Oct. 1. 1919-Mar. IS, 1920 Illustrations xvii 



Page 

 Fig. 15. Development of the composition of the ash in various parts of the 



sorghum plant 18 



16. Distribution of the sugars and other solids in the various joints of sor- 



ghum cane 24 



17. Development of the constituents of the juice of sorghum 25 



18. Comparison of Early Amber sorghum growTi in Minnesota with that 



growTi in the District of Columbia 26 



Rate of Absorption of Soil Constituents at Successive Stages of 



Plant Growth 



Fig. I. Growth reached by barley at different periods of cutting. Experi- 

 ment of 1910 59 



2. Gro^\lh reached by barley at different periods of cutting. Experi- 



ment of 1917 59 



3. Relation of gro\\lh of barley to absorption of potassium, nitrogen, 



phosphate, calcium, and magnesium, for entire plant except roots. 

 Experiment of 1916 60 



4. Relation of growth of barley to absorption of potassium, nitrogen, 



phosphate, calcium, and magnesium, for entire plant except roots. 

 Experiment of 1917 61 



5. Relation of growth of barley to absorption of potassium, nitrogen, 



phosphate, calcium, and magnesium, for stems and leaves. Experi- 

 ment of 1916 62 



6. Relation of growth of barley to absorption of potassium, nitrogen, 



phosphate, calcium, and magnesium, for heads. Experiment of 



19 16 62 



7. Relation of growth of barley to absorption of potassium, nitrogen, 



phosphate, calcium, and magnesium, for stems and leaves. Experi- 

 ment of 1917 63 



8. Relation of growth of barley to absorption of potassium, nitrogen, 



phosphate, calcium, and magnesium, for heads. Experiments of 



1917 63 



9. Absorption of nitrogen by barley, expressed as the nitrate (NO3) 



equivalent and computed to parts per million of soil 66 



10. Absorption of potassium by barley, computed to parts per million of 



soil 67 



11. Absorption of calcium by barley, computed to parts per million of 



soil 67 



12. Absorption of magnesium by barley, computed to parts per million of 



soil 68 



13. Absorption of phosphorus by barley, expressed as the phosphate 



(PO4) equivalent and computed to parts per million of soil 68 



Relation of the Concentration and Reaction of the Nutrient Medium 

 to the Growth and Absorption of the Plant 



Fig. I Water culttires, series i. Graph showing net absorption in parts per 

 million from solutions of four concentrations: Solution I with con- 

 centration of 0.10 atmospheres. Solution II with concentration 

 of 0.32 atmospheres. Solution III with concentration of 0.85 atmos- 

 pheres. Solution IV with concentration of 2.07 atmospheres 88 



