What is land , what are the characters of land
Answers
Answer:
These natural gifts include: (i) rivers, forests, mountains and oceans; (ii) heat of sun, light, climate, weather, rainfall, etc. which are above the surface of land; (iii) minerals under the surface of the earth such as iron, coal, copper, water, etc. According to Marshall, “By land is meant…
Answer:
Explanation:
A land characteristic is an attribute of land that can be measured or estimated. Examples are slope angle, rainfall, soil texture, available water capacity, biomass of the vegetation, etc. Land mapping units, as determined by resource surveys, are normally described in terms of land characteristics.
If land characteristics are employed directly in evaluation, problems arise from the interaction between characteristics. For example, the hazard of soil erosion is determined not by slope angle alone but by the interaction between elope angle, slope length, permeability, soil structure, rainfall intensity and other characteristics. Because of this problem of interaction, it is recommended that the comparison of land with land use should be carried out in terms of land qualities.
A land quality is a complex attribute of land which acts in a distinct manner in its influence on the suitability of land for a specific kind of use. Land qualities may be expressed in a positive or negative way. Examples are moisture availability, erosion resistance, flooding hazard, nutritive value of pastures, accessibility. Where data are available, aggregate land qualities may also be employed, e.g. crop yields, mean annual increments of timber species.
Table 1 gives an illustrative list of land qualities related to productivity from three kinds of use and to management and inputs. It is not exhaustive, nor is each land quality necessarily relevant for a particular area and type of land use. The qualities listed in B and C are in addition to those of A, which may be relevant to all three kinds of use (based in part on Beek and Bennema, 1972). There may also be land qualities related to major land improvements. These vary widely with the types of improvement under consideration. An example is land evaluation in relation to available supplies of water where irrigation is being considered.
A land quality is not necessarily restricted in its influence to one kind of use. The same quality may affect, for example, both arable use and animal product
There are a very large number of land qualities, but only those relevant to land use alternatives under consideration need be determined. A land quality is relevant to a given type of land use if it influences either the level of inputs required, or the magnitude of benefits obtained, or both. For example, capacity to retain fertilizers is a land quality relevant to most forms of agriculture, and one which influences both fertilizer inputs and crop yield. Erosion resistance affects the costs of soil conservation works required for arable use, whilst the nutritive value of pastures affects the productivity of land under ranching.
Land qualities can sometimes be estimated or measured directly, but are frequently described by means of land characteristics. Qualities or characteristics employed to determine limits of land suitability classes or subclasses are known as diagnostic criteria.
A diagnostic criterion is a variable which has an understood influence upon the output from, or the required inputs to, a specified use, and which serves as a basis for assessing the suitability of a given area of land for that use. This variable may be a land quality, a land characteristic, or a function of several land characteristics. For every diagnostic criterion there will be a critical value or set of critical values which are used to define suitability class limits.
Table 1 EXAMPLES OF LAND QUALITIES
A. LAND QUALITIES RELATED TO PRODUCTIVITY FROM CROPS OR OTHER PLANT GROWTH
- Crop yields (a resultant of many qualities listed below)
- Moisture availability
- Nutrient availability
- Oxygen availability in the root zone
- Adequacy of foothold for roots
- Conditions for germination
- Workability of the land (ease of cultivation)
- Salinity or alkalinity
- Soil toxicity
- Resistance to soil erosion
- Pests and diseases related to the land
- Flooding hazard (including frequency, periods of inundation)
- Temperature regime
- Radiation energy and photoperiod
- Climatic hazards affecting plant growth (including wind, hail, frost)
- Air humidity as affecting plant growth
- Drying periods for ripening of crops.
B. LAND QUALITIES RELATED TO DOMESTIC ANIMAL PRODUCTIVITY
- Productivity of grazing land (a resultant of many qualities listed under A.)
- Climatic hardships affecting animals
- Endemic pests and diseases
- Nutritive value of grazing land
- Toxicity of grazing land
- Resistance to degradation of vegetation
- Resistance to soil erosion under grazing conditions
- Availability of drinking water.
C. LAND QUALITIES RELATED TO FOREST PRODUCTIVITY
The qualities listed may refer to natural forests, forestry plantations, or both.
- Mean annual increments of timber species (a resultant of many qualities listed under A.)
- Types and quantities of indigenous timber species
- Site factors affecting establishment of young trees
- Pests and diseases
- Fire hazard.