Cost of plant food Value of increased Value of increase 



per acre. yield per $i invested 



Corn in plant food 



Manure $15.00 $16.00 $1.07 



Chemicals 10.00 17.08 1.7 1 



Ashes 10.00 7.15 -7 T /^ 



Prepared fertilizer 10.00 7.37 .74 



Sweet Corn 



Chemicals 10.00 30.28 3.03 



Ashes 10.00 24.35 2.43^ 



Prepared fertilizer 10.00 2 9- r S 2.91^ 



Potatoes 



Manure x S-oo 3°-5o 2.03 



Chemicals 10.00 42.00' 4.20 



Ashes 10.00 Loss 



Prepared fertilizer 10.00 2 °-75 2.07^ 



CONCLUSIONS. 



1st. Chemicals when properlv mixed can fully take the 

 place of farm yard manure as a source of plant food, this is 

 shown by the averages of the best plots in each set (see table 3) 



2nd. Chemicals when properly mixed can and do give 

 greater increase of crop than Commercial fertilizers (see table 

 3 and page 7. 



4th. The average chemical composition of fertilizers for 

 New Hampshire should be Phosphoric ac'd, q to it per cent., 

 Potash, 9 to i q p'r rent., Nitrogen 2 to 4 Percent., whereas the 

 fertilizers offered to us in the market average Phosphoric acid, 

 iT°f . Potash 2.5%., Nitrogen, 2.5% 



To get such a fertilizer as the soil and plant demand farm- 

 ers must buy crude chemicals and mix them in proportions which 

 prove best by trial, until such time as the fertilizer manufac- 

 turers discard the present stereotyped 12 — 3 — 3 formula which 

 does not and never did rest upon any basis either of theory or 

 practice. 



Wifh increased confidence in their value and adantation to 

 New Hampshire conditions, I reprint a few of the combinations 

 given in Bulletin No 6. The amounts are for one acre where 

 no manure is used, and in all cases, with hoed crops, two-thirds 

 of the mixture is to b^ sown broadcast and harrowed in, the 

 remaining third to h a . put in the hill or drill. 



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