How soil is important for
our plant growth
Soil provides plants with foothold for their roots and holds the necessary nutrients for plants to grow
Soil is the uppermost, fertile layer of the earth. It is one of the natural resources present on the earth. It is formed by the physical, substance, genetic, and organic changes that take place constantly in the layers of the earth, by the external forces like water, wind, glacier, ocean waves, etc., the weathered rock can be of different size. The numbers of factors contribute a lot to the formation of the soil.
Climate has a significant role in influencing the decomposition of the different rocks to a great extent. The quality and amount of moisture and dryness in the soil depend upon the climate. The soil-forming processes take place differently in varying climatic conditions. It took place more rapidly in the summer and rainy reason. The classification and patterns of soils also depend on the climate.
The nature of weathered particles is responsible for the formation of soil. The particles may be obtained from the weathering of rocks or depositing of material by river, winds, glaciers, etc. The physical and chemical compositions of soil particles determine the relative proportions of different minerals in the layers.
The topography of a region affects the formation of soil. Steep slopes in the mountainous areas have thin soil layers. It’s due to the erosion and the state of moisture in the different layers. In areas of bad drainage and rigid topography, the soil is not well developed.
Time is an important factor in soil formation. Rich and fertile soil is formed only when the weathered particles of rocks remain uninterrupted in the same place for a long time.
It is only the longevity of time that the action of physical, chemical, and organic processes takes place. It leads to the formation of deep and well- developed layers of soil. If time is not sufficient, the soils will remain undeveloped and skinny.
Each type of soil has a well-developed vertical section called the soil profile. There are four distinct layers in the soil profile.
The top layer is the biological layer and consists of fine particles and natural matter from decayed plants and animals. It is about 1-2 inches thick. Living things carry on with their life activities in this layer. Therefore, it is called humus.
The second layer is the horizon A. This layer has bacteria, which helps in the recycling of different material, and has plant’s roots, fungus, etc.
The next layer is called horizon B, containing materials obtained from the top layer by the seepage of water from the surface. It has a few symptoms of life. Below the subsoil, there are the layer rocks and pebbles, of partly weathered rocks. In some areas, it contains water, depending on the water table.
Almost all garden soils can be improved by adding organic matter to make the soil more workable. Organic matter:
- Loosens tight clay
- Helps sand hold more water
- Makes soil easier to dig
- Add nutrients
Some common organic matter additives are:
- Plant materials: This includes leaves, straw, and grass clippings. Work material into the soil several months before planting to allow it time to decompose. Most gardeners do this during the winter.
- Manure: Use composted manure and incorporate it into the soil well ahead of planting. Do not use fresh manure, as it can damage plants and introduce diseases. Apply 30 to 40 pounds of composted manure for every 100 square feet.
- Compost: Compost consists of decayed plant materials. Work it into the soil before planting.
- Sawdust: Compost this before adding it to the garden. Do not use uncomposted sawdust because it will rob the soil of nitrogen and, consequently, starve the plants of this essential nutrient.
- Green manure: Plant rye or oats in the fall and plow or spade it under in the spring. These cannot be used if a fall garden is planted.
Source: Soil profile from wikipedia.org
Functions of soil
The most immediately apparent function of soil is a medium to support plant life. It provides support both physical and biologically. Physical support is provided by allowing the plant to grow its roots through the soil to hold itself. Biological support is provided by its ability to hold nutrients and water that the plant needs. It supports other types of life, as well. Microorganisms and insects live in the soil, and they, in turn, aid plant life by helping to decay organic material and adding structure to the soil. Soil allows the growth of food crops consumed by humans and plants used in the creation of medicines. Microorganisms like fungi and bacteria that live in soil and are used to produce antibiotics. All life on earth is dependent on it either directly or indirectly. This includes plant life in your garden.
What is soil made of?
The four major components of soil are mineral matter, organic matter (humus), water, and air. Mineral matter refers to the inorganic elements in the soil e.g., stones, gravel, and makes up to 40%-60% of its volume. This part of the soil usually originates from the bedrock that lies beneath the soil. Organic matter (humus) is the decayed remains and waste products of plants and animals and has a great effect on the chemical properties of the soil e.g., availability of nutrients. Almost 40%-60% of a soil’s volume can be space, and this is occupied by water and air.
Different types of soil texture
Soil texture is defined as the size distribution of different mineral particles. These mineral particles are at their most basic level the following: sand, silt, and clay. Sand particles are 2 to 0.05 mm diameter; silt particles are 0.05 to 0.002 mm diameter, and clay particles are less than 0.002mm.
Clay soil contains a high percentage of clay particles and feels lumpy to the touch. The small size of the clay particles means that they clump together quite readily, and there is less room for air spaces. Consequently, clay soils have poor drainage and do not hold nutrients very well. This is heavy soil and is sticky when wet making it hard to work with. As much as possible, you should take steps to improve the drainage of this type of soil.
- Silty soil
Contains a high percentage of silt particles and feels smooth to the tough. This soil is a well-drained soil due to the size of the particles allowing space for water from permeating. This soil holds nutrients more readily than clay soil due to the spaces. It is easy to cultivate but can be compacted quite easily.
- Sandy soil
Contains a high percentage of sand particles and feels gritty to the touch; it allows for quite a lot of space in between particles and, as a result, is very free draining. However, this has its disadvantages as it does not hold water, and essential nutrients can get washed away.
- Loamy soil
This is the best type of soil texture you can have in your garden. This is soil whose properties are controlled equally by the percentages of clay, silt, and sand particles. It is well-drained but does not loose water too easily, as is the case with sandy and sometimes silty soils. The fact that it retains water means it also retains nutrients for your plants to use. It has a great structure and is easy to cultivate.
How healthy soil affects plants
The benefits of healthy soil in sustaining crop production are evident when growing conditions are less than ideal. Healthy soils increase crops’ capacity to withstand weather variability, including short-term extreme precipitation events and intra-seasonal drought. Increasing highly variable weather conditions present increased ricks to crops and require more careful attention to conversation planning to mitigate impacts on soil health and crop productivity.
Soil health is defined by the level to which it can continually provide multiple functions to sustain plants, animals, and humans’ lives. The complex biological, physical, and chemical interlink of healthy soil can influence plant water availability under dry conditions, off-field nutrient losses to nearby streams during rain events, and the availability of nutrients through nutrient cycling for food and fiber production. Furthermore, healthy soils maintain or enhance water and air quality by improving soil C storage and water infiltration and supporting human health and wildlife habitat.
The benefits of healthy soils in sustaining crop production are most evident when growing conditions are less than ideal. Healthy soils increase the capacity of crops to withstand weather variability and short term extreme precipitation events and intra-seasonal drought.
How healthy soil affects human health
The soil has a profound effect on the health and well-being of humans. Depending upon the condition of the given soil and the interactions of interests, this effect can be either positive or negative and direct or indirect. Soils that affect human health include natural soil, which usually has little anthropogenic contamination, and soils in agroecosystems, urban areas, mines, oil and gas extraction areas, landfill sites and other locations where anthropogenic contamination is more likely. People in professions that work closely with soil, such as farmers, construction workers, or miners, are at a greater risk of health problems that involve direct contact with soil. Still, everyone’s health is affected by soil to some extent. This is because soil provides many of the nutrients we require and can pass on harmful substances through the food that we eat.
What makes a soil healthy?
Healthy soil must be fertile and have a good structure.
For soil to be fertile, it must have nutrients readily available and a PH value at a recommended level for the plants that will reside in it. Nutrients that should be available are the essential nutrients nitrogen (lead growth), phosphorous (root growth), and phosphorous (overall health). As well as the essential nutrients, there should also be trace elements like calcium and magnesium. The soil’s pH level refers to its acidity or alkalinity, and each plant has its preferred value range. Plants placed into fertile soil will grow up to be very strong and healthy specimens (that is, if other conditions like light levels and climate are favorable).
The other determiner of healthy soil is its texture. We learned about different types of soil texture earlier in this article. Soil having a loamy texture is the healthiest, and it should be strived for if at all possible. In general, soil that retains nutrients and allows water and air to permeate it will be beneficial for your plants’ lives.
Testing the pH of the soil
It is important to soil has the proper pH balance. Soil meters such as the Rapitest Digital 3-Way Soil Analyzer allows you to test the soil yourself quickly and accurately. The pH can be elevated by adding lime to the soil, and the pH can be decreased by adding sulfur or peat moss to the soil.
Source: GMM testing pH level in soil for plants using Rapitest Digital 3-Way Soil Analyzer
You can to look up online the appropriate pH value required for your plant to grow healthy. When adding lime to the soil, a general rule of thumb is to use 4 pounds of product per 100 square feet of soil for every point the pH is below 6.5 and uses 1 pound of sulfur per 100 square feet of soil for every point the pH is above 7.5.
Soil, like a lot of things in garden, requires maintenance. We have learned about the different soil textures types, what constitutes a fertile, healthy soil and how to create it if it does not exist. The next step is to step out into your garden, take a look at your soil, and help your plants out if your soil is of poor quality.