The Bulletin. 21 



cost of g-uano. At Iredell, the most profitable ones were applications 

 of 200 pounds of acid plios])liate, 50 pounds of manure salt and 75 

 pounds of dried blood (see Fig. 4), and 300 pounds of Peruvian 

 guano with 25 pounds of nitrate of. soda per acre just before planting. 

 The gains from these applications were $14.35 and $13.72 per acre 

 respectively in excess of the unfertilized plat (see Fig. 5). Applica- 

 tions of 300 and 500 pounds of Peruvian guano per acre at this farm 

 this year produced respectively profits of $0.95 and $7.35 in excess of 

 the plat without fertilization. It is very significant that an applica- 

 tion of 200 pounds of acid phosphate, 50 pounds of manure salt and 

 75 pounds of dried blood; and 300 pounds Peruvian guano and 25 

 pounds of nitrate of soda per acre each, produced almost twice the 

 clear profit of the unfertilized plat, as is shown by results contained 

 in the last column of Table VII. Three hundred pounds of Peru- 

 vian guano alone per acre produced 1.6 times the profit of the plat 

 without fertilization. 



CONCLUSIONS. 



Of course from two years' results only tentative inferences can 

 safely be made, as experimental work of this nature should be care- 

 fully conducted at least four or five years before attempting to draw 

 anything like definite conclusions. Results of one or two years' 

 work, however, are frequently strongly indicative of what the avail- 

 able fertilizer deficiencies of the soil are. 



Taking the compiled results obtained during 1904 and 1906 at the 

 Edgecombe and Iredell farms it appears evident as seen by results 

 contained in Table VIII — 



(1) That with cotton, all the fertilizer applications used in these 

 experiments were profitable investments. 



(2) That a mixture of 200 pounds of acid phosphate, 50 pounds 

 of manure salt and 75 pounds of dried blood per acre gave more 

 remunerative returns than any of the other fertilizing materials or 

 combinations used. 



(3) That 300 pounds of Peruvian guano and 25 pounds of nitrate 

 of soda per acre applied just before planting was very little indeed 

 below in value the mixture given above in producing clear profit. 



(4) That the use of nitrate of soda in conjunction with Peruvian 

 guano is advisable, as is shown by 25 pounds of it increasing in 1906 

 the profit on the use of 300 pounds of Peruvian guano by $3.89 at 

 Edgecombe and $3.77 at Iredell. 



(5) That the judicious use of nitrate of soda on cotton up to 150 

 pounds per acre is indicated to be a profitable investment, on soils 

 of the character represented by the Edgecombe and Iredell farms. 



(6) That the use of Peruvian guano on cotton pays well as a fer- 

 tilizing material, at its present price per ton, either alone or in con- 

 junction with nitrate of soda, when applied to the land at or just 

 before planting. 



