APES Ch 10: Food, Soil, and Pest Management

Plantation Agriculture

A form of industrialized agriculture used primarily in tropical developing countries. It involves growing cash crops on large monoculture plantations, mostly for sale in developed countries. An increasing amount of livestock production in developed countries is industrialized. Large numbers of cattle are brought to densely populated feedlots where they are fattened up for about 4 months before slaughter. Most pigs and chickens in developed countries spend their lives in densely populated pens and cages and eat mostly grain.

Are fish and shellfish a large part of the human diet?

An important source of food for about 1 billion people, mostly in Asia and in coastal areas of developing countries. Globally, however, they supply only 7% of the world's food and about 6% of the protein in the human diet.

Pest

Any species that competes with us for food, invades lawns and gardens, destroys wood in houses, spreads diseases, invades ecosystems, or is simply a nuisance. Worldwide, only about 100 species of plants, animals, fungi, and microbes cause about 90% of the damage to crops we grow.

Is increasing irrigation the answer?

Approximately 40% of the world's food production comes from the 20% of the world's cropland that is irrigated. 1950-2004,the world's irrigated areas tripled. However, the amount of irrigated land per person has declining since 1978 and is projected to fall much more between 2005-2050. Since 1978, the world's population has grown faster than irrigated agriculture. Depletion of underground water supplies, inefficient use of irrigation water, and salt buildup in soil on irrigated cropland. The majority of the world's farmers do not have enough money to irrigate their crops.

Agribusiness

Big companies and larger family-owned farms have taken control of almost 3/4 of U.S. food production. Industrialized farming has evolved into this.

What are the environmenta consequences of meat production?

Meat production uses more than half of the water withdrawn each year to irrigate and wash away animal wastes. About 14% of U.S. topsoil loss is directly associated with livestock grazing. Cattle release 16% of the methane released into the atmosphere. Some of the nitrogen in fertilizer is converted to nitrous oxide. Livestock produces 20 times more waste than is produced by the country's humans. Manure washing off the land or leaking from lagoons used to store animal wastes can kill fish by depleting oxygen. These lagoons can rupture or leak and contaminate ground water and nearby streams and rivers. Torrential rains can also cause them to overflow. Overgrazing occurs when too many animals graze for too long and exceed the carrying capacity of a grassland area. It lowers the NPP of grassland vegetation, reduces grass cover, and when mixed with prolonged drought, can cause desertification. It also exposes soil to erosion and compacts soil. Producing meat also endangers wildlife species.

Compost

Produced when microorganisms in soil break down organic matter such as leaves, food wastes, paper, and wood in the presence of oxygen.

Alley cropping

(Agroforestry) One or more crops are planted together in strips or alleys between trees and shrubs that can provide fruit or fuelwood. Trees provide shade and help retain and slowly release soil moisture. They also can provide fruit, fuelwood, and trimmings that can be used as mulch for crops and as fodder for livestock.

Agroforestry

(Alley cropping) Crops and trees are grown together

Industrialized Agriculture

(High-input agriculture) Uses large amounts of fossil fuel energy, water, commercial fertilizers, and pesticides to produce single crops or livestock animals for sale. Practiced on 1/4 of all cropland, mostly in developed countries.

Sustainable Organic Agriculture

(Low input agriculture) It produces roughly equivalent yields with lower CO2 emission, uses 30-50% less energy per unit of yield, improves soil fertility, reduces soil erosion, and is generally more profitable than high-input farming. It consists of more high-yield polyculture, organic fertilizers, biological pest control IPM, irrigation efficiency, perennial crops, crop rotation, use of more water-efficient crops, soil conservation, and subsidies for more sustainable farming and fishing. As a result, there is less soil erosion, soil salinization, aquifer depletion, overgrazing, overfishing, loss of biodiversity, loss of prime cropland, food waste, subsidies for unsustainable farming and fishing, population growth, and poverty. In order to transition to this, you can waste less food, reduce or eliminate meat consumption, feed pets balanced grain food instead of meat, use organic farming to grow some of your food, buy organic food, and compost your food wastes.

Narrow-spectrum pesticides

(Selective) Effective against a narrowly defined group of organisms

Pheromones

(Sex attractants) Can lure pests into traps or attract their natural predators into crop fields. These chemicals attract only one species, work in trace amounts, have little chance of causing genetic resistance, and are not harmful to non-target species. However, it is costly and time-consuming to identify, isolate, and produce the specific chemical for each pest and predator.

Windbreaks

(Shelter belts) Trees to reduce wind erosion, help retain soil moisture, supply wood for fuel, and provide habitats for birds, pest-eating and pollinating insects, and other animals.

Hot water

(Spraying) The approach has worked well on cotton, alfalfa, and potato fields and in citrus groves in Florida, and its cost is roughly equal to that of using chemical pesticides.

Describe the ideal pest-killing chemical?

-Kill only the target pest -Not cause genetic resistance in the target organisms -Disappear or break down into harmless chemical after doing its job -Be more cost-effective than doing nothing

Vitamin A Deficiency

120-140 million children in developing countries are deficient in Vit. A. Globally, 250,000 children younger than age 6 go blind each year from this and as many as 80% die within a year.

Types of organic fertilizer

1) Animal manure 2) Green manure 3) Compost

3 systems of food production

1) Croplands (mostly produce grain and provide about 77% of all food) 2) Rangelands (produce meat, mostly from grazing livestock, supply about 16% of all food) 3) Oceanic fisheries (supply about 7% of all food)

3 steps of the first green revolution

1) Develop and plant monocultures of selectively bred or genetically engineered high-yield varieties of key crops like rice, wheat, and corn 2) Produce high yields by using large inputs of fertilizer, pesticides, and water 3) Increase the number of crops grown per year on a plot of land through multiple cropping

What are the 2 main problems with soil erosion?

1) Loss of soil fertility (through depletion of plant nutrients in topsoil) 2) Occurs when eroded soil ends up as sediment in nearby surface waters, where it can pollute water, kill fish and shellfish, and clog irrigation ditches, boat channels, reservoirs, and lakes.

4 interplanting strategies

1) Polyvarietal Cultivation 2) Intercropping 3) Agroforestry 4) Polycultures

Disadvantages of modern synthetic pesticides

1) They accelerate the development of genetic resistance to pesticides by pest organisms (pesticide treadmill) 2) Some insecticides kill natural predators and parasites that help control the populations of pest species 3)Pesticides do not stay put 4) Some pesticides harm wildlife 5) Some pesticides threaten human health

Advantages of modern synthetic pesticides

1) They save human lives 2)They increase food supplies 3)They increase profits for farmers 4) They work faster and better than alternatives 5) When used properly, their health risks are very low compared with their benefits 6) Newer pesticides are safer and more effective than many older ones 7) Many new pesticides are used at very low rates per unit area compared to older products. Many are 1/100 that rates of older ones.

Main causes of soil erosion

1) Wind 2) Water 3) People

How much pesticide is used by households vs. agriculture?

1/4 of pesticides in the U.S. are devoted to ridding houses, gardens, lawns, parks, playing fields, swimming pools, and golf courses of pests. The average lawn is doused with 10 times more synthetic pesticides per hectare than U.S. cropland.

The U.S. uses industrialized agriculture to produce about what % of the world's grain in an efficient manner?

17%

Intercropping

2 or more different crops are grown at the same time on a plot (Ex: A carbohydrate-rich grain that uses soil nitrogen and a nitrogen-fixing plant that puts it back)

Traditional Agriculture

2 types - Subsistence and Intensive Together practiced by 42% of the world's people

What percent of the annual commercial fish/shellfish catch comes from the ocean

55% (the rest comes from aquaculture)

Rachel Carson

A pioneer in increasing public awareness of the importance of nature and the threat of pollution from pesticides. She began her career as a biologist for the Bureau of U.S. Fisheries. She carried out research on oceanography and marine biology and wrote articles about these topics. She wrote "The Sea Around Us," which told of the natural history of oceans and how humans were harming them. A friend of her's had several birds in her sanctuary die after DDT was sprayed to control mosquitos nearby and that friend asked Carson to investigate. Carson published "Silent Spring," which told of all the problems pesticides cause wildlife, and it was well received by the public, though the industries tried to tell people she was crazy.

Commercial inorganic fertilizer

Active ingredients typically are inorganic compounds that contain nitrogen, phosphorous, and potassium. Other plant nutrients may be present in low or trace amounts. These fertilizers account for about 1/4 of the world's crop yield. However, without careful control, they can run off the land and pollute nearby bodies of water. They can replace depleted inorganic nutrients, but not organic matter.

Genetic engineering

Can be used to speed up the development of pest and disease-resistant crop strains. Controversy persists over whether the projected advantages of increased use of genetically modified plants and foods outweigh their projected disadvantages.

Terracing

Can reduce soil erosion on steep slopes by converting the land into a series of broad, nearly level terraces that run across the land's contours. This practice retains water for crops at each level and reduces soil erosion by controlling runoff.

Commercial Extinction

Caused by prolonged overfishing. It's when the population of a species declines to the point at which it is no longer profitable to hunt for them.

Pesticies

Chemicals that kill or control populations of organisms we consider undesireable

Which country leads the world in aquaculture produtcion?

China - produces more than 2/3 of the world's aquaculture output

Fisheries

Concentrations of particular aquatic species suitable for commercial harvesting in a given ocean area or inland body of water.

Green manure

Consists of freshly cut or growing green vegetation that is plowed into the soil to increase the organic matter and humus available to the next crop.

Organic fertilizer

Created from plant and animal materials

Fish farming

Cultivating fish in a controlled environment (often a coastal or inland pond, lake, reservoir, or rice paddy) and harvesting them when they reach the desired size.

Conservation tillage farming

Disturbs the soil as little as possible while planting crops

Animal manure

Dung and urine of cattle, horses, poultry, and other farm animals. It improves soil structure, adds organic nitrogen, and stimulates beneficial soil bacteria and fungi

What is IPM?

Each crop and its pests are evaluated as parts of an ecological system. The farmers develop a control program that then includes cultivation, biological, and chemical methods applied in the proper sequence and with the proper timing. The overall aim is to not eradicate pest populations but rather to reduce crop damage to an economically tolerable level. Fields are monitored carefully and when an economically damaging level of pests is reached, farmers first use biological methods (natural predators, parasites, disease organisms) and cultivation controls, including vacuuming up harmful bugs. Small amounts of insecticides are applied only as a last resort. Different chemicals are used to slow the development of genetic resistance and to avoid killing predators of pest species.

Iodine Deficiency

Elemental iodine is essential for proper functioning of the thyroid gland, which produces a hormone that controls the body's rate of metabolism. It's found in seafood and crops grown in iodine-rich soils. Chronic lack of iodine can cause stunted growth, mental retardation, and goiter - an abnormal enlargement of the thyroid gland - that can lead to deafness. 26 million children suffer brain damage each year from lack of iodine.

Interplanting

Farmers grow several crops on the same plot simultaneously. This reduces the chance of losing most or all of the year's food supply to pests, bad weather, and other misfortunes.

Intensive (Traditional Agriculture)

Farmers increase their inputs of human and draft-animal labor, fertilizer, and water to obtain a higher yield per area of cultivated land. They produce enough food to feed their families and to sell for income.

Waterlogging

Farmers often apply large amounts of irrigation water to leach salts deeper into the soil. Without adequate drainage, water may accumulate underground and gradually raise the water table. Saline water then envelops the deep roots of plants, lowering their productivity and killing them after prolonged exposure.

What is crop rotation and why is it useful?

Farmers plant areas or strips with nutrient depleting crops one year. The next year, they plant the same area with legumes whose root nodules add nitrogen to the soil. This method also reduces erosion by keeping the soil covered with vegetation. Crops such as corn, tobacco, and cotton can deplete nutrients in the topsoil if they are planted on the same land several years in a row. Crop rotation provides a way to reduce these losses.

Fishing methods

Fish farming in a cage, trawler fishing, spotter airplane, sonar, purse-seine fishing, longline fishing, drift-net fishing

2 main agents of soil erosion

Flowing water and wind

FQPA

Food Quality Protection Act (1996) Increases public protection from pesticides. Federal laws regulating pesticide use in the U.S. are inadequate and poorly enforced.

Fungicides

Fungus killers

Negative effects of agriculture on the environment

Harmful effects on air, soil, water, and biodiversity. Agriculture has a greater harmful environmental impact than any human activity. Soil erosion, salt buildup, and waterlogging of soil on irrigated lands, water deficits and droughts, and loss of wild species that provide the genetic resources for improved forms of solid food. Nearly 30% of the world's cropland has been degraded to some degree by these, and 17% has been seriously degraded.

Fish ranching

Holding anadromous fish species, such as salmon that live parts of their lives in fresh water and part in salt water, in captivity for the first few years of their lives, usually in fenced-in areas or floating cages in coastal lagoons and estuaries. The fish are then released, and adults are harvested when they return to spawn.

Biological control

Importing natural predators, parasites, and disease-causing bacteria and viruses to help regulate pest populations. This approach is nontoxic to other species, minimizes genetic resistance, and can save large mounts of money. However, these cannot always be mass-produced, are often slower acting and more difficult to apply than conventional pesticides, can sometimes multiply and become pests themselves, and must be protected from pesticides sprayed nearby.

Where has IPM been effectively used?

In 1986, the Indonesian government banned many pesticides and launched a nationwide education program to help farmers switch to IPM. Between 1987 and 1992, pesticide use dropped 65%, production of rice rose by 15%, and more than 250,000 farmers were trained in IPM techniques. Sweden and Denmark have used IPM to cut their pesticide use in half.

How big is agriculture in the U.S.?

In total annual sales, agriculture is bigger than the country's automotive, steel, and housing industries combined. It generates about 18% of the nation's GDP and almost 1/5 of all jobs in the private sector, employing more people than any other industry. U.S. farms produce about 17% of the world's grain and nearly half of its grain exports. Since 1950, the yield of key crops such as wheat, corn and soybeans has doubled without cultivating more land. Putting food on the table consumes about 17% of all commercial energy used in the U.S. each year.

Green Revolution

Increased yields per unit of area of cropland, based on the increase in population. It was the switch to industrial farming.

Insecticides

Insect killers

IPM

Integrated Pest Management

Soil Conservation

Involves using a variety of ways to reduce soil erosion and restore soil fertility, mostly by keeping the soil covered with vegetation. Eliminating plowing and tilling is the key to reducing erosion and restoring healthy soil.

What is the relationship between subsidies and the issue of overfishing?

It costs the global fishing industry about $120 billion per year to catch $70 billion worth of fish. Government subsidies such as fuel tax exemptions, price controls, low-interest loans, and grants for fishing gear make up most of the $50 billion annual deficit of the industry. Without such subsidies, some of the world's fishing boats and fleets would go out of business and the number of fish caught would approach their sustainable yield. Continuing to subsidize excess fishing allows some fishers to keep their jobs and boats a little longer while making less and less money until the fishery collapses.

Traditional Crossbredding

It has been used by farmers and scientists for centuries to develop genetically improved varieties of crop strains. It is a slow process, typically taking 15 years or more to produce a commercially valuable new variety, and it can combine traits only from species that are close to one another genetically. It also provides varieties that remain useful for only 5-10 years before pests and diseases reduce their effectiveness.

Why is the term biocide used?

It's a more accurate name for these chemicals because most pesticides kill other organisms as well as their pest targets.

Persistence

Length of time they remain deadly in the environment

What are the problems with expanding the green revolution?

Many analysts believe we can produce all the food we need in the future by spreading the use of existing high-yield green revolution crops and genetically engineered crops to more of the world. Others disagree. Without huge amounts of fertilizer and water, most of these yields are no higher than those from traditional strains. These also cost too much for most subsistence farmers in developing countries. Continuing to increase fertilizer, water, and pesticide inputs eventually produces no additional increase in crop yields. Yields in some areas may decline as soil erodes and loses fertility, irrigated soil become salty and waterlogged, underground and surface waters become depleted and polluted, and pests develop genetic immunity to pesticides.

Polyculture

Many different plants maturing at various times are planted together. Needs less fertilizer, water, insecticides and herbicides, and provides protection against erosion and bad weather. A way of growing food by copying nature.

Malnutrition

Many of the world's poor can afford only a low-protein, high carbohydrate diet consisting of grains like wheat, rice, and corn. Many suffer this resulting from deficiencies of protein, calories, and other key nutrients.

Soil is eroding faster than it is forming on more than what portion of the world's crop land?

More than 1/3

Process of salinization of soils

Most irrigation water is a dilute solution of various salts that are picked up as the water flows over or through soil and rocks. Water that isn't absorbed into the soil evaporates, leaving behind a thin crust of dissolved salts in the topsoil. Repeated annual applications of irrigation water leads to the gradual accumulation of salts in the upper soil layers, a process called salinization. It stunts group growth, lowers crop yields, and eventually kills plants and ruins the land.

Case Study: Winged Beans and Bug Cuisine

Most of the world's people live mainly on a diet of wheat, rice, or corn, but lack protein. The poor cannot afford meat. Modern agriculture has a greater harmful environmental impact than any other human activity. The Winged Bean is a fast-growing, protein-rich plant with edible winged pods, spinach-like leaves, tendrils, and seeds that contain as much protein as soybeans. It also has many different edible parts. Edible insects (micro-livestock), about 1,500 edible bugs in the world. Bugs are high in protein, low carbs, consuming more of the plentiful insects would help reduce malnutrition and lessen the large environmental impact of producing conventional forms of meat.

What is the role of natural enemies in pest control?

Natural enemies (predators, parasites, and disease organisms) control the populations of about 98% of the potential pest species as part of the earth's free ecological services. They help keep any one species from taking over for too long. Spiders (30,000 known species), kill far more insects every year than insecticides do. When we clear forests and grasslands, plant monoculture crops, and douse fields in pesticides, we upset many of these natural population checks and balances. Then we must devise ways to protect our monoculture crops, tree plantations, and lawns from insects and other pests that nature once controlled.

Are humans responsible for all soil erosion?

No - some is natural, some is caused by human activities. In undisturbed vegetated ecosystems, the roots of plants help anchor the soil, and usually soil is not lost faster than it forms. Soil becomes more vulnerable to erosion through human activities that destroy plant cover, including farming, logging, construction, overgrazing by livestock, off-road vehicle use, and deliberate burning of vegetation.

Are fertilizers the best option for maintaining soil fertility?

No. The best way is through soil conservation. The next best option is to restore some of the plant nutrients that have been washed, blown, or leached out of the soil or removed by repeated crop harvesting.

Overnutrition

Occurs when food energy intake exceeds energy use and causes excess body fat. Too many calories, too little exercise, or both, can cause it. Lower life expectancy, greater susceptibility to disease and illness, and lower productivity and life quality. 1 in every 4 people in the world is overweight and 5% are obese. In developed countries, it causes preventable deaths, mostly from heart disease, cancer, stroke, and diabetes.

Land Degradation

Occurs when natural or human-induced processes decrease the ability of land to support crops, livestock, or wild species in the future

Gully Erosion

Occurs when rivulets of fast-flowing water join together and with each succeeding rain cut the channels wider and deeper until they become ditches or gullies. This usually occurs on steep slopes where all or most vegetation has been removed.

Bad news about global grain production

One in every six people in developing countries is not getting enough to eat because food is not distributed equally among the world's people. This occurs because of differences in soil, climate, political and economic power, and average income per person. The root cause of hunger and malnutrition is poverty, war, and corruption.

Does desertification always lead to the formation of a desert?

Only in extreme cases does it lead to what we call deserts. Moderate = 10-25% drop in productivity Severe = 20-50% drop Very severe = 50% or more drop, usually creating huge gullies and sand dunes

Causes of desertification?

Over thousands of years the earth's deserts have expanded and contracted, mostly because of natural climate changes. However, human activities can accelerate it in some parts of the world. Overgrazing, deforestation, erosion, salinization, soil compaction and natural climate change are all causes of desertification.

Undernutrition

People who cannot grow or buy enough food to meet their basic energy needs suffer from this. Chronically undernourished children are likely to suffer mental retardation and stunted growth, and are susceptible to infectious diseases like measles and diarrhea.

Polyvarietal Cultivation

Planting a plot with several genetic varieties of the same crop

Strip Cropping

Planting alternating strips of a row crop and another crop that completely covers the soil. The cover crop traps soil that erodes from the row crop; catches and reduces water runoff, and helps prevent the spread of pests and plant diseases.

Coevolution and pesticides

Plants have been producing chemicals to ward off, deceive, or poison herbivores that feed on them for nearly 225 million years. This battle produces a never-ending, ever-changing coevolutionary process: Herbivores overcome various plant defenses through natural selection, then new plant defenses are favored in an ongoing cycle.

Contour farming

Plowing and planting crops in rows across the slope of the land rather than up and down. Each row acts as a small dam to help hold soil and to slow water runoff.

Aquaculture

Raising fish and shellfish for food like crops instead of going out and hunting and gathering them. It's the world's fastest growing type of food production and accounts for about 1/3 of the fish and shellfish that we eat.

Rodenticides

Rat and mouse killers

Circle of Poison

Residues of some of the banned or unapproved chemicals exported to other countries can return to the exporting countries on imported food. The wind can also carry persistent pesticides such as DDT from one country to another.

Cultivation Strategies

Rotating the types of crops planted in a field each year, adjusting planting times so major insect pests either starve or get eaten by their natural predators, and growing crops in areas where their major pests do not exist. Increase the use of polyculture, which uses plant diversity to reduce losses to pests. Reduce weed invasions by cutting grass no lower than 8 cm high. That height provides a dense enough cover to keep out weeds.

What are the negative consequences of waterlogging?

Saline water envelops the deep roots of plants, lowering their productivity and killing them after prolonged exposure. At least 1/10 of the world's irrigated land suffers from waterlogging, and the problem is getting worse.

Kwashiorkor

Severe protein deficiency usually because a new baby has arrived and the older child is displaced to eat less nutritional grains and potatoes

Good news about food production

Since 1950, there has been a staggering increase in global food production from all 3 systems. Technological advances such as increased use of tractors and farm machinery, and high-tech fishing boats and gear, inorganic chemical fertilizers, irrigation, pesticides, high-yield varieties of wheat, rice, corn, densely populated feedlots and enclosed pens for raising cattle, pigs, and chickens, and aquaculture ponds and ocean cages for raising some types of fish and shellfish has caused growth to occur.

Minimum-tillage farming

Soil is not disturbed in the winter. At planting time, special tillers break up and loosen the subsurface soil without turning over the topsoil, previous crop residues, or any cover vegetation.

What are the issues with producing more meat?

Some analysts expect most future increases in meat production to come from densely populated feedlots, where animals are fattened for slaughter by feeding on grain grown on cropland or meal produced from fish. Feedlots are horrible conditions for animals. Expanding feedlot production of meat will increase pressure on the world's grain supply because feedlot livestock consume grain instead of grass. It will also increase pressure on fish.

No-till farming

Special planting machines inject seeds, fertilizers, and weed killers (herbicides) into thin slits made in the unplowed soil and then smooth over the cut.

Commercial extinction and overfishing in relation to the concept of the "Tragedy of the Commons"

Subsidies allow fishermen to keep jobs a little longer while making less money until the fishery collapses. Then all the jobs are gone, and fishing communities suffer even more - an example of the TotC in action. 3/4 of the world's 200 commercially valuable marine fish species are either overfished or fished to their estimated maximum sustainable yield.

Second Green Revolution

Taking place since 1967. Fast-growing dwarf varieties of rice and wheat, specifically bred for tropical and subtropical climates have been introduced into several developing countries. Producing more food on less land is also an important way to protect biodiversity by saving large areas of forests, grasslands, wetlands, and easily eroded mountain terrain from being used to grow food. Yield increases depend not only on fertile soil and ample water but also on high inputs of fossil fuels to run machinery, produce and apply inorganic pesticides, and pump water for irrigation. In total, high-input, green revolution agriculture uses about 8% of the world's oil output.

With water resources being scarce, why would a farmer waste water and end up waterlogging?

The farmer would be trying to leach salts deeper into the soil.

U.S. agriculture's relationship to the oil industry

The industrialization of agriculture has been made possible by the availability of cheap energy, most of it from oil. Putting food on the table consumes about 17% of all commercial energy used in the U.S. each year. About 10 units of nonrenewable fossil fuel energy are needed to put 1 unit of food energy on the table.

U.S. agriculture efficiency

The major inputs of labor and resources with the exception of pesticides, to produce each unit of that output have fallen steadily since 1950. The input of energy needed to produce a unit of food has fallen considerably so that today most plant crops in the U.S. provide more food energy than the energy used to grow them.

Soil Erosion

The movement of soil components, especially surface litter and topsoil, from one place to another

Desertification

The productive potential of drylands (arid or semiarid) falls by 10% or more because of a combination of natural climate change that causes prolonged drought and human activities that reduce or degrade topsoil.

Overfishing

The taking of so many fish that too little breeding stock is left to maintain the species numbers.

Is cultivation of more land the answer?

Theoretically, clearing tropical forests and irrigating arid land could more than double the world's cropland. But, much of this is marginal land with poor soil fertility, steep slopes, or both. Cultivation of this land is likely to be unsustainable. Most of the potentially cultivatable land lies in dry areas, so irrigation would be expensive and damaging. It would not even offset the loss of cultivated land due to erosion, overgrazing waterlogging, salinization, and urbanization.

Hormones

They disrupt an insect's normal life cycle, thereby preventing it from reaching maturity and reproducing. Insect hormones have the same advantage as pheromones, but they take weeks to kill an insect, often are ineffective with large infestations of insects, and sometimes break down before they can act. They must also be applied at exactly the right time in the target insect's life cycle, can sometimes affect the target's predators and other nonpest species, and are difficult and costly to produce.

Pesticide Treadmill

They pay more and more for a pest control program that often becomes less and less effective

Challenges we face in food production

To feed the billions of people expected to exist in 2050 (8.9 billion?), we must produce and equitably distribute more food than has been produced since agriculture began about 10,000 years ago, and do so in an environmentally friendly and sustainable manner. Analysts are concerned that environmental degradation, pollution, lack of water for irrigation, overgrazing by livestock, overfishing, and loss of vital ecological services may limit future food production. We also have to sharply reduce poverty because out of every five people, one doesn't have enough land to grow food or enough money to buy enough food regardless of how much is available.

Anemia

Too little iron - a component of the hemoglobin that transports oxygen in the blood - causes anemia. 1 in every 3 people in the world, mostly women and children in tropical developing countries, suffers from iron deficiency. This condition causes fatigue, makes infections more likely, and increases a woman's chance of dying in childbirth and an infant's chances of dying of infection in its first year of life.

Preserving the world's ____ is the key to producing enough food for the world's growing population

Topsoil

Soil erosion worldwide and in the U.S.

Topsoil is eroding faster than it is forming on about 38% of the world's cropland. Soil erosion and degradation have reduced food production on 16% of the world's cropland. Some analysts contend that erosion estimates are overstated because they underestimate the abilities of some farmers to restore degraded land. In some places, thanks to the erosion and movement of topsoil, the loss in crop yields in one area could be offset by increased yields elsewhere. Soil on cultivated land in the U.S. is eroding 16 times faster than it can form. However, government-sponsored soil conservation programs and planting crops without disturbing the soil has cut soil losses by about 2/3. Effective soil conservation is practiced today on only half of all agricultural land and half of the country's most erodible cropland.

Broad-spectrum pesticide

Toxic to many species

Most people eat what? Why?

Traditional grains They cannot afford meat. As incomes rise, most people consume more meat and other products of domesticated livestock, which in turn means more grain consumption by those animals.

Genetic Engineering

Used to develop genetically improved strains of crops and livestock animals. It involves splicing a gene from one species and transplanting it into the DNA of another species. Compared to traditional crossbreeding, this takes about half as long to develop a new crop, cuts costs, and allows, the insertion of genes from almost any other organism in crop cells. More than 2/3 of the food products on U.S. shelves now contain some form of genetically engineered crops.

Subsistence (Traditional Agriculture)

Uses mostly human labor and draft animals to produce only enough crops or livestock for a farm family's survival

Marasmus

Wasting away because of a lack of both calories and protein (in infants and children mostly)

Can more meat be produced sustainably?

We can reduce the environmental impacts of meat production by relying more on fish and chicken and less on beef and pork. We have to shift from less grain-efficient forms of animal protein to more grain-efficient ones. Some environmentalists have called for reducing livestock production to decrease its environmental effects and to feed more people. This would decrease the environmental impact of livestock production, but would not free up much land or grain to feed more of the world's hungry people. Livestock that graze on rangleland eat grass, which humans cannot eat, and most of that land is not suitable for growing crops. Due to poverty, insufficient economic aid, and the nature of global economic and food distribution systems, very little additional grain grown on land once used to raise livestock feed would reach the world's hungry people.

Good news about global grain production

We produce more than enough food to meet the basic nutritional needs of every person on the earth

Herbicies

Weed killers

What are the big three? Why are they called that?

Wheat, rice, and corn They provide more than half of the calories people consume and 2/3 of the world's people survive primarily on these because they cannot afford meat

Is soil salinization a big problem?

Yes. Severe salinization has reduced yields on about 1/5 of the world's irrigated cropland, and another 1/3 has been moderately salinized. It affects almost 1/4 of irrigated cropland in the U.S.