IX.] CONDITION 237 



clay that the effect is palpable until the land has been 

 fallowed again or even laid down to grass. Once 

 protected from the action of frost, stiff soil which has 

 been worked ? when at all wet never seems able to 

 recover its texture, as may be seen by examining the 

 clods that are to be found on digging up an old post, 

 the result of the trampling when the post was originally 

 put in. The dependence of "condition" upon the 

 maintenance of a good texture is to be seen in the 

 custom of regarding wheat as an exhausting crop, 

 whereas few of our farm crops withdraw less plant 

 food from the soil. The popular opinion really 

 represents the fact that the wheat crop occupies the 

 land for nearly a year during which period it receives 

 little or no cultivation and so falls into a poor state of 

 tilth. 



From the chemical side "condition" means the 

 accumulation within the soil of compounds that will 

 by normal decay yield sufficient available plant food 

 for the requirements of an ordinary crop, e.g., of 

 organic compounds of nitrogen which readily nitrify, 

 of phosphoric acid and potash compounds which readily 

 become " available " for the plant. 



The condition of land cannot be restored all at once 

 by manuring ; the residues of manures left in the soil 

 after the first season are slow-acting, i.e., only a small 

 proportion of them becomes available year by year, 

 so that there must be a considerable accumulation of 

 such residues before the proportion becoming avail- 

 able during the period of growth is sufficient for the 

 crop. Per contra, the condition can be only too easily 

 destroyed by cropping without manure ; the unexhausted 

 residue left after each year is successively less and less 

 active, the crop falls off rapidly, till at last a sort of 

 stationary condition is reached, and the somewhat inert 



