Oat Forage Production in the Cool Tropics as Represented by Colombia 1

In the cool tropics, forage yields of imported oat varieties and selections ranged from 5.5 to 9.5 T/A of dry material when harvests were made at the milk stage of growth. Production declined with two cuts, one made at the vegetative stage and one at the milk stage. Yields were considerably reduced when several harvests were made at the vegetative stage. Crude protein content of forage cut when the plants were 12 to 15 inches high varied between 15 and 20% on a dry weight basis. The more mature forage (milk stage) had from 6 to 10% protein. On land previously uncultivated, oats responded to application of P and, to a lesser extent, N. After several fertilized cash crops, a response to N was observed in the early stage of growth of the oats and at the harvests taken in the vegetative stage. As the plants became more mature and were harvested in the milk stage, less benefit was noted from applied N and little or no response occurred with P. Oats planted after potato harvest gave high yields without the use of additional fertilizer. Interseeded grasses and legumes became well established when oats were harvested several times in the vegetative stage of growth. When oats reached the milk stage, plant competition for soil water, light, soil nutrients and space often caused poor stands of the intersown crop, especially under water stress. Excellent oat silage was made from plants harvested in the milk stage and stored in a tower silo. Feeding trials showed that oat silage alone gave daily beef gains of 1.6 pounds per day.