Relação de atributos do solo com a estabilidade de agregados

Abstract

Soil aggregate distribution by size classes, quantity and stability are important in determining amount and distribution of soil pore space. Soil clay type knowledge and their behavior when subjected to different wetting and drying conditions is a very important criterion for assessing soil structure, taking into account their participation as aggregation agent. For the study on the factors that influence aggregate stability is important to know the activity, amount and soil clay type, organic matter, total sand and sand fractions. Relationship of these factors with soil aggregate stability analysis via wet and dry processes provide knowledge about soil structure stabilization. Thus, six soils with different levels and types of clay were evaluated, being five predominantly with 1:1 clay and one with 2:1 clay. Results showed that it’s possible to determine the COLE substituting Saran resin for paraffin. Kaolinitic soils (Ultisol Red-Yellow, Typic Hapludox and Haplic Cambisol) showed expansion-contraction presence assessed by COLE. Organic matter, clay, and sand fraction <0.1 mm were the most important factors for soil aggregation, both in wet and in dry processing. Red-Yellow Oxisol was the soil with the highest aggregate stability in water presence, followed by Yellow Oxisol and, finally, Red-Yellow Ultisol, Haplic Cambisol, Haplic Cambisol-Oxisol, and Vertisol.