Agriculture Under Anthropocene PDF

Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 Environment under the Anthropocene Agriculture Environmental Sciences...

Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 Environment under the Anthropocene Agriculture Environmental Sciences Department of Biological Sciences College of Science 1 Agriculture the science, and art, of cultivating the soil, producing crops, and raising livestock. Even relatively simple agricultural rappler.com practices can greatly increase the production of food, compared with the hunting and gathering of wild animals and plants. 2 1 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 Agriculture as Major Food Source About 10,000 years ago, humans began to shift from hunting for and gathering their food to growing it and raising Croplands animals for food and labor. About 66% of the world’s people survive primarily by eating rice, wheat, and corn. FOOD SUPPLY Only a few species of mammals and fish provide most of the world’s meat and Ra seafood. an d pa ngel es ure stu an r i fee res, ds, Since 1960, there has been an increase he lt Fis uacu dlo and q ts in global food production a 3 Crop Plants Almost all the important agricultural crops have been domesticated. Domestication refers to the progressive modification of crops through the selective breeding of cultivated races (or cultivars), which are now genetically, anatomically, and physiologically different from their wild ancestors. corn, grains, rice, oats, legumes, vegetable fruits 4 2 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 Impacts of Agriculture to the Environment 5 Environmental Impacts Desertification Declining Site Capability Salinization Nutrient Loss Organic Compaction Matter Soil Erosion 6 3 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 Declining Site Capability Land Use Change The management or modification of the earth’s land surface by human agents. refers to the conversion of natural landscapes like forests or wetlands into built environments or agricultural production, but also includes activities such as mining or the storage of waste into landfills. www.worldbank.org 7 Agricultural Site Capability refers to the ability of an ecosystem to sustain the productivity of crops. Soil fertility is an important aspect of this – it is related to the amount of nutrients present and to factors affecting their availability, such as drainage, tilth, and organic matter in the soil. Site quality can be degraded by agricultural practices, which may result in the erosion of topsoil, loss of organic matter and nutrients, and a buildup of weed populations. 8 4 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 9 The expansion of agriculture has been one of humanity’s largest impacts on the environment. 10 5 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 Monoculture and Plantation Agriculture used to grow crops can be divided roughly into two types: Industrialized agriculture, or high-input agriculture, uses heavy equipment and large amounts of financial capital, fossil fuel, water, commercial inorganic fertilizers, and pesticides to produce single crops, or monocultures. Major goal of industrialized agriculture is to increase yield, the amount of food produced per unit of land. Used on about 25% of the world’s cropland, mostly in more-developed countries, and produces about 80% of the world’s food. 11 Monoculture and Plantation Plantation agriculture is a form of industrialized agriculture used primarily in tropical less-developed countries. Grows cash crops such as bananas, soybeans, sugarcane, coffee, palm oil, and vegetables. Crops are grown on large monoculture plantations, mostly for export to more-developed countries. Modern industrialized agriculture violates the three principles of sustainability by relying heavily on fossil fuels, reducing natural and crop biodiversity, and neglecting Oil palm plantation the conservation and recycling of nutrients in topsoil. 12 6 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 Industrialized agriculture involves several important shifts: 1 2 3 4 supplementing such producing a few types of producing food for using government energy with cheap crops and animals global consumption subsidies and policies to energy from fossil fuels. (monocultures) help manipulate supply and demand and keep food prices artificially low. 13 Soil Erosion Soil erosion is the movement of soil components, especially surface litter and topsoil from one place another by the actions of wind and water. increased by agricultural practices Erosion of topsoil has two major harmful effects. Loss of soil fertility through depletion of plant nutrients in topsoil. Water pollution in nearby surface waters, where eroded topsoil ends up as sediment. This can kill fish and shellfish and clog irrigation ditches, boat channels, reservoirs, and lakes. 14 7 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 Soil Erosion By removing vital plant nutrients from topsoil and adding excess plant nutrients to aquatic systems, we degrade the topsoil and pollute the water, and thus alter the carbon, nitrogen, and phosphorus cycles. Agricultural practices that increase the rate of soil erosion include the following: cultivating land on moderate to steep slopes ploughing furrows up and down slopes rather than contouring along them leaving fields without a cover (such as stubble or a cover-crop) during the winter 15 Topsoil erosion is a serious problem in parts of the world Serious concern Some concern Stable or nonvegetative 16 8 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 Compaction occurs when soil particles are pressed together, reducing pore space between them waterlogging oxygen-poor conditions impaired nutrient cycling poor root growth decreased crop productivity Compaction can be largely avoided by avoiding any unnecessary passages of heavy machinery over fields, using large tires to spread the load, and reducing the density of livestock kept in outdoor stockades. 17 Desertification Desertification in arid and semiarid parts of the world threatens livestock and crop contributions to the world’s food supply. Desertification occurs when the productive potential of topsoil falls by 10% or more because of a combination of prolonged drought and human activities that expose topsoil to erosion. The FAO’s 2007 report on the Status of the World’s Forests estimated that some 70% of world’s arid and semiarid lands used for agriculture are degraded and threatened by desertification. Sand dunes threaten to take over an oasis in West Africa 18 9 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 Variation in desertification in arid and semiarid lands, 2007 19 Salinization The buildup of soluble minerals in the surface soil, or salinization, is a major problem in drier regions. occurs when there are high concentrations of salts in the soil, and the rate of evaporation exceeds the water input from precipitation. Saline soil is toxic to most crops, largely because of interference with the uptake of water, along with ion imbalance and toxicity. 20 10 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 Pollution Caused by Agriculture 21 Nutrient Pollution Nitrogen, in the forms of nitrate, nitrite, or ammonium, is a nutrient needed for plant growth. About 78% of the air that we breathe is composed of nitrogen gas. Nutrients, such as nitrogen and phosphorus are essential for plant and animal growth and nourishment, but the overabundance of certain nutrients in water can cause several adverse health and ecological effects. Side effect of too much nitrogen and phosphorus Overstimulation of growth of aquatic plants and algae leading to clogging of water intakes Harmful to organisms 22 11 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 How can we restore soil fertility? 23 Restore soil fertility Topsoil conservation is the best way to maintain soil fertility, with restoring some of the lost plant nutrients being the next option. Organic fertilizer from plant and animal materials. Animal manure Green manure Compost Organic agriculture uses only organic fertilizers and crop rotation to replenish the nutrients. Synthetic inorganic fertilizers are usually inorganic compounds that contain nitrogen, phosphorus, and potassium. 24 12 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 Reduce soil salinization and desertification One way to prevent and deal with soil salinization is to reduce the amount of water that is put onto crop fields through use of modern efficient irrigation. Reducing desertification is not easy because we can’t control the timing and location of prolonged droughts caused by changes in weather patterns. 25 How to prevent salinization and desertification? diversion of surface flows installation of a subsurface drainage system using longer crop rotations (including deep-rooted forage species), practicing conservation tillage increasing organic matter in the soil. Salt-tolerant crops may be grown on moderately salinized soil, such as barley (Hordeum vulgare) or forage plants such as alfalfa (Medicago sativa) and slender wheatgrass (Agropyron trachycaulum). 26 13 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 Three types of systems commonly used to irrigate crops Drip irrigation (efficiency 90–95%) Center pivot (efficiency 80% with low-pressure sprinkler and 90–95% with LEPA Above- or below-ground Gravity flow sprinkler) pipes or tubes deliver (efficiency 60% and 80% with surge valves) Water usually pumped from water to individual plant underground and sprayed roots. Water usually comes from an aqueduct from mobile boom with system or a nearby river. sprinklers. Fig. 10-24, p. 229 27 Philippine Agriculture 28 14 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 III. Philippine Agriculture Agriculture remains of crucial importance of the Philippine Economy. Relative contribution to gross domestic product (GDP) has been declining over the years. provides employment to close to 30% of the country’s Labor force. https://ap.fftc.org.tw/article/500 29 PRINCIPAL CROPS Rice Sugar Cane Corn Abaca Coconut Tobacco www.worldbank.org Philippine Agricultural land from1961- 2018 30 15 Intended for UST ELE-ES students only. 2/17/22 Second Term, 2021-2022 Challenges of Philippine Agriculture Low agricultural diversification and low productivity Climate change Natural resources degradation declining number of workforce Lack of technology investment. gradual industrialization 31 Summary 32 16