Banca de QUALIFICAÇÃO: MARIA ALICE FORMIGA PORTO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE: MARIA ALICE FORMIGA PORTO
DATA: 27/09/2019
HORA: 17:30
LOCAL: Auditório do Programa de Pós-Graduação em Fitotecnia
TÍTULO:

Manuscript I - Sorption-desorption of three mobile herbicides in an agricultural soil amended with eucalyptus, rice hull, and native bamboo biochar.

Manuscript II- Biochar additions to agricultural soils: impacts on sorption-desorption and mineralization of metribuzin in three agricultural soils.

PALAVRAS-CHAVES:

carbonaceous material, mobile herbicide, persistence, soil amendment

PÁGINAS: 56
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
RESUMO:

Manuscript I - Sorption-desorption of three mobile herbicides in an agricultural soil amended with eucalyptus, rice hull, and native bamboo biochar

Abstract: Mobile herbicides have a high potential for contaminating groundwater. An alternative to reduce the mobility of herbicide is to apply to soils, materials with high sorbent capacity, as biochars. The objective of this research was to evaluate the effect of eucalyptus, rice hull and native bamboo biochar amendments on sorption and desorption of hexazinone, metribuzin and quinclorac in a tropical soil. The sorption-desorption were evaluated using the batch equilibrium method at five concentrations of hexazinone (0.14, 0.16, 0.19, 0.26 and 0.39 μg mL-1), metribuzin (0.40, 0.80, 1.60, 3.20, and 6.40 mg L-1) and quinclorac (0.31, 0.63, 0.94, 1.25, and 1.56 mg L-1). Soil was amended with eucalyptus (Eucalyptus grandis), rice hull (Oryza sativa), and native bamboo (Merostachys skorvotzii) biochar at rate of 0 (control – unamended) and 1% (w w-1), corresponding 0 and 12 t ha-1, respectively. The highest sorption in unamended soil followed the decreasing order of herbicides: quinclorac (65.9 %) > metribuzin (21.4 %) > hexazinone (16.0 %). Native bamboo biochar provided the highest sorption compared rice hull and eucalyptus biochar amended soils for the three herbicides. The highest desorption in unamended soil followed the decreasing order of herbicides: metribuzin (18.35 %) > hexazinone (15.9 %) > quinclorac (15.1 %). Addition of native bamboo biochar provided the lowest desorption among the biochar amendments on the three herbicides. As conclusion, the addition of biochar is a good alternative to increase the sorption of hexazinone, metribuzin, and quinclorac mobile herbicides in a tropical soil. Thus, the addition of eucalyptus, rice hull and native bamboo are expected to affect the transport of mobile herbicides, even though further researches are needed to adjust the ratio of biochars that better fit to this type of soil.


Manuscript II

Biochar additions to agricultural soils: Impacts on sorption-desorption and mineralization of metribuzin in three agricultural soils

Abstract: Biochar is a carbon‐rich product obtained by biomass pyrolysis that have been proposed as a soil amendment to retain and limit the transport of herbicides and other environmental contaminants in soil and water sources. The objective of this research was to evaluate the effect of grape wood and loblolly pine biochar amendments on sorption-desorption and mineralization of metribuzin in three agricultural soils. Each soil was amended with grape wood (Vitis vinifera L.) and loblolly pine (Pinus taeda) biochars at rate of 0 (control – unamended) and 5% (w w-1). Sorption of metribuzin on the three unamended soils followed the decreasing order: drummer (61.3 %) > oakville (24.56 %) > ipava (22.35 %). Grape wood biochar (82.6 – 83.3 %) showed the highest sorption compared to loblolly pine biochar (43.9 – 68.4 %) in all the three soils. Ipava soil provided the highest desorption of metribuzin in both, first (40.52 %) and second (57.97 %) desorption step. Loblolly pine provided the lowest desorption on first (16.4 – 29.5 %) and second (24.7 – 42.5 %) desorption steps between the two biochars in all the three soils. Consecutive steps of metribuzin desorption showed that more than 65 % of the sorbed metribuzin was retained in the soils amended with grape wood biochar. Grape wood and loblolly biochars have great potential to reduce the risk of environmental contamination due to the application of metribuzin.

MEMBROS DA BANCA:
Presidente - 2213033 - DANIEL VALADAO SILVA
Externo à Instituição - KASSIO FERREIRA MENDES - UFV
Externo à Instituição - LUIZ FRANCISCO DA SILVA SOUZA FILHO - UFOB