Interceptação de luz como ferramenta de manejo do capim Buffel Cenchrus ciliares cv. Aridus

Abstract

In the context of world livestock production, researchers have focused on animal production systems using forage plants as an economic alternative to compose the herd's diet, aiming at improving the quality of the products generated, reducing production costs and increasing the quality of life of the animals. This research aimed to identify the best value of light interception (IL) of the buffel grass forage canopy. The research was carried out at the agricultural school unit of the Apodi Campus of the Federal Institute of Education, Science and Technology of Rio Grande do Norte - IFRN. The experiment was conducted in a randomized block design, with 3 blocks containing 6 repetitions per block, totaling 18 experimental plots. The treatments corresponded to values of 85%, 90% and 95% of IL. Monitoring was carried out from the seventh day of cutting, as the plots reached the percentage of Light Interception according to the assigned treatment. The following variables were evaluated in this research: canopy height (AD), regrowth period (PR), leaf mass (MF), stem mass (MC), dead material mass, leaf/stem ratio (F/C) and chemical composition (dry matter (DM), mineral material (MM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents). Forage canopy heights did not differ between treatments, with an average height of 36 cm for treatments with 85% and 90% IL, in the first two cuts, with the treatment with 95% IL having the highest canopy height in the moment of the cut with 55 cm. Leaf mass production (PMF) did not differ between 85% and 90% IL in the second and third cuts. The dry matter (DM) content did not differ between treatments 90% and 95% in the first and third cuts. Crude protein (CP) content did not differ for treatments with 85% and 90% in cuts 2 and 3, with an average of 8.12%. In the forage mass in the 3 cuts, a significant difference was observed for the 95% IL treatment (3,520 kg/ha), however it needed a greater number of days to reach the cut date, when compared to the other treatments. In general analysis, it was observed that the treatment with 90% resulted in the best leaf/stem ratio, with an average value above 1.5 when compared with the treatments using 85% and 95% of IL, respectively. With this, the work contributed to determine the best way to choose the best moment for the interception of the forage canopy of the grass for the region, reaching the conclusion that, under the conditions presented, the cutting of Buffel grass with 90% of interception and with 39cm of canopy height stands out for its better vegetative performance and better chemical responses compared to the other treatments studied.