[Fertilizers]
When the crop is planted on extremely poor soils, good stands and growth cannot be expected. Such soil conditions may be improved by the application of manure and phosphate fertilizers or by turning under such crops as cowpeas, soybeans, or lespedeza. In many soils of low fertility the use of 50 to 100 pounds per acre of a nitrogen fertilizer will encourage early seedling growth and establishment. On the fertile soils of this region crimson clover may be successfully grown without fertilizer, but on most soils applications of 200 pounds of phosphate fertilizer per acre are profitable in obtaining stands and vigorous growth ([fig. 3]). The use of potash is recommended when a deficiency is known to exist.
Figure 3.—Effect of phosphate application on good soil: Treated (left); untreated (right).
[Seed Sources]
Of the total amount of seed normally used approximately 60 percent is of foreign origin, coming principally from Hungary and France. Most of the domestic crimson clover seed offered on the market is produced in south-central Tennessee. While white-flowered strains and others differing in maturity have been isolated, they are little used. Claims have been made that locally grown seed is superior to seed from other sources including that of foreign origin. Further experiments are needed to determine whether such differences actually exist.