The outermost and uppermost level of soil found in the top inches within a range of 5 to 10 inches is known as Topsoil. The uppermost layer of soil contains the maximum concentration or potentiality of microorganisms and organic matter along with the most rate of biological soil action. The topsoil constitutes of air, water, mineral particles, and organic matter. The concentration of topsoil varies with the aspect of the number of different forms of soils. Existing organic content in the soil decreases the soil’s strength and structure as it stimulates a weaker capacity of the soil. The organic content in the soil settles in and condenses in various ways in specific conditions like foundation and roadbeds.
Drained water directly impacts the soil structure. This phenomenon also decreases the volume of the soil. The topsoil also suffers due to wind erosion. The outcome of the decomposition of leaves, stems, and roots of plants is the organic matter in the topsoil. The constituents that prepare the topsoil are microbes, creatures like beetles, insects, and worms as well as nitrogen and carbon content. The topsoil determines the fertility of the soil by involving the presence of phosphorous, iron and potassium.
The nature of the topsoil differs with the changing climatic conditions and the geographical area along with the effects of human activities. The topmost layer, topsoil consists of the content of nutrients, organic matter formed through the phenomenon of slow weathering process of the rocks as well as from decaying of the organic matter in a period of thousand years. The quality and nutrient content in the topsoil cannot be guaranteed in every region due to the incidences like stripping off the upper layer of contamination. The presence of topsoil can be witnessed in the form of three purposes including, premium, general-purpose and economy, dependent on the rate of organic and nutrient content in the soil.
The categorization of topsoil can be witnessed in various forms depending on the particle size, usage, application, and purposes. The main two forms of topsoil are unscreened and screened soil. Screened soil of the topsoil is passed through a number of processes and filtration, which ultimately allows the right consistency and full potentiality of the topsoil. For the commercial and personal use, the screened soil is assessed and filtered based on the demand of the customers and leading towards the sizes and consistency of the soil, which may vary between 5/8 inches to 3/4 inches. Similar consistency is the key for identifying the screened topsoil and this consistency enables the efficiency in the water flow with significant nutrients for the purpose of healthy vegetation and gardening. On the other hand, unscreened topsoil eliminates the filtration and assessment process. The unscreened topsoil reflects a rough, uneven and coarse consistency and lacks the quality as screened soil.
The identification of topsoil is categorized by particle sizes. Topsoil is considered to be the uppermost layer of the soil surface, which is usually found in the uppermost layer ranging between 5 to 10 inches. Topsoil has the highest rate of organic matter concentration with the presence of microorganisms. The main constituents of topsoil are organic matter, air, water and mineral particles. Topsoil is also called by the term A Horizon. Topsoil can be identified by the darkest layer due to the maximum percentage of the organic matter content. The topmost layer, the topsoil witnesses the most amount of biological activities including the community of worms, insects, animals and stretching roots of plans. The roots of the plants support the holding up of soil. Smallest particles of the soil like clay usually get seeped in by the water moving down the layers. The soil structure of the topsoil can be categorized based on particle sizes such as clay soil, sandy soil, and silty soil. Clay soils are considered fertile, however, they are prone to high water content or logging. On the other hand, sandy soils demonstrate nature, which enables wash away of nutrients due to the smaller particles. Silty soil or silt has the size of the soil particles in between the clay and sand. Silty soil is usually found in the water suspended form or with sediment as well as found in the river bodies.
According to the farmers, the most significant layer of soil is the uppermost layer, topsoil. Although the top layer is considered the most crucial layer for the environment at the same time, it is considered for its vulnerability. The functionalities of the topsoil are as follows:
The statistics of 2014 reflected that the current arable land present for a single person is around is 0.19536 ha. By the year 2050, the total area estimated to be allotted or present per person will become 0.15 ha, which indicates the alarming situation of saving the topsoil.
The topsoil in various regions of the Earth has been the prey of disc plow for the purpose of grinding the soil with harsh pressure as well as the topmost layer has also witnessed the effects of mouldboard plough. These activities result in the bare state of soil without the presence of any cover. Bare soil can lead to the state of vulnerability and proneness to various harmful conditions like:
The soil cover for the topsoil should be focused on creating a protective layer that answers the problems of runoff and degradation as well as aims at increasing the nutrient content and organic matter concentration in the topsoil, thereby ultimately contributing to the quality of the soil. Organic content in the soil can enhance and build the quality of the soil. It can contribute to the process of preventing runoff, erosion and surface sealing. It improves the process of water infiltration; it helps in offering energy for the microorganisms under the soil, offers value in the form of glue in binding the particles of soil. The technique of soil cover also contributes to improving the condition of soil aeration as well as presents a slow-release store-house for nutrients. This strategy also helps in improving the capacity to hold water from the soil.
Topsoil can be considered very crucial for vegetation and agriculture as it is the source of offering nutrients to the plants and crops. The reason for the importance of the topsoil is the functioning of biological nutrients cycling, offers nitrogen and carbon for the growing crops. The nutrient cycle is the process, which utilizes the existent nutrients from the environment and involves the stage of recycling over the base of the topsoil. The nutrient cycle does not only concentrate on the non-living constituents but also helps with the living organisms.
A home for a wide range of microbe communities, which is involved in the process of nutrient cycling, topsoil is crucial for maintaining the food cycle of the environment. The effective nutrient cycle can ensure the decreasing rate of diseases and contamination in the topmost layer. A well-established nutrient cycle helps in ensuring the lower dependence on the inclusion of pesticide and herbicide and thereby leading to the result of healthy crops. The uses of topsoil can be limitless as it is the topmost, most accessible and organically rich layer of soil. The benefits of topsoil range from the feature of covering the ground to becoming a base for the plants. Topsoil helps in constructing a base and borders for the seeds and plants. Being the top layer of the surface of the earth, it tends to hold the nutrient content and organic matter as serves as land for plants and vegetation. Topsoil can be bought for personal and commercial purposes for agricultural activities and/or for gardening. Topsoil sold the market in bulk is often termed as black dirt.