grade 11-agriculture_fetena_net_48cc
Natural Resources
10.1 Definition and Importance of Natural Resources
Natural resources are objects, materials, creatures, or energy found in nature that humans can use. Humans do not produce them but utilize them. They are classified as:
Renewable resources: Capable of regenerating after use (e.g., forests, soils, water, biodiversity, atmospheric air).
Non-renewable resources: Cannot regenerate after being used once (e.g., oil, coal, minerals).
Natural resources provide direct and indirect benefits, influencing food, shelter, and the survival of our species. Economic growth relies on the quality and management of these resources.
10.2 Major Types of Natural Resources
The supply of natural resources is fixed by nature and can be classified to enable sustainable management for current and future generations. Forests, soils, and water are key natural resources closely tied to agriculture.
10.2.1 Forests
Forests contain closely packed plants or trees, forming a continuous canopy that reduces light and influences climatic variables. This canopy determines the number and types of plants, animals, and microorganisms within the forest ecosystem.
Trees offer numerous products and services:
Firewood, fruits, medicines, timber, and food.
Construction materials.
Shade and protection from wind.
Aesthetic and spiritual value.
Habitats for wildlife and sources of non-timber products like honey.
Improvement of soil fertility through roots and leaf litter.
Protection against soil erosion and flooding.
Absorption of carbon dioxide and production of oxygen via photosynthesis, thus reducing carbon release into the atmosphere.
10.2.2 Soils
Soil is a mixture of mineral and organic particles formed by weathering processes on rocks. Weathering breaks rocks into soil parent materials. Air and water enter cracks, forming chemical substances. Bacteria and plants colonize rock fragments, transforming them into soils. Decomposition of dead plants by bacteria enhances soil fertility over time.
Soils consist of 5\% organic material, 45\% minerals, 25\% water, and 25\% air. They serve as a source of essential nutrients for plant growth, providing water, oxygen, and nutrients within pore spaces. Soils support plant growth, including food and forage crops, and act as habitats for soil organisms.
Soils store carbon, reducing carbon dioxide release and minimizing climate change effects. Soil properties like nutrient content, organic matter, acidity, alkalinity, topsoil depth, salinity, and organism diversity affect crop productivity. Changes in these properties can lead to soil improvement or degradation. Improvement of soil properties through specific activities results in high crop yields.
10.2.3 Water
Water is essential for all living organisms and covers 70\% of the Earth’s crust. Approximately 97\% of the total water is in oceans and seas, with only 2\% as fresh water and 1\% frozen in ice caps and glaciers.
Surface water includes lakes, rivers, streams, and ponds. It is used in agriculture, industry, electricity generation, recreation, and domestic purposes, as well as for the survival of fish and wildlife.
Ethiopia is known as the 'water tower of Africa' due to its water resources. The country has eight river basins and one lake basin: Abbay, Awash, Baro-Akobo, Genale-Dawa, Mereb, Omo-Gibe, Tekeze, Wabishebele and Rift valley Lakes.
Ethiopia has significant groundwater resources and potential for irrigation expansion, which could improve agricultural productivity and food security. There is also potential for hydropower development to meet energy demand.
10.3 Degradation of Natural Resources
Natural resource degradation is any change or disturbance to the environment that causes deterioration, destruction, or depletion of resources like soil, trees, water, or air. It can destroy ecosystems and cause wildlife extinction.
10.3.1 Soil Degradation: Causes and Consequences
Soil degradation is a long-term decrease in soil productivity. It includes:
Water and wind erosion.
Chemical degradation (soil acidification, salinization, pollution).
Physical degradation (soil compaction).
Soil erosion is the washing away of topsoil by water and wind. Human activities like vegetation removal, tillage, overgrazing, mining, and construction accelerate it. This loss results in lower yields, nutrient loss, increased production costs, water pollution, and sediment accumulation in dams, which reduces power generation.
Soil chemical degradation involves nutrient loss, acidification, salinization, and fertility decline, caused by deforestation, agricultural mismanagement, and industrial pollution. Soil acidification is common in high-rainfall highland areas, caused by leaching of basic nutrient ions or improper use of acid-forming fertilizers, resulting in decreased soil pH. The most suitable soil pH is between 6.5 and 7.2
Soil salinization is the excessive accumulation of soluble salts, mainly in lowland areas with low rainfall and salt-rich irrigation. Evaporation leads to salt accumulation, causing dehydration of plants and restricting cropping options.
Soil physical degradation is the deterioration of soil composition and structure, resulting in compacted soils due to erosion, intensive tillage, overgrazing, and urban expansion. This leads to reduced root growth, water and air movement, nutrient uptake, microbial activity, water storage, and increased flooding, which reduces plant growth and yields.
10.3.2 Water Pollution: Causes and Consequences
Water pollution is the presence of harmful substances in water, spoiling its quality. Sources include:
Industrial waste containing acids and alkaline chemicals.
Organic wastes from humans, animals, agriculture, and food processing.
Inorganic substances such as phosphorus and nitrogen fertilizers.
Metals from kitchen tools, paints, and fuels.
Toxic substances like chlorine from disinfectants.
Organic pollutants like gasoline, oil, diesel, and pesticides.
Solid particles such as sands, silts, clays, and plant fragments.
Microscopic organisms like bacteria and viruses.
These pollutants can kill aquatic animals, cause diseases in humans and livestock, reduce visibility, harm bottom-dwelling organisms, and make water treatment difficult and expensive.
10.3.3 Forest and Wildlife Degradation: Causes and Consequences
Forests provide firewood, construction materials, medicines, timber, and food. They reduce carbon release by storing it in their biomass and provide habitats for wildlife.
Forest degradation results from increasing forest fires, diseases, logging, and climate change. Fires are often used to clear forests for agriculture. This loss contributes to climate change, desertification, and soil erosion, reducing food production.
Wildlife degradation is a reduction in population size and types of wildlife species and happens because of habitat destruction. Endangered species are at risk of extinction, while threatened species may become endangered soon. Major causes include:
Expansion of agriculture.
Environmental pollution.
Loss of habitat and mobility.
Limitation of vegetation expansion.
Introduction of non-native species.
International trade of animal products and medicinal plants.
Degradation results in the loss of wildlife resources, reducing species diversity.
10.3.4 Causes and Consequences Air Pollution
The atmosphere is composed of nitrogen gas (78%) and oxygen (21%), with other gases making up only 1%. Air pollution occurs with high concentrations of harmful substances, including solid particles and harmful gases, emitted from cars, industries, agriculture, and construction activities. Other causes include soot, smoke from biomass burning, and pollen and spores from plants.
Health problems caused by air pollution include respiratory issues, heart diseases, and lung cancer, reducing the quality of human life and life expectancy. It also harms livestock and plants by reducing their health and productivity.
10.3.5 Environmental Impact of Mineral Exploitation
Mining provides raw materials for industries but can cause environmental problems. Surface excavation releases dust particles, polluting the air. Crushed rocks and leftover materials pollute soils and water. Separation processes use water and chemicals, including heavy metals and radionuclides, which can pollute water resources.
Air pollution from mining can cause serious health problems. Water and soil pollution can harm soil, aquatic organisms, and humans.
11.1 Concepts of Natural Resource Use
Many natural resources are available in limited quantities which makes wise use and proper management of resources is important. Understanding the terminologies and concepts of natural resource management is also vital for sustainability.
Carrying capacity: The maximum population level a given resource can sustain (e.g., grassland supporting livestock).
Sustainable use: Resource use that meets current needs without compromising future generations' access.
11.2 Soil Management
Soil management affects soil erosion and degradation. Repeated cultivation causes compaction, increasing runoff and erosion. Bare soils are easily washed away by water or wind. Effective soil management reduces soil erosion and promotes crop productivity, Soil loss by erosion reduces the productivity of soils.
Agronomic measures like mulching, mixed cropping, contour cultivation, and strip cropping are used in annual crop production to protect soils from erosion.
Mulching: Spreading organic or inorganic materials on the soil surface to prevent direct exposure to raindrops and runoff which absorbs rain drop energy and reduces run off.
Mixed cropping: Growing crops in mixture to provide better coverage for the soil. An example is growing beans with maize.
Contour cropping: Planting different crops along the contour to control soil erosion; plant strips reduce sediment transport down the slope.
Contour cultivation: Cultivating soil opposite the slope direction to reduce runoff water speed.
Improving soil organic matter content through legume crops, manure, compost, or organic fertilizers improves soil fertility and resistance to soil erosion. Traditionally, wood ash is added to reduce soil acidity.
Soil Acidity can be addressed by
Liming: Adding calcium and magnesium-rich materials to increase soil pH.
Planting of acid tolerant crops
Management of saline soils includes leaching accumulated salts with good quality water and adding organic fertilizers. Also, salt-tolerant crops (sorghum, barley, and wheat) can be used.
11.3 Agricultural Water Management
Agriculture depends on water resources, often lost through evaporation, transpiration, runoff, and deep percolation. Effective water management practices improve water availability for plant growth.
Rainwater conservation: Using water harvesting techniques to store rainwater for use during shortages.
Reducing evaporative loss of water using mulching
Soil conservation practices: Contour farming, contour bunding, and bench terraces reduce runoff and increase water infiltration, making water available for crops and selecting appropriate crops for diy areas.
Bench terrace: used to reduce flooding and soil erosion.
In areas that use irrigation, water losses should be minimnized.
11.4 Forest and Wildlife Management
Maintaining and improving forest cover increases carbon storage, reduces carbon emission, protects soils against erosion and provides habitat for wildlife , increases carbon storage, protect soils, and provide habitat for wildlife.
Forest management practices include afforestation, reforestation, controlled timber harvesting, and fire prevention. Needed to provide for fuel wood, timber, employment and reduce climate change vulnerability.
Wildlife destruction occurs due to habitat loss. Protection of wildlife habitats is an integral part of management and conservation of wildlife resources. This includes reducing agricultural encroachment, preventing invasive species, creating buffer zones, and controlling population growth.
11.5 Environmental Management
Environment refers to climatic, biological, and chemical conditions affecting organisms. Environmental management aims to protect human health, wellbeing, and conservation of all life forms. The major aim of environmental management is to prevent the release of harmful chemcials into the environment, and ensuring the protection of human health and wellbeing.
The goals of environmental management are to:
Prevent air pollution and improve air quality.
Minimize water pollution.
Reduce health and environmental risks of pesticides.
Introduce sound solid waste management practices.
Ensure farmers meet environmental regulations.
11.6 Indigenous Knowledge Applicable in Natural Resources Management
Farmers in north Shewa apply indigenous practices for soil and water conservation, including:
Constructing waterways between farms.
Constructing ditches.
Using stone lines across farms.
Planting trees on the edge of farms.
Using local vegetative barriers.
The Gumuz community in northwestern Ethiopia has indigenous knowledge in natural resource management based on traditional beliefs.
Beliefs include:
Natural resources are sacred gifts from God.
Natural resources are ancestral heritage owned by the whole community.
This knowledge includes norms, values, ethics, and taboos enforced as customary laws by elders.
12.1 What is Biodiversity?
Biodiversity encompasses all forms of life on Earth, including plants, animals, humans, bacteria, and other organisms. It includes the number of species, genetic diversity, population of each species and the diversity of habitats and landscapes of the species.
It can be assessed at different scales.
12.2 The Scope of Biodiversity
Biodiversity deals with the diversity of:
Plant species (crop and forest genetic resources).
Animal species (farm animal and wildlife genetic resources).
Microbial genetic resources.
12.3 Values and Services of Biodiversity
Biodiversity provides various values and services, including:
Food production.
Firewood, fiber, and construction materials.
Medicinal resources.
Climate regulation.
Disease and pest control.
Pollination.
Purification of water and air.
Soil erosion control.
Waste decomposition.
Recreation.
Education and research etc.
12.4 Threats to Biodiversity
Biodiversity faces threats from:
Conversion of natural habitats for agriculture (land use change). Results in several number of plant and animal species.
Overexploitation of resources (overgrazing, hunting. Results soil erosion and can result in loss of plant and animal species.
Invasive species (Parthenium weed, Prosopis juliflora, water hyacinth).
Climate change (increased temperatures, altered rainfall patterns). This shorterns crop growing season in many areas.
Environmental pollution (improper waste management).
Population growth (increased demand for food and resources).
12.5 Biodiversity Conservation and its Status in Ethiopia
Biodiversity conservation refers to the planned management of biodiversity in a particular ecosystem to prevent habitat destruction , overexploitation, polution to ensure biodiversity is maintained.The major focus should be maintaining a sustainable use of species, ecosystem and life suporting systems of the ecosystem to manage losses Human activities disrupt the natural habitats of various species of plants leads reduction in the number of species.
Ethiopia has diverse ecosystems with rich biological resources including field crops, horticultural crops, medicinal plants and forests. This also includes animal and wildlife resources. The ecosystems in the country is seriously threatened by deforestation,habitat destruction and poor regeneration.
There are are different efforts already in place in different regions to reduce the destruction of forest resources. This involved several protected areas such as national parks, wildlife sanctuaries, wildlife reserves and botanical gardens
13.1 Definitions of Climate Change and Variability
Climate change is a long term change in temperatures that result in warming of the earth.
Climate variability are short term days, weeks or months, and does not cause fundamental changes in the ecosystems .
It causes production of green house gases in the atmosphere. Some causes of climate change are: Decrease crop,animal and Species productivity; Changes in water availability,storm p;atterns and increased flooding of coastal areas; Increased Drought.
Greenhouse gases mainly consists of Carbon dioxide(CO2), Methane(CH4) and Nitrous Oxide (N_2O) causes pollution and increase in surface temperature and depletion of Ozone Layer.
13.2 Climate Change and Its Effects
Climate change causes changes in the rainfall amount, distribution , global temperatures and the melting of ice-caps and glaciers that will increase sea level and droughts as consequences.
Effects include: Decrease in water availability; Increase in soil erosion, in temprature and may cause disease and increase in global warming and decreased livestock yields.
This makes Ethiopian agriculture high vulnerable for its low use of production which is needed to reduce climate change effects in the sector .Climate change also afects reduced vegetation productivity
This causes the forest to:
store carbon properly.
Regulate Climate ,be a habilat for various organisims and loss plant and animal biodiversity.
This casues ocean acidification and can damage the overall ecosystem
13.3 Strategies of Mitigating Climate Change
Climate change mitigation is the activities implemented to either reduce or remove or remove the emissions of green house gasses to the atmosphere and energy.
This is done through Reducing green house gas emissions.
The Largest use Carbon Dioxide from Fossil fule energy burning and it has reduced Deforestation reducing carbon emmissions
Enhancing Carbon Sincks through Afforestation that is increasing carbon storage capacity and helps in improveing soil Management like soil conservation practices .The practices include crop rotation, mixed cropping, mulch and use of terraces and other physical soil conservation structures
13.4 Climate Change Adaptation Strategies in Ethiopia
Climate change adaptation refers to the adjustments that framerers and other major communities make in response to actual or expected change that happens in climate, crop production and animal rearing practices.
The most common climate change adaptation practices, Include: changing crop calendar/ type with weather and crop condictions like plant and animal breeds which are better with the temperatures ,less water and better feed conversion
Farmers make adjustaments in farming system with a: Income sources and Diversicication.
Climate Smart Agriculture (CSA) is an intergrated approach where crop livestock management and natural resourses are managed to increase sustainable productivity. It reduce climate varability improve crop capcity to adapt to climate changes reduce emission from plant managment and integrated resources
13.5 Indigenous Knowledge in Climate Change Mitigation Strategies
The protection of environment is supported throughout the community. The Gedeo community in southern Ethiopia has rich culture and indigenous knowledge that encourages environmental protection by respecting Mountains , Trees and riversides . This has maintain the Agroforesry systems in the community by the konso Community that they help reduce soil degradation and has created a more agriculture space. There are also other traditional soil conservation terraces.
14.1 Introduction to Mechanized Farming
Mechanization is the use of machines to replace human or animal labor.
Advantages of farm Mechanization include:
Saves Time; Reduces Difficulty in Farming; Save labor; Reduces farm Health Hazards; Encourage Large Scale Farming; Increase the farm output/income ,encorage framers cooperation
Disadvatages of farm mechanization:
Machinery can be expensive to purchase or hire. Machineries Driven by Fossils fuel cause environmental pollution ,Poor soil Compaction; Requires Continous supply of energy form fules and elctricity
Three Levels of Mechanization:
Low, Fair and High Leves
1) Low Level: manual labour greater than 33%.
2) Fair Level: animal power used is 34-66%.
3) High Level: mechanical power used is over 67%.
14.2 Types of Farm Tools and Equipments
Soil Cultivation Implementation: this is used for plowing and preparing it for Soil Cultivation by tilers disk hallows and moldboard ploughs.
Planting Machine: this is used for planting trees and seed after the soil is cultivated like a Seeder
Harvesting Equipment: This is used to gather crops , digger , pickers and trailers
Irrigation machinery: Used for central pivot irrigation systems and pump units, the equipment here is used for watering crops on large farms.
Feed Processing equipment: Measuring scale,shovel,Baler ,Millers/Grinders, Hackers and Choppers and mixers
Daily Machinery: Milk container,Buckets,Automatic machinery ,Pasturisers and Coolers,Separator, continuous freezers and butter churner and cheese molder.
Miscellaneous agricultural equipmnet: Aeresols,forestry machine,sophisticated Machinery Remote Sensing And fruit pickers Equipment’s These are used for carring our operations such heavy marketing loading shedding etc. .These are also some of agriculture.
14.3 Tools and Equipment Used In Farms
A Plough and tractor for the tilling of the soil.
Sub-Soiler: This is a tractor use to looses the deep soils. And helps the growth of crops that had Soil Compaction. Sub-Soiler is used for soil compaction.
A set of Harrows are there to level the soil by smoothing by breaking up the soil,and helps create structure and seed bed from lumps of soil
Seed drill for planting seed as the same depth for planting.
A sprinkler system is there to irrigate the whole land in mainating huumdity, while Combine harvester is to the efficiently harvest all grains crops from the field and Collect straws etc
Millers and Grinders that Helps reducing wheats ,barley and corns to help feeding A feed Mixer that mixes the feed ingredients to help form a good rection.
Coolers, churners
An incubator help keeps the eggs for a heat and keeps it warm.
A Sprayer this is to spray chemicals on the farm.
Pruning shears are strong sheers that sharp heavy that helos cut branches of tree and plant stems to help plant growth.
15.1 Definition of Basic Terms in Human Nutrition
Nutrition is the Science of ingesting the body,assimilation absorbing, biosynthesizing of nutrients in the body.
Food :are substances eaten or drank maintains life for a culture and nutritious substance to maintain life and growth.
Diet: refers the way and foodstuffs that people use and how
Nutrients are chemical substance that are uses to sustain a life and growth
Macronutrireants used for body systems ,are Carbohydrates Fats and Proteins.
Micronutrients used for healthy and for growth they are vitamins
balanced diet contains, sufficient nutrient, balance and variety
15.2 Nutrients and Their Functions
There are 6 main clases of nutirens that human body needs:They are:
1) Carbodhydrate 2) Protein
3) Lipids/oils/ fats 4) Vitamins