48 



mated cost of applying it to the meadow; 



3. The value of hay at the ranch. 



With the answers or approximate answers to these questions, ranchers 

 can then look at table 18 to determine the approximate most profitable rate 

 of nitrogen application. 



The method of determining the most profitable rate first requires that the 

 maximum number of pounds of nitrogen per 0. 25 ton per acre be determined, 

 based on the cost of nitrogen and the value of hay. Second, using this sum, 

 the point at which this amount of nitrogen increases the yield by approximately 

 0. 25 ton per acre at the right end of the fertilizer response curve must be 

 found. When this is determined, the most profitable rate is the midpoint for 

 the amount that gives this 0.25 ton per acre increase. 



This procedure is illustrated by using two different response curves 

 (figure 6). Both curves are based on the data in table 2. Curve "A" is based 

 on data shown for ranch No. 7 and curve "B" is based on data shown for ranch 

 No. 6. Curve "C" is based on the calculated yield from table 2. Under the 

 cost -value conditions used throughout the publication, twine -tied hay valued 

 •at $20 per ton and nitrogen applied to the meadow at $0. 15 per pound, shows 

 that the maximum amount of nitrogen the rancher can afford to apply to in- 

 crease production per acre by 0. 25 ton is 32 pounds (table 18). Curve "A" 



Table 18. - Quantity of nitrogen per acre that will cost the same as the value 



of 0. 25 ton of hay 



Value of hay 

 per 0. 25 ton 

 (dollars) 



7. 50 

 6. 25 

 5.00 

 3. 75 



13 cents 



Pounds 



58 

 46 

 36 

 27 



Price of nitrogen per pound 



15 cents 



Pounds 



50 

 40 

 32 

 24 



17 cents 



Pounds 



44 

 35 

 28 



21 



19 cents 



Pounds 



39 

 31 

 25 

 19 



