Banca de DEFESA: GABRIEL ALVES BOTELHO DE MELLO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : GABRIEL ALVES BOTELHO DE MELLO
DATE: 29/05/2024
TIME: 13:30
LOCAL: Auditório Joana Dobereinher da Embrapa Agrobiologia
TITLE:

Evaluation of N-green organic fertilizer prototypes obtained by processing Gliricidia sepium aerial biomass.

KEY WORDS:

Organic fertilizer; Plant biomass; Nitrogen.

PAGES: 120
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SUMMARY:

The use of biomass from leguminous plants (Fabaceae) as a raw material to produce organic fertilizers is proving to be a promising strategy for increasing nutrient availability in agroecological farming. To optimize the efficiency of these bio-inputs, it is essential to consolidate the involved biotechnological techniques. Different processing methods applied to the above-ground biomass of gliricídia have been studied, resulting in distinct prototypes of organic fertilizers known as N-verde and by-products. This thesis is divided into three chapters. In the first, the impact of manufacturing methods of pelleted nitrogen fertilizer from gliricídia biomass was analyzed, resulting in the production of seven prototypes. One of these fertilizers consists solely of leaves, while the other six contained both leaves and stems. Subsequently, these fertilizers were evaluated and compared based on their physical and chemical characteristics. The differences among the prototypes are associated with the raw material used, processing method, and composting periods. Production is standardized, covering stages such as harvesting, drying, grinding, and pelletization. However, in prototypes subjected to composting, this additional stage is included. Additionally, a study was conducted on the composting process of gliricídia biomass over 120 days to better understand the decomposition of this biomass. In the following chapter, two bioassays were conducted to evaluate the nitrogen bioavailability efficiency of these prototypes. A field experiment with kale, grown in an organic system and fertilized with N-verde, in contrast to fertilization using castor meal, along with a treatment without fertilization, was conducted. A greenhouse experiment was also conducted to assess the potential use of gliricídia biomass composted for 120 days as a substrate for pot production of loose-leaf lettuce. In the third chapter, the production of seedlings of loose-leaf lettuce and eggplant from gliricídia compost with 120 days was evaluated. Tests were carried out using mixtures of organic materials, such as gongocompost and commercial substrates, in the formulation of an alternative substrate that was cost-effective and of superior quality. Three experiments were conducted with lettuce seedlings, and one experiment was carried out with eggplant seedlings. The processing of gliricídia biomass resulted in N-verde prototypes with distinct chemical and physical characteristics, and the composting of gliricídia biomass proved to be like other organic materials, with a mass loss of almost 60% after 120 days and nitrogen volatilization close to 39% in the first 45 days. During the nitrogen recovery bioassays, the N- verde prototypes exhibited different nitrogen availabilities. In the field experiment with kale, N-verde fertilizers resulted in significant productivity increases compared to the treatment without fertilization and had a similar performance to the castor meal treatment. The 120-day- old gliricídia compost did not present problems for potted loose-leaf lettuce plants and, when used as part of an alternative substrate mixture, provided good quality eggplant and loose-leaf lettuce seedlings.

COMMITTEE MEMBERS:
Interno - ***.282.827-** - BRUNO JOSÉ RODRIGUES ALVES - EMBRAPA
Interno - 2213075 - EVERALDO ZONTA
Externo à Instituição - JOSÉ ANTONIO AZEVEDO ESPINDOLA - EMBRAPA
Externo à Instituição - JOSÉ GUILHERME MARINHO GUERRA - EMBRAPA
Presidente - ***.320.637-** - MARIA ELIZABETH FERNANDES CORREIA - EMBRAPA