34 



The Bulletin. 



Table XVIII— RESULTS OF TESTS WITH FINELY GROUND PHOSPHATE 



ROCK WITH COTTON IN 1906. 



Iredell Faem. 



u 



B 



9 



Fertilizer Application per Acre. 



75 pounds dried blood 



200 pounds phosphate rock- 

 50 pounds manure salt 



j 2,000 pounds stable manure-- 

 V 160 pounds phosphate rock- 

 [ 10 pounds manure salt 



150 pounds dried blood 



200 pounds phosphate rock- 

 50 pounds manure salt 



Nothing 



J 4,000 pounds stable manure-- 

 I 600 pounds phosphate rock- 



75 pounds dried blood 



400 pounds phosphate rock- 

 50 pounds manure salt 



\- 



000 pounds stable manure — 



350 pounds phosphate rock- 



10 pounds manure salt 



3 



5 





NPoK 



NP2K 



(NP)2K 



(NP)->K 



NP4K 



NP4K 



o 



O o 



712.50 

 650.00 



430.00 



310.00 

 495.00 



487.50 

 480.00 



c 

 o . 



o c 



■SfS 



CO V 



.hO, 



O B) 



.2 <o 

 <«U 



$28.50 

 26.00 



17.20 



12.40 

 19.80 



19.50 

 19.20 



2 

 < 



<U 

 P, 



« 





m 

 O 



$ 3.75 



2.90 



6.00 



7.00 

 4.75 



3.85 



Value of 

 Increase — 



o 



§g 



> a 



u o 



$24.75 1.99 



23.10 



11.20 



12, 

 12. 



14.75 



1.86 



.90 



1.00 

 1.03 



1.19 



15.35 j 1.24 



KESULTS OF PHOSPHATE EOCK TESTS WITH COTTON. 



The two applications per acre producing the clearest increase over 

 cost of fertilizer, as seen by seventh column of Table XYIII, were 

 mixtures of 75 pounds of dried blood, 200 of finely gTound phosphate 

 rock and 50 pounds of manure salt (see Fig. 7), and 2,000 pounds of 

 stable manure, 160 pounds finely ground phosphate rock and 10 

 pounds of manure salt. These plats produced at the rate of $12.35 

 and $10.70 per acre respectively more than the unfertilized plat after 

 deducting the cost of the fertilizing mixtures added to each ; in other 

 words, the first application yielded almost twice as much profit while 

 the other one cleared one and eighty-six hundredths more per acre 

 than the unfertilized portion. 



The evidence points strongly to the cause of the poor showing made 

 by an application of 150 pounds of dried blood, 200 pounds of finely 

 ground phosphate rock and 50 pounds of manure salt per acre as due 

 largely to a greater damage done by a very early frost. This plat 



