6 4 
Journal of Agricultural Research 
Vol. XI, No. a 
LITERATURE CITED 
(1) Buckingham, Edgar. 
1904. CONTRIBUTIONS TO OUR KNOWLEDGE OF THE AERATION OF SOILS. U. S. 
Dept. Agr. Bur. Soils Bui. 25, 52 p. 
(2) Call, L. E., and Sewell, M. C. 
1917. The soil mulch. In Jour. Amer. Soc. Agron., v. 9, no. 2, p. 49-bi. 
(3) Djarenko, A. G. 
1915. the aeration of cultivated soils. (Abstract.) In Intern. Inst. 
Agr. [Rome] Bui. Agr. Intel, and Plant Diseases, year 6, no. io, p. 
1299-1302. (Original article in Izv. Moskov. Selskoch. Inst. (Ann. 
Inst. Agron. Moscou), year 21, v. 1, p. 1-41. Original not seen.) 
(4) Jodidi, S. L-, and Wells, A. A. 
1911. influence of various factors on decomposition of soil organic 
matter. In Iowa Agr. Exp. Sta. Res. Bui. 3, p. 135-154, 4 fig. 
(5) King, F. H., and Whitson, A. R. 
1901. development and distribution of nitrates and other soluble 
salts in cultivated soils. Wis. Agr. Exp. Sta. Bui. 85, 48 p., 
11 fig. 
( 6 ) -. 
1902. DEVELOPMENT AND DISTRIBUTION OF NITRATES IN CULTIVATED SOILS. 
Second paper. Wis. Agr. Exp. Sta. Bui. 93, 39 p., 6 fig. 
(7) Lau, Erich. 
1906. beitrage zur kenntnis der zusammensetzung der im ackerboden 
befindlichen luft. 34 p., illus., 3 fold. tab. Rostock. Inaugural 
Dissertation. 
(8) Leather, J. W. 
1915. soil GASES. In Mem. Dept. Agr. India, Chem. Ser., v. 4, no. 3, p. 
85-134, 4 fig- 
(9) Lipman, C. B., and Sharp, L. T. 
1912. STUDIES on the phenoldisulphonic acid method for determining 
nitrates in soils. In Univ. Cal. Pub. Agr., v. 1, no. 2, p. 21-37. 
(10) Rahn, Otto. 
1912. die bakterientatigkeit im boden als funktion von korngrOsse 
und wassergehalt. In Centbi. Bakt. [etc.], Abt. 2, Bd. 35, No. 
17/19, p. 429-465. 
(11) Russell, E. J., and Appleyard, Alfred. 
1915. THE ATMOSPHERE OF THE SOIL; ITS COMPOSITION AND THE CAUSES OF 
variation. In Jour. Agr. Sci., v. 7, pt. 1, p. 1-48, 17 fig. 
(12) Schlcesing, Th6ophile. 
1873. Etude de la nitrification dans les sols. In Compt. Rend. Acad. 
Sci. [Paris], t. 77, no. 3, p. 203-207; no. 5, p. 3S3-35 6 - 
(13) Stoklasa, Julius. 
1912. methoden ztfR biochemischen untersuchung des bodens. In 
Abderhalden, Emil. Handbuch der Biochemischen Arbeitsmetho- 
den, Bd. 5, T. 2, p. 843-910, fig. 215-221. Berlin, Wien. 
