ESS TOPIC 5
Explain why commercial farming tends to reduce soil fertility more than subsistence farming?
A significant amount of chemical and energy input is required in commercial and industrialized food production systems. This is achieved through the application of synthetic chemicals, genetically modified organisms, and a number of other industrial products. This method usually alters the natural environment, deteriorates soil quality, and eliminates biodiversity. The goal of commercial and industrialized food production systems is to maximize the potential yield of crops.. In maintaining a conventional system, biodiversity, soil fertility, and ecosystems health are compromised. Sustainable agriculture is a more holistic approach to farming than conventional in that it relies on ecological processes, biodiversity and cycles adapted to local conditions, rather than the use of inputs with adverse effects Sustainable agriculture is a natural way to produce food and has a number of social, economic, and environmental benefits.
What are the causes of imbalanced food distribution?
Cause in imbalance food distribution Ecological: some climate and soils are better for food production Economic: advance technology and money can overcome ecological limitation (transportation of water) Socio-political: underinvestment in rural area and rapid area in LEDC; poor human health weaken available labor force
Explain the relationship between soil ecosystem succession and soil fertility.
First, lichens, which grow on rock, appear in a destroyed region. The lichens help break down the rock. Then, as lichens die and decompose, and weathering breaks apart rock, soil begins to form. As soil becomes richer, small plants like mosses and ferns appear, and the lichens start to disappear. The soil continues to become richer as plants continue to die and decompose, and flowering plants and grasses appear, bringing insects to the region. In time, shrubs and small trees cover the region, creating a suitable habitat for reptiles, birds, and mammals. As the shrubs and trees grow, smaller plants die from lack of sunlight and add more organic material to the soil. Eventually, the shrubs and trees die because taller trees cover the region. This all happens gradually over a long period of time.
What are the ways to increase the sustainability of terrestrial food production systems?
Increased sustainability may be achieved through: altering human activity to reduce meat consumption and increase consumption of organically grown and locally produced terrestrial food products, improving the accuracy of food labels to assist consumers in making informed food choices, monitoring and control of the standards and practices of multinational and national food corporations by governmental and intergovernmental bodies, planting of buffer zones around land suitable for food production to absorb nutrient runoff.
What are the inputs and outputs in a soil system.
Inputs: -fertillizer -nitrogen fixation -plant& animal residues -precipitation Outputs: -crop removal -leaching loss -denitrification -erosion -gaseous losses: High losses of nutrients can also occur when specific environmental conditions promote the export of nutrients in a gaseous form. When the soil is wet and anaerobic, many compounds are chemically reduced to a gas from solid forms in the soil. This is especially true of soil nitrogen.
What are the relative environmental impacts of commercial farming?
Negative impacts include escalating water and land use, soil erosion and degradation through loss of fertility or desertification, loss of biodiversity, and intensive use of energy (for production, notably for fertiliser manufacture, and for supply, especially in transport and refrigeration) with associated greenhouse gas emissions
What are the benefits of eating on the lower food chain?
Not as much land and other resources raising grain to feed to animals. Overgrazing on public and private range lands could decrease. Would not have to farm or graze marginal lands as intensively More people in the world could receive an adequate diet Less fossil fuel energy (and associated emissions of CO2) would be required to produce our food.
What is overgrazing and what are the consequences of it?
Overgrazing is grazing by livestock at high density which removes the vegetation covers. The consequences are that there is increase in soil erosion due to the increasing fragility of the soil which can lead to desertification.
What are the effects of reduced soil fertility?
Reduced soil fertility may result in soil erosion, toxification, salination and desertification.
What are some soil conservation methods?
Soil conservation measures include soil conditioners (such as organic materials and lime), wind reduction techniques (windbreaks, shelter belts), cultivation techniques (terracing, contour ploughing, strip cultivation) and avoiding the use of marginal lands.
How do Socio-economic, cultural, ecological, political and economic factors influence societies in their choices of food production systems?
Social influences on food intake refer to the impact that one or more persons has on the eating behavior of others, either direct or indirect, either conscious or subconscious. The relationship between low socio-economic status and poor health is complicated and is influenced by gender, age, culture, environment, social and community networks, individual lifestyle factors and health behaviors. There are clear differences in social classes with regard to food and nutrient intakes. Low-income groups in particular, have a greater tendency to consume unbalanced diets and have low intakes of fruit and vegetables. Education level and income determine food choices and behaviors that can ultimately lead to diet-related diseases. The origins of many of the problems faced by people on low incomes emphasizes the need for a multidisciplinary approach to targeting social needs and improving health inequalities.
Discuss the influences of human activities on soil fertility and soil erosion
Soil is a non-renewable resource that once it is eroded it is not renewed. Soil erosion is the permanent change of the main characteristics of soil that could see it lose its fertility, pH, colour, humus content or structure. Soil erosion occurs naturally by wind or harsh climatic conditions but human activities include overgrazing, overcropping and deforestation. Overgrazing occurs when farmers stock too many animals such as sheep, cattle or goats on their land. The animals damage the soil surface by eating the vegetation and either digging into wet soil or compacting dry soil with their hooves. Overcropping is when the land is being continuously under cultivation and is not allowed to lie fallow between crops. This constant farming of the land reduces the soils ability to produce valuable humus for soil fertility as it is constantly being ploughed or stripped for crop growth. The soil becomes drier and less fertile. Deforestation is the cutting down of large areas of forests leaving an open, exposed landscape. Deforestation occurs for many reasons such as the sale of wood, charcoal or as a source of fuel, while cleared land is used as pasture for livestock, plantations of commodities, and settlements. The removal of trees without sufficient reforestation has resulted in damage to habitat, biodiversity loss and aridity (drying of soil).
Explain how soil can be viewed as an ecosystem.
Soil is the link between the air, water, rocks, and organisms, and is responsible for many different functions in the natural world that we call ecosystem services. These soil functions include: air quality and composition, temperature regulation, carbon and nutrient cycling, water cycling and quality, natural "waste" (decomposition) treatment and recycling, and habitat for most living things and their food. We could not survive without these soil functions. Billions of organisms inhabit the upper layers of the soil, where they break down dead organic matter, releasing the nutrients necessary for plant growth. The micro-organisms include bacteria, actinomycetes, algae and fungi. Macro-organisms include earthworms and arthropods such as insects, mites and millipedes. Each group plays a role in the soil ecosystem and can assist the organic farmer in producing a healthy crop. Micro-organisms can be grouped according to their function: free-living decomposers convert organic matter into nutrients for plants and other micro-organisms, rhizosphere organisms are symbiotically associated with the plant roots and free-living nitrogen fixers.
What is the sustainability of terrestrial food production systems influenced by?
The sustainability of terrestrial food production systems is influenced by factors such as scale; industrialization; mechanization; fossil fuel use; seed, crop and livestock choices; water use; fertilizers; pest control; pollinators; antibiotics; legislation; and levels of commercial versus subsistence food production.
What are the three main ways to manage salt-affected soils?
The three main ways of managing salt-affected soils is by: flushing the soil with water and leaching the salt away using gypsum and calcium sulfates to replace sodium ions on the clay and colloids reduction in evaporation losses to reduce the upward movement of water in the soil
What are the transfers of matter within the soil system.
Transfers of material within the soil, including biological mixing and leaching (minerals dissolved in water moving through soil), contribute to the organization of the soil.
What are the transformations of matter within the soil system.
Transformations include decomposition, weathering and nutrient cycling.
Compare and contrast the structure and properties of sand, clay and loam soils.
Water retention and availability: Clay--> sticky and easily waterlogged Loam--> High to medium Sand --> Fast draining soils that dry easily Nutrient storage capacity: Clay--> High loam--> medium sand --> low Air space: clay --> low sand --> high loam --> medium Primary productivity: Clay --> medium/low sand-->low loam --> medium
Discuss the links that exist between sociocultural systems and food production systems.
Wet rice systems of South-East Asia Rice can be grown in dry fields but wet rice agriculture (padi field), has become the dominant form of growing rice in South-East Asia. It is another example of intensive subsistence farming, using high labor and low technology. Padi fields are usually placed in areas that flood naturally bringing in new deposits of silt which increase productivity. See also rice fish farming. The system may only be appropriate if there is a reliable water supply and fields located close to the family house so that they can be monitored.
What are the inputs, outputs and system characteristics of a farming system?
inputs, such as fertilizers (artificial or organic); water (irrigation or rainfall); pest control (pesticides or natural predators); labour (mechanized and fossil-fuel dependent or physical labour); seed (genetically modified organisms—GMOs—or conventional); breeding stock (domestic or wild); livestock growth promoters (antibiotics or hormones vs organic or none) outputs - outputs, such as food quality, food quantity, pollutants (air, soil, water), consumer health, soil quality (erosion, degradation, fertility); common pollutants released from food production systems include fertilizers, pesticides, fungicides, antibiotics, hormones and gases from the use of fossil fuels; transportation, processing and packaging of food may also lead to further pollution from fossil fuels system characteristics—selective breeding, genetically engineered organisms, monoculture versus polyculture, sustainability, system characteristics - such as diversity (monoculture versus polyculture); sustainability; indigenous versus introduced crop species socio‑cultural—the Maasai cattle equals wealth and quantity is more important than quality; environmental impact—pollution (air, soil, water); habitat loss; biodiversity loss; soil erosion or degradation; desertification; disease epidemics from high-density livestock farming socio-economic factors - arming for profit or subsistence, for export or local consumption, for quantity or quality; traditional or commercial farming.
What human activities cause desertification?
over-cultivation exhausts the soil, overgrazing removes the vegetation cover that protects it from erosion deforestation destroys the trees that bind the soil to the land and poorly drained irrigation systems turn croplands salty. the lack of education and knowledge the movement of refugees in the case of war, the unfavorable trade conditions of developing countries and other socio-economic and political factors enhance the effects of desertification.
What are some human activities that can reduce soil fertility?
● Human activities that can reduce soil fertility include deforestation, intensive grazing, urbanization and certain agricultural practices (such as irrigation and monoculture). ● Commercial, industrialized food production systems generally tend to reduce soil fertility more than small-scale subsistence farming methods.
What are the storages in a soil system.
● Soil system storages include organic matter, organisms, nutrients, minerals, air and water.
