ISO NOKTH-CAEOLINA GEOLOGICAL SURVEY. 



pastures, it is more valuable as a permanent grass. Its stem 

 is used in the manufacture of straw plait. 



The common broom-sedge is another grass whose stem and 

 leaves become hard and wiry with age, and still more unfit 

 for food for cattle than any ot the preceding. It takes posses- 

 sion of old and worn out fields, and imparts to them a look 

 of barrenness, which, in many instances, they do not deserve. 

 Cattle eat this grass only in the spring, when it first springs 

 up, and w T hen it is comparatively tender. Although almost 

 worthless for fodder when mature, it is still better for the 

 ground to be covered and protected by this grass than to be 

 naked and exposed to the heat of the sun and the action of 

 rains. This grass has but a small proportion ot nutrient mat- 

 ter ; at the same time the consideration how fields should be 

 treated when covered with it, is worth a moment's considera- 

 tion. When such a field is to be ploughed for a crop of wheat, 

 it is important to lay it under while it is still green, or before 

 it has reached its full maturity. At this period it is more 

 valuable as a fertilizer ; the proportion of silex in the stem 

 being relatively less and the more valuable elements are 

 greater. When mature, it contains about 72 per cent, of sil- 

 ica, and only 8 per cent, of the phosphates of lime and mag- 

 nesia. The only grass which approaches this in its mature 

 state in the proportion of silica, is the Italian rye-grass, which 

 contains 60 per cent. In burning off a crop of broom-grass, 

 a large proportion of this silica becomes insoluble. Hence it 

 should be ploughed under when well grown, when all its nu- 

 tritive elements are in the best condition to aid the growth of 

 the succeeding crop. 



