Sub- theme - II FUNCTIONS OF LAND

Sub theme: II

FUNCTIONS OF LAND

The only compensation for land is land.
-Winona LaDuke,

Land resources representing largely the soil and water phases contribute significantly to the development and sustenance of various living components in terms of flora and fauna. It is our basic resource alongside air and water. It is one of the marvellous products of nature without which there would be no life. It is a productive economic factor in agriculture, forestry, grazing, fishing, mining and various other industrial and social activities. Land systems function through general capabilities of soils that are important for various agricultural, environmental, nature protection, landscape architecture and urban applications.

Soil performs multiple functions starting from providing physical, chemical and biological support for plant growth. It provides habitat for variety of flora and fauna including human. Lives. It acts as natural filter and buffered media against abrupt changes occurring in it. It also acts as a sink of organic carbon and thus global CO2 flux. It is the platform for manmade structure and perpetuates cultural heritage

The upper thin layer of land surface in the form of thin creamy layer of birthday cake is the most favourable medium for plant growth. Plant anchors and draws nutrients and water from this layer. Soil in this layer performs a number of ecosystem services like storage, decomposition, transformation, and detoxification and thereby provides right soil condition for crop/plant growth. Numbers of biogeochemical cycles like carbon, nitrogen, phosphorus and sulfur cycles are being operated and nutrients are being released for plant and soil organisms and thus biomass production are sustained in the earth.

Drivers, behind the lifeline activities maintaining soil fertility and ecosystem stability, are the frontier soil organisms. It is hard to believe that a single teaspoonful of soil contains over 4 billion micro-organisms, which is more than half of the planet’s entire human population!! Can you even begin to imagine how many you would find in a garden, or even your nearest park? Soil is populated by an amazing variety of living creatures, ranging from tiny microbes such as bacteria and fungi to smaller insects such as centipedes, termites, ants, mites and other animals such as worms and larger animals such as moles and rabbits. Many of these organisms have very important functions. For example, certain microbes can break down
resistant organic matter such as lignin, or chemicals such as toxins and pesticides. Others perform a similar process on minerals, thereby releasing nutrients for the plant. Wide rages of soil micro-organisms are responsible for much of the decomposition of organic material in soils. They are usually present in top soils in very large numbers and play an important role in converting more inert forms of nitrogen to ones that can more readily be taken up by plants. Earthworms are another vital species, because they help in the decomposition of organic matter in the soil, as well as improving vital functions such as aeration, water infiltration, and drainage. In fertile soils they can number 2 million per hectare or more!

Soil is the hot-spot of biodiversity. Beneath feet they construct a wonderful world, called “Black Box” by soil ecologist. Each community of this world is working honestly for correcting the soil condition and making soil live so that above ground plant growth is ensured and thus biodiversity is maintained. Thus, belowground diversity influences the nature and makeup of above ground diversity.



Land acts as a reservoir of rich gene pool. But it is amazing to know that till date only 1-10% of total soil microorganisms can be isolated and characterized. So, there is a tremendous potentiality to explore and exploit rest of unknown soil residents for the benefit of human community.

Another amazing feature of soil is the way it acts as a 'filter' against many forms of harmful substances (pollutants).Research by soil scientists has shown that soil can have a major role in the transport of pollutants. Water in soil can transport substances such as nitrate, phosphorus and pesticides to water sources such as rivers, and whilst they are important to soil and plant life, these materials are generally considered harmful to humans and wildlife when they exceed certain quantities. However, land can also modify the impact of pollutants. For example, in wet conditions in the soil nitrate is converted into nitrogen gas, where it can be safely released into the atmosphere. Similarly, pesticides can be broken down into harmless substances by certain micro-organisms present in the soil. Phosphates are mostly filtered naturally during drainage of water as they become tied to soil particles, and are trapped in the soil. Soil is also effective at filtering ‘urban’ pollutants like oil and metals. Oil in particular is an organic substance which soil microbes can break down into carbon dioxide and water. Metals such as lead from petrol however cannot be broken down in such a manner, but the soil can often retain them until they can be absorbed into plants, which can then be disposed of safely. This filtering and buffering capacity of soil also help to sustain the quality of ground water at safe level. Porous soils with good vegetation encourage percolation of surface water, received through rainfall, irrigation or effluent discharge, clean it through filtration and add to good quality ground water. It needs to be emphasized that without this filtering activity of the soil, the quality of ground water might have been deteriorated to such a level that it would have become unsuitable for human population.

It is also one of the biggest reservoirs of organic carbon. Organic matter applied to cultivated land or dumped in low land for land filling is decomposed by soil microorganisms. During their course of decomposition process a portion of organic matter is converted into relatively hardy carbonaceous material resistant to microbial breakdown. Thus, carbon is buried and conserved for longer period. Thereby, CO2 emission potentiality from that organic matter can be reduced and thus, environment is protected from GHG.

Soils provides a platform for manmade structures like buildings, road, highways, mall, multiplex etc.. It is the platform for civil and engineering works. Soil itself is a raw material for many small-scale industries like pottery, terracotta, tiles, brick etc. However, in many cases we are wasting much of our valuable land resources for various industrial uses. Time has come to assess the magnitude of damage we are causing our land resources through such activities and to find the alternative uses or remedies.