Rolling in the spring does not serve to settle heaved alfalfa plants. The tap-roots are long, and when they have been lifted by action of frost, they cannot be driven back into place.
It is believed that the permanence of an alfalfa seeding may be increased by the use of mineral fertilizers in the early spring. In the case of one alfalfa field of fifteen years' standing in the east, the fertilizers were applied immediately after the first hay crop of the year was removed. Three hundred and fifty pounds of acid phosphate and 50 pounds of muriate of potash per acre is the mixture recommended. When old alfalfa plants do not stand thickly enough on the ground, grasses and other weeds come in readily. They can be kept under partial control by use of a spring-tooth harrow, the points being made narrow so that no ridging will occur. The harrow should be used immediately after the harvest, and will not injure the alfalfa.
It does not pay to use alfalfa for pasturage in our eastern states because the practice shortens the life of the seeding.
Alfalfa makes a seed crop in profitable amount only in our semi-arid regions. No attempt to produce a seed crop in the east should be made.
CHAPTER VII
GRASS SODS
Value of Sods.—The character of the sods is a faithful index of the condition of the soil in any region adapted to grass. The value of heavy sods to a soil cannot be overestimated. They not only give to a farm a prosperous appearance, but our country's agriculture would be on a much safer basis if heavy coverings of grass were more universal. We do not hold the legumes in too high esteem, but the emphasis placed upon their ability to appropriate nitrogen from the air has caused some land-owners to fail in appreciation of the aid to soil fertility that may be rendered by the grasses. One often hears the statement that they can add nothing to the soil, and this is serious error. They add all that may be given in the clovers, excepting nitrogen only, and that is only one element of plant-food, important though it be. A great part of the value of clover lies in its ability to supply organic matter to the soil and to improve physical condition by its net-work of roots. Heavy grass sods furnish a vast amount of organic matter which not only supplies available plant-food to succeeding crops, but in its decay affects the availability of some part of the stores of potential fertility in the land.
