July 15,1925 Influence of Irrigation Water and Manure on Com 
189 
SUMMARY 
Corn grown on a highly calcareous soil with and without irrigation 
water and manure showed a decrease in the nitrogen content of the 
kernel due to the irrigation water and an increase due to the manure, 
the nitrogen content of the grain being a function of the available 
nitrogen content of the soil. Although irrigation water increases 
the speed with which nitrogen is rendered soluble in the soil, the 
water carries the readily soluble nitrogen beyond the feeding area of 
the plant. Hence the nitrogen available to the plant, proportionately 
to the requirements, is greater under nonirrigation than under 
irrigation. 
The ash, calcium, phosphorus, and potassium contents are increased 
with the application of irrigation water. All the constituents are 
greatly increased by manure. The results all bear out the idea that 
the increased ash and mineral constituents of the grain are due to an 
increased bacterial activity which increases the available plant food 
in the soil. 
The increased calcium, potassium, and phosphorus and the nar¬ 
rower calcium-phosphorus ratio in the corn kernel grown with irri¬ 
gation water make such corn more valuable for human and animal 
nutrition than similar corn grown without irrigation water. 
LITERATURE CITED 
(1) Association op Official Agricultural Chemists. 
1920. OFFICIAL AND TENTATIVE METHODS OF ANALYSIS. AS COMPILED BY 
THE COMMITTEE ON REVISION OF METHODS. REVISED TO NOV. 1, 
1919. 417 p., illus. Washington, D. C. 
(2) Greaves, J. E., and Carter, E. G. 
1916. INFLUENCE OF BARNYARD MANURE AND WATER UPON THE BACTERIAL 
activities of the soil. Jour. Agr. Research 6: 889-926, illus. 
(3) -Stewart, R., and Hirst, C. T. 
1917. INFLUENCE OF CROP, SEASON, AND WATER ON THE BACTERIAL AC¬ 
TIVITIES of the soil. Jour. Agr. Research 9: 293-341, illus. 
(4) -and Carter, E. G. 
1920. INFLUENCE OF MOISTURE ON THE BACTERIAL ACTIVITIES OF THE 
soil. Soil Sci. 10: 361-387, illus. 
(5) -and Carter, E. G. 
1923, THE INFLUENCE OF IRRIGATION WATER ON THE COMPOSITION OF 
GRAINS AND THE RELATIONSHIP TO NUTRITION. Jour. Biol. Chem. 
58: 531-541. 
(6) -and Nelson, D. H. 
1923. THE INFLUENCE OF NITROGEN IN SOIL ON AZOFICATION. Utah Agr 
Exp. Sta. Bui. 185, 23 p. 
(7) Hirst, C. T., and Greaves, J. E. 
1925. the influence of manure and irrigation water on the car¬ 
bon, PHOSPHORUS, CALCIUM, AND MAGNESIUM CONTENT OF SOIL. 
Soil Science 19: 87-97. 
(8) Hopkins, C. G. 
1910. SOIL FERTILITY AND PERMANENT AGRICULTURE. 653 p., illllS. 
Boston, New York [etc.]. 
(9) Yoder, P. A. 
1904. a new centrifugal soil elutriator. Utah Agr. Exp. Sta. Bui. 
89, 47 p., illus. 
