Effects Of Different Levels Of Nitrogen Application And Cutting Intervals On The Dry Matter Yield Of Mulato (Brachiaria Hybrid) And Tanner (Brachiaria Arrecta) Grasses

One of the methods identified for increasing forage production and the carrying capacity of the land is via the introduction of new and improved grass species. In keeping with this method, a factorial arrangement in a randomised complete block design was used to compare the effects of different levels of nitrogen (N) and cutting intervals on the dry matter (DM) yield of an improved grass, Mulato (Brachiaria sp.) to that of a local grass, Tanner grass (Brachiaria arrecta). At land preparation, agricultural limestone, triple super phosphate and muriate of potash were applied at rates of 1,000 kg/ha, 100 kg /ha and 100 kg/ha, respectively. The area was rotovated immediately after this application and plots (9 m χ 3 m) were cut. Tanner was planted from cuttings of mature plants. Mulato seeds were sown. Seventy-seven days after planting, all plots were cut back to six inches by using a motorized brush cutter and Ν was applied according to treatment, signaling days zero of the regrowth (RG). Harvesting began according to treatment, three, six and nine weeks thereafter. After each harvest, plots were cut back. Harvesting continued for seventy-two weeks. Fresh and dry weights were recorded. Data was analyzed by using Genstat Release 11.1 statistical software and Minitab 15 statistical software. Analysis of the data shows that at 0 kg Ν application, the three-week RG between species varied significantly (P<0.01) with Mulato and Tanner yielding 58,846 kg DM and 46,448 kg DM, respectively, over the 72-week period. However, with Ν applications of 100 kg/ha/yr and 200 kg/ha/yr, yields within and between species were statistically not different. Where no Ν was applied and the RG was harvested at six weeks, no differences were observed. At 100 kg Ν application, the yield of Mulato (49,385 kg DM) was higher (P<0.05) than that of Tanner grass (41,885 kg DM). Increasing Ν application to 200 kg bears no significant benefit (P>0.05) in terms of dry matter yield between or within species. With regard to dry matter yield at nine weeks RG, there was a significant response (P<0.05) by Tanner grass when fertiliser was applied at the 200-kg Ν level when compared to DM yields at 0 and 100 kg N. The highest dry matter yields for both grasses were obtained in the three-week regrowth with Ν applications of 200 kg. Yields were 68,479 kg DM for Mulato over the study period and 54,177 kg DM for Tanner.