The Bulletin 39 



average mechanical analysis of congarbe silty clay loam. 



LOCATION OF EXPERIMENTS. 



Experimental field work is now being conducted on five of tlie larger 

 and more important soil-type areas of tlie Piedmont Region of the 

 State. The results secured in these experiments have given us much 

 information of practical value with reference to the plant-food deficien- 

 cies, and the fertilizer requirements of the different types of soil for the 

 chief crops of the different sections of the Piedmont Plateau in which 

 the experiments have been conducted. The work is at present located 

 at tbe following places : 



1. The Central Farm which lies about two miles west of Raleigh 

 in Wake County. This farm is about 400 feet above sea level. 



2. The Iredell Test Farm which is located about one and one-half 

 miles northwest of the town of Statesville in Iredell County. It is well 

 up in the Piedmont Section of the State and has an elevation of about 

 950 feet above sea level. This is one of seven test farms owned and 

 operated by the State Department of Agriculture, 



3. Charlotte field ISTo. 1 located on the farm of "W. M. Long, four 

 miles southwest of the center of Charlotte ; and Charlotte field No. 2 on 

 the farm of 0. H. Bailes, eleven miles southwest of Charlotte. 



4. The Monroe field, situated one and one-quarter miles west of the 

 to'wn of Monroe on the farm of J, J. Crow. 



5. The Gastonia field, two and one-half miles south of Gastonia on 

 the farm of C. M. Faires. 



FERTILIZERS USED AT THE CENTRAL AND IREDELL FARMS. 



At these farms, the fertilizer was applied in the drill just before 

 planting the crop, the exact quantity of material for each row being 

 weighed out separately so that each would get its proper amount of the 

 several fertilizer constituents. Acid phosphate was used as the source 

 of phosphoric acid; dried blood as the source of nitrogen; manure salt 

 as the Source of potash, and rock or building lime for lime. The ferti- 

 lizer materials were analyzed each year and applications made on basis 

 of actual analyses, so as to give the exact quantities of nitrogen, phos- 

 phoric acid, and potash indicated for each plat. For the sake of 

 simplicity and convenience in presenting the results of a number of 

 years' experiments, the fertilizer applications are expressed in terms 

 of acid phosphate containing 16 per cent available phosphoric acid, 

 dried blood containing 13 per cent nitrogen, and manure salt con- 

 taining 20 per cent potash, which figures represent the average compo- 

 sition of these materials. The normal (ITPK) fertilizer application for 

 cotton in the experiments is 400 pounds of a mixture containing 7 per 

 cent available phosphoric acid and 2^/^ per cent each of nitrogen and 



