Fertility can refer to the ability of soil to sustain plant growth, or it can refer to the number of live births occurring in a population.
Agronomists, or people who study the uses of plants, use the term to refer to soil. Plants grow easily in fertile soil because it contains large amounts of nutrients. These nutrients, which help keep plants healthy, come from minerals and decaying plant and animal matter. Minerals may have been deposited in the soil during the last glacial period, or Ice Age.
Fertilizers can be added to soil to increase fertility. Fertilizers contain nutrients such as phosphorous, nitrogen, and potassium. Composted plant matter, called humus, is a natural fertilizer that can improve soil fertility. Manure, or the droppings of some animals such as bats or cows, is also an excellent fertilizer. Many companies manufacture fertilizers for use on specific crops. These fertilizers can be applied directly to the soil or to the plants.
Poor farming techniques, certain grazing practices, and erosion can make the soil less fertile. Planting a single crop, year after year, can drain the soil of nutrients. Overgrazing by too many cows, goats, or sheep can prevent new grasses from growing. Erosion allows the soil to either blow away by wind or drain away by water.
Fertile soil is usually found in river basins or in places where glaciers deposited minerals during the last Ice Age. Valleys and plains are usually more fertile than mountains. The Pampas, for example, is an extremely fertile plains region in South America. The Pampas includes parts of Argentina, Brazil, and Uruguay. The Pampas supports both farming and ranching.
For demographers—people who study population statistics—fertility means the number of live births occurring in a population.
The general fertility rate is the number of live births per 1,000 women of childbearing age (usually ages 15 to 44) in a given year. Governments keep track of the general fertility rate to determine if their population will grow, shrink, or stay the same size. This determines such things as how much food needs to be produced, what sort of public transportation is needed, and how health care is addressed.
Fertility rates tend to be lower in industrialized nations, such as the United States, than in underdeveloped countries. There are many reasons for this. Mothers and children have greater access to health care in industrialized nations. This means children’s mortality rates, or the number of children who die before turning five, are much lower. Women also have greater access to family planning services. The fertility rate in the developed, industrialized nation of South Korea, for instance, is about 1.2. This means that most women have one child. The fertility rate in neighboring North Korea is nearly 2, meaning most women have two children. North Korea is a developing country.
Women in industrialized nations have access to more education and professional development. Many women choose to go to school or get a job instead of having children at a young age. Many choose not to have children at all. This lowers the fertility rate in industrialized nations.
Industrialized nations usually have a school system for young children. In developing nations, young children may work to support their families instead of going to school. The fertility rate may rise because more children means more workers. In industrialized nations, children are not expected to take care of their parents and grandparents.
The tendency for industrialized nations to have lower birth rates is not always true. The United States has the highest birth rate of all industrialized nations, at about 2. This is far higher than developing nations such as Uruguay (1.9), Tunisia (1.7) or Thailand (1.6).
In order to maintain a stable population, each woman must bear two children—one to replace each parent. High fertility rates—where most women give birth to more than two healthy babies—can lead to overpopulation. Low fertility rates—where most women give birth to one child or no children—can lead to a dwindling population.
Some nations want to increase their fertility rate. Japan has one of the lowest fertility rates in the world. The general fertility rate hit a record low of 1.21 in 2009, even though the Japanese government made efforts to encourage women to have children. The country's population is declining and the average age is getting older.
Some want to decrease their fertility rate. China’s famous “one child policy” is a good example of this. China is the most populous country in the world. The Chinese government believes that lowering the fertility rate would increase the resources, such as education and jobs, available to its citizens. In the late 1970s, China set taxes and economic fines for families with more than one child. (The fines and taxes do not apply to ethnic minorities and other groups, such as rural farm families.) As a result, the fertility rate in China has dropped. China now has a lower fertility rate than the United States.
Fourteen countries have fertility rates with at least six children per woman. These countries are Afghanistan, Angola, Burkina Faso, Burundi, Chad, the Democratic Republic of the Congo, Guinea-Bissau, Liberia, Mali, Niger, Sierra Leone, Somalia, Timor Leste, and Uganda.
Fertility does not always correspond to population. Despite their high fertility rates, the countries listed above make up less than five percent of the world’s population. Countries with much larger populations, such as India, China, and the United States, have lower fertility rates.
The Fertile Crescent is an area in the Middle East where many aspects of civilization, including agriculture and writing, were first practiced. The region stretches in an arc from the modern-day countries of Iraq and Kuwait on the Persian Gulf, up to the southern part of Turkey, down along the Mediterranean coast of Jordan and Israel, and ending in northern Egypt. The soil of the Fertile Crescent is extremely fertile, which allowed agricultural communities, and eventually cities and civilization, to develop.
Soil fertility and human fertility were both extremely important to ancient people. Almost every ancient culture had a deity associated with fertility. The deity was worshipped and offered sacrifices in order to ensure a healthy crop and healthy children. Fertility deities can be gods, such as Kokopelli, the fertility deity of many cultures of the American Southwest. Fertility deities can also be goddesses, such as Hathor, who was worshipped in Egypt.
person who studies soil and its role in agriculture.
age at which a female can give birth to offspring.
mixture of decaying organic material, such as food waste and plants.
to match or be similar to.
to rot or decompose.
very holy or spiritual being.
person who studies patterns in human populations.
to place or deliver an item in a different area than it originated.
to inspire or support a person or idea.
act in which earth is worn away, often by water, wind, or ice.
the art, science, and business of cultivating the land for growing crops.
capacity of soil to sustain plant growth; or the average number of children born to women in a given population.
nutrient-rich chemical substance (natural or manmade) applied to soil to encourage plant growth.
general fertility rate
number of live births per 1,000 women of childbearing age.
time of long-term lowering of temperatures on Earth. Also known as an ice age.
mass of ice that moves slowly over land.
system or order of a nation, state, or other political unit.
type of plant with narrow leaves.
to feed on grass, usually over a wide pasture.
fertility goddess of ancient Egypt.
system for addressing the physical health of a population.
material that forms when plant and animal matter decays.
last glacial period, which peaked about 20,000 years ago.
having to do with factories or mechanical production.
fertility god of the ancient North American southwest.
animal excrement or waste used to fertilize soil.
inorganic material that has a characteristic chemical composition and specific crystal structure.
the ratio of the total number of deaths to the total population in a given time and area. Also called the death rate.
landmass that forms as tectonic plates interact with each other.
chemical element with the symbol N, whose gas form is 78% of the Earth's atmosphere.
substance an organism needs for energy, growth, and life.
situation where the amount of organisms in an area is too large for the ecosystem to support.
flat grasslands of South America.
chemical element with the symbol P.
flat, smooth area at a low elevation.
total number of people or organisms in a particular area.
patterns in populations of organisms.
chemical element with the symbol K.
opportunities to improve in a career.
methods of movement that are available to all community members for a fee, and which follow a fixed route and schedule: buses, subways, trains and ferries.
large farm on which livestock are raised.
destruction or surrender of something as way of honoring or showing thanks.
top layer of the Earth's surface where plants can grow.
country that has fallen behind on goals of industrialization, infrastructure, and income.
depression in the Earth between hills.