University Studies 



Vol. XIV APRIL igi4 No. 2 



I._ON THE DISTRIBUTION AND COMPOSITION OF 



THE HUMUS OF THE LOESS SOILS OF 



THE TRANSITION REGION 



BY MORRIS J. BLISH 



CONTENTS 



Page 



Introduction 112 



The Official Method for the Determination of Humus 113 



The Hilgard Method 114 



The Rather Method 115 



The Bhsh Method 115 



The Colorimetric Method 116 



Comparison of Soil Colors 117 



The Photometric Method 118 



The Alway-Bishop and the Hilgard Methods for the Determination 



of Humus Nitrogen 120 



Conclusions 143 



LIST OF TABLES 



Page 



Table l. Comparison of Different Methods for the Determination 



of Humus 121 



Table 2. Humus Nitrogen in Lincoln Surface Soil 122 



Map of Nebraska Showing Fields Sampled 120 



Table 3. Soils from Wauneta Area 123 



Table 4. Soils from McCook Area 123 



Table 5. Soils from Holdrege Area 124 



Table 6. Soils from Hastings Area 124 



Table 7. Soils from Lincoln Area 125 



Table 8. Soils from Weeping Water Area 125 



Table 9. Humus Ash Content of the Individual Fields 126 



Table 10. Humus and Humus Ash in Composite Samples from Dif- 

 ferent Areas 127 



III 



