The utilization of grasses, legumes and other forage crops for cattle feeding in Puerto Rico III. Comparison of fertilized guinea grass, para grass and tropical kudzu and guinea grass and tropical kudzu

Abstract

A third grazing trial of 221 days was conducted under the same procedure as in trial number one (2). A modification was introduced consisting in that the calculation of T.D.N, was made using the chemical analysis of the roughages, and the digestion coefficients given by the Pasture Research Committee (1). The grasses under trial were: Para grass-Kudzu, in its third year; Guinea grass-Kudzu, in its first year; and fertilized Guinea grass, in its second year. In this experiment Guinea grass received only two applications of nitrogen instead of three as in trial number 2. This was due to the fact that according to the observations of the investigator the grass was growing well and having a nice green color. Nitrogen was applied when the leaves began turning yellowish. Para grass-Kudzu has been uniform in performance; the carrying capacity being one head in the first trial, one head in the second and 0.77 for this trial. The carrying capacity of the mixture of Guinea grass and Kudzu was 1.09, but due to the fact that this grass was planted in the old Kudzu stand, it received the benefits of the nitrogen accumulation in the soil, producing an exhuberant growth at the beginning of the trial. As a result of this, larger amounts of residue were clipped after rotations affecting favorably the carrying capacity. Although the results are encouraging, further investigations are needed to make definite recommendations. Guinea grass alone had a carrying capacity of 0.68. It was lower than in the previous trial. The difference can be attributed to the difference in nitrogen supplied, as nitrogen increases the amount of roughage produced and the nutritive value of the forage.