Plan of a set of plats upon which the farmer may ask the soil and the plant 

 what fertilizers are needed : 



Size of plats i-io acre. Upon each plat the same crop is to be grown, care 

 being taken that the seed is pure and that each plat receives exactly the same 

 amount of seed. 



(vS, stable manure; K, potash; N, nitrogen; P, phosphoric acid; O, no 

 fertilizer). 



