24 The Bulletin. 



mature seed readily reseeds itself. In fact, there is a field of bur clover 

 at the Edgecombe Test Farm which has reseeded itself for the past ten 

 years. 



Bur clover's chief value is as a soil improver, though it can be made 

 into hay, but the quality does not compare with hay made from the 

 other clovers. 



From the July, 1904, Bulletin, issued by the North Carolina State 

 Board of Agriculture, I find the following concerning this plant : 



"Bur clover (Medicago maculata, Sibth). Annual, much branched, 15 

 to 60 branches at the base, ascending and spreading, smooth ; stems 15 to 

 30 inches long. Leaves petioled, three-parted ; leaflets broad at the apex, 

 pointed at the base, emarginate, cuneate, wavy margin, 3-8 by 1-2 inch; 

 Jtiples, small, dentate. Flowers yellow, 1-8 inch long, in small heads of 

 two to four. Pods 1-4 by 3-4 inch, spirally twisted in two to four coils; 

 coils flat, veined, each provided with two rows of reflex prickles. Seeds 

 three to five to the pod, 1-8 to 3-16 inch long, strongly kidney-shaped, 

 deep yellow in color. Nitrogen tubercles forked, rather flattened, 1-8 to 

 1-2 inch in diameter. Native of Europe and Asia, supposed to have been 

 introduced into America in ship ballast. 



"The two illustrations (Nos. 13 and 14), and the printed matter give 

 i fair idea of the growth and habits of bur clover. When the stand 

 is thin single plants occupy considerable space, varying from 2 1/2 to 

 more than 4 feet square. On plants of ordinary size we have found 40 

 or more stems, with 60 or more burs, each bur bearing 3 to 7 seed, 

 usually 5. Ou this basis a single plant would have 2,400 burs and 12,000 

 ■seed. 



Inoculation of Soil for Bur Clover. 



**To grow bur clover successfully on a soil that has never grown this 

 legume, it is generally unnecessary to resort to artificial inoculation, 

 as the burs containing the seed after maturity fall to the ground and 

 have to be swept up, hence enough germs will be contained in the soil 

 that clings to the burs to insure tolerably complete inoculation when 

 they are sown. On an uninfected piece of land, certainly the inocula- 

 tion will be completed by the beginning of the second year. 



Bar Clover for Soil Improvement. 



''As shown in Table 1, bur clover, as an average of two years' experi- 

 ments — 1903 and 1904 — has produced on the fine sandy loam soil of 

 the Edgecombe Test Farm 2.91 tons of hay per acre, the fertilizing 

 constituents of which, at the prices assigned them in mixed fertilizers 

 this year, are worth $36.24 per acre. Of this amount $28.27, or 78 per 

 cent, is due to the nitrogen it contains, which was gathered principally, 

 as with vetch, from the air through the instrumentality of bacteria in- 

 habiting the nodules on the roots of the plants. With this legume 87.2 

 per cent of the total nitrogen and 89.5 per cent of the total fertilizing 

 constituents are contained in the stems, leaves, leaf-stalks, burs, seeds, 

 etc. This leaves in the soil, after removing the tops, 12.8 per cent of 

 the total nitrogen and 10.6 per cent of the total fertilizing constituents 

 of the entire crop as roots and stubble. 



