Sistema de Eventos Acadêmicos da UFMT, X Mostra da Pós-Graduação: Direitos Humanos, trabalho coletivo e redes de pesquisa na Pós Graduação

Tamanho da fonte: 
Integrated Farm System Model for beef cattle and pasture in the Cerrado biome
Luana Molossi, Lorena Machado Pedrosa, João Alex de Medeiros, Kaio Furlan Andreasse, Aaron K. Hoshide, Daniel Carneiro de Abreu

Última alteração: 16-10-18

Resumo


The expansion of agricultural areas in Brazil has generated not only local but global effects. Low productivity livestock has been one of the greatest sustainability. Models that simulate the impacts caused by production systems are necessary for management to be adopted and reduce economic and environmental impacts. The objective of this study was to use the Integrated Farm System Model (IFSM) version 4.4 to evaluate and compare pasture productivity and consumption (t DM) and environmental impacts from an extensive system of continuous grazing in relation to a system using increased pasture fertilization in Brazil’s Cerrado biome. IFSM models all major processes on farms: animal production, harvesting, grazing and forage storage, and nutrient cycling. Agricultural systems are simulated over many years of meteorological data to determine performance. A cooperating farm provided comprehensive data on its operations. The performance of the farm was simulated based on the meteorological data collected on the property from July 2016 to June 2017. We validated this cooperating farm’s extensive grazing production system, where dry season (May to September) supplementation was provided. The average pasture consumed simulated by the IFSM was 3.31 t/ha/year, corresponding to the minimum estimate of 2.99 t/ha/year and 79% of the maximum estimate of 4.15 t DM/ha/year calculated for the farm based on values from the literature. To simulate fertilization of the pastures we adjust IFSM parameters for applied fertilizer. In the extensive production system, a total of 37.50 Kg N/ha, 24.54 Kg P2O5/ha and 0.40 t lime/ha were used annually. To model increased fertilization per year, these parameters were adjusted to 100 kg N/ha, 50 kg P2O5/ha, 50 kg K2O/ha and 1.50 t lime/ha. Fertilization levels were collected through interviews with cooperating producers and literature from this agricultural region. For both levels of fertilization, the average pasture forage consumed simulated by IFSM was 3.29 t/ha/year. Pasture consumption (t DM/ha) was similar in both systems since the number and category of animals did not change in the systems. The forage yield for fertilization was 8.37 t DM/ha, an increase of 3% when compared to the extensive system. In addition, forage yield remained more constant between the months of the year with fertilization. However, fertilization resulted in reactive nitrogen loss of 716.475 g/kg body weight more compared to the extensive system. This may have occurred due to the excess of nutrients deposited in the system and therefore not used by the forage, where this nitrogen becomes more susceptible to leaching. The increased fertilization reduced CO2e emissions and reduced enteric fermentation by 2%. This was likely due to greater supply of fodder due to increased fertilization, increased efficiency of forage digestion, and less GHG gases emitted from the rumen compared to lower fertilization levels which results in forage with higher fiber content (e.g. degraded pastures). IFSM can be used to analyze and identify strategies to mitigate greenhouse gases and reduce resource use. Future research needs to develop economic budgets for the sustainable intensification strategies evaluated, since IFSM economic accounting is too aggregated for such analysis.


Palavras-chave


Cerrado; beef; Bos indicus; environmental impacts; sustainable intensification; carbon footprint

Referências


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