Soil is the most valuable abiotic factor in an ecosystem because everything that lives on land depends directly or indirectly on soil. Soil is a mixture of rock particles, minerals, decayed organic materials, air, and water. Therefore, for agricultural purposes soil plays an important role. Soils can be basic or acidic and usually measure 4 – 10 on the pH scale. Regardless of the nutrients present in the soil, if the pH is not suitable those nutrients will be inaccessible to the organisms.
Human beings are dependent upon water for survival, not only for drinking but for agriculture and industry as well. Earth is 71% water with 3% freshwater. Since much of the freshwater is in the form of ice, very little is left as “usable” freshwater for humans. Without water, we cannot live. So water is important for crop cultivation as well as for human beings.
Sunlight, or solar energy, is considered a renewable resource because it will continue to be available for billions of years. It provides a source of energy for all processes on Earth. Light is used by the plants to prepare their own food. Without light no one can live even human beings. So for the better cultivation of crops and their growth sunlight plays an inevitable role.