MARL ON CALCAREOUS AND NEUTRAL SOILS. 



land had received. Within two feet of the surface the sub-soil of 

 this land is of red clay, which probably helped its growth of clover. 



CHAPTER XVI. 



EFFECTS OF CALCAREOUS MANURES ALONE, OR WITH GYPSUM, ON 

 CALCAREOUS AND NEUTRAL SOILS. 



PROPOSITION 5 continued. 



Reason had taught that applications of calcareous earth alone 

 to calcareous soils were so manifestly useless, that no more than two 

 experiments of that kind have been made by me, of which, as ex- 

 pected, neither had any improving effect that could be noticed, in 

 the twelve ensuing years during which the experiments were ob- 

 served. 



When calcareous manures have been applied to neutral soils, 

 whether new or worn, no perceptible and manifest benefit has been 

 obtained on the first crop. The subsequent improvement has gra- 

 dually increased, as would be expected from the power of fixing 

 manures ascribed to calcareous earth. But however satisfactory 

 these general results were to myself, they are not such as could be 

 reported in detail, with any advantage to other persons. It is 

 sufficiently difficult to make fair and accurate experiments where 

 early and remarkable results are expected. But no cultivator of a 

 farm can bestow enough care, and patient observation, to obtain 

 true results from experiments that scarcely will show their first 

 feeble effects in several years after the commencement. On a mere 

 experimental farm, such things may be possible ; but not where the 

 main object of the farmer is to reap profit from his general and 

 varied operations. The effects of changes of season, of crops, of 

 the mode of tillage the auxiliary effects of other manures, and 

 many other circumstances would serve to defeat any observations 

 of the progress of a slow improvement, though the ultimate result 

 of the general practice might be abundantly evident. 



Another cause for being unable to state with any precision the 

 practical benefit of marling neutral soils, arises from the circum- 

 stance that nearly all the calcareous manure thus applied by me 

 has been accompanied by a natural admixture of gypsum ; and 

 though I feel confident in ascribing some effects to one, and some 

 to the other of these two kinds of manure, yet this division of 

 operation must rest merely on opinion, and cannot be received as 

 certain by any other than him who makes and carefully observes 



