Presentation on theme: "STRUKTUR TANAH. Soil Structure Structure – arrangement of individual particles in relation to each other. Soil structure is the arrangement of particles."— Presentation transcript:
Soil Structure Structure – arrangement of individual particles in relation to each other. Soil structure is the arrangement of particles into small groups, or aggregates. Aggregates may be bound together with other aggregates in larger masses called peds. Peds come in different shapes that roughly resembel sphere, blocks, columns and plates. If the individual particles are arranged in small aggregates with rounded edges, we speak granular structure. This is very desirable for plant growth bc it provides both large and small pores. Some soils lack structure. Sandy soils the individual grains act independently of each other. No binding substances hold the particles together, so the soil has no peds.
Struktur tanah Struktur granular Struktur prismatic Cause and Effect (description in laboratory)
+ Flocculation Pembentukan strktur tanah (chemical)
Luas Permukaan - aggregate of small particles - large grain vs
Agregasi Pembentukan struktur tanah Organik dan Anorganik ‘glues’
Lateral Stress Forces (what breaks the ‘glue’) Vertical
Spheriodal Granular Sruktur tanah : Surface Horizons
Pengelolaan yang tidak baik Granular Massive
Pemadatan horison permukaan - Platy Structure - compaction
---- Prismatik ---- Struktur tanah: Lapisan bawah Increased length in vertical direction lateral stress > vertical stress
Columnar structure occurs in dry, desert soils with high sodium content
Single Grained Massive Soil Structure (continued) Without Structure Pencil is 19 cm
Soil Consistence Squeeze a moist soil ped to see if it is: Loose* You have trouble picking out a single ped and the structure falls apart before you handle it.* Extremely Firm The ped can’t be crushed with your fingers (you need a hammer!). Firm The ped breaks when you apply a good amount of pressure and dents your fingers before it breaks. Friable The ped breaks with a small amount of pressure * Soils with “single grained” structure always have loose consistence.