1. Land Use
2. Environmental Factors
3. Natural Farming Regions
Agriculture is a term that defines the utilisation of land through various activities such as crop and livestock production which provide food, fibre, medicines including many other products that support life, and wildlife management to promote tourist attraction in a nation. The study of Agriculture is defined as Agricultural Science.
Key Points to Note:
? Utilisation of Land
? Crop and Livestock Production
? Wildlife management
? Provision of food, fibre, medicines and tourism
It is also defined as a term used to describe the science and art of crop cultivation, wildlife management and livestock production.
When defined in terms of science, agriculture involves experiments and application of scientific intellectual knowledge in areas such as:
– Soil analysis which include soil sampling
– Pest and disease control
– Agric Mechanisation which include Farm structure and machinery
– Breeding of Crop and Livestock
– Pedology which refers to the study of soil science
– Pathology which refers to the study of diseases and how they can be controlled
– Entomology which is the study of insects and their control
– Ecology which is the study of environment
– Genetics which is applied in plant and animal breeding
When defined as an art, it involves the use of academic expertise in:
– Land tillage e.g. land preparation
– Construction e.g. farm structures
– Measurement of land size (determinant of land carrying capacity)
– Crop harvesting e.g. harvesting of maize using a combine harvester
– Livestock feeding and handling
The history of Agriculture
The history of agriculture dates back to thousands of years ago where people gathered wild grains which they began to plant before the era of domestication. The domestication of pigs, sheep and cattle dates back to about 10, 000 ages back. The domestication of sheep was practised in Mesopotamia between the ages of 13, 00 and 11, 00 years ago.
An estimated age of around 10, 500 back in the areas of Morden Turkey and Pakistan is where the domestication of cattle was practised from aurochs. Pigs had multiple centres of origin in Eurasia, including Europe, East Asia and Southwest Asia and the wild boar was first domesticated about 10,500 years ago. The Andes of South America domesticated potato about 10,000 and 7,000 years ago along with beans, coca, llamas, alpacas and guinea pigs.
Crops originate from 11 regions of the world and these separate regions of the Old and New World were involved as independent centres of origin. Wild grains were collected and eaten from at least 105, 000 years ago and Rye was cultivated 11, 050BC. Around 11, 500 years ago, emmer and einkorn wheat, hulled barley, peas, lentils, bitter vetch, chick peas and flax were cultivated in the Levant. Rice was domesticated in China between 11 500 and 6, 200 BC with the earliest known form of cultivation form 5,700 BC followed by mung, soy and azuki beans.
Sugar cane including some root vegetables began to be domesticated around 9,000 years ago in New Guinea. In Africa domestication of Sorghum was done in the Sahel Regions of Africa by ages of 7,000 back. By 5,000 years back cotton was domesticated in Peru and independently in Eurasia. In Mesoamerica, wild teosinte was domesticated to land use by 6,000 years ago.
Agricultural development enabled population growth outclassing the life that hunting and gathering provided. It was the key development in the rise of sedimentary human civilisation, where by farming of domesticated species created food surplus that enabled the human race to live in cities
Importance of Agriculture
Branches of Agriculture
There are four main branches of agriculture which are:
? Deals with production of field crops through cultivation
? Part of the Agronomy
? An agronomist is a specialist in crop production
Figure 1 shows a crop production system of garden peas
Crop production can be subdivided into:
1. Field Crop Production which encompasses crops like maize, beans, potatoes, coffee, tea, cotton among others. Fig 2 shows Field Crop production
2. Horticulture which involves the production of perishable crops which of high value. This is also further subdivided into:
a. Floriculture – the growing of flowers such as Tuberose, Roses and Carnations among other flowers.
b. Olericulture – the growing of vegetables such as cabbages, tomatoes, French beans as shown in fig. 4 below.
c. Pomiculture – the growing of fruits
These different crop production systems are shown below in fig 2. In field crop production different crops are produced depending on type, some are annual crops like cereals and pulses for example garden peas (Fig. 1). and some are perennial crops like coffee, tea and sugar can.
Figure 2 shows different kinds of crop farming (arable farming) systems
? Deals with the rearing of livestock both ruminants and non-ruminants
? Also called Animal production and technology
? A specialist in Animal Production and Technology is called an Animal Scientist.
Figure 3 shows a female pig (sow) feeding its litter of more than 3
livestock sector can be further divided into;
a. Pastoralism which is the rearing of mammalian livestock (ruminants and no-n ruminants) such as cattle, sheep, goats, rabbits, pigs and camels
b. Aquaculture involves the rearing of aquatic organisms such as fish in ponds. It also refers to the breeding, rearing and harvesting of plants and animals in all types of water environments. There is also Pisciculture which refers to the husbandry of fin fish at densities greater than would normally occur under natural conditions purposely to enhance production for human consumption.
c. Apiculture – the rearing of bees under confinements known as beehives also known as Bee Keeping.
d. Poultry Production – involves the rearing of domesticated birds such as layers, indigenous birds popularly known as road runners.
? Deals with the use and maintenance of Farm tools, machinery and structures
Figure 4 shows a disc harrow used for land tillage
Figure 5 shows a combine harvester (which is a farm machine) harvesting a corn field
? Is a branch that deals with the use and maintenance of farm tools, machinery and structures
? This is a branch dealing with the wise use of resources to maximize profits. The utilization of scarce resources aims at maximizing output at minimum costs in the production cycle. It is also a function of marketing agricultural produce
Figure 6 shows a pomiculture market
1) What are the benefits of Agriculture? 8
2) Identify the agricultural activities practiced in fig. 2 above and explain each system from A to D 4
3) Differentiate between agriculture when defined as an art and science 10
4) List down the branches or agriculture and define each branch. 12
5) Why is agricultural economics important in agriculture? 2
6) What is the difference between Agriculture mechanization and agriculture engineering 4
Total Marks (40)
Since Agriculture utilises land and water in all its production systems, there is need for land evaluation and land planning to determine the land use i.e. to get knowledge of what agricultural systems are suitable in which area, why and to what extent is the productivity of the land of benefit to human and the environment. For example, to what extend is aquaculture production system suitable for a specific environment, what are the consequences, profit margin and how sustainable is the system.
Land and Land Use
Definition of Land use
Land use describes the management and modification of the nature (Soil, Water and Air) by humans to create a conducive environment that is suitable for settlements, arable and non-arable lands, pastures, wetlands to suit population growth of all living and non-living organisms.
It constitutes the total arrangements, activities and inputs undertaken by humans in a certain land cover type.
Land use decision is always a part of the human society as in the past, changes in land use came more often by gradual revolution resulting in many separate decisions being taken by individuals. However, the wise use of land demands proper planning in order to know the carrying capacity of the land and come out with a plan that suits a particular place whether for production or settlements.
Land use planning takes place in all parts of the world including both developing and developed countries which lead to more crowded and complex world at present. It is also concerned with putting environmental resources to new kinds of productive use.
Land Use Planning
The need for land use planning is to resolve the changing of needs and pressures, including competition for use of the same land. The functionality of land use planning is brought about the benefits realised by man and at the same time the conservation the resources for the future. For proper land use planning there is need for an understanding of both the natural environment and the land use envisaged.
Damage of natural resources and unsuccessful land use enterprise emanates from failure to take into account of the mutual relationship between land and the uses to which it will be exposed to. This understanding is a function of land evaluation, it exposes the planners to the best and most promising land use programs and is more concerned with the assessment of land performance when utilised for a specific purpose.
It involves the implementation and clarification of basic surveys of climate soils, vegetation and other aspects of land in terms of the requirements of alternative forms of land use. The value of planning is recognised when the range of land uses are relevant within the physical (climatic conditions), economic and social context of the area and the comparison must incorporate economic considerations.
? Define Land use
? What is the difference between land use and land evaluation
? Identify the problems associated with land use planning and evaluation
? Land evaluation is important in land use planning process. Explain?
? What are the advantages associated with land use planning?
? Explain the benefits of land evaluation
The aims of land evaluation
Land evaluation is concerned with the present land performance, change in the use of land and the land itself, and its effects taking into account land sustainability for future use. Other factors include the economics of the proposed enterprises, the social consequences for the people in the area and the country concerned, and the consequences, benefits or adverse, for the environment.
Questions answered by land evaluation:
? How the land is currently managed and the future prospects of the land if the present practices remain the same/don’t change
? What improvements in management practices are possible to implement within the present use
? What other uses of land that are physically possible, economically and socially relevant in the area
? Which uses offer the possibility of sustainable production and other benefits
? What recurrent input that are necessary to bring about the desire production and minimize the adverse effects. What are the benefits of each form of use?
However, if the introduction of a new use involves a significant change in the land itself, for example irrigation schemes, then land evaluation must be able to answer:
? What changes in the condition of the land are feasible and necessary, and how can they be brought about
? What non-recurrent inputs are necessary to implement these changes
The process of land evaluation provides data as a determinant to the decision-making process in land use and doesn’t determine itself the land use changes to be carried out. To be effective in this role, the output from an evaluation normally gives information on two or more potential forms of use for each area of land, including the consequences, beneficial and adverse, of each.
Land Evaluation and Land Use Planning
Land evaluation is a part of the process of land use planning and its precise role varies indifferent situations. In the contemporary framework it is satisfactory to represent the land use planning process by the following generalized sequence of activities and decisions:
1. Recognition of a need for change
2. Identification of aims
3. Formulations of proposals, involving alternative forms of land use, and recognition of their main requirements
4. Recognition and delineation of the different types of land present in the area
5. Comparison and evaluation of each type of land for the different uses
6. Selection of a preferred use for each type of land
7. Project design, or other detailed analysis of a selected set of alternatives for distinct parts of the area. This can take the form of a probability study in certain cases.
8. Decision to implement
10. Monitoring of the operation
Land evaluation plays a major role in stages 3, 4 and 5 of the above sequence and contributes information to the succeeding activities. Thus, land evaluation is heralded by the recognition of the need for some change in the use to which land is exposed to; which may be exposure to the development of new prolific uses, such agricultural development schemes or forestry plantations or the establishment of services, such as the designation of a national park or recreational area.
The recognition of this need is followed by identifying the aims of the anticipated alteration and formulation of the general and specific proposals. The evaluation process itself include the explanation of a range of promising categories of practice, and the assessment and comparison of these with respect to each type of land identified in the area leading to the recommendations involving one or a small number of preferred uses of land.
The Six-Factor Principles of Land Evaluation
There are basic fundamental principles that are considered in the approach and methods employed in land evaluation which include:
Assessment of land and classification.
This is a principle to determine land suitability. Land suitability is assessed and classified with respect to the specific kinds of use and this principle is embodied with the recognition fact that different land use production systems have different requirements.
For example, in areas that are affected by floods there are alluvial flood plains with impeded drainage and this can be utilized for or favors rice production than for forestry. The meaningfulness of the land suitability concept lies within the specific categories of land use, each with their own requirements, e.g. soil moisture, rooting depth etc.
The qualities of each type of land, such drainage, availability of moisture or liability to flooding are compared with the requirements of each use. This make the land and the land use to be equally fundamental to land suitability and evaluation.
Least cost principle of land production
Evaluation process requires a comparison of the benefits obtained and the inputs needed on different types of land. The productive potential of land is determined by the input installed in it, even in the collection of wild fruits input required is labor and the use of natural wilderness for nature conservation requires measures of protection.
The appropriateness for each practice is assessed by comparing the required input, such as labor, fertilizers or road construction, with goods produced or other benefits obtained.
The multidisciplinary approach system
A multidisciplinary approach is required where contributions are done from the fields of natural science, the technology of land use, economics and sociology to the evaluation process. Evacuating land according to the suitability principle of approach always incorporates economic considerations to a greater or lesser degree.
The degree of economic consideration in qualitative evaluation may be employed in general terms but without the calculation of costs and returns. In quantitative evaluation the comparison of benefits and inputs in economic terms plays a major role in the destination of suitability. The major role in the fortitude of suitability in quantitative evaluation is played by the comparison of benefits and inputs in economic terms i.e. the inclusion of cost and returns.
This principle follows that a team carrying out an evaluation and encompasses the study of land, land use, social aspects and economics. This however require a range of specialist which include geomorphologists, soil surveyors, ecologist who are specialist under natural science, agronomist, foresters, irrigation engineers, experts in livestock management, economist and sociologist.
Physical, economic and social context of the area
Under this principle evaluation is made in terms of the physical, economic and social context of the are concerned. The factors that form the context within which evaluation takes place include:
i. Regional Climate/Climatic conditions
ii. Standards of living
iii. Population Density
iv. Labor cost and availability
v. Potential market/Marketability – both local and export market
vi. Land tenure systems which are acceptable socially and politically
vii. Capital fluidity and accessibility
The assumptions in evaluation will differ from one country to another and to some extent also differs between areas of the same country. To avoid misunderstanding and to assist in comparisons between different areas many of these factors are often indirectly assumed and such assumptions should be explicitly stated.
Suitability refers to the use of land in a sustainable manner with respect to the aspect of environmental degradation. For example, some forms of lands use appear to be highly profitable in the short run economies of scale but likely to lead to soil erosion, progressive pasture degradation or adverse changes in river regimes downstream. These consequences will determine the fate of land use as they would outweigh the short-term profitability and cause the land to be classed as not suitable for such purposes.
This principle states the proper utilization of land through environment preservation for future use. Under normal circumstance agriculture is encompasses the replacement of the natural vegetation and normally soil fertility under arable cropping is either high or low depending on management but rarely at the same level as under the original vegetation.
The requirement is that, for any proposed form of land use, the probable consequence for the environment should be assessed thoroughly and accurately, and such assessments should be taken into consideration when determining suitability.
Best-Fit Principle of Analysis
The best-fit principle of analysis corelate the relationship between land use, population density and returns. In the context of agriculture, it corelates the relationship between land use, the factors influencing agricultural production which include (human, biotic, climatic and edaphic factors) and the tangible returns/profit realization.
Evaluation involves the comparison of more than a single kind of use and the comparison can be done for example, between two or more different faming systems, agriculture and forestry, or between individual crops. The reliability of land evaluation is dominated by the benefits and inputs from any given kind of use which can be compared to at least one and usually several different, alternatives. Considering only one use draws the danger that, whilst the land may be indeed suitable for that use, some other and more beneficial use may be ignored.
Levels of Intensity and Approaches
A number of activities are common to all types of land evaluation and in all cases, it commences with initial consultations, concerned with the objectives of the evaluation, assumptions and constraints and the methods to be followed. The details of the subsequent activities and the sequence in which they are carried out, vary with circumstances which include the level of survey intensity and the two overall approaches that have to be followed.
Level of Intensity
There are three levels of intensity that may be distinguished which are normally reflected in the scales of resulting maps
1. Investigation/Reconnaissance survey
The first level of intensity, reconnaissance, is more concerned with broad inventory of resources and development possibilities at regional and national levels. The evaluation of land is qualitative and economic analysis is only in very general terms. The results contribute to the creation of national plans, permitting the selection of development areas and priorities.
At semi-detailed or intermediate level of intensity, the level is concerned with more specific aims which include feasibility studies of development projects. The work includes farm surveys, economic analysis is considered more important and the evaluation of land is quantitative. Information provided at this level is for decisions on the selection of projects or whether a particular development or other change is to be applied.
The detailed level covers surveys for actual planning and design, or farm planning and advice, often carried out after the decision to implement has been made.
Two-stage and parallel approaches to land evaluation
The approaches to land evaluation adopted as shown in Fig. 7 below relates the relationship between of resource surveys and economic and social analysis, and the manner in which the kinds of land use are formulated depends on
1. A two-stage approach,
a. the first stage is mainly concerned with qualitative land evaluation,
b. the second stage consist of economic and social analysis.
The two-stage approach is often used in resource inventories for broad planning resources and in studies for the assessment of biological productive potential.
Classification in the first stage stages in land evaluation are based on the suitability of the land for the kinds of land use which are selected at the beginning of the survey e.g. arable cropping, dairy farming, maize or tomatoes.
Economic and social analysis contribution in the first stage is limited to a check on the relevance of the kinds of land use. However, it is utilized in the second stage either immediately or after an interval of time when the first stage has been completed ad its results presented in map and report form.
The basic components of land comprise the physical environment, including climate, relief, soils, hydrology and vegetation to the extent that these are influential factors for potential land use. It includes the past and present results of human activities e.g. reclamation from the sea, vegetation clearance, and also adverse results e.g. soil salinization.
A land mapping unit is a mapped area of land with specified characteristics. These land mapping units are defined and mapped by natural resource surveys, e.g. soil survey, forest inventory. The scale and intensity of study variates the degree of homogeneity or of internal variations. A single land mapping unit in some cases may include two or more distinct types of land, with different aptness e.g. a river flood plain, mapped as a single unit but known to contain both well drained alluvial areas and swampy depressions.
Figure 7 shows Two-stage and parallel approaches to land evaluation
Two-stage Approach Parallel Approach
Land is thus a wider concept than soil or terrain. Soils, soils and landform variation is usually the main cause of difference between land mapping units within a local area and it is for this reason that soil surveys are sometimes the main basis for definition of land mapping units. Nevertheless, soil fitness for land use cannot be assessed in isolation form other aspects of the environment, and hence it is land which is employed as the basis for suitability evaluation.
The relationship between land mapping units and specified type of land use is a result of suitability evaluation. The type of land use put into consideration are limited to those which appear to be relevant under general physical, economic and social conditions prevailing in an area. These kinds of land use serve as the subject of land evaluation and they may also consist of major kinds of land use or land utilisation types.
Major kinds of Land Use and Land Utilisation Types
Major kind of land use
This is a key subdivision of rural land use and these include rainfed agriculture, irrigated agriculture, grassland, forestry or recreation. These major kinds of land use are usually considered in land evaluation studies of a qualitative nature.
Land utilization type
This is a kind of land use that is well-defined in a degree of detail greater than of a major kind of land use. In quantitative land evaluation studies, the kind of land use considered will usually consists of land utilization types and are described with as much detail and precision as the purpose requires. Thus, land utilization types are not a categorial level in the classification of land use but refer to any use below the level of the major kind of land use.
In a given physical, economic and social setting, a land utilization type consists of a set of technical specification and this may be the current environment or a future.
Attributes of land utilization types Data or Assumptions;
a. Produce including goods e.g. (crops, livestock, timber), cervices (e.g. recreational facilities) or other benefits (e.g. wildlife conservation).
b. Market orientation, including whether towards subsistence or commercial production
c. Capital intensity
d. Labor intensity
e. Power sources for example man’s labor, draught animals. machinery and fuels
f. Technical knowledges and attitudes of land users
g. Technology used for example implements and machinery, fertilizers, livestock breeds, farm transport, methods of timber felling.
h. Infrastructure requirements e.g. sawmills, tat factories, agricultural advisory services
i. Size and configuration of land holdings, including whether consolidated or fragmented.
j. Land tenure, the legal customary manner in which rights to land are held, by individuals or groups
k. Income levels, expressed per capita, per unit of production (a farm) or per unit area.
In land utilization, the management systems on different areas within one land are not necessarily the same for example a land utilization type may consist of mixed farming, with part of the land under arable use and part allocated to pastures/grazing. These differences may arise from variation in the land, from the requirements of the management system, or both.
Examples of land utilization types:
1. Rainfed annual cropping
? This is based on low cost production system for example groundnuts with subsistence maize using low capital resources, cattle drawn implements and high labour intensity on freehold farms that are 5 – 10 ha by small holders.
? Also identified as small-scale subsistence farming system
2. Communal Farming
? This is similar to (1) in reverence of production, capital, labour, power and technology but farms of 200=500ha operated on a communal basis.
? Also identified as medium-scale communal farming systems
3. Commercial Farming
? Characterized by high capital and low labour intensity with high levels of mechanization and inputs on freehold farms for example wheat production
? This is also identified as large scale commercial farming.
4. Extensive Cattle ranching
? Medium levels of capital and labor intensity
? Land is held and central services operated by a government agency for example Grassland Research Institute in Marondera, Zimbabwe.
? Operated by a government department of forestry for example a softwood plantation
? High capital intensity
? Low labour intensity
? High levels of technology – advanced technology
6. Wildlife Management
? A national park for recreation and tourism for example Hwange National Park
Where it is wished to relate agricultural land utilization types to general classification, the Typology of World of Agriculture of the International Geographical Union may be considered (Kostrowicki, 1974) and the role of land utilization types in land evaluation is discussed further in Beek (1975).
Multiple and Compound Land Use
the two terms multiple and compound land utilisation types refer to the situation in which more than one kind of land use is practised within area and this is typical of a mixed farming practice.
Constituency of multiple land utilization type:
? Consist of more than one kind of use simultaneously undertaken on the same area of land
? Each use has its own input requirements, production system and produce
? For example, a timber plantation utilised simultaneously as a recreational area.
Constituency of compound land utilization type:
? Consist of more than one kind of use undertaken simultaneously on areas of land but by evaluation are treated as a single unit.
? These different kinds of use may occur in time sequence e.g. as in crop rotation
? Or simultaneously on different areas of land within the same organisational unit
? For example, mixed farming involving both arable use and grazing i.e. crop and livestock branches of agriculture being practised.
Land utilisation types are defined for the purpose of land evaluation and these descriptions need not to comprise full varieties of farm management practices, nonetheless only those related to land management and improvement.
At detailed levels of land evaluation, the closely-defined land utilisation types can be extended into farming systems. This is done by adding other aspects of farm management conversely, farming systems that have already been studied and described can be adopted as the basis for land utilisation types.
Land Characteristics, Land Qualities and Diagnostic Criteria.
This is an attribute of land that can be measured or estimated.
Figure 8 shows land characterised with slope, water and ice
? Examples include slope, rainfall, biomass of the vegetation, carrying capacity, soil texture, availability of water capacity.
? Normal land mapping units determined by resource surveys are described in terms of land characteristics.
? Direct employment of land characteristics in evaluation arises problems from interaction between characteristics e.g. a 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.
? Thus, the recommendation that the comparison of land with land use should be carried out in terms of land qualities.
This is a complex attribute of land that acts in a distinct manner in its influence on suitability of land to specific kind of use.
Figure 9 shows land being utilised for agriculture purposes because of its quality
Land qualities may also be expressed in a positive or negative way.
Examples include resistance to erosion, moisture availability, flooding, nutritive of pastures, accessibility, moisture availability etc.
With resourceful and data availability, collective land qualities may also be employed, e.g. crop yields, mean annual increment of timber yields etc.
List of land qualities related to productivity from three kinds of use and to management and inputs.
1. Land qualities related to productivity from crops or other plant growth
? Crop yields – a resultant of many qualities listed below
? Availability of moisture
? Nutrient availability
? Oxygen availability in the root zone
? Adequacy of foothold for roots
? Conditions for gemination
? Workability of the land – easy of cultivation
? Salinity or alkalinity
? Soil toxicity
? Resistance to soil erosion
? Flooding hazard including frequency, periods of inundation
? Radiation energy and photo period
? Climatic hazards affecting plant growth including wind, hail, frost
? Air humidity as affecting plant growth
? Drying periods of ripening of crops
2. Land qualities related to domestic animal productivity
? Productivity of the grazing land
? Climatic calamities affecting animals
? Endemic and pandemic pest and diseases
? Grazing land nutritive value
? Toxicity of grazing land
? Vegetation resistance to degradation
? Resistance to soil erosion under grazing conditions
? Availability of drinking water
3. Land qualities related to natural forests, forestry plantations, or both
? Veld fires
? Pest and diseases
? Site factors affecting establishment of young trees