Permanent Pastures.--There is a large total area of land that can be brought into profitable production of food only by means of pasture grasses. A small part is too low and moist for tillage, but a larger part is too rough or too infertile. It can be made to yield profit in grasses that are harvested without expense by animals. The grasses afford feed and at the same time protect the soil from waste. The efficiency of much pasture land is kept low by poor stands of grass, the encroachment of weeds, bushes, and briers, close grazing, and the failure to supply fertility. When making a sod for mowing, the aim is to select varieties of plants that mature near the same time. Pastures need varieties maturing at different times, and this is a matter under control when temporary pastures are used. Permanent pasture land soon becomes occupied by the grasses best fitted to soil conditions or most able to crowd other plants.
[Illustration: Good Pasture Land in Chester County, Pa.]
Seed-mixtures.--Several varieties of grasses should be used when making a sod for grazing. They occupy all the surface more quickly and surely than a single variety, and the pasturage is better. The character of the soil determines the character of the mixture in large measure. When land can be well fitted, a heavy seeding is best, but the cost is nearly prohibitive for thin, rough lands. A brief description of the leading pasture grasses east of the semi-arid region, and north of the gulf states, is given:
_Blue-grass._--No other pasture grass equals Kentucky blue-grass wherever it thrives. It makes a close sod, preventing the growth of weeds and withstanding tramping, and contains a high percentage of protein. While it is best adapted to limestone soils, it is grown with success on clay land outside of limestone areas. It is slow in making a heavy sod, as a rule, and partly because the seeding is too light on account of low germination. The rule is to seed with timothy and other grasses which furnish the greater part of the pasturage for two or three years. When seeded alone, 20 to 30 pounds of seed per acre should be used. It may be seeded in the spring or fall, and preferably in August or September.