The soil texture is one of the physical properties of soil sifta a very big influence on the growth of plants and other soil properties. Overall the physical properties of the soil is determined by:
- The size and composition of the particles making up ground the result of weathering material;
- The type and ratio of the composition of the soil particles.
- The balance between the supply of water, energy and materials with a loss.
- The intensity of chemical and biological reactions that have been or are in progress.
Definition Texture
Soil Soil texture is the relative proportion (in percent) of the particles making up ground between the sand fraction (sand) in diameter from 2.00 to 0.20 mm or 2000-200 μm, dust (silt) with a diameter of 0.20 to 0.002 μm or 200 – 2 μm, and clay (clay) (<2 m). Particles larger sized 2 mm as gravel and small rocks are not classified as a fraction of the land, but should be taken into account in the evaluation of soil texture. When viewed from the side of the size of the constituent particles of soil, the comparative picture of the size of the diameter of sand, silt and clay can be seen in Figure 1.5 below.
Figure 1.5. Comparison of the size of sand, silt and clay
Classification of the size, number and surface area fractions of land according to the USDA system and the International System are listed in Table 1.1 below.
Table 1.1. Classification fractions of land according to the USDA and the International System
Table 1.1 shows that the smaller the particle size means more numerous and more surface area per unit weight of the soil. It also shows the increasing density of particles per unit volume of soil.
This means that the more finely ground particle size, the more the size of the micropores formed and vice versa if the particle size the greater the soil. Land predominantly of sand will have a lot of macro pores are larger, while the soil is dominated by the dust will have a lot of medium-sized pores (somewhat porous), and predominantly clay soil will have a lot of micro pores or porous.
It is inversely proportional to the surface area that is formed. The surface area reflects the cross-sectional area that can come into contact with water, energy or other materials, so the more dominant sand fraction would be vanishingly small holding capacity of the soil is the third material, and conversely, if it is dominated by clay, the surface area will increase. Based on the above, then:
1. The more porous soil, the roots will be more easy to get into the soil, as well as the more easily water and air to circulate (good drainage and aeration). Water and air are widely available for the plants, but the easier it is for the water lost from the soil, and vice versa.
2. The less porous soil would be more difficult to root into the soil, as well as the increasingly difficult water and air to circulate (drainage and poor aeration), air and water less available, but the water is not easily lost from the soil.
Good soil is characterized by the arrangement of the ideal of both conditions, so in general-textured soils dust and clay will have the availability of water, air and nutrients optimum for plants, but in terms of nutrients, soil texture clay better than textured soil dust.