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CGEO 702 TECHNOLOGY & CONTEMPORARY ENVIRONMENT [Agriculture and food production systems] Dr Abednego Aryee Geography Department Ryerson University Soil as a system Soil consists of mineral matter, organic matter, air, and water Dead and living microorganisms, and decaying material Bacteria, algae, earthworms, insects, mammals, amphibians, and reptiles FIGURE 7.1 7-* A soil profile consists of horizons Horizon = each layer of soil Soil profile = the cross-section of soil as a whole Topsoil = inorganic and organic material most nutritive for plants Leaching = dissolved particles move down through horizons 7-* AGRICULTURAL SYSTEMS Subsistence rural agriculture - Shifting cultivation - Slash and burn (swidden agriculture) - Pastoral nomadism - Intensive subsistence Commercial agriculture - Mixed farming - Livestock Agricultural systems continued Agro-forestry Plantation agriculture Palm Oil Plantation Three agricultural revolutions domestication, continued Origin of plant and animal domestication. Two types of plant domestication: vegetated planting and seed agriculture. Agriculture arose 10,000 years ago Agriculture was invented independently by different cultures FIGURE 7.8 7-* Source: Rural Heritage Collection, University of Guelph Archives, XA1 MS A182 #77 Loading Hay with hayloader, 1916 Pulling Flux, 1919 Source: Rural Heritage Collection, University of Guelph Archives, XA1 MS A182 #77 AGRICULTURE REVOLUTIONS First agriculture revolution Second agriculture revolution Third agriculture revolution Industrial agriculture The Von Thunen Model Location-Rent Gradients for Competing Crops Fig. 6. 23 Farmers choose the highest-profit crop at each distance from the market. Traditional vs. Industrial agriculture FIGURE 7.9 7-* Solar Radiation Abiotic substances Current photosynthesis Rumen flora Decomposers (Bacteria, fungi etc.) Primary production Organic Useful Respiration residues yield losses & pests Air and soil energy & moisture Primary consumers Organic Useful Respiration Residue yield losses & pests Secondary consumers (man) Useful Organic Respiration yield residue losses & pests Concentrated Energy Dispersed Source: Duckham and Masefield (1971) Heat loss Heat loss Heat loss Heat loss Heat loss Light or heat energy or power Chemical energy in food Abiotic sustances or manufacture Human energy Energy flow in a simple farming systems Solar Radiation Abiotic substances on farms Current photosynthesis Rumen flora Decomposers (Bacteria, fungi etc.) Primary production Organic Useful Respiration Residues yield losses & pests Industrial & scientific inputs Primary consumers Organic Useful Respiration Residue yield losses & pests Secondary consumers (man) Useful Organic Respiration yield residue losses & pests Concentrated Energy Source: Duckham and Masefield (1971) Heat loss Heat loss Heat loss Heat loss Light or heat energy or power Chemical energy in food Abiotic substances or manufacture Human energy Feeding stuffs, seeds, livestock, Purchased from other agric systems Energy flow in a complex farming systems Prehistoric photosynthesis Fossil fuels Wind power Water power (current) Non-food Human demands Manufacture transport Abiotic Substances not on farms Air and soil energy & moisture Dispersed GREEN REVOLUTION - Classical breeding - Transgenic ally modified organisms The term is widely used since the 1940s to describe the effort to increase and diversify crop yields in agriculturally less advanced regions of the world. High-yielding modern varieties (MV) of wheat, maize and rice characterized the green revolution Green revolution seeds were more responsive to controlled irrigation and synthetic fertilizers and the miracle seeds spread throughout develop ing world. BENEFITS OF BIOTECHNOLOGY Intensification & extensification Reduce the acquisition of new lands for cultivation Precision farming - genes lethal to pests eg. Bt PROBLEMS OF GREEN REVOLUTION 1. Excessive use of water, fuels, chemical fertilizers and pesticides 2. Biodiversity loss through monoculture 3. Disease and pests 4. Narrowing human diet 5. Bio-fuels affect food availability 6. Biotech companies like Monsanto into bio-powers AGRO-ECOSYSTEM HEALTH 1. Biological control 2. Bt = Bacillus thuringiensis 3. Integrated pest management 4. Increase and protect pollinators SOIL MANAGEMENT Many alternative cropping systems include; - crop rotation - contour farming - terracing - intercropping - shelterbelt - Reduced tillage Other farmers are practicing organic farming Crop rotation Crop Rotation = alternating the crops grown field from one season or year to the next Cover crops protect soil Contour Farming = plowing furrows sideways across a hillside, perpendicular to its slope, to prevent rills and gullies Contour farming 7-* Terracing level platforms are cut into steep hillsides, forming a “staircase” to contain water Intercropping = planting different types of crops in alternating bands or other spatially mixed arrangements to increase ground cover Terracing Intercropping Shelterbelts or Windbreaks = rows of tall, perennial plants are planted along the edges of fields to slow the wind Alley cropping = shelterbelts + intercropping Shelterbelts Reduced tillage Reduced Tillage = furrows are cut in the soil, a seed is dropped in and the furrow is closed 7-* WHAT IS ORGANIC FARMING? The Food and Agriculture Organization (FAO)/World Health Organization (WHO) defines Organic farming as; “A holistic production management system which promotes and enhances agro-ecosystem health, including biodiversity, biological cycles and soil biological activity. The primary goal of organic agriculture is to optimize the health and productivity of interdependent communities of soil life, plants, animals and people”. Source: Food and Agriculture Organization “Mixed cropping optimizes nutrient and energy flows” Diversification Decreases Vulnerability to Weather Vagaries & Other Factors Source: FAO, Edible Nasturtium flowers attract pollinators Organic Agriculture Promotes Pollinators Organic Honey Enjoys a Growing Demand Source: FAO Organic Bee Keeping, Italy
