Ciro Alberto de Oliveira Silva
AUTHOR: Ciro Alberto de Oliveira Silva
TITLE: QUALITY INDEX OF A DYSTROPIC RED LATOSOL UNDER DIFFERENT MANAGEMENT ENVIRONMENTS
ADVISOR: Prof. Dr. Hildeu Ferreira da Assunção, Co-advisor: Prof. Dr. Simério Carlos da Silva Cruz
APPROVAL DATE: 05/28/2020
Abstract
The soil quality index (SQI) is an edaphic analysis tool in order to monitor changes in soil properties and functions, sustainability and environmental quality, which occur over time, in response to land use and management practices. The SQI uses chemical, physical and biological attributes as parameters of analysis, whose importance is related to the functions that enable the soil to integrate its properties, which enables it to perform its functions in fullness. Therefore, the objective of this work was to evaluate the edaphic quality of a dystrophic Red Latosol, submitted to management systems, using SQI as an analysis tool. The experimental design used was completely randomized, with 5 different environments: Cerrado Nativo (CN); Notillage (NT); Forestry (T); Pasture (P); and Agroforestry (AF). Three samples were taken in the 0 to 20 inch layer for each environment. The chemical variables (pH, m%, v%, Total Nitrogen, CTC and K and P-laile contents), physical (Total pore volume, Penetration resistance, Density, Average diameter of aggregates) and biological (Edaphic Fauna, Organic Matter, Organic Carbon and Microbial Biomass Carbon) were organized and analyzed with the aid of the GENES application, subjecting them to variance analysis and discrimination by Tukey test (p<0.05) and then submitted to principal component analysis and grouping of environments by tocher method. Subsequently, the variables were organized according to their importance in each soil function: (PEA - Allow water entry, FDA - Facilitate the movement and availability of water, RDE - Resist structural degradation and SQP - Sustain quality and productivity) and inserted in the general IQS model for analysis of variance and quality classification. The reductions of the physical and biological variables indicate the loss of soil quality for environments with intensive use through the presence of anthropic pressure. The chemical evaluation of the soils shows increased availability of nutrients and reduction of acidity and toxicity for all environments compared to cerrado soils. None of the anthropized patients presented a grouping with the native Cerrado area. Principal component analysis indicates that biological and physical attributes form quality indicators with greater contributions to the discrimination of environments. While Agroforestry and native cerrado have the highest final quality indexes, especially 4 Agroforestry with "optimal" quality, the other no-tillage, forestry and pasture systems were classified as "medium" quality.
