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

 what fertilizers are needed : 



S plat. 



K plat. 20 lbs. muriate of potash. 



3 N plat. 20 lbs. nitrate of soda, or 40 lbs. tankage or dried blood. 



„ ^ , . j 20 lbs. muriate of p tash, / 20 lbs. muriate of potash, 



■^ " P • I 20 lbs. nitrate of soda; °^ \ 40 lbs. tankage, etc. 



O plat. No fertilizer. 



--I T> 1 f / 40 lbs. plain superphosphate 

 0| rpiat. I 15% phosphoric acid. 



with 



"K" P PI t / ^° ^^^" ™^ri^te of potash, 

 1 40 lbs. superphosphate. 



(20 lbs. nitrate of soda, r4o lbs. tankage, etc., 



20 lbs. muriate of potash, or < 20 lbs. muriate of potash, 

 40 lbs. superphosphate ; ( 40 lbs. superpho.sphate. 



T^^ p , , / 20 lbs. nitrate of soda, ( 40 lbs. tankage, etc. , 



° ■^ P • ]^ 40 lbs. superphosphate ; ( 40 lbs. superphosphate. 



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. 



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

 fertilizer). 



