Banca de DEFESA: ELDERSON PEREIRA DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ELDERSON PEREIRA DA SILVA
DATE: 07/03/2022
TIME: 14:00
LOCAL: UFRRJ (via meet)
TITLE:

Biological Nitrogen Fixation and Estimation of Energy Efficiency and Greenhouse Gas Emissions in Areas of High Soy Productivity in Brazil. 

KEY WORDS:

Glycine max, Nitrogen use efficiency, ¹⁵N natural abundance.

PAGES: 58
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitotecnia
SUMMARY:

With each passing year, soybeans have reached new records in grain productivity, reaching in some areas producing 120% more than the average soybean productivity in Brazil. These high yields (> 4200 kg ha^-1) require a large amount of nitrogen in the system, which in Brazil is guaranteed almost exclusively by the biological fixation of N₂ from the air. Therefore, the objective of this project was to evaluate the contribution of FBN at the field level, using the technique of natural abundance of ¹⁵N in areas of high soybean productivity in Rio Verde, GO (Chapter I), in addition to estimating the EE and GHG of some of these areas (Chapter II). To this end, 2 areas were evaluated in the 2019/2020 crop and 5 areas in the 2020/2021 crop with a history of high soybean productivity and/or that were champions of the National Maximum Productivity Challenge promoted by the Soja Brasil Strategic Committee. For the evaluation of BNF, each representative area was divided into 4 quadrants and within each quadrant a repetition was taken for each analyzed variable. The following variables were evaluated in Chapter I: crop index for nitrogen (ICN), contribution of FBN by the technique of natural abundance of ¹⁵N, and the balance and gap of N. With regard to FBN, all areas evaluated with their respective varieties were able to supply the N demand by the crop, where FBN assumed values ranging from 67.05% to 82.11%. Regarding the N balance in the soil x plant system, all varieties showed a positive balance, where the highest value observed was 205.29 kg ha^-1 of N in the 2020/21 crop with the BMX Foco IPRO variety and the lowest value was 68.88 kg ha^-1 of N for the BMX Voraz IPRO variety, confirming the efficiency of the inoculants used in the culture today. In Chapter II, the inputs and outputs of energy from agricultural operations and/or inputs used were calculated by multiplying the amount used by its calorific value or energy coefficient at each stage of production. Energy efficiency was obtained by the ratio between the amount of total energy output and the total energy consumption during the production process. The results showed that for every 1.0 MJ of energy consumed in the production of high-yield soybeans, an average of 10.8 MJ of energy was produced in the form of grains of this crop. The main energy expenditures were with seeds, fertilizers, herbicides and fuel. For every 1 kg of soy beans produced, respectively, 0.17 kg of CO₂eq are emitted during their production and warehouse delivery cycles. The main sources of CO₂eq emission to the atmosphere are phosphate fertilizers, potassium fertilizer and seeds.

BANKING MEMBERS:
Presidente - 058.898.198-28 - SEGUNDO SACRAMENTO URQUIAGA CABALLERO - EMBRAPA
Externa ao Programa - 1815763 - IRENE DA SILVA COELHO
Externa à Instituição - CLÁUDIA POZZI JANTALIA