An aggregate is a naturally formed assemblage of sand, silt, clay, organic matter, root hairs, microorganisms and their "glue" like secretions mucilages, extracellular polysaccharides, and hyphae (filaments) of fungi as well as the resulting pores. ![]() ![]() Aggregates can be broadly classified into macroaggregates (>250 µm) and microaggregates (20-250 µm) (Six et al. Soil texture and structure determine the pore-size distribution, soil water holding capacity and the amount of water to air-filled pore space in soil aggregates that provide habitat for soil organisms. This article addresses the role of soil biota in the pedosphere using ecological principles that link soil organisms and plants to biogeochemical processes occurring within the soil in natural and managed ecosystems.Īggregates: Model of a Pedosphere Soil texture (fineness or coarseness) affects plant rooting, soil structure and organic matter content. It exists at the interface of the lithosphere (rock), atmosphere (air), hydrosphere (water), and biosphere (living matter). Biogeochemical processes are dependent upon the biota in the soil or pedosphere, the outermost layer of the Earth that is composed of soil and subject to soil formation processes. The process of biogeochemical cycling is defined as the transformation and cycling of elements between non-living (abiotic) and living (biotic) matter across land, air, and water interfaces (Madsen 2008). In a similar vein, one might see the ‘biological universe' in a single gram of fertile soil, approximately a teaspoon in size, containing all the domains ( Bacteria, Archaea and Eukarya) and elements of life! The majority of life on Earth is dependent upon six critical elements: hydrogen (H), carbon (C), nitrogen (N), phosphorus (P), oxygen (O), and sulfur (S) that pass through, and are transformed by, soil organisms (the soil biota). In his famous poem, The Auguries of Innocence, the poet William Blake wrote:
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |