There are two stages that occur in the formation of soil structure, namely (1) clotting (coagulation) of colloidal soil as a result of the influence of Ca2 + ions into the soil micro-aggregates, and (2) cementation (binder) micro aggregate into the aggregate macro. Meurut soil structure formation theory, based on the flocculation occurs on land that is in solution, for example on the ground that the aggregates have been destroyed by rain water or on land fields.
In the event of cracks due to swelling and shrinkage as a result of wetting and drying that was instrumental in the formation of aggregates. Then the soil aggregates are formed as a result of the interaction of a single grain, clay, iron or aluminum oksioda and organic materials. Good aggregate formed because clots or by the occurrence of cracks the soil and strengthened by bonding occurs chemically or their biological activity.
Factors Influencing the Formation of Soil Structure
There are several factors that influence the formation of soil structure, namely (1) the parent material, (2) soil organic matter, (3) plants, (4) soil organisms, (5) time, (6) Climate.
i) Parent Material
Differences constituents of the soil will affect the formation of soil aggregates and soil structure stability is formed. The content of the clay fraction will be very decisive in the formation of soil aggregates, because the clay serves as a binder substance absorbed on the surface of the soil particle. If the clay content> 30% will affect the aggregation of soil structure, while the clay content <30% has no effect on aggregation.
ii) Soil Organic Matter
Soil organic matter is a binder after experiencing laundering. The leaching is accelerated in the presence of soil organisms. So that the organic matter in the soil and the organisms are closely interconnected.
Plant in an area can help the formation of stable aggregates. Plant roots can penetrate the soil and form cracks. Besides, with the pressure of the roots, the soil grains and solid increasingly attached. Additionally celahcelah can be formed from water that is absorbed by plants proficiency level.
iv) Soil Organisms
Soil organisms can accelerate the formation of soil aggregates. It is also able to play a direct role by making a hole and loosen the soil. Indirectly organism will overhaul the plant remains that once used to be dikeluarlan again be the binder soil.
Time determine all the factors forming ongoing land. The longer time goes on, the soil aggregates are formed on the land growing steadily.
Climate influence on the process of drying, wetting, freezing, thawing. Climate is a factor that affects the establishmen-Tukan soil aggregates.