Introduction

The lithosphere is the 70-100 km thick topmost layer of the earth. The lithosphere consists of plates (major and minor) which are moving relative to each other at a very slow rate (2-5 cm/ year) over the aesthonosphere which extends up to a depth of 700km. The surface of the lithosphere is called land. Land, in a broader sense, encompasses all the natural materials present on the earth’s surface composed of rocks and soil. Rock is the natural aggregate of minerals. Variation of rock is due to the different mineralogical combinations. Rocks are of three types: Igneous (formed by solidification of magma i.e. granite, basalt etc); Sedimentary (formed by consolidation of materials carried out by wind, river, glacier etc. e.g. sad stone, lime stone etc) and Metamorphic (formed by transformation of igneous and sedimentary rocks, e.g. gneiss, marble, slate etc.). Physical, chemical and biological processes, by their constant interaction with the different rock types, produce the thin outer skinny layer called soil which contains living and non – living materials. Plants are grown well in the soil containing rich macro and micro (trace elements) nutrients. Macro-nutrients include nitrogen (N), phosphorous (P), potassium (K), calcium (Ca), magnesium (Mg) and sulphur (S). Trace elements include, iron (Fe), manganese (Mn), copper (Cu) and zinc (Zn). Healthy soil is a combination of minerals, rock, water, air, organic matter (plant and animal residue), microorganisms, including bacteria, fungi and protozoa and a variety of insects and worms. This intricate web carries out a process that continually replenishes the soil and maintains long-term soil fertility. A healthy soil should have the mechanism of supplying the nutrients produced by natural weathering processes as well as mediated by organisms to the plants perennially for sustainability. For optimum plant growth, soil must be capable of storing these nutrients and transferring them to the root surface for uptake by plants.

Soil is one of our most precious natural resources, as it integrates all parts of the ecosystem and provides a medium for plant growth, filters water, decomposes waste, stores heat, and exchanges gases. Soil is alive; it is the home to billions of micro- and macroscopic organisms. It is a material used for construction, medicine, and art. It produces a snapshot of the geologic, climatic, biological, and human history at the place that they are found. Unfortunately, there is a limited amount of soil that can actually be used for growing food, and all of the other uses that we require it for. When improperly managed, soil can become eroded, polluted, or destroyed. It can also cause damage to other parts of the ecosystem.

To understand the nature of soil, one has to have knowledge on rocks and their mineral composition. Generally, mineral content of soil is referred to as the elements that are responsible for growth of plants. In fact, rocks are made of minerals (structured atomic arrangement of elements in a crystal form) that in turn disintegrate into different soil components that are easily taken by the plants and used for their better growth. The mobility of nutrients from rock to soil is decided by the geological processes that initiate weathering. To understand the mobility and distribution of micro and macronutrients (calcium, potassium, sodium, nickel, zinc) in the soil system will certainly lead us to manage agricultural practices. The soil system is affected by influences of man intervention as well as natural processes. The removal of topsoil by cutting down the forests and banned agricultural practices would force us to live in environmentally adverse conditions. The environmental degradation of both soil and land makes our planet stressful and initiate us to think over sustainable development. As our interference with natural processes cause many situations unfit for our well being and also for the well being of future generations in stake. In this context we have to look for alternative solutions for enrichment and sustainability of soil as resource mine and in order to sustain for long new management methods are to be adopted.

Collecting data on the past and present land use practices would help us to predict the future pattern of change, which would throw light on our sustainable development. There are diseases caused by the excess presence of certain toxic elements such as fluoride, arsenic and selenium in the biological system introduced through rocks to water and to soil. A Systematic documenting of temporal and spatial distribution of diseases provides a better database for identifying the root cause for their respective diseases.