Soil is a unique substance that covers most of the land on our planet with a thin layer. In different areas it has different physical and chemical properties and a different biological component. Information about the main properties of soil, the most important physical and chemical parameters will be useful to summer residents, farmers and simply curious readers.
Concept of soil
The main quality of soil, the most important for the Earth, is fertility. This is the ability of the top layer to provide the plant seeds that have fallen into it with resources for growth and development.It depends on several factors and can change under the influence of natural conditions or human economic activity.
Fertility depends on the ratio of mineral and organic substances in the top layer of soil, on the ability to absorb and retain moisture, and absorb oxygen. Over the millennia of its development, man has learned to improve the composition of the earth; the artificial formation of a fertile layer (plowing, the application of organic and mineral fertilizers) has made it possible to provide people with food and made it possible to settle in new areas.
The concepts of soil and soil are different. Mineral substances (sand, clay, rocks) are the basis of the soil on the site. It can be used for construction, road and other types of work. A small percentage of organic matter makes such land unsuitable for cultivation and use in agriculture. Soil is usually called land of any composition, soil - only its fertile part.
The main mineral substance of the soil affects the fertility of the soil; the variability of the composition of the soil on the site is achieved by adding mixtures of sand, peat, and organic matter to it.
Systematic correct application of fertilizers, organization of irrigation, seasonal digging make it possible to make areas where nothing grew fertile, and illiterate use of pesticides, violations in the irrigation system, and desertification of lands due to climate change make the most fertile areas in the past unsuitable for farming.
Mechanical composition
Mineral particles are important components of soil. They can be of different diameters, particles of identical size form a fraction. The predominance of certain particles in soil samples made it possible to develop a classification of soils. There are:
- sandy;
- sandy loam;
- loamy;
- clayey.
Each variety differs in its ability to retain moisture and heat, breathability, and degree of difficulty of cultivation.
Loams and clayey surfaces are the most difficult to process. The mechanical composition of the soil on the site is determined simply - you should moisten the soil sample and roll it into a “sausage”:
- If this cannot be done, the soil on the site is sandy.
- A “sausage” is obtained, but it quickly crumbles - it’s sandstone.
- When you try to roll the resulting flagellum into a ring, the soil crumbles - there is loam.
- The soil produces a “sausage” that can be rolled into a ring without any problems—the soil is clay.
Sandstone and clayey varieties of soil require significant fertilization. Sand heats up and cools down quickly and does not retain moisture well. Clay retains heat and water perfectly. Both types of soil require the addition of large amounts of organic matter and regulated watering.
What physical properties does it have?
There are several important physical characteristics of the soil that determine its fertility.
Duty factor
Porosity, porosity or porosity is the amount of voids between mechanical soil particles and aggregates. These voids are filled with air, water, and plant roots enter them. 40-60% duty cycle is optimal for plants. The indicator is determined in the laboratory.
There are capillary and non-capillary duty cycles.Capillary determines the number of pores filled with water, non-capillary - with air. Porosity is a unique indicator that determines the water and air permeability of the soil. It may vary depending on soil moisture.
Grading
This is the number of mechanical elements in a completely dry soil sample. Classification by particle size distribution depends on the ratio of physical sand and physical clay in the sample.
Density
This is the mass of a unit volume of absolutely dry soil taken in its natural composition. Depends on the mechanical, granulometric composition of the soil, and the amount of organic matter. It decreases immediately after mechanical impact on the ground (digging, harrowing, loosening), after some time it acquires static values. Optimal values are from 0.8 to 1.
Humidity
This indicator determines the percentage of water relative to the mass of dry soil. Since waterlogging of the soil leads to the death of crops, this indicator is very important; the recommended humidity for vegetables is 60-70%, forage grasses - 70-80%, cereals - up to 85%.
Hardness
The value shows the soil’s ability to compress and wedge (resistance to penetration of mechanical tools into the soil). Measured with a hardness meter, it affects seed germination, water, air and thermal conditions during cultivation of the site, and resistance during machine processing.
Stickiness
Determines the ability of soil particles to stick to each other and machine parts during processing. Affects the quality of land cultivation, the productivity of agricultural machines and working personnel.
Of course, when purchasing a summer cottage, one is usually limited to a visual inspection and the characteristics of the soil on the territory of the gardening partnership.The acquisition of large areas for lease or ownership is not complete without ordering a soil science examination, which takes into account the physical, chemical and biological parameters of the soil.
