ILLUSTRATIONS 



PAGE 



Fig. 1 — Rod forms of bacteria from a fenugreek nodule; magnified 2,000 



times 8 



Fig. 2 — Branching forms of bacteria from a clover nodule; magnified 



2,000 times 8 



Fig. 3 — Roots of garden pea showing nodules 9 



Fig. 4 — Comparative water holding powers of soil 10 



Fig. 5 — Stems of red clover in different stages of bloom 13 



Fig. 6 — Young red clover plant showing tubercles on roots 14 



Fig. 7 — Red clover field, showing the effect of top-dressing with manure. 

 The area in the immediate foreground received no manure; 

 the area immediately behind received a light application, re- 

 sulting in a very vigorous stand of clover 15 



Fig. 8 — Field dodder on stems of red clover. At the right the dodder is 

 shown in flower; at the left, in the mature or seed-producing 



stage 17 



Fig. 9 — A single plant of crimson clover 18 



Fig. 10 — Crimson clover in an old corn field. The clover was seeded in 

 the corn at the last cultivation. A fodder stack is to be ob- 

 served in the middle foreground. The corn stalks have been 



removed to avoid difficulty in mowing the clover 19 



Fig. 11 — Crimson clover and wheat in mixture. In the foreground the 

 crop has been cut and fed green to stock. The remainder was 

 cut the next day for hay. The grain prevents the crimson 



clover from lodging 20 



Fig. 12 — A crimson clover failure on ground too poor in humus 22 



Fig. 13 — Bur clover stem, showing leaf, bur and flower development 23 



Fig. 14 — Bur clover plant, Edgecombe Test Farm, May 12, 1903 25 



Fig. 15 — Cotton after bur clover, fertilized with acid phosphate and kainit 



only (K. P.) Yield per acre 1,620 pounds seed cotton 26 



Fig. 16 — Cotton close to plot shown in Fig. 15, fertilized with acid phos- 

 phate, kainit and cotton-seed meal (N. P. K.). Yield per acre, 



1,220 pounds seed cotton 26 



Fig. 17 — Corn after bur clover, 1903, Edgecombe Test Farm 28 



Fig. 18 — Bur clover after cotton, clover 15 inches high, April 15, 1903... 31 

 Fig. 19 — Bur clover after cotton on sandy land, Edgecombe Test Farm, 



May 12, 1903 33 



Fig. 20 — Sweet-clover plant near the close of the second season's growth. . 34 



Fig. 21 — Roots of melilotus (sweet clover) showing nodules 35 



Fig. 22 — Hogs pasturing on sweet clover in Iowa in late October 36 



Fig. 23 — A plant of lespedeza, showing the upright growth made where 



the stand is reasonably thick 37 



Fig. 24 — Roots of young alfalfa plants showing nodules 39 



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