Species of sweet clover 4 White sweet clover 5 Biennial yellow sweet clover 8 Annual yellow sweet clover 9 Other species of sweet clover 9 History 10 Distribution 10 Climatic adaptations 12 Requirements for obtaining a stand 12 Soils suitable for sweet clover 13 Resistance to alkali 13 Need of lime on acid soils 14 Fertilizers 17 Use of a nurse crop 18 Choice of seed 19 Preparation of the seed bed 21 Seeding 22 Hulled sweet-clover seed 23 Unhulled sweet-clover seed 24 Rate of seeding 25 Methods of seeding 25 Inoculation 27 The soil-transfer method 28 The pure-culture method 29 Treatment of the stand 30 Treatment the first season 30 Treatment the second season 32 Sweet clover in mixtures 32 Eradication of sweet clover 33 INTRODUCTION. Sweet clover is an important forage crop in many regions. Although one of the oldest of known plants, not until very recently has it been considered seriously as a forage plant in this country. The principal causes for not utilizing this crop were its aggressiveness on uncultivated land in many localities, the tendency of the stems to become woody as they mature, and the refusal of stock to eat sweet clover before they had become accustomed to the bitter taste. Another reason was the fact that until recently red clover could be grown in the eastern half of the United States without difficulty. In northern Kentucky the continuous growing of tobacco or of tobacco and wheat impoverished the soil to such an extent that crops no longer could be grown successfully. Upon the abandoned farms in this section sweet clover was introduced as a honey plant. Owing to the remarkable yields of tobacco that were obtained on such farms after sweet clover had been grown for a few years the acreage of this plant increased very rapidly. For a number of years sweet clover has been grown on the Selma chalk (rotten-limestone) soils of Alabama and Mississippi as a soil-improving crop. At the present time it is being cultivated in practically every State, and the acreage is increasing very rapidly. After it had been demonstrated that sweet clover would grow successfully on soils too depleted for other crops, many experiments were conducted to determine its value as forage. It was found that it was not only a valuable soil-improving crop, but that it made an excellent pasture and hay plant, quite palatable and rich in protein.