158 



VIRGII^IA. 



Virginia Agricultural and Mechanical College Experiment Station. 



Depart liicnt of \'if</ijuu Ai/riciiUtiral ami Mechanical CdUeiie. 

 Location, Blaeksburg. Director, William B. Preston. 



BULLETIN No. 1. 1889. 



Fir:i,D EXPERIMENTS AVITH FERTILIZERS OX AVHEAT (pp. 1-19).— Tlie 



chief object of these experiments was to observe the effects of nitro- 

 gen, phosphoric acid, and potasli, singly; of phosphoric acid and 

 potash together (mixed minerals), and of nitrogen when added in 

 different forms and amounts to the phosphoric acid and potash. 

 Phosphoric acid Avas supplied in acid phosphate, potash in kainit, and 

 nitrogen as nitric acid in nitrate of soda, as ammonia in sulphate of 

 ammonia, and as organic nitrogen in dried blood. The phosphoric 

 acid and kainit were used at the rate of 400 pounds each per acre, the 

 former containing 56 pounds of phosphoric acid, the latter 56 pounds 

 of potash and the corresponding amount of chloride of sodium. Each 

 form of nitrogen was applied by itself, and was also used in combina- 

 tion with the phosphoric acid and potash in three different amounts, 

 " one-third ration," " two-thirds ration,'* and " full ration,'" supply- 

 ing, respectively, 23 pounds, 46 pounds, and 60 pounds of nitrogen 

 per acre. There were thus three groups of complete fertilizers in 

 which nitrate of soda, sulphate of ammonia, and dried blood were 

 used in turn in three different quantities, the amounts of mixed min- 

 erals remaining the same in all. Stable manure was also used at the 

 ]-ate of 30 tons per acre, and one plat was left unmanured. 



The soil is " a calcareous clay, well drained, averaging 9 inches in 

 depth, and underlaid with a stiff clay subsoil.'' As precautions to 

 secure evenness of soil, the field, a clover sod from which the first 

 crop had been removed, was plowed in September, 1886, and seeded 

 to wdieat, and " slight additions of manure were made wherever it 

 was deemed necessary." It was diA^ided into plats and seeded to 

 wheat in Se])tember, 1887. These plats were again plowed in 1888, 

 and Fultz wheat sown. The plats Avere one-fourth of an acre each, 

 and separated by strips 4 feet in Avidth. 



In the order of heading out, the plat treated Avith acid phosphate 

 Avas first. Taking this as a standard, that Avith mixed minerals was 

 four days late; those Avithout manure and Avith complete manures, six 

 days; Avith nitrogen alone, eight days; and Avith stable manure, ten 

 days. The relatiA^e order Avas the same in the ripening of the crop. 



Tables are gi\^en showing the yield of gi^ain and straAV, the propor- 

 tion of grain to straw, the quantities of nitrogen, phosphoric acid, and 

 l^otash a]Dplied in the fertilizers and recovered in the crop, the cost of 

 fertilizers, the value of the crop, and estimates of the increase in yield 

 in each case OA^er the yield of the unmanured plat, and the pecuniary 

 profit or loss from the use of the fertilizers on the assumption that 

 the increase Avith fertilizers was due to their action. 



