122 THE GRASSES OF TENNESSEE. 



yield of hay. Here, as is often seen in the production of 

 wheat, the abnormal development of straw is attended with 

 a decrease in the yield of seed. 



These experiments demonstrate that the quantity of sul- 

 phuric acid applied to the field, bears no proportion to the 

 increase in the crop. Baron Liebig, after numerous exper- 

 iments made with gypsum upon clover, comes to the con- 

 clusion that the action of gypsum is very complex ; that it 

 indeed promotes the distribution of both magnesia and pot- 

 ash in the soil. He thinks that gypsum exercises a chemi- 

 cal action upon the soil, which extends to any depth of it, 

 and that in consequence of the chemical and mechanical 

 modification of the earth, particles of certain nutritive ele- 

 ments become accessible to and available for the clover plant, 

 which were not so before. 



Though having my mind constantly directed to this point, 

 I have rarely found an application of gypsum beneficial 

 upon clayey loams, but its effects are very apparent on 

 strong limestone soils, such as are found in the Central 

 Basin. On the chocolate-colored soils of Warren, Mont- 

 gomery, Stewart and Robertson, gypsum benefits clover 

 very little. Upon the soils of the Unaka and Cumberland 

 mountains, it is indispensable to secure a remunerative yield 

 of foliage. Red Clover has two growing seasons. It make* 

 its most vigorous growth from the first of April until the 

 15th of June, beginning to bloom usually in the central 

 parts of the State about the 15th of May, and attaining its 

 full inflorescence about the 1st of June. After this, unless 

 depastured by stock or cut for hay, the heads begin to dry 

 up, and stems and leaves begin to fall, forming a mat upon 

 the land. Sometimes this mat is so thick as to catch and 

 concentrate the heats of summer to such a degree as to scald 

 the roots and destroy the clover. Usually it is best after 

 clover has attained its full bloom, either to cut it for hay or 

 pasture with stock until about the first of July. When the 

 stock is removed, or the clover hay cured and taken off, and 



