Banca de DEFESA: JOÃO AUGUSTO DOURADO LOIOLA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JOÃO AUGUSTO DOURADO LOIOLA
DATE: 06/05/2025
TIME: 09:00
LOCAL: VIDEOCONFERÊNCIA
TITLE:

Alternative to KCl: Innovative Bioinputs Based on Marine Macroalgae with Multitarget Technology and Regenerative Potential.

KEY WORDS:

Regenerative agriculture, sustainable bioinputs, slow release, macroalgae.

PAGES: 50
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SUMMARY:

Brazil is dependent on imported nutrient sources, such as potassium, to meet agricultural demand. In this context, the algae Kappaphycus alvarezii (K.A) emerges as an alternative source of potassium, since the biosolids of the macroalgae contain approximately 200 g kg-1 of K2O. In this context, it is challenging to evaluate the viability and performance of potassium bioinputs with multi-target and regenerative technology. Therefore, the present study aims to evaluate the viability and performance of potassium bioinputs with multi-target and regenerative technology, developed from Kappaphycus alvarezii, humic substance and biochar. The proposal aims not only to mitigate the challenges of conventional potassium fertilization in Brazil and worldwide, but also to promote a qualified contribution of carbon to the soil, favoring root growth and aligning with the principles of bioeconomy and agricultural sustainability. In chapter 1, the feasibility of formulating multi-target potassium regenerative bioinputs was assessed through chemical, physical and structural characterization. All bioinputs presented potassium and nitrogen contents higher than those established by MAPA. The bioinputs presented high TOC contents (above 30%), demonstrating that they are a concentrated source of carbon. The bioinputs that were granulated with water sprays showed greater resistance to rupture when compared to other forms of granulation. Potassium sulfate showed greater electrical conductivity and pH when compared to the bioinputs. Fertlio showed the highest C.E. among the bioinputs. The bioinputs showed good particle distribution and high porosity, in addition to potassium on the surface of the granule. The technologies developed in this chapter demonstrated satisfactory results to proceed to leaching and bioactivity tests. In chapter 2, the objective was to evaluate the dynamics of potassium leaching in columns, through the use of multi-target bioinputs produced with potassium from Kappaphycus alvarezii Biosolids, humic acid and sewage sludge biochar (500° C). The multi-target bioinputs demonstrated low potassium leaching rates, in addition to presenting considerable potassium residuals when compared to commercial fertilizers. Despite presenting sodium levels in their formulation, the multi-target bioinputs did not present residuals of this element in the soil in the studied conduction. Multi-target bioinputs are capable of contributing recalcitrant carbon to the soil, even under high precipitation rates. ASE70BA, ASE80BA, ASE70BIO, ASE80BIO and FERTLIO showed better results in the leaching test and were selected for the bioactivity test. In chapter 3, the objective of the study was to evaluate the multi-target bioinputs in the rice crop, in increasing doses of K2O (0, 30, 60, 90 and 120 kg ha-1), as an alternative technology for the contribution of potassium, as well as the contribution of recalcitrant carbon to the soil. In all doses studied, the multi-target bioinputs presented statistically similar height to the commercial fertilizer. In the study of the Absolute Growth Rate (AGR), FERTLIO and ASE80BIO showed greater growth compared to the other treatments. The leaf area of ASE70BIO showed statistically superior performance to KCl at a dose of 90 kg ha-1 of K2O. The treatments ASE70BIO and FERTLIO showed increases in the number of leaves with increasing dose. At a dose of 60 kg ha-1 of K2O, ASE80BA showed a greater number of leaves. At a higher dose of K2O, the treatments ASE80BA and ASE70BIO showed a greater number of leaves when compared to KCl. In the study of the production of dry mass of the roots, there was an increase in the production of roots with increasing dose. At a dose of 120 kg ha-1 of K2O, ASE70BIO showed a higher average in root production in relation to KCl. The accumulation of K+ increased linearly in both shoots and roots with increasing doses. Multitarget bioinputs showed lower potassium levels in the soil, thus suggesting a slow release of the element. Multitarget technologies with soil regenerative potential significantly increased the organic carbon content in the soil. Chapter 4 aimed to study the morphological parameters and their cohesion with the kinetics of transient chlorophyll a fluorescence emission with the application of multitarget bioinputs, at increasing doses of K2O (0, 40, 60, 80 and 100 kg ha-1), in corn crops. KCl and the bioinputs ASE70BIO and ASE70BA showed greater plant height at the highest doses of 80 and 100 kg ha⁻¹ of K₂O. The Absolute Growth Rate (AGR) was higher in the ASE70BA and ASE70BIO treatments when compared to KCl. KCl showed better performance in stem diameter and leaf area at the lowest doses of K₂O. The production of dry mass of leaves and stem was also influenced by the doses, the treatments ASE70BIO and ASE80BA showed similar performance in these parameters at the highest doses of K₂O (80 and 100). KCl showed greater photosynthetic efficiency at the lowest doses (40 and 60 kg ha⁻¹ of K₂O). At the highest doses (80 and 100 kg ha⁻¹ of K₂O), the ASE70BIO, ASE80BIO and FERTLIO treatments showed photosynthetic performance statistically similar to the commercial treatment. The formulations developed in this study demonstrated the capacity to partially or totally replace KCl in potassium fertilization, providing potassium efficiently. In addition, they were efficient in incorporating recalcitrant carbon into the soil, being a promising source for acting in the regeneration of sandy soils.

COMMITTEE MEMBERS:
Presidente - 1399485 - ANDRES CALDERIN GARCIA
Interno - 2626406 - LEANDRO AZEVEDO SANTOS
Externo à Instituição - MARCIO OSVALDO LIMA MAGALHÃES - UNEMAT