Impacts of intensification of pasture-based beef production in tropical systems
Nitrogen fertilization, forage, forage production, technical indicators
The aim of this study is to evaluate the impacts of intensifying pasture-based beef production systems. An experiment will be conducted at Embrapa's experimental field, located in Palmas - TO, between November 2023 and November 2024. The treatments will be distributed in a randomized block design (RBD) with four replications and under a 3 x 5 x 2 complete factorial arrangement, with the following factors: 3 different forages (Megathyrsus maximus cv. Mombaça, Urochloa brizantha cv. BRS Piatã and Andropogon gayanus cv. BRS Sarandi), 5 levels of nitrogen topdressing fertilization (0, 80, 160, 240 and 320 kg/ha/year of N) and 2 levels of phosphate topdressing fertilization (0 and 60 kg/ha/year of P2O5), totaling 30 treatments. Forage accumulation (kg of dry matter/ha/year), morphological composition (leaves, stems, inflorescence and senescent material), chemical composition (dry/mineral/organic matter, crude protein and neutral detergent fiber), gas production (total, carbon dioxide and methane) and in vitro digestibility (48 hours) of forage organic matter will be evaluated. Additionally, data collected between the 2017/2018 and 2023/2024 harvests will be analyzed on farms participating in the ABC Corte program. Technical indicators (average daily gain, stocking rate and productivity), economic indicators (effective operating cost, gross margin, technical margin, disbursement and sales value) and environmental indicators (kg of carbon dioxide equivalent/kg of carcass produced, kg of nitrous oxide/kg of carcass produced and kg of methane/kg of carcass produced) will be evaluated. Given the results, it is expected to demonstrate that the intensification of pasture-based beef production increases the productivity of livestock systems and reduces greenhouse gas emissions per kilogram of meat produced.