. As no danger was then feared from such a course, marl 

 was applied heavily, that no future addition might be required \ 

 and for this reason, I have to report my greatest disappointments 

 exactly in those cases where the most evident success and increas- 

 ing benefits had been expected. However, these failures will be 

 stated fairly, and as fully as the most successful results ; and they 

 may at least serve to warn from the danger of error, though not to 

 show, as was designed, the greatest profits of judicious marling. 



[It should be observed that the general rotation of crops pur- 

 sued on the farm, on all land net recently cleared, was that of four 

 shifts (corn, wheat, and then the land two years at rest and not 

 grazed), though some exceptions to this course may be remarked 

 in some of the experiments to be stated.] 



Experiment 8. 



Of a poor sandy acid loam, seven acres were marled at the rate 

 of only ninety bushels (37 per cent.) to the acre ; laid on and 

 spread early in 1819. 



Results, 1819. In corn the benefit too small to be generally 

 perceptible, but could be plainly distinguished along part of the 

 outline, by comparing with the part not marled. 



