This directorate deals with the upper layer of earth in which plants grow, a black or dark brown material typically consisting of a mixture of organic remains, clay, and rock particles. Soil is a material composed of five ingredients — minerals, soil organic matter, living organisms, gas, and water.
1) Department of Minerals for Environmental Sustainability
This department deals with minerals. A mineral is a naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties.
2) Department of Soil Organic Matter for Environmental Sustainability
This department focuses on soil organic matter. This is the fraction of the soil that consists of plant or animal tissue in various stages of breakdown or decomposition. Most of our productive agricultural soils have between 3 and 6% organic matter. Soil organic matter contributes to soil productivity in many different ways.
3) Department of Living Organisms in the soil for Environmental Sustainability
This department deals with living organisms in the soil. Plants, animals, and micro-organisms (fungi and bacteria) all affect soil formation by producing or contributing to humus production. They increase the fertility of the soil and also help in maintaining the structure and aeration of the soil.
4) Department of Gas in the Soil for Environmental Sustainability
This department deals with soil gases. These are the gases found in the air space between soil components. The spaces between the solid soil particles, if they do not contain water, are filled with air. The primary soil gases are nitrogen, carbon dioxide and oxygen.
5) Department of Soil Water for Environmental Sustainability
This department deals with soil water. Water supply through soils is vital for both plants and soil organisms—they need water to survive. Soil water contains nutrients that move into the plant roots when plants take in water. Water enters the soil through large pores (macropores) and is stored in many small pores (micropores).
Soil water is the medium from which all plant nutrients are assimilated by plants. Soil water, sometimes referred to as the soil solution, contains dissolved organic and inorganic substances and transports dissolved nutrients, such as nitrogen, phosphorus, potassium, and calcium, to the plant roots for absorption.