AND HORTICULTURE. 58 
on this experimental field shows the same improved qualities 
as that on the first experimental field. , 
We must now call attention to the difficulties which 
always arise in the choice of experimental and control 
fields. Already at these experiments, which embrace only 
four different cornfields, accidental circumstances have, in 
two cases, diminished the increase per cent. or have trans- 
formed this into a minus quantity. In the first case it was 
a fault in the drainage, in the second case an unusually 
great fertility of a control field. And this notwithstanding 
the previous careful mixing of the soil. Unfortunately, the 
quality of the subsoil seems to be of such great consequence 
to the success of the experiments that this method has not 
been a sufficient safeguard. It will therefore be necessary 
to improve the method to ensure a regular increase per 
cent. (see pages 33 and 37), 
If all circumstances are taken into consideration we 
must conclude that the increase per cent. during 1903 has 
been between 35 and 40 per cent. for the corn crop, added 
to the improved quality of the corn, shown not only by the 
Tables above, but especially by the chemical analysis of 
the crops (pape 60). 
Second Group Roots. 
On the Exp. Field. | On the Control Field. 
, Mean ; Mean 
nerease Weight Weight 
Crop. per cent. No. of , of Ge No. of of on 
Roots. Root Roots. Root 
in g. in g. 
Potatoes ...... 48 ss ney ven ve 
Sugar beets ... 6:22* 398 357 406 337 
Fodder beets | - 24 305 803 316 823 
Carrots ......... —8'9 578 358 549 393 
A chemical analysis of the sugar beets gave as the per- 
centage of sugar of the beets from the experimental field an 
* The increase per cent. is determined by the mean weight of one root. 
