The fertilization and management of grasslands

1. Most of our agricultural land is used for the support of our livestock population. 2. The carrying capacity of pastures and range lands differ widely, in accordance with the character of the soil, climate, herbage, and the treatment which pasture lands may receive. 3. In the United States grasslands in the humid sections will maintain an animal unit on each 5 acres. The carrying capacity of the grasslands in Western Europe is much better. On some of them an average of 1 acre is sufficient per animal unit for the entire grazing season. On the best pastures it has been shown that as many as two animal units per acre may be carried, especially where chemical fertilizers are intelligently used. 4. The expansion in the production of synthetic nitrogen fertilizers and the declining cost of these are encouraging more intensive methods of grassland management. 5. Grass, when cut young or when eaten by animals under pasture conditions, corresponds in character to concentrates, whereas grass that is allowed to mature is designated as roughage. The grass cut at weekly or fortnightly intervals will yield, under the same conditions, scarcely more than half as much as may be harvested when the grass is allowed to mature. On the other hand, the grass frequently cut or grazed is much more valuable as a source of digestible protein and carbohydrates. 6. Economic studies of grasslands and pastures are serving to emphasize their significance as an economic resource. 7. Increased yields of forage and a higher carrying capacity involve the removal of larger quantities of plant food from the soil. This emphasizes the problem of replacements. 8. The more intensive utilization of pastures calls for more careful consideration of questions of pasture sanitation. 9. The more intensive fertilization of grasslands and pastures creates the need of better provision for conserving the seasonal surplus of forage. Ensilaging and artificial drying are being investigated as a means of solving this problem.