Land Resources

Land Resources

Intended Learning Outcomes

At the end of this session, students will be able to

• Explain land as a resource

• Discuss land degradation

• Describe man-induced land-slides

• Explain soil erosion and desertification

Contents

• Land as a resource

• Land degradation

• Man-induced land-slides

• Soil erosion and desertification

Land as a resource

• Landforms such as hills, valleys, plains, river basins and wetlands include different resource generating areas that the people living in them depend on

• Many traditional farming societies had ways of preserving areas from which they used resources

• If land is utilized carefully it can be considered a renewable resource

• The roots of trees and grasses bind the soil

• If forests are depleted, or grasslands overgrazed, the land becomes unproductive and wasteland is formed

• Intensive irrigation leads to water logging and salination, on which crops cannot grow

• Land is also converted into a non-renewable resource when highly toxic industrial and nuclear wastes are dumped on it

• Land on earth is as finite as any of our other natural resources

• Man needs land for building homes, cultivating food, maintaining pastures for domestic animals, developing industries to provide goods and supporting the industry by creating towns and cities

• Equally importantly, man needs to protect wilderness area in forests, grasslands, wetlands, mountains, coasts, etc. to protect our vitally valuable biodiversity

Land Degradation

• Farmland is under threat due to more and more intense utilisation

• Every year, between 5 to 7 million hectares of land worldwide is added to the existing degraded farmland

• When soil is used more intensively by farming, it is eroded more rapidly by wind and rain

• Over irrigating farmland leads to salinisation, as evaporation of water brings the salts to the surface of the soil on which crops cannot grow

• Over irrigation also creates water logging of the topsoil so that crop roots are affected and the crop deteriorates

• Use of more and more chemical fertilizers poisons the soil so that eventually the land becomes unproductive

• As urban centers grow and industrial expansion occurs, the agricultural land and forests shrink

• This is a serious loss and has long term ill effects on human civilisation

Soil erosion:

• Characteristics of natural ecosystems such as forests and grasslands depend on the type of soil

• Soils of various types support a wide variety of crops

• The misuse of an ecosystem leads to loss of valuable soil through erosion by the monsoon rains and, to a smaller extent, by wind

• The roots of the trees in the forest hold the soil, Deforestation thus leads to rapid soil erosion

• Soil is washed into streams and is transported into rivers and finally lost to the sea

• The process is more evident in areas where deforestation has led to erosion on steep hill slopes as in the Himalayas and in the Western Ghats

• These areas are called ‘ecologically sensitive areas’ or ESAs

• To prevent the loss of millions of tons of valuable soil every year, it is essential to preserve what remains of our natural forest cover

• It is equally important to reforest denuded areas

• The linkage between the existence of forests and the presence of soil is greater than the forest’s physical soil binding function alone

• The soil is enriched by the leaf litter of the forest

• This detritus is broken down by soil micro-organisms, fungi, worms and insects, which help to recycle nutrients in the system

• Further losses of our soil wealth will impoverish our country and reduce its capacity to grow enough food in future

Summary

• If land is utilized carefully it can be considered a renewable resource

• Land is also converted into a non-renewable resource when highly toxic industrial and nuclear wastes are dumped on it

• To prevent the loss of millions of tons of valuable soil every year, it is essential to preserve what remains of our natural forest cover

• Further losses of our soil wealth will impoverish our country and reduce its capacity to grow enough food in future