The Lois Wcedon Plan of Groiclnrj JVIicat. 587 



more than twice as much ; and, as we shall see in the next Table, 

 in 1856, it gave once and a half as much as the continuously 

 cropped and continuously unmanured plot. 



In contrast to these very marked effects of fallow, it is inte- 

 resting to observe, that when in 1855 this common fallow plot grew 

 Avheat aftPT ivheat^ the produce was, within half a bushel of corn 

 and within half a hundredweight of straw, the same as was 

 obtained on the continuously unmanured plot of the adjoining 

 field in tfiat same season, wfiich was the twelfth in succession of 

 wheat on that plot. So perfect an illustration could iiardly have 

 been expected, of the fact of the equal icheaf-rjroicinfj condition to 

 which these two adjoining fields were reduced by the growth of 

 the crop ; or, what is the same thing, of the absolutely equal 

 condition for practical purposes, to which these two soils were 

 brought, in relation to tlie climatic resources of growth of one and 

 the same season. 



Lastly, in regard to these effects of falloio, it may be noticed 

 that in no case is the amount of produce found to be equal 

 simply to the sum of the continuous unmanured produce of the 

 season of the fallow and of that of the succeeding crop. That is 

 to say, the produce after fallow is not simply the produce of that 

 particular season, taken together with that of the immediately 

 preceding season. It is the result, not only of the unexpended 

 resource of the fallow year, and of the resources (atmospheric 

 and terrestrial) of the actual' season of growth, but there is 

 also an effect of the season of growth (whether for increase or 

 decrease), reacting itself upon a two years' resource ; and conse- 

 quently, throughout the season, upon a different stage of progress 

 and area of food collectors of the growin'2: plant. Or, the differ- 

 ence between the actual produce after fallow and the simple sum 

 of the produce of the two years may further depend upon the 

 more or less favourable adaptation of season as regards the 

 healthi/ development of the crop, as distinguished from the were 

 amuiint of the available resources of the soil and seasons. 



13ut with this very marked increase of crop as the result of 

 the common fallow, how is it that the more expensive processes of 

 trenching and forking, with the thinner seeding, &c., which on 

 the soil at Lois VVeedon yielded such excellent results, have on 

 the Rothamsted soil been so ineffective? 



Undoubtedly the too thin seeding has been one cause of this. 

 It is also certain tliat the same amount of labour expended upon 

 the Rothamsted soil as upon the Lois Wcedon one, was quite 

 inellicient to get the same amount of staple and of exposure of sur- 

 face to atmospheric influences. It may be here stated, liowever, 

 that the trenching at Rothamsted cost on the average about once 

 and a half as mu( h as is estimated by Mr. Smith. It is granted 



