Banca de DEFESA: SILVER RODRIGUES ZANDONA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : SILVER RODRIGUES ZANDONA
DATE: 26/07/2024
TIME: 09:00
LOCAL: Sala 24 do Departamento de Solos
TITLE:

Soil quality indicators in mountain agriculture areas in the Atlantic Forest biome, southeastern Brazil.

KEY WORDS:

Soil management. Conservation systems. Soil indicators. Environmental sustainability.

PAGES: 143
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SUMMARY:

Mountain areas, despite being relegated to a secondary level when it comes to agriculture, are of great relevance as they are significant in food production and the provision of ecosystem services. In this way, understanding the changes that occur in these environments during management can prevent impacts resulting from inappropriate use. The present study was divided into three chapters with different objectives. In chapter I i) the morphological, chemical and physical characterization of soil attributes from profiles collected in areas with different agricultural crops and vegetation cover was carried out; ii) the main soil classes of these areas were verified; and iii) the capacity for agricultural use was evaluated, as well as the suitability classes and main limitations. In chapter II, i) the storage of carbon (C) and nitrogen (N) in these areas was quantified, and ii) the origin of these elements was evaluated. Chapter III aimed to i) verify the possible influence of monoculture of different plant species in a mountain environment on the accumulation and composition of litter; ii) evaluate possible changes imposed by these covers and forms of cultivation in the chemical attributes associated with soil fertility; and iii) analyze the compartmentalization of soil organic matter (SOM), identifying which types of coverage are contributing to an increase in organic carbon levels and their respective organic fractions. Three areas cultivated with banana (BN), coffee (CF) and cocoa (CC) and a reference area (FS, forest fragment of the Atlantic Forest) were evaluated at three different points with steep terrain, typical of the southeastern region of Brazil. In Chapter I, a large part of the profiles identified at the first categorical level (order) as Cambisols, due to the presence of an incipient subsurface diagnostic horizon B, and at the second categorical level (suborder) as Haplicos, were verified. Regarding agricultural suitability, the greatest limitations of use were low natural fertility, susceptibility to erosion and impediments to mechanization or cultivation, resulting from the slope, stonyness and rockiness. In chapter II it was found that the magnitude of the effects caused by agricultural crops and vegetation cover on soil attributes increased in the FS – BN and CC – CF direction. BN and CC crops increased the contents and stocks of C (on the surface) and N (in depth) in the soil when compared to areas with FS coverage, while the CF crop promoted reductions in the values of these attributes. Through isotopic analyzes of δ¹³C and δ¹⁵N, differences between agricultural crops were evident, with emphasis on the CC cultivation area that was separated from BN and CF crops. In chapter III it was found that the largest litter stocks were quantified in the BN and FS areas (~34.0 and 22.0 Mg ha^-1). Among the SOM fractions, light organic matter in water was the most sensitive to the effect of agricultural crops and vegetable covers, especially in terms of stoichiometric ratio values. Similarity was verified for the contents of total C, total N, total organic C and total phosphorus (P) between the areas of FS, BN and CC. Differentiated patterns were observed for the stoichiometric ratios between the compartments. The responses of C, N, P content and their stoichiometry to different agricultural crops and vegetation cover have significant applications in the development of sustainable management strategies.

COMMITTEE MEMBERS:
Externo à Instituição - DAVID VILAS BOAS DE CAMPOS - EMBRAPA
Externo ao Programa - 1246489 - EDUARDO CARVALHO DA SILVA NETO - nullExterna ao Programa - 1740899 - ERIKA FLAVIA MACHADO PINHEIRO - nullPresidente - 1060711 - MARCOS GERVASIO PEREIRA
Externo à Instituição - RENATO LINHARES DE ASSIS - EMBRAPA