Presentation on theme: "“In the end we will conserve only what we love; we will love only what we understand; and we will understand only what we have been taught.” – Baba Dioum."— Presentation transcript:
“In the end we will conserve only what we love; we will love only what we understand; and we will understand only what we have been taught.” – Baba Dioum CP551 Sustainable Development 28 March 2008 R. Shanthini
Module 8: Use of fertilizers and pesticides, green revolution and agricultural biotechnology in the agricultural sector, and their impact on sustainable development. 28 March 2008 R. Shanthini
between 1960 and 2000: –world population doubled from 3 to 6 billion people –global economy increased more than sixfold to meet this demand: –food production increased 2 ½ times –water use doubled –wood harvests for pulp and paper production tripled –timber production increased by more than half –installed hydropower capacity doubled 28 March 2008 R. Shanthini Source:
–Food production has more than doubled since 1960 –Food production per capita has grown –Food price has fallen Source: 28 March 2008 R. Shanthini
Growing crops need carbon (C), hydrogen (H), oxygen (O), energy, and other nutrients
Air gives C as CO 2 ; O as O 2 ; H as water vapour Water gives H Sunlight gives energy Soil gives other essential nutrients 28 March 2008 R. Shanthini Major nutrients: Nitrogen (N) Phosphorus (P) Potassium (K) Sulphur (S) Calcium (Ca) Magnesium (Mg) Minor nutrients: Iron (Fe) Molybdenum (Mo) Boron (B) Copper (Cu) Manganese (Mn) Zinc (Zn) Chlorine (Cl) and others…
Fertilizers are chemicals that supply the essential plant nutrients, mostly N, P and K, which are removed by crop plants in the largest quantities. 28 March 2008 R. Shanthini With high yielding varieties of crops, it is not possible for most soils to supply the needed amounts of plant nutrients and that is why fertilizers are needed.
28 March 2008 R. Shanthini Source: Nitrogen cycle
28 March 2008 R. Shanthini Source: Nitrogen fertilizer producing factory Nitrogen cycle
Since 1960: –Flows of biologically available nitrogen in terrestrial ecosystems doubled –Flows of phosphorus tripled More than 50% of all the synthetic nitrogen fertilizer ever used has been used since % of the increase in the atmospheric concentration of CO 2 since 1750 has taken place since March 2008 R. Shanthini Source:
Humans produce as much biologically available N as all natural pathways and this may grow a further 65% by March 2008 R. Shanthini Source:
28 March 2008 R. Shanthini Nitrogen-based fertilizers can be washed from the fields into rivers and streams, and from there into our water supply. Drinking water contaminated by nitrates can damage our health. For example, nitrates can cause "blue-baby syndrome" - a serious illness in infants which is caused when nitrate is converted into nitrite inside the body. Nitrite interferes with the oxygen-carrying capacity of the child's blood, and can be fatal.
Fertilizer run-off 3. Aquatic plants begin to die 4. Dead matter feeds the microbes 5. Microbes compete for dissolved oxygen 6. Water becomes deoxygenated 7. Fish die 1.Algae grow fast, using up lots of oxygen dissolved in water. 2.Algae block sunlight Eutrophication Source: 28 March 2008 R. Shanthini
Workers try to clean up a massive algal bloom spreading over Taihu Lake at Wuxi, in China's Jiangsu province. Photo: AFP
28 March 2008 R. Shanthini Severe algae bloom in the Great Lakes, USA
28 March 2008 R. Shanthini Source: This cyanobacterial bloom has the typical appearance of a thick layer of green paint. The bloom was found to consist of toxic species in the genus Microcystis. Photo by W. Carmichael
28 March 2008 R. Shanthini Dead fish from a Karenia brevis bloom in Texas. At high concentrations, toxins produced by this organism can cause massive fish kills. Photo by Brazosports Source:
28 March 2008 R. Shanthini This massive “red tide” of the dinoflagellate Noctiluca stretched for more than 20 miles along the southern California coast. It is a non-toxic bloom However, it can cause extensive mortalities of plants and animals in shallow waters when the bloom biomass decays, stripping oxygen from the water. Photo by P. Franks Source:
28 March 2008 R. Shanthini Source: Large blooms of Phaeocystis lead to the formation of noxious foams that accumulate on nearby coastal areas
28 March 2008 R. Shanthini Source: An example of foam produced during a Phaeocystis bloom in the North Sea. This material is unsightly and bothersome to coastal residents.
28 March 2008 R. Shanthini Source: Expansive blooms of several Caulerpa spp. occurred off the Florida coast in 1997 and Caulerpa spp. can grow year-round and have transformed some reefs into “Caulerpa meadows” where more than 70% of the coral surface is now dominated by these macroalgal HAB species. Photo by B. LaPointe
28 March 2008 R. Shanthini Harmful algal blooms are caused by species of tiny plants—phytoplankton— some of which produce potent chemical toxins. Abundance of nutrients in the ocean cause the algae multiply and proliferate until they can cover tens to hundreds of miles of coastal ocean. Photo by D. Anderson Source:
28 March 2008 R. Shanthini When shellfish accumulate dangerous toxins after filtering algae from water as food, public health is at risk. State and federal agencies monitor these shellfish for biotoxins and close affected areas, posting signs like this. Note that although the water appears clear, there is a danger present. Photo by J. Kleindinst Source:
28 March 2008 R. Shanthini Source: Researchers are investigating the use of natural clays in Florida’s Sarasota Bay as a potential tool to mitigate harmful algal blooms, or “red tide”. Photo by J. Culter
28 March 2008 R. Shanthini Every year, we spray 16.4 mm of active pesticide ingredients on every bit of land on earth. Pesticide Use:
28 March 2008 R. Shanthini Agriculture has become increasingly dependent on the use of pesticides. According to the EPA, 5351 million pounds of active ingredient were used in agriculture practices across the world in 2006 at a cost of US$26 billion dollars.
28 March 2008 R. Shanthini A plant retains only half of this applied spray as the leaf creates a non-wetting interface for the pesticide. The remaining pesticide runs off and contaminates soil and water supplies and kills terrestrial and aquatic life.
28 March 2008 R. Shanthini Fate processes of pesticides in the environment - Adsorption - Transfer - Degradation Volatilization Crop removal PhotodegradationRunoff Chemical degradation Absorption Adsorption Leaching Microbial degradation
28 March 2008 R. Shanthini Fate of pesticide in the environment is also determined by its characteristics, such as solubility in water (water solubility) tendency to adsorb to the soil (soil adsorption) pesticide persistence in the environment (half-life) Pesticides with high water solubility, low tendency to adsorb to soil particles and long persistence or half-life have the highest potential to move into water.
28 March 2008 R. Shanthini Soil adsorption is measured by Koc, which is the tendency of pesticides to be attached to soil particles. Higher values (greater than 1000) indicate a pesticide that is very strongly attached to soil and is less likely to move unless soil erosion occurs. Lower values (less than ) indicate pesticides that tend to move with water and have the potential to leach or move with surface runoff.
28 March 2008 R. Shanthini Water solubility is measured in parts per million (ppm), which measures how easily a pesticide may be washed off the crop, leach into the soil or move with surface runoff. Pesticides with solubilities of less than 1 ppm tend to remain on the soil surface. They tend not to be leached, but may move with soil sediment in surface runoff if soil erosion occurs. Pesticides with solubilities greater than 30 ppm are more likely to move with water.
28 March 2008 R. Shanthini Pesticide persistence is measured in terms of the half-life, or the time in days required for a pesticide to degrade in soil to one-half its original amount. For example, if a pesticide has a half-life of 15 days, 50 percent of the pesticide applied will still be present 15 days after application and half of that amount (25 percent of the original) will be present after 30 days. In general, the longer the half-life, the greater the potential for pesticide movement. A pesticide with a half-life greater than 21 days may persist long enough to leach or move with surface runoff before it degrades.
28 March 2008 R. Shanthini Pesticides / herbicides may contain compounds that are detrimental to human or to ecosystem health. DDT, a compound found in pesticides, had worked its way up the food chain, bioaccumulating or increasing in concentration at every level until it was enough to weaken the shells of eagle eggs. Although DDT has been banned, chemical pesticides and herbicides still contain substances that may have unforseen effects on human and animal life.
28 March 2008 R. Shanthini Integrated Pest Management (IPM) IPM doesn't rely solely on chemicals for pest control. Biological control, cultural practices, and timely chemical applications are used to obtain the necessary level of control. Pesticides are the last line of defense and are used only when pest levels are causing sufficient damage to offset the expense of the application. Ways to Minimize Pesticide Impact
28 March 2008 R. Shanthini Native Plants Garden - planned for no use of herbicides / pesticides - weeds removed by hand during seasonal work days - choose plants that grow quite densely, leaving little room for weeds once they are established. - Tolerate many insects as part of the garden's mini- ecosystems. (Caterpillars and aphids will be allowed to munch on milkweed PROVIDED FOR THEM, etc. BIRDS IN TURN CAN EAT THE CATERPILLARS) Ways to Minimize Pesticide Impact
28 March 2008 R. Shanthini –Consider weather and irrigation plans –Pesticide use and storage –Dispose of pesticide and chemical wastes safely –Leave buffer zones around sensitive areas –Reduce off-target drift –Application equipment Ways to Minimize Pesticide Impact
28 March 2008 R. Shanthini Green Revolution of the 20th century - It is the ongoing transformation of agriculture that led in some places to significant increases in agricultural production between the 1940s and 1960s. - It is said to have allowed food production to keep pace with worldwide population growth. - It has had major social and ecological impacts. Medieval Green Revolution or the Arab Agricultural Revolution of the 8 th century Green Revolution
28 March 2008 R. Shanthini - Introduced high-yielding varieties of seeds (that are often developed elsewhere and must be purchased) - Increased the use of pesticide/herbicide which were necessary to limit the high levels of pest damage that inevitably occur in monocultures - Increased the use of synthetic fertilizers - increased dependence on fossil fuels from which pesticides, herbicides and synthetic fertilizers are produced - Increased the use of irrigation which has created significant problems of arsenic contamination, salinization, waterlogging, and lowering of water tables in certain areas - Affected both agricultural biodiversity and wild biodiversity Green Revolution of the 20 th century
28 March 2008 R. Shanthini Green Revolution in India - High-yielding varieties of seeds of wheat (producing best results), rice, and other grains that had been developed in Mexico and in the Philippines was introduced in India after Use of synthetic fertilizers, irrigation and pesticide/ herbicide increased - Increased production made India self-sufficient in food grains - Famine in India, once accepted as inevitable, has not returned since the introduction of Green Revolution crops.
28 March 2008 R. Shanthini Is food production actually related to famine? Prof. Amartya Sen claimed large historic famines such as the Bengal Famine of 1943 (in which about 4 million people died) were not caused by decreases in food supply, but by socioeconomic dynamics and a failure of public action. Nobel Prize in Economics (1998) However, economist Peter Bowbrick has accused Sen of misrepresenting historical data, telling outright lies and being wrong on his theory of famines.
28 March 2008 R. Shanthini Socioeconomic impacts - Green Revolution agriculture required the purchase of inputs (fertilisers, irrigation pumps and regular fresh supplies of seed) which led to the widespread establishment of rural credit institutions (contrast it with traditional agriculture in which inputs were generated on- farm). - Smaller farmers often went into debt, which in many cases result in a loss of their farmland. Because wealthier farmers had better access to credit and land, the Green Revolution increased class disparities. - Because some regions were able to adopt Green Revolution agriculture more readily than others (for political or geographical reasons), interregional economic disparities increased as well.
28 March 2008 R. Shanthini Socioeconomic impacts - Many small farmers are hurt by the dropping prices resulting from increased production overall. - The new economic difficulties of small holder farmers and landless farm workers led to increased rural-urban migration. - The increase in food production led to a cheaper food for urban dwellers. - The increase in urban population increased the potential for industrialization (with cheap labour).
28 March 2008 R. Shanthini Green Revolution was a product of globalization - International agricultural research centers shared information - Transnational funding by Rockefeller Foundation, Ford Foundation, and USAID. - Inputs required in Green Revolution agriculture created new markets for seed and chemical corporations, many of which were based in the United States. (For example, Standard Oil of New Jersey established hundreds of distributors in the Philippines to sell agricultural packages composed of HYV seed, fertilizer, and pesticides.) Green Revolution was a product of Neo-colonialism
28 March 2008 R. Shanthini Agricultural Biotechnology Genetic engineering has been used to modify all of the crops and products shown, although most are not commercially available.
28 March 2008 R. Shanthini Genetic engineering is a process of inserting a foreign gene into a plant/animal cell and cloning that cell into a genetically engineered crop/animal.
28 March 2008 R. Shanthini When the bacterium infects the plant, it penetrates the plants cells and transfers its modified DNA to the plant. Once the DNA reaches the cell nucleus, it inserts itself at random into one of the host chromosomes. The genetically modified plant is then grown from the transformed cell. The DNA may also be physically shot into the plant nucleus carried on microscopic particles of tungsten or gold.
Increased crop productivity Crop productivity could be increased by introducing such qualities as disease resistance and increased drought tolerance to the crops. Researchers from the University of Hawaii and Cornell University developed two varieties of papaya resistant to papaya ringspot virus by transferring one of the virus’ genes to papaya to create resistance in the plants. Seeds of these two varieties have been freely distributed to papaya growers since May of Genes from naturally drought-resistant plants can be used to increase drought tolerance in many crop varieties growing in dry climates so that crops shall use waster as efficiently as possible.. 28 March 2008 R. Shanthini
Enhanced crop protection An effective transgenic crop-protection technology can control pests better and more cheaply than existing technologies. For example, with Bt bred into a corn crop, the entire crop is resistant to certain pests, not just the part of the plant to which Bt insecticide has been applied. In these cases, yields increase as the new technology provides more effective control. 28 March 2008 R. Shanthini
Improvement in food processing The first GMO food product to receive regulatory approval, in 1990, was chymosin, an enzyme produced by genetically engineered bacteria. It replaces calf rennet in cheese-making and is now used in 60 percent of all cheese manufactured. Its benefits include increased purity, a reliable supply, a 50% cost reduction, and high cheese-yield efficiency. 28 March 2008 R. Shanthini
Improved nutritional value Transgenic crops in development include - soybeans with higher protein content, - potatoes with more nutritionally available starch and an improved amino acid content, - beans with more essential amino acids, - and rice with the ability produce beta-carotene, a precursor of vitamin A, to help prevent blindness in people who have nutritionally inadequate diets. 28 March 2008 R. Shanthini
Improved flavor Flavor can be altered by enhancing the activity of plant enzymes that transform aroma precursors into flavoring compounds. Types of peppers and melons with improved flavor are currently in field trials. 28 March 2008 R. Shanthini
Fresher produce Genetic modification can result in improved keeping properties to make transport of fresh produce easier, giving consumers access to nutritionally valuable whole foods and preventing decay, damage, and loss of nutrients. Transgenic tomatoes with delayed softening can be vine- ripened and still be shipped without bruising. Research is under way to make similar modifications to broccoli, celery, carrots, melons, and raspberry. The shelf-life of some processed foods such as peanuts has also been improved by using ingredients that have had their fatty acid profile modified. 28 March 2008 R. Shanthini
Environmental Benefits When genetic engineering results in reduced pesticide dependence, we have less pesticide residues on foods, we reduce pesticide leaching into groundwater, and we minimize farm worker exposure to hazardous products. With Bt cotton’s resistance to three major pests, the transgenic variety now represents half of the U.S. cotton crop and has thereby reduced total world insecticide use by 15 percent! According to the U.S. Food and Drug Administration (FDA), “increases in adoption of herbicide-tolerant soybeans were associated with small increases in yields and variable profits but significant decreases in herbicide use.” 28 March 2008 R. Shanthini
Antibiotic resistance Antibiotic resistance genes are used to identify and trace a trait of interest that has been introduced into plant cells. This technique ensures that a gene transfer during the course of genetic engineering was successful. Use of these markers has raised concerns that new antibiotic- resistant strains of bacteria will emerge. The rise of diseases that are resistant to treatment with common antibiotics is a serious medical concern of genetic engineering. 28 March 2008 R. Shanthini
Potential gene escape and development of “superweeds” New transgenic crops might cross-pollinate with related weeds, possibly resulting in “superweeds” that become more difficult to control. Genetic engineering could improve a plant’s ability to “escape” into the wild and produce ecological imbalances or disasters. 28 March 2008 R. Shanthini
Impacts on “non-target” species Modified crops released into the environment could have unforeseen and undesirable effects. Bt corn, for instance, produces a very specific pesticide intended to kill only pests that feed on the corn. In 1999, however, researchers at Cornell University found that pollen from Bt corn could kill caterpillars of the harmless Monarch butterfly. When they fed Monarch caterpillars milkweed dusted with Bt corn pollen in the laboratory, half of the larvae died. 28 March 2008 R. Shanthini
Insecticide resistance Insect pests could develop resistance to crop-protection features of transgenic crops. There is fear that large-scale adoption of Bt crops will result in rapid build-up of resistance in pest populations. Insects possess a remarkable capacity to adapt to selective pressures, but to date, despite widespread planting of Bt crops, no Bt tolerance in targeted insect pests has been detected. 28 March 2008 R. Shanthini
Loss of Biodiversity While transgenic crops help ensure a reliable supply of basic foodstuffs, loss of agricultural biodiversity and wild biodiversity could not be overruled consequence. 28 March 2008 R. Shanthini
Source: Rat babies of same age Allergens and Toxins The process of inserting a foreign gene into a plant cell and cloning that cell into a genetically engineered crop could cause the natural plant genes to be deleted or permanently turned on or off, and hundreds can change their function. This massive collateral damage is why GM soy has less protein, an unexpected new allergen, and up to seven times higher levels of a known soy allergen. It also may explain why British soy allergies skyrocketed by 50% soon after GM soy was introduced.
28 March 2008 R. Shanthini Born to and raised by a mother on a conventional soy diet Born to and raised by a mother on GM soy diet Source:http://www.biotech-weblog.com/ /genetically_modified_soy_in_russia.php Rat babies of same age Research results of a team led by Irina Ermakova, Doctor of Biology, at the Institute of Higher Nervous Activity and Neurophysiology of the Russian Academy of Sciences (RAS).Irina Ermakova
28 March 2008 R. Shanthini Source: Rat babies of same age GM corn and cotton have genes inserted that produce a pesticide called Bt. If the gene transferred from corn snacks, for example, it could turn our intestinal flora into living pesticide factories. Farmers on three continents link Bt corn varieties with sterility in pigs and cows, or deaths among cows, horses, water buffaloes and chickens. Hundreds of farm workers who pick Bt cotton get allergic reactions.
28 March 2008 R. Shanthini Rat babies of same age Although biotechnology may be a powerful and intellectually stimulating tool, GM crops are developed largely for profit motives and therefore could carry significant yet hard to quantify risks. Maria Alice Garcia Instituto de Biologia, Universidade Estadual de Campinas Miguel A. Altieri University of California, Berkeley
Sustainable Agriculture 28 March 2008 R. Shanthini “…an integrated system of plant and animal production practices…that will satisfy human food and fiber needs enhance environmental quality make the most efficient use of nonrenewable resources sustain economic viability enhance quality of life.” 1990 Farm Bill
Sustainable Agriculture All agricultural production systems and practices are economically viable, environmentally sound, and socially acceptable. 28 March 2008 R. Shanthini General definition
economically viable 28 March 2008 R. Shanthini provides a secure living for farm families provides a secure living to other workers in the food system provides access to good food for all
environmentally sound 28 March 2008 R. Shanthini preserves the quality of soil, water, and air cooperates with and is modeled on natural systems
socially acceptable 28 March 2008 R. Shanthini good for families supports communities fair to all involved
28 March 2008 R. Shanthini NAVDANYA, India owning life, owning seeds and owning water Source: M. Ganguly, Seeds of Self-Reliance. Time, Sept 02, 2002: p71. - encourages farmers to produce hardy native varieties of crops that can be grown organically with natural fertilizer and no artificial chemicals - has collected 2,000 native seed varieties which they distribute among farmers - helps local farmers form their own self-supporting organization and seed bank - has set up a marketing network through which farmers sell their organic harvest - has shown that organic farmers with the knowledge of local conditions and traditional methods can achieve high yields at little cost to the environment, and thereby has set an eco- friendly standard
28 March 2008 R. Shanthini “.. high-tech agriculture is a short- term solution that will ultimately destroy the land” -Vandana Shiva (a physicist, a teacher, an ecologist, an activist, a feminist, and an organic farmer Green Revolution of the 20 th century
Biofertilizers - Nitrogen fixing symbiotic systems such as Sesbania rostrate Azolla and free-living cyanobacteria to rice crop - Symbiotic nitrogen fixer Azospirillum to rainfed crops - Solubilization and mobilization of nutrients by phosphobacteria and VA mycorrhiza and their role as bioinoculants, - Acetobacter diazotrophicus as a novel biofertilizer for sugarcane 28 March 2008 R. Shanthini
28 March 2008 R. Shanthini
The good earth will fail us of we fail her – but she will sustain us if we treat her right 28 March 2008 R. Shanthini