THE INFLUENCE OF NITRATE NITROGEN UPON THE 
PROTEIN CONTENT AND YIELD OF WHEAT 1 
By Edmund Burke 
Chemistry Department , Montana Agricultural Experiment Station 
REVIEW OF LITERATURE 
The factors which influence the formation of protein in wheat have 
been studied by several investigators. From their results two 
theories appear worthy of consideration, (1) that the moisture con¬ 
tent of the soil during the growing period is the controlling factor 
in protein formation, a high moisture content generally resulting in 
the production of wheat of low protein content, and (2) that the 
quantity of nitrate nitrogen present in the soil during the growth of 
the wheat is the most important factor in the production of a high 
protein content. No attempt will be made in this paper to give a 
complete review of the literature published. 
INFLUENCE OF MOISTURE UPON PROTEIN FORMATION 
Most of the results of the work of the early investigators indicate 
that moisture is the controlling factor in protein formation, an 
opinion shared by most farmers in the irrigated sections of Montana. 
The general opinion seems to be that when the moisture is increased a 
wheat of low protein content is produced. Thatcher ( 6 ) 2 found that 
certain factors of climate, such as rainfall and temperature, have a 
decided influence on protein formation, and he concluded that the 
protein content of wheat in eastern Washington decreases with an 
increase of rainfall. He also calls attention to the length of the grow¬ 
ing period as a factor in protein production. Widtsoe and Stewart (7) 
found that a variation in the quantity of irrigation water caused a 
difference in the protein content of wheat. From their analytical 
data they concluded that the protein content is lowered »with an in¬ 
crease of irrigation water. Harris (#), working in the greenhouse 
where Controlled conditions were possible, found that the percentage 
of nitrogen in both grain and straw was influenced by the quantity 
of moisture in the soil. The highest protein content was obtained 
from wheat grown in soil of low moisture content, and the lower 
protein content from soil containing the higher percentages of 
moisture. Harris found further that fertilizers high in nitrogen 
brought about an increase in the nitrogen content of wheat crops. 
INFLUENCE OF NITRATE NITROGEN ON PROTEIN FORMATION 
Headden ( 3 ) conducted an extensive investigation of the factors 
which influence protein formation, and he was among the first to 
make a study of the available nitrogen present in the soil during 
plant growth. In addition, he studied the influence of a varying 
1 Received for publication April 30, 1925; issued December, 1925. Published with the approval of the 
director of the station. 
2 Reference is made by number (italic) to “Literature cited,” p. 1199. 
Journal of Agricultural Research, 
Washington, D. C. 
( 1189 ) 
Vol. XXXI, No. 12 
Dec. 15.1925 
Key No. Mont.-14 
