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NA TURE-STUD Y REVIEW [16:8— Nov., 1920 



so minute it requires about 25,000 of 

 them put end to end, to reach an inch, 

 — that they extract nitrogen from the 

 air and change it so that the clover can 

 absorb it, — and that when the roots 

 are left in the ground after the clover 

 crop is harvested, the soil extracts the 

 nitrogen from these well-filled store- 

 houses. 



We had become so absorbed in our 

 conversation that we had not noticed 

 the approach of Farmer Brown's 

 wagon. 



Farmer Brown is an up-to-date man, 

 always ready to get and give valuable 

 information. Overhearing Bobby's 

 "My! but I never thought there was so 

 much to learn about clover!" he in- 

 quired into the subject of our interest. 

 Hearing of our morning's discoveries, 

 he pointed his whip toward a crop of 

 clover that grew on a hillside not far 

 distant. 

 "A number of years ago," he said, "the soil in that field was so 

 poor that it hardly seemed worth the plowing. I heard of your 

 wonderful bacteria story and planted it in clover. From that time 

 on the soil produced better crops. Now, every three or four years 

 one or another of the clover family is planted in one of my fields. 

 And, too, I've always found that because the roots are so long and 

 fibrous they prevent wash outs when we have heavy rains and 

 freshets. 



"Crimson clover makes an excellent crop for covering the ground 

 in winter. It keeps down weeds and keeps the ground from losing 

 too much of its mositure by evaporation. Besides it acts as a good 

 fertilizer when I turn it under in the spring. 



"Then I've used white clover seed on my lawn. Have you ever 

 noticed how flat it seems to be compared with other clover ? That's 

 because the stem has a queer twist which brings its leaves close 

 together. 



Yellow Sweet Clover 



