Project 4: How does organic component influence different Soil Properties?
Organic material is very important to agriculture. Farmers and gardeners use it to increase the nutrients in their soil. Organic matter retain higher amount of water and in turn supply it to the plants on which they grow. Moreover organic matter may influence various soil properties like soil color, pH, organic-carbon content etc. So by studying soils containing different level of inherent organic material in your soil will provide a relative idea of water availability, soil colour,organic-carbon content, soil pH etc. Organic material also supply nutrients into soil and plants can take both water and nutrient from soil. This assist better plant growth.
Objectives:
1. To study variation of organic matter content of soils under different land use
2. To determine the water retention capacity of soils under different land use
3. To determine the colour, pH, organic-carbon content of soils under different land use
Materials Required:
Spade/ Khurpi, Colour chart, Wash bottle, Sieve set, Sample collection bags, Paper Tags/label
Soil test kit for Organic Carbon, Perforated container
Methodology:
1. Prepare a land use map of your locality
2. Collect representative surface (0-15 cm) soil sample from each land type and land use (for example, forest land, grass land, barren land, steep land, soil under agricultural crops, orchards, etc.). Air dry the samples, grind and pass through 2mm sieve for studying the following parameters.
Water holding capacity
1. Take 500g soil sample in perforated containers. Add the soil slowly followed by tapping so that soil of the container comes to natural compaction.
2. Place a plant saucer under each container to collect the leachate.
3. Pour measured volume of water from a measuring cylinder to each container and record the volume of water needed to completely saturate the column. Add approximately 100ml of water additionally to form a thin film of water over the soils of the container.
4. Wait for 12 hours
5. Measure the volume of water collected in the saucer,then substract this from total quantity of water added.
6. Repeat the experiment thrice for soils of each land type/use
Observations:
Mean value
WHC
Soil Colour
Soil pH
Organic Carbon
Soil Colour
Take table-spoon of soil and place into individual petri-dishes, or any similar glass or plastic containers. Be sure to label each dish appropriately. Now compare the colour of the soil with the Munshell colour chart (may be collected from Soil/Agriculture department) and note their dominant colours (red, brown, grey, yellow, yellowish red etc.). Moist the soil with few drops of water and record the moist colour also. Repeat the experiment thrice for soils of each land type/use.
Soil pH
Take tablespoon of soil and place into individual petri-dishes, or any similar glass or plastic containers. Be sure to label each dish properly. Wet each soil sample with 2 tablespoons of distilled water. Allow to sit for 3 to 5 minutes. Place one piece of pH paper on each soil sample. (Use pH paper with a range from at least 5-10). Determine the approximate pH or acid/base level of your soil. Repeat the experiment thrice for soils of each land type/use.
Soil Oxidizable Organic-Carbon (KIT METHOD)
Take 1 gram of soil in test tube. Add 2 ml of organic carbon reagent I ( 1N K2Cr2O7 ) and 2 ml of organic carbon reagent II ( conc. sulphuric acid) in the test tube. After 15 minutes stay determine the approximate Organic Carbon content of the soil under experiment from the colour chart matching. Repeat the experiment thrice for soils of each land type/use.
Colour Oxidizable organic Carbon,(%) Soil Quality
Dark green >0.75 High
Red 0.50 – 0.75 Medium
Orange < 0.50 Low
Results:
Water drained from the soil was measured exactly 12 hours after the water was initially added.
Then draw inference of the experiment
Relevance:
The study will throw light on the variation of water retention capacity, colour, pH,organic carbon content of soils under different land type and land use and gives an idea of importance of organic matter in controlling the availability of water, regulation of temperature due to colour, soil pH & organic carbon content thus nutrient availability for plant growth.
Suggested Additional Activities
1. Knowing water holding capacity of soil of the locality
2. Know your land – soil, water and land-scape relationship
3. Study of soil profile under different land use
4. Fluctuation of water tables in any season of the year of the locality/region
5. Distribution & quantification of water bodies for water use planning
6. Delineation and characterization of local watershed based on topography, drainage network and local knowledge
7. Distribution and mapping of important minerals of the region
Members:
Prof. S.S. Sahu, Prof. M.C. Talukdar, Dr. K. Das, Dr. M. De Roy, Mr. A. Chanak
தே.கு.அ.மாநாடு 2010
NCSC 2010 - Tamil Nadu
2. Sub- theme - I KNOW YOUR LAND லேபிளுடன் இடுகைகளைக் காண்பிக்கிறது. அனைத்து இடுகைகளையும் காண்பி
2. Sub- theme - I KNOW YOUR LAND லேபிளுடன் இடுகைகளைக் காண்பிக்கிறது. அனைத்து இடுகைகளையும் காண்பி
வெள்ளி, 18 ஜூன், 2010
Project 3: Know the vertical distribution of soil layers of your locality
Project 3: Know the vertical distribution of soil layers of your locality
Soils develop over long periods of geologic time and are an important part of the natural environment. Soil is formed by the weathering of rocks, the action of water, wind or ice which carries earth materials and by the living and once-living things (organic matter) that are found in it. As time goes on, soils become deeper and develop distinct layers or horizons. A soil profile is a vertical cross-section of the soil and is usually taken to a depth of a meter. Scientists use soil profiles to decide likely uses for soil in an area. The layers or horizons in the soil profile which vary in thickness have different morphological characteristics which includes colour texture, structure, etc. the horizons are generally designated as O, A, E, B, C and R.
Materials Required:
Spade, Pickaxe, Dagger/knife, Measuring tape, Colour chart, Wash bottle, Sieve set, Sample collection bags, Paper Tags/label, 10% Hydrochloric Acid (HCl) solution, Magnifying lens, Agar agar solution.
Methodology:
Measure 1 square foot (0.9 square meters) of ground within the forested plot/ cultivated land/school ground (Corners can be marked with sticks.) Try to choose a site that closely represents the overall projected plot. For example, if your forest plot is mostly wet and covered with ferns, don’t choose a spot that is dry and has no ground cover. Then dig a soil pit of 5 ft x 4ft x 5ft (dimension) taking care to keep the excavated soils on the two sides avoiding the east and west directions. Enter the pit and study the soil vertically. Demarcate the soil layers (if possible the layers may be separated based on differences in morphological properties viz., colour, texture, structure, nature and presence of roots, acid effervescence, etc.). Record physical/morphological properties of different layers standing in the soil pit through visual observation. Collect bulk soil samples (about 500g) from different soil layers starting from the top. Samples are collected in plastic bags and are taken to the school laboratory for air drying, grinding and sieving and stored in labeled bags for further analysis.
Observation:
Observations may be recorded in a tabular form .
Other soil properties -
Soil moisture: Determine moisture content level from soils at different depth from freshly collected samples. By feeling the soil, you can tell whether the soil is dry, good moisture or saturated soils. The depth of organic matter is an important factor influencing soil moisture. Measure how far the organic matter extends into the soil.
Soil Texture: Characterize soil texture in each soil layer depth as loam, sand, or clay. Use the “Soil Analysis Chart” as a reference.
Examine the soil for other characteristics such as color, smell, and the presence of glacial till and erratic.
Soil Microorganisms
Detect microorganisms in the soil by mixing a teaspoon of soil in 500 ml of water, then
put 0.5 ml (about 12 drops) of this diluted mixture on agar in a petri-dish. Place the petri-dishes in a dark place to incubate at room temperature. After one week, record the number and type of colonies that form on the agar. Compare microorganisms in samples taken at 3 inches (7.5 cm), 6 inches (15 cm), and 1 foot (30 cm) depths of soil profile.
Soil pH
Take tablespoon of soil from each depth and place into individual petri-dishes, or any similar glass or plastic containers. Be sure to label each dish appropriately. Wet each soil sample with 2 table spoon of distilled water. Allow to sit for 3 to 5 minutes. Place one piece of pH paper on each soil sample. (Use pH paper with a range from at least 5-10.) Determine the approximate pH or acid/base level of your soil.
Soil Colour
Take tablespoon of soil from each depth and place into individual petri-dishes, or any similar glass or plastic containers. Be sure to label each dish appropriately. Now compare the colour of the soil with the Munshell colour chart (may be collected from Soil/Agriculture department) and note their dominant colours (red, brown, grey, yellow, yellowish red etc.).Moisten the soil with few drops of water and record the moist colour also.
Relevance:
The study of soil profile under natural conditions in three dimensions would help students to understand the processes of soil formation under a set of climatic and topographic conditions and depth-wise variation of soil properties.
Soils develop over long periods of geologic time and are an important part of the natural environment. Soil is formed by the weathering of rocks, the action of water, wind or ice which carries earth materials and by the living and once-living things (organic matter) that are found in it. As time goes on, soils become deeper and develop distinct layers or horizons. A soil profile is a vertical cross-section of the soil and is usually taken to a depth of a meter. Scientists use soil profiles to decide likely uses for soil in an area. The layers or horizons in the soil profile which vary in thickness have different morphological characteristics which includes colour texture, structure, etc. the horizons are generally designated as O, A, E, B, C and R.
Materials Required:
Spade, Pickaxe, Dagger/knife, Measuring tape, Colour chart, Wash bottle, Sieve set, Sample collection bags, Paper Tags/label, 10% Hydrochloric Acid (HCl) solution, Magnifying lens, Agar agar solution.
Methodology:
Measure 1 square foot (0.9 square meters) of ground within the forested plot/ cultivated land/school ground (Corners can be marked with sticks.) Try to choose a site that closely represents the overall projected plot. For example, if your forest plot is mostly wet and covered with ferns, don’t choose a spot that is dry and has no ground cover. Then dig a soil pit of 5 ft x 4ft x 5ft (dimension) taking care to keep the excavated soils on the two sides avoiding the east and west directions. Enter the pit and study the soil vertically. Demarcate the soil layers (if possible the layers may be separated based on differences in morphological properties viz., colour, texture, structure, nature and presence of roots, acid effervescence, etc.). Record physical/morphological properties of different layers standing in the soil pit through visual observation. Collect bulk soil samples (about 500g) from different soil layers starting from the top. Samples are collected in plastic bags and are taken to the school laboratory for air drying, grinding and sieving and stored in labeled bags for further analysis.
Observation:
Observations may be recorded in a tabular form .
Other soil properties -
Soil moisture: Determine moisture content level from soils at different depth from freshly collected samples. By feeling the soil, you can tell whether the soil is dry, good moisture or saturated soils. The depth of organic matter is an important factor influencing soil moisture. Measure how far the organic matter extends into the soil.
Soil Texture: Characterize soil texture in each soil layer depth as loam, sand, or clay. Use the “Soil Analysis Chart” as a reference.
Examine the soil for other characteristics such as color, smell, and the presence of glacial till and erratic.
Soil Microorganisms
Detect microorganisms in the soil by mixing a teaspoon of soil in 500 ml of water, then
put 0.5 ml (about 12 drops) of this diluted mixture on agar in a petri-dish. Place the petri-dishes in a dark place to incubate at room temperature. After one week, record the number and type of colonies that form on the agar. Compare microorganisms in samples taken at 3 inches (7.5 cm), 6 inches (15 cm), and 1 foot (30 cm) depths of soil profile.
Soil pH
Take tablespoon of soil from each depth and place into individual petri-dishes, or any similar glass or plastic containers. Be sure to label each dish appropriately. Wet each soil sample with 2 table spoon of distilled water. Allow to sit for 3 to 5 minutes. Place one piece of pH paper on each soil sample. (Use pH paper with a range from at least 5-10.) Determine the approximate pH or acid/base level of your soil.
Soil Colour
Take tablespoon of soil from each depth and place into individual petri-dishes, or any similar glass or plastic containers. Be sure to label each dish appropriately. Now compare the colour of the soil with the Munshell colour chart (may be collected from Soil/Agriculture department) and note their dominant colours (red, brown, grey, yellow, yellowish red etc.).Moisten the soil with few drops of water and record the moist colour also.
Relevance:
The study of soil profile under natural conditions in three dimensions would help students to understand the processes of soil formation under a set of climatic and topographic conditions and depth-wise variation of soil properties.
Project 2: Land use pattern analysis
Project 2: Land use pattern analysis
India covers a land area of 3,287,263 sq km. There are different types of land in India about 54.7% of it is cultivated land. The several types of land available in India are: Agricultural Land, Barren Land, Real Estate Land, Commercial Land, Farm Land and Residential Land. Indian people are mainly employed in Agricultural activities thus agricultural land is almost 54.7% of the total Land Mass. The agricultural lands are located on the outskirts of the Metro Cites. Usually the agricultural land shares space with the Industrial areas outside the city. There are Agricultural lands in almost all the States of India. Agriculture resources considered to be one of the most important renewable and dynamic natural resources. Comprehensive, reliable and timely information on land use pattern of an area would focus on its optimal use and development of an area in viewpoint to food security. A close study of the present land use and utilization patterns and land use history will help to suggest suitable land use plan with the farmers’ available knowledge.
Objectives:
1. To study the land use pattern of the project area
2. To study the cropping pattern, cropping intensity in different land types.
3. To suggest alternate land use plan for the locality
Materials Required:
1. Square data sheet for inventory documentation
2. Primary and secondary data sources from Agriculture offices of block, subdivision and district, panchayat, NGOs, farmers’ club etc.
3. Large scale base map of the area
Methodology:
A. To collect data from primary/ secondary sources for the past few years on the following parameters.
1. Total area under study
2. Forests
3. Area put to non agricultural uses
4. Barren and uncultivable land
5. Total cultivated area
6. Area sown more than once
7. Gross cropped area
8. Cropping intensity (percentage)
9. Irrigated area, if available
10. Un-irrigated area
11. Percentage of net irrigated area to net cultivated area
12. Area under cereals, pulses, oilseeds, fibre crops, horticultural crops and others
13. Share of area under different crops.
B. Analyze data for variation of present and past last 10 years) land use
C. Suggestion of optimal land use based on farmers needs
D. Graphical representation of change in parameters with time (years).
Relevance:
The students can get an insight on the changes occurring in the land use patterns over the years due to a host of biotic and abiotic factors viz., climate change, land degradation, human interference, etc. and will help suggest ways for the planners, administrators and the end users to cope with the changing scenario.
Important Terminologies:
Cropping pattern: Sequence of crop (or crops) and fallow of a given area in a year.
Cropping Intensity: The ratio of gross cropped area to net cultivated area which is multiplied by hundred and represented in percentage. It is calculated with the formula as given below.
Cropping intensity = (Gross cropped area / Net cropped area) x 100
Net cropped area: The area under cultivation.
Gross cropped area: The area of net area sown plus the area sown more than once in a year.
India covers a land area of 3,287,263 sq km. There are different types of land in India about 54.7% of it is cultivated land. The several types of land available in India are: Agricultural Land, Barren Land, Real Estate Land, Commercial Land, Farm Land and Residential Land. Indian people are mainly employed in Agricultural activities thus agricultural land is almost 54.7% of the total Land Mass. The agricultural lands are located on the outskirts of the Metro Cites. Usually the agricultural land shares space with the Industrial areas outside the city. There are Agricultural lands in almost all the States of India. Agriculture resources considered to be one of the most important renewable and dynamic natural resources. Comprehensive, reliable and timely information on land use pattern of an area would focus on its optimal use and development of an area in viewpoint to food security. A close study of the present land use and utilization patterns and land use history will help to suggest suitable land use plan with the farmers’ available knowledge.
Objectives:
1. To study the land use pattern of the project area
2. To study the cropping pattern, cropping intensity in different land types.
3. To suggest alternate land use plan for the locality
Materials Required:
1. Square data sheet for inventory documentation
2. Primary and secondary data sources from Agriculture offices of block, subdivision and district, panchayat, NGOs, farmers’ club etc.
3. Large scale base map of the area
Methodology:
A. To collect data from primary/ secondary sources for the past few years on the following parameters.
1. Total area under study
2. Forests
3. Area put to non agricultural uses
4. Barren and uncultivable land
5. Total cultivated area
6. Area sown more than once
7. Gross cropped area
8. Cropping intensity (percentage)
9. Irrigated area, if available
10. Un-irrigated area
11. Percentage of net irrigated area to net cultivated area
12. Area under cereals, pulses, oilseeds, fibre crops, horticultural crops and others
13. Share of area under different crops.
B. Analyze data for variation of present and past last 10 years) land use
C. Suggestion of optimal land use based on farmers needs
D. Graphical representation of change in parameters with time (years).
Relevance:
The students can get an insight on the changes occurring in the land use patterns over the years due to a host of biotic and abiotic factors viz., climate change, land degradation, human interference, etc. and will help suggest ways for the planners, administrators and the end users to cope with the changing scenario.
Important Terminologies:
Cropping pattern: Sequence of crop (or crops) and fallow of a given area in a year.
Cropping Intensity: The ratio of gross cropped area to net cultivated area which is multiplied by hundred and represented in percentage. It is calculated with the formula as given below.
Cropping intensity = (Gross cropped area / Net cropped area) x 100
Net cropped area: The area under cultivation.
Gross cropped area: The area of net area sown plus the area sown more than once in a year.
Project 1: Agro-ecological mapping of a locality
Project 1: Agro-ecological mapping of a locality
Agro-ecological analysis is an important tool for management of farming system at village level. Agro-ecosystem mapping can help improve the location specific recommendation, technology adoption and dissemination based on resource base and socio-economic status of the community. Overlays of land type enterprise and socio-economic parameters highlight interaction for specific resource allocation, in addition to facilitating agriculture based developmental agencies (like social forestry, community development department, etc,) and target groups for implementation of site-specific technology intervention.
Objective:
1. To take stock of resource base of the neighbourhood/village
2. To identify opportunity and constraints for resource base of the area
3. To plan/intervene different developmental programmes of the village in team sprit
Materials required:
1. Square data sheet for inventory documentation
2. Primary and secondary data sources from Agriculture offices of Block, Sub-division and district, Panchayat, NGOs, Farmers’ club etc.
3. Large scale base map of the area
Methodology:
1. Collection of base map
Revenue map or village map can be obtained from the district revenue departments/ panchayat office or can be downloaded from Google Earth website.
2. Map of topography and hydrology:
This map is prepared by eliciting every land type that they can distinguished and ascertaining spatial distribution can be a map of roads, homes, orchards and other land marks (temple, tank, etc.) Establishing land type boundaries requires considerable amount of walking around. Farmers can be requested to indicate flood and drainage direction and main water resources.
3. Map of enterprises
This map is prepared by eliciting from farmers what enterprises they conduct or allocate on each land type. Major enterprises are crops, animals, fish, orchards, social forestry, etc. Special attention should be given to agriculture and non-agricultural activities like dwellings, rocky or stony areas, steep land or barren areas, etc.
4. Map of social groups
This map is made by questioning farmers to name the castes or social group that live in the locality. Spatial distribution of houses can be drawn in the map.
5. Transect of Agro-ecological zones:
This is prepared from a composite section through overlays on land type. For each land type local name, soil type, crops trees, livestock, fish, specific opportunities and constraints should be listed from the information collected from the local inhabitants.
Relevance:
The project will help to gain insight on holistic interaction among the different segments viz., geomorphology, soils, hydrology, flora, fauna and the human population of the area for developing sustainable land use plan based on the existing agro-ecosystem. This knowledge can serve as a model for extrapolation in similar agro-ecosystems. Further, it will also educate on rational and group behavior and focus on constraints and opportunities of the study area.
Agro-ecological analysis is an important tool for management of farming system at village level. Agro-ecosystem mapping can help improve the location specific recommendation, technology adoption and dissemination based on resource base and socio-economic status of the community. Overlays of land type enterprise and socio-economic parameters highlight interaction for specific resource allocation, in addition to facilitating agriculture based developmental agencies (like social forestry, community development department, etc,) and target groups for implementation of site-specific technology intervention.
Objective:
1. To take stock of resource base of the neighbourhood/village
2. To identify opportunity and constraints for resource base of the area
3. To plan/intervene different developmental programmes of the village in team sprit
Materials required:
1. Square data sheet for inventory documentation
2. Primary and secondary data sources from Agriculture offices of Block, Sub-division and district, Panchayat, NGOs, Farmers’ club etc.
3. Large scale base map of the area
Methodology:
1. Collection of base map
Revenue map or village map can be obtained from the district revenue departments/ panchayat office or can be downloaded from Google Earth website.
2. Map of topography and hydrology:
This map is prepared by eliciting every land type that they can distinguished and ascertaining spatial distribution can be a map of roads, homes, orchards and other land marks (temple, tank, etc.) Establishing land type boundaries requires considerable amount of walking around. Farmers can be requested to indicate flood and drainage direction and main water resources.
3. Map of enterprises
This map is prepared by eliciting from farmers what enterprises they conduct or allocate on each land type. Major enterprises are crops, animals, fish, orchards, social forestry, etc. Special attention should be given to agriculture and non-agricultural activities like dwellings, rocky or stony areas, steep land or barren areas, etc.
4. Map of social groups
This map is made by questioning farmers to name the castes or social group that live in the locality. Spatial distribution of houses can be drawn in the map.
5. Transect of Agro-ecological zones:
This is prepared from a composite section through overlays on land type. For each land type local name, soil type, crops trees, livestock, fish, specific opportunities and constraints should be listed from the information collected from the local inhabitants.
Relevance:
The project will help to gain insight on holistic interaction among the different segments viz., geomorphology, soils, hydrology, flora, fauna and the human population of the area for developing sustainable land use plan based on the existing agro-ecosystem. This knowledge can serve as a model for extrapolation in similar agro-ecosystems. Further, it will also educate on rational and group behavior and focus on constraints and opportunities of the study area.
Sub- theme - I KNOW YOUR LAND
Sub- theme:I
KNOW YOUR LAND
We know we belong to the land, and the land we belong to is grand!
-Oscar Hammerstein
Understanding land resources, its potential, utilization and management of any area reflect the levels of development and standard of living of the locality. Improper use of land due to anthropogenic pressure has created many problems like shrinkage of arable land due to encroachment, decline in fertility due to over use of inorganic fertilizers without soil test information and land degradation. In land resource management approach, spatial distribution of land use, intervention of local and scientific decision support system and control and conservation measures are of primary importance.
Land may be defined as a physical environment consisting of relief, soil, hydrology, climate and vegetation in so far as they are determined by the land use. Value of land depends on its size, location, distance from the market and nature of potential use besides productivity. The sum total of characteristics that distinguish a certain kind of area in the earth’s surface in contrast to other kind of areas to give it a distinguishing pattern is a landscape.
Soil is a dynamic natural body developed as a result of pedogenic processes during and after weathering of rocks, consisting of minerals and organic constituents, possessing definite chemical, physical, mineralogical and biological properties having a variable depth over the surface of earth and providing a medium for plant growth. Soils are formed by interaction of many factors, viz., climate, relief, organisms, parent materials and time etc. Soils are derived from their parent materials which are invariably derived from different rocks. There are three main kinds of rocks, viz. igneous rock, Sedimentary rock and metamorphic rock. Rocks are chemically composed of oxides of Si, Al, Fe, Ca, Mg, Mn, K, P etc. Chemical and physical disintegration and decomposition of rocks under different temperature, pressure and moisture condition results in the formation of parent material (C horizon or regolith) over which soil formation takes place. Afterwards both weathering and soil formation processes proceed simultaneously leading further development of soil.
Each soil is characterized by a given sequence of horizons. Combination of this sequence is known as soil profile i.e. a vertical section of the soil through its entire horizon. The layers or horizons in the soil profile which vary in thickness have different morphological characteristics. This includes colour texture, structure, etc. Horizons are generally designated as O (organic), A, E, B, C and R (regolith on which weathering processes act leading to soil formation). Therefore soil profile is taken as unit of study which helps the investigators not only to classify the soils but also to understand soil-moisture-plant-relationship. The soil profile in the field therefore furnishes a base which has to be supplemented by physical, chemical and biological properties of soils.
Soil mapping
The physical properties of soil are important since this determine the manner in which it can be used either for agriculture, forestry etc., and non agriculture purposes like habitat, recreation site etc. Properties viz: infiltration rate, water holding capacity, aeration, plasticity and nutrient supplying ability are influenced by the size, proportion, arrangement and mineral composition of the soil particles. Four major components of soil viz. inorganic or mineral particles, organic matter, water and air vary with different regions. Based on soil water plant relation, the soil water may be classified as gravitational water, capillary water, hygroscopic water etc. Water mostly available to plant growth held as capillary water within -15 bars.
Soil chemical properties are mainly due to most reactive part of the soil namely soil
colloids consisting of organic and inorganic phases. The organic phase consists of either fresh or decomposed residues of plants, animals, and microbes (fungi, bacteria, actinomycetes etc.) which may remain associated with inorganic phase or may be present in free form.
The life of mankind and almost all the flora and fauna on the earth is continuously influenced by an unending flux of water known as hydrologic cycle. In hydrologic cycle, soil act as a reservoir and water is always in transitory storage in soils. There are two interlocking cycles both starting with evaporation, from sea to atmosphere. The first shorter cycle is from rainfall into the soil and then as evaporation and transpiration back to atmosphere. This is sometimes called green water. The second cycle is blue water follows the longer part from rainfall through soil moisture, ground water and rivers to sea. It may be noted that hydrologic cycle is not always punctual and uniform in delivering precipitation to earth surface.
India is a vast country with a total area of 328.72 million hectare of which approximately 30 per cent is occupied by mountains and hills, 25 per cent by plateau and 45 per cent is occupies by plain valley. Out of the total geographical area forest covers an area of 69.02 m ha, area not available for cultivation 28.48 m ha, other uncultivated land including fallow land 53.38 m ha, cultivable wasteland 13.83 m ha, permanent pasture and grazing land 11.04 m ha, fallow land including current fallow 24.90 m ha, area not available for agriculture, forest etc. 50.19 m ha and net area under cultivation is 189.74 m ha. Out of the total geographical area, around 45 per cent of total geographical area is subjected to degradation problems. The area suffering due to water erosion, wind erosion, water logging, salinity/alkalinity, acidity and other complex problems are 93.6, 9.4, 14.3, 5.9, 16.0 and 7.4 million hectare, respectively.
Physiographically, the country can be put under seven regions, viz., northern mountains including the Himalayas and the mountain ranges in the north-east, Indo-Gangatic plain, Central Highlands, peninsular plateau, East coast, West coast and bordering seas and islands.
India has a diverse geology. Different regions of India contain rocks of various types belonging to different geologic periods. Some of the rocks are severely distorted and transmuted while others are lately deposited alluvium. Great variety of mineral deposits in huge quantity is found in the Indian Geological survey. India’s geographical land area can be categorized into Deccan Trap, Gondwana and Vindhyan. The Deccan Trap covering almost the entire state of Maharastra, a part of Gujrat, Karnataka, Madhya and Andhra Pradesh. Indian soils are normally divided into four broad groups. These comprise of alluvial soil, black soil, red soil and laterite soil. Allivial soils are derived from the deposition led by diffirent tributaries of Indus, Ganges and the Brahmaputra system. It includes soils in deltic alluvium, calcarious alluvium and coastal alluvium. It covers 40 per cent of land area. Black soils are dark in colour gently calcarious low in organic matter, high in clay content, high in cation exchange capacity. They are sticky and plastic. It covers about 22.2 per cent of total land area. Red soil of India covers almost all the states. The colour of red soil is due to wide diffusion of iron. These soils are poor in nitrogen, phosphorus and humus. Kaolinitic type of mineral is prevalent in red soil. Laterite soils are highly weathered materials rich in secondary oxides of iron, aluminum or both. It contains large amount of quartz and kaolinite.
The land system of our country is affected by influences of man interventions well as various natural processes. The removal of top soil, deforestation and banned agricultural practices would, many a time, force us to live in environmentally adverse conditions. The environmental degradation of land makes our country stressful situations, which has become concern for us to think over and act for sustainable development. Our future generation is in stake as a result of interference with natural processes causing many situations unfit for our well being and also for the well being of future generation. Therefore, the database on the past and present land use practices will lead us to predict the future pattern of change which will enrich us towards sustainable development.
KNOW YOUR LAND
We know we belong to the land, and the land we belong to is grand!
-Oscar Hammerstein
Understanding land resources, its potential, utilization and management of any area reflect the levels of development and standard of living of the locality. Improper use of land due to anthropogenic pressure has created many problems like shrinkage of arable land due to encroachment, decline in fertility due to over use of inorganic fertilizers without soil test information and land degradation. In land resource management approach, spatial distribution of land use, intervention of local and scientific decision support system and control and conservation measures are of primary importance.
Land may be defined as a physical environment consisting of relief, soil, hydrology, climate and vegetation in so far as they are determined by the land use. Value of land depends on its size, location, distance from the market and nature of potential use besides productivity. The sum total of characteristics that distinguish a certain kind of area in the earth’s surface in contrast to other kind of areas to give it a distinguishing pattern is a landscape.
Soil is a dynamic natural body developed as a result of pedogenic processes during and after weathering of rocks, consisting of minerals and organic constituents, possessing definite chemical, physical, mineralogical and biological properties having a variable depth over the surface of earth and providing a medium for plant growth. Soils are formed by interaction of many factors, viz., climate, relief, organisms, parent materials and time etc. Soils are derived from their parent materials which are invariably derived from different rocks. There are three main kinds of rocks, viz. igneous rock, Sedimentary rock and metamorphic rock. Rocks are chemically composed of oxides of Si, Al, Fe, Ca, Mg, Mn, K, P etc. Chemical and physical disintegration and decomposition of rocks under different temperature, pressure and moisture condition results in the formation of parent material (C horizon or regolith) over which soil formation takes place. Afterwards both weathering and soil formation processes proceed simultaneously leading further development of soil.
Each soil is characterized by a given sequence of horizons. Combination of this sequence is known as soil profile i.e. a vertical section of the soil through its entire horizon. The layers or horizons in the soil profile which vary in thickness have different morphological characteristics. This includes colour texture, structure, etc. Horizons are generally designated as O (organic), A, E, B, C and R (regolith on which weathering processes act leading to soil formation). Therefore soil profile is taken as unit of study which helps the investigators not only to classify the soils but also to understand soil-moisture-plant-relationship. The soil profile in the field therefore furnishes a base which has to be supplemented by physical, chemical and biological properties of soils.
Soil mapping
The physical properties of soil are important since this determine the manner in which it can be used either for agriculture, forestry etc., and non agriculture purposes like habitat, recreation site etc. Properties viz: infiltration rate, water holding capacity, aeration, plasticity and nutrient supplying ability are influenced by the size, proportion, arrangement and mineral composition of the soil particles. Four major components of soil viz. inorganic or mineral particles, organic matter, water and air vary with different regions. Based on soil water plant relation, the soil water may be classified as gravitational water, capillary water, hygroscopic water etc. Water mostly available to plant growth held as capillary water within -15 bars.
Soil chemical properties are mainly due to most reactive part of the soil namely soil
colloids consisting of organic and inorganic phases. The organic phase consists of either fresh or decomposed residues of plants, animals, and microbes (fungi, bacteria, actinomycetes etc.) which may remain associated with inorganic phase or may be present in free form.
The life of mankind and almost all the flora and fauna on the earth is continuously influenced by an unending flux of water known as hydrologic cycle. In hydrologic cycle, soil act as a reservoir and water is always in transitory storage in soils. There are two interlocking cycles both starting with evaporation, from sea to atmosphere. The first shorter cycle is from rainfall into the soil and then as evaporation and transpiration back to atmosphere. This is sometimes called green water. The second cycle is blue water follows the longer part from rainfall through soil moisture, ground water and rivers to sea. It may be noted that hydrologic cycle is not always punctual and uniform in delivering precipitation to earth surface.
India is a vast country with a total area of 328.72 million hectare of which approximately 30 per cent is occupied by mountains and hills, 25 per cent by plateau and 45 per cent is occupies by plain valley. Out of the total geographical area forest covers an area of 69.02 m ha, area not available for cultivation 28.48 m ha, other uncultivated land including fallow land 53.38 m ha, cultivable wasteland 13.83 m ha, permanent pasture and grazing land 11.04 m ha, fallow land including current fallow 24.90 m ha, area not available for agriculture, forest etc. 50.19 m ha and net area under cultivation is 189.74 m ha. Out of the total geographical area, around 45 per cent of total geographical area is subjected to degradation problems. The area suffering due to water erosion, wind erosion, water logging, salinity/alkalinity, acidity and other complex problems are 93.6, 9.4, 14.3, 5.9, 16.0 and 7.4 million hectare, respectively.
Physiographically, the country can be put under seven regions, viz., northern mountains including the Himalayas and the mountain ranges in the north-east, Indo-Gangatic plain, Central Highlands, peninsular plateau, East coast, West coast and bordering seas and islands.
India has a diverse geology. Different regions of India contain rocks of various types belonging to different geologic periods. Some of the rocks are severely distorted and transmuted while others are lately deposited alluvium. Great variety of mineral deposits in huge quantity is found in the Indian Geological survey. India’s geographical land area can be categorized into Deccan Trap, Gondwana and Vindhyan. The Deccan Trap covering almost the entire state of Maharastra, a part of Gujrat, Karnataka, Madhya and Andhra Pradesh. Indian soils are normally divided into four broad groups. These comprise of alluvial soil, black soil, red soil and laterite soil. Allivial soils are derived from the deposition led by diffirent tributaries of Indus, Ganges and the Brahmaputra system. It includes soils in deltic alluvium, calcarious alluvium and coastal alluvium. It covers 40 per cent of land area. Black soils are dark in colour gently calcarious low in organic matter, high in clay content, high in cation exchange capacity. They are sticky and plastic. It covers about 22.2 per cent of total land area. Red soil of India covers almost all the states. The colour of red soil is due to wide diffusion of iron. These soils are poor in nitrogen, phosphorus and humus. Kaolinitic type of mineral is prevalent in red soil. Laterite soils are highly weathered materials rich in secondary oxides of iron, aluminum or both. It contains large amount of quartz and kaolinite.
The land system of our country is affected by influences of man interventions well as various natural processes. The removal of top soil, deforestation and banned agricultural practices would, many a time, force us to live in environmentally adverse conditions. The environmental degradation of land makes our country stressful situations, which has become concern for us to think over and act for sustainable development. Our future generation is in stake as a result of interference with natural processes causing many situations unfit for our well being and also for the well being of future generation. Therefore, the database on the past and present land use practices will lead us to predict the future pattern of change which will enrich us towards sustainable development.
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