ix.] CONDITION 277 



residues in the soil which have become active : at the 

 same time, these reserves are protected from depletion 

 by renewal from the inactive portions of the current 

 manuring. On the other hand, if the land is in poor 

 condition the crop gets little or no assistance from 

 the soil, but is grown from the active part only 

 of the manure : the rest of it accumulates and begins 

 to build up condition, which, however, does not tell 

 on the yield for some time. As a practical conse- 

 quence, it is noticed that only land in good condition 

 gives a paying return year after year for the application 

 of manure : yet if the experiment be made of omitting 

 the manure on a portion of the land for one year, 

 there is little corresponding reduction of yield, as 

 though the manure went to keep up the "condition," 

 and the crop was grown out of that rather than from 

 the manure applied. 



From the point of view of analysis the estimation of 

 the "condition" of a given piece of land is a difficult 

 matter on which light is only just beginning to be 

 thrown by the determination of " available " plant food, 

 such as the nitrates and the phosphoric acid and potash 

 soluble in dilute acid solvents. By considering such 

 factors as these and the amount of humus soluble in 

 alkali, the ratio of the soil carbon to the nitrogen, 

 and the proportion of calcium carbonate, the agricul- 

 tural chemist may form an idea as to the immediate 

 state of the land. Doubtless, the prevalence and dis- 

 tribution of such necessary bacteria as those making 

 ammonia are also important factors in determining 

 the fertility, but on this point we are without exact 

 information. It will be seen that " condition " is one 

 of the most valuable of the properties of the soil to 

 the cultivator ; as it may be destroyed or created by 

 the tenant during his occupation of the land, it should 



