Banca de DEFESA: LETÍCIA CUNHA DA HUNGRIA
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.STUDENT : LETÍCIA CUNHA DA HUNGRIA
DATE: 27/10/2022
TIME: 09:00
LOCAL: Por videoconferência na sala do google meet
TITLE:
"DOSES OF BIOCHAR FROM COCONUT WATER PRODUCTION RESIDUES ADDED TO UREA FOR NITROGEN LEACHING MITIGATION IN SOILS"
KEY WORDS:
cocoinoculture residues; thermodegradation; adsorptive capacity; N release; clay soil.
PAGES: 55
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Fertilidade do Solo e Adubação
SUMMARY:
Coconut farming is a major generator of waste, mainly green coconut husk, resulting from the coconut water in agro-industries production. These residues can be converted into biochar (BC), a carbonaceous product, obtained by the biomass of animal or plant origin thermodegradation. When added to urea, BC can constitute a sustainable alternative for the use of these residues and as a potential mitigator of nitrogen (N) losses through the leaching process, when applied to the soil, thus improving edaphic quality. In this context, the aim were: to characterize BCs of residues from the coconut water production produced at 400, 500, 600 and 700 °C, to evaluate the adsorption capacity of ammonium (N-NH4+) and nitrate (N-NO3-) in solution of BCs produced at temperatures of 400 and 700 °C; and to evaluate the effect of BC doses added to urea on the leaching of N-NO3- and N-NH4+ in two soils with different textures (180 and 880 g kg-1). Increasing the temperature to 700 °C produced BCs that were more alkaline (pH=10.8) and with a pHPCZ twice as high compared to that produced at 400 °C. At higher temperatures, BCs showed higher concentrations of K and Ca. BCs produced at lower temperatures have higher yields, volatile material content and fixed carbon. CEC and AEC were increased by 2 and 4 times in BCs produced at 700 °C, which exhibited maximum capacity to adsorb N-NH4+ and N-NO3- higher 17 and 70%, respectively, when compared to BCs at 400 °C. The BC produced at a temperature of 700 °C, due to its higher N adsorption capacity and better physicochemical characteristics, was used in the leaching test. Two doses of urea, 200 mg kg-1 (100%) and 100 mg kg-1 of soil (50%) were used as experimental control units, to be added to BC. The treatments were as follows: 50% (T1) and 100% (T8) of the urea dose, 50% urea + 10% BC (T2), 50% urea + 20% BC (T3), 50% urea + 30% BC (T4), 100% urea + 10% BC (T5), 100% urea + 20% BC (T6), 100% urea + 30% BC (T7). After the application of the treatments in the soils, the leaching events were carried out after 3, 7, 14, 21 and 28 days, and the leached material was collected for further analysis of the concentration of N-NH4+ and N-NO3-. The results enriched with urea (T4 and T6 treatments), reduced by up to 20 and 90%, respectively, the leaching of N-NH4+ during the 28 days of evaluation, compared to their respective control treatments in very clayey soil, and 30 and 50% in predominantly sandy textured soil. Reduction for N-NO3- leaching, in treatments T4 and T6, was also observed. The product of the addition of biochar from the green coconut husk produced at 700 ºC in the composition of mineral fertilizers, particularly urea, is a material with high potential for mitigating losses inorganic N in soils, regardless of texture.
BANKING MEMBERS:
Presidente - 6388356 - ANTONIO RODRIGUES FERNANDES
Externa à Instituição - EDNA SANTOS DE SOUZA - UNIFESSPA
Externo à Instituição - JAMIL CHAAR EL-HUSNY - EMBRAPA
Externo à Instituição - MICHEL KEISUKE SATO - IFPA
Externo à Instituição - RAPHAEL MARICHAL - CIRAD