NEWER SOIL PROBLEMS 59 



food below the plow line, but showed a loss of some elements. 



While the general movement of plant food is upward, from the 

 roots to the tops, in general cropping, there is a reversed movement 

 from the tops to the roots in the case of deep-rooting perennial legume 

 plants during the fall in preparation for winter maintenance and 

 future growth. To what extent we can utilize this habit of certain 

 plants will need investigation. We know that limestone will sink 

 into the deep soil, in the form of hard water, from a supply main- 

 tained at the surface, but we need also to have active organic matter, 

 nitrogen, and phosphorus added to the deeper soil if we want a deep 

 root development on our grain plants. A single instance is not proof 

 but it is indicative : A field on which has been grown a rotation of 

 corn, oats, wheat, and clover (which was mostly alfalfa), with the 

 late growth plowed under after translocation for winter had been 

 made ; on which limestone was maintained at the surface, and to which 

 one ton of raw phosphate was applied during each rotation until five 

 tons had been applied, showed by a single analysis, that there were 

 about twenty tons more organic matter per acre and about twice as 

 much phosphorus and sulfur in the soil below the plowed soil where 

 treatment had been made as described above, than on the check half- 

 acre which had had the same rotation but no mineral treatments. 



AN OPPORTUNITY FOR THE PLANT PHYSIOLOGIST 



In the study of the plants themselves there is a wonderful oppor- 

 tunity for the plant physiologist to solve many of the problems now 

 perplexing us; and when we come to the relations between the soil, 

 with all its factors, and the plant, there is a field almost untrodden. 

 It is conceded that sweet and acid reactions in animal bodies are 

 factors in resisting diseases. Are plants also enabled by these different 

 reactions to resist plant diseases, more or less? And what are the re- 

 lations of the soil to these reactions? In plants the changing of 

 sugars to starches and oils, and of oils and starches to sugars, is in- 

 fluenced by a number of factors, with temperature an apparent factor. 

 What are the relations between the soil, climate, and latitude, and 

 these factors? If quality of grains depends on maturity, and ma- 

 turity depends on the change from sugars to starches and oils, we must 

 know more about the factors which induce maturity, if we are to grow 

 grains of high quality. 



Many seeds and plants which prepare for a dormant period dur- 

 ing the winter do not grow well again until some changes have taken 

 place during the period of dormancy. Winter wheat, if sown in the 



