Mar. 10, 1919 Organic Matter and Water-Holding Capacity of Soil 275 



heavier than on No. 3. The second growth, being too light to make a 

 fair cutting of hay, was plowed under and the field seeded to winter rye 

 {Secale cereale), which gave a good yield in 191 8, it being almost as heavy 

 on plot 4 as on plot 3. The yield of hay, straw, and grain combined, for 

 1917 and 1918, amounted to 9,738 pounds per acre on plot 4, compared 

 with 9,088 pounds on plot 3. Evidently the lessened water-holding ca- 

 pacity on the former had no serious effect upon the crop yields. 



Table X. — Relative productivity of ploti j and 4 



Season. 



1896 



1897 

 1901 



1905 

 1909 



1915 



1916 



1917 

 1918 



Crop. 



Com: 



Grain, bush 



Stover, cw-t 



Grain, bush 



Stover, cwt 



Grain, bush 



Stover, cwt 



Grain, bush 



Stover, cwt 



Grain, bush 



Stover, cwt 



Grain, bush 



Stover, cwt 



Sorghum, as cut green, cwt 

 Ttunips: 



Roots, tons 



Tops, tons 



Mangels: 



Roots, tons 



Tops, tons 



Wheat: 



Grain, bush 



Straw, cwt 



Clover hay, tons 



Winter rye: 



Grain, bush 



Straw, cwt 



Yield per acre. 



Plots. 



61. 7 

 44.8 



33-3 

 18.8 

 40. 6 

 20. 4 

 71. I 

 20.8 

 96.6 

 25. 6 



79-7 

 56.0 

 16. 4 



12. 9 

 3-4 



20. 7 

 2.9 



29. 6 



35-2 



2. o 



40.3 

 26.7 



Plot 4. 



44.0 



10. o 



6.2 



37-8 

 26. 4 

 26.6 

 12.8 

 48.9 

 31-4 

 55- o 

 44.0 

 12. 6 



7-4 

 1-5 



11. 4 



20. 5 



24-5 

 2.44 



38-3 

 25.6 



Produc- 

 tivity of 

 plot 4.<» 



71 



33 



33 



93 



129 



37 

 62 



SI 



123 



69 



78 



77 



58 

 44 



55 

 62 



69 



70 



122 



95 



a Yield on plot 3=100. 



The moisture content of the soil on the two plots was determined on 

 four occasions during the past season, and, in general, plot 3 was found 

 the more moist in the surface 6 inches (Table XI). When, as in Table 

 XII, we compare the ratios of moisture content to hygroscopic coeffi- 

 cient with those for 191 5 (Table IX) it is evident that there was little 

 difference between the two plots in the moisture content of the whole 

 three-foot section in 191 8; the subsoil on both plots was much drier 

 than in the earlier year, so dry in fact that until the rains of November 

 fell (Table XIII), there was no opportunity for loss of water by percola- 

 tion from this section. The dryness of the third foot indicates that it 

 had been fully occupied by the rye roots and hence that all the water 



