Yield 



Jushels or Cwt 



Returns & Cost. 

 Shillings . 



Mineral Manures +200 lb. *400lb. - +600lb. +800 lb. Amm. Salts. 

 Fig. 5. — Rel.\tion between Cost of Production and Returns with 



V.\RYING oUANTITIES OF MANURE. 



[To face page 284. 



