Tropical agriculture
Encyclopedia
Worldwide more human beings gain their livelihood from agriculture
than any other endeavor; the majority are self-employed subsistence farmer
s living in the tropics
. While growing food for local consumption is the core of tropical agriculture, Cash crop
s (normally crops grown for export
) are also included in the definition.
When people discuss the tropics, it is normal to use generalized labels to group together similar tropical areas. Common terms would include the humid-tropics (rainforest
s); the arid-tropics (desert
s and dry areas); or monsoon
zones (those areas that have well defined wet/dry season
s and experience monsoons). Such labeling is very useful when discussing agriculture, because what works in one area of the world will normally work in a similar area somewhere else, even if that area is on the opposite side of the globe.
Most temperate zone agricultural techniques are inappropriate for tropical areas. The second half of the 20th century saw many attempts to duplicate in the tropics farming practices that had been successful in temperate climates. Due to differences in climate
, soil
s, and patterns of land ownership, these largely failed. When they did succeed they tended to heavily favor farmers with substantial land holdings, as a high percentage of temperate agricultural practices are economically "scale-based" and favor large scale production. This in turn pushed many small-scale farmers on to ever more marginal land, as the better quality land was consolidated into larger farms.
" is the name given to the most successful agricultural improvement program ever undertaken in the tropics. Funded initially by the Rockefeller Foundation
, it aimed to improve corn
, rice
, and other cereal
cultivators – breeding
plants that would produce more grain for the same amount of effort.
From that point it expanded out to improved basic farming practices, particularly for rice farmers. The growth of crop yields was such that agriculture was able to outstrip population growth — per capita production increased every year following 1950 - with Asia leading the way. One of the more remarkable aspects of the Green Revolution is that the total cost of the program by 1990 was approximately US$100 million, less than what a single Boeing 747
airliner costs in 2005.
It can be concluded that the Green Revolution
was a success, with only a minor flaw: although the crops gave more yield, they were more subject to disease since this was not a primary concern in the program.
In order to address this problem together with an approach to more small-scale farming crops, there is today substantial interest in creating a second Green Revolution, based on sustainable
agricultural practices and geared towards (small-scale) farmers with limited financial
resources.
The Humidtropics CGIAR Research Program on Integrated Systems in the Humid Tropics, called Humidtropics (www.humidtropics.org) is a new initiative (2010) that progresses the "Green Revolution
" approach by considering research for development (R4D) for complex agricultural livelihood systems.
s. Seeds are necessary for plant embryo
s to survive the winter and other harsh conditions such as drought
. However, where the weather is normally conducive to growth year-round, it is often advantageous for plants to reproduce through means other than seeds. By bypassing the seed stage plants can greatly accelerate their reproductive cycle. Despite this, anyone who wishes so, may still grow tropical crops (e.g. fruit, ...) from seed. To do so, some special seed germination techniques to germinate it more quicker may be best used.
Many (tropical) plants use toxin
s to protect themselves. Cassava
, one of the most important tropical food crops, produces cyanide
upon ingestion
if improperly processed. Other plants are high in oxalate
s (the agent that binds calcium
to form kidney stone
s); castor beans are the source of ricin
, one of the most powerful poison
s in existence; and velvet beans
contain 7-10% L-DOPA. The list of toxic plants is long, but toxicity does not always mean a particular plant should be avoided, the knowledge needed to render toxic plants safe to use already exists in most communities.
fertilizer
is described in terms of NPK -nitrogen
(N), phosphorus
(P) and potassium
(K); with nitrogen being the main component of most commercial fertilizers.
Oxygen
is only a small part of the air; the largest component of air is nitrogen. Nitrogen is the main building block of protein
; muscle
in mammal
s and plant tissue
in plants. If the level of nitrogen in the soil
is increased, plant growth can be significantly increased. Legumes are a group of plants that interact with bacteria
(rhizobia
) in the soil to fix nitrogen
from the air, and deposit the nitrogen into the soil where it is available for other plants to use. The nitrogen deposited by legumes can be readily converted into larger harvests.
Green manure
s are plants grown to improve the soil, suppress weed
s, limit erosion
, and — when legumes are used — to increase the nitrogen content of the soil. The most common type of green manure used in the tropics is Velvet bean. It produces a thick blanket
of vine
s and leaves
that in addition to infusing the soil with nitrogen also smother most weeds. In addition it has reasonable tolerance to drought, low soil fertility, and highly acid
ic soil. Alternatives to the Velvet bean include the Lablab bean, the Jack bean, and for use above 500 m altitude, the Scarlet runner bean.
Once the blanket is several centimeters thick, it is chopped down with a machete
, and the vines are chopped up. This produces thick mulch
on top of the ground that both inhibits weed growth and adds vital nutrient
s to the soil. Corn or other crops are then planted directly into this mulch.
Slash/mulch is popular in southern Mexico, Guatemala
, and Honduras
; and in recent years has gained a following in many areas of the tropics, from Brazil to central Africa. Where it has been embraced it has pushed aside slash and burn
agriculture, and allowed farmers to utilize the same land continuously for many years.
Cornell University
has taken a leading role in research
ing the effects of mulches and slash/mulch practices in the tropics.http://ppathw3.cals.cornell.edu/mba_project/moist/home2.html
occurs to grow enough food to feed the local population; however, it many not fall in a timely or convenient manner. Making maximum use of the water that does fall is an ongoing challenge.
Water is a particularly important issue in dryland farming
. The ability to collect and store water at a low cost and without damaging the environment, is what opens up deserts and other arid
regions to farmers. When it rains in dryland areas, the rain storms are normally heavy, and the soil unable to absorb the large amounts of rain that comes down. This leads to excessive surface run-off that needs to be captured and retained.
Commercial farms growing cash crops often use irrigation techniques similar to or identical to what would be found on large scale commercial farms located in temperate regions; as an example, the Israeli drip-irrigation lines.
- the farmer digs bathtub
sized pits into his fields and lines them with plastic sheets to collect rainwater. Then once the dry season
sets in the farmer uses the collected water to irrigate his crops. The technique is especially useful in mountainous areas, where rapid run-off
would otherwise occur.
During years with normal precipitation the growing season can be increased by an extra month or more by using harvesting pits. An extra month in many places means an extra crop can be grown. For instance if the local growing season
is 5 months long, and the farmers main crop takes 3 or 4 months to grow, an extra month may be enough time to grow a secondary crop. During times of drought, what rain does fall can be collected in the pits and used to secure the farmer's main crop.
hung from a pole
, with a hose
coming out of the bottom, and holes punched into the hose. The bucket is filled, and gravity feeds the water to the plants. As a rule about 40 litres of water per day are needed for every 100 plants, although this can vary depending upon what is being grown.
pump
is a human-powered pump designed to lift water from a depth of seven meters or less. A treadle is lever device pressed by the foot to drive a machine, in this case a pump. The treadle pump can do most of the work of a motorized pump, but costs considerably less to purchase, and needs no fossil fuel
as it is driven by the operators body weight and leg muscle
s. It can lift five to seven cubic meters of water per hour from wells
and borehole
s up to seven meters deep and can also be used to draw water from lakes and rivers. Most treadle pumps used are of local manufacture, as they are simple and inexpensive to build.
Standard treadle pumps are suction
pumps, and where first developed in the early 1980s in Bangladesh
. Most treadle pumps manufactured in Africa are pressure
treadle pumps; a modification to the original design that means water is forced out of the pump under pressure. Pressure treadle pumps are more versatile as they allow farmers to pump water uphill, or over long distances, or fill elevated tanks.
is the cornerstone pest control
in the tropics. When a single crop is planted repeatedly in the same soil, insect
s and disease
s that attack that crop are allowed to build up to unmanageable levels, greatly reducing the farmer's harvest
.
The most basic form of crop rotation is also the simplest: never plant the same thing in the same place twice. This results in naturally breaking the cycles
of weed
s, insects and diseases that attack food crops. Rotations are used to prevent or at least partially control several pests and at the same time to reduce the farmer's reliance on chemical pesticide
s. Crop rotations often are the only economically feasible method for reducing insect and disease damage.
Crop rotation replaces a crop that is susceptible to a serious pest with another crop that is not susceptible. Each food crop comes with its own set of pests that attack that particular crop. By planting a different crop each time, the farmer is able to starve out those pests. Often a set of three or four crops are planted on a rotating basis, ensuring that by the time the first crop is replanted, the pests that attack it are substantially reduced.
Another side benefit of crop rotation is it improves the soil. Constantly growing the same crop in the same location will strip the soil of the nutrient
s that particular crop requires. Rotating to a different crop will reduce the pressure placed on the soil. Or if a green manure is used as part of the rotation sequence, the soil can actually be improved.
(IPM) was developed as an alternative to the heavy use of chemical pesticides. Eliminating all insect pests requires the extensive use of chemical pesticides, which over time can become self-defeating. Farmers end up using more and more chemicals with diminishing effect as pests quickly adapt –while at the same time natural predator insects are eliminated from the farm. Under IPM chemicals should be a secondary line of defense, while building up the number of natural predators on a farm is the main goal. The IPM approach calls for keeping the pest populations below the levels at which they cause economic injury, not total eradication.
IPM in its pure form is extremely complex, and beyond the ability of most farmers to manage; however, the underlying principals have gained widespread acceptance in the tropics, with most governments sponsoring IPM educational programs.
is momentarily researching indigenous alternatives to western crops.
is rapid because of high temperatures, high humidity
, and frequent heavy rains. Heavy rains, especially monsoon rains, lead to rapid nutrient leaching
, and chemical weathering of the soil. Standard temperate strategies for improving nutrient poor soil, such as composting, have limited application in such an environment due to rapid leaching.
Aluminum is the most common metal found in the Earth's crust
. It is found in all soils and in all environments, from temperate to tropical. In a soluble state it is highly toxic to plant life, as it inhibits root
growth; however, in neutral
and alkaline soils common to the temperate zones it is insoluble and therefore inert
. Soil fertility
is directly influenced by how acidic it is, as the more acidic the higher the level of aluminum toxicity; in areas where the pH
drops below 5, aluminum becomes soluble and can enter into plant roots where it accumulates.
Approximately a third of all tropical soils are too acidic to support traditional food crops. These highly acidic tropical soils represent the largest untapped arable land
left in the world, and therefore more productive utilization of these lands is key to expanding the world food supply.
Winrock International states "In the humid tropics, the relative importance of acid soils is greatest in Latin America (81%), but also significant in Africa (56%) and Asia (38%)" http://www.winrock.org/forestry/FACTPUB/AIS_web/AIS10.html.
Traditionally on commercial farms aluminum toxicity is countered by adding lime
to the soil, which neutralizes the acid and renders the aluminum inert. However, many small land holders and resource-poor farmers cannot afford lime, and instead rely on slash-and-burn agriculture. As the original plant life is burnt, the ash acts to neutralize the acidic soil and makes the area acceptable for food plants. In time acidity increases and only native plants will grow, forcing the farmer to move on and clear a new area.
Soil color in humid areas is related to the level of oxidation that has occurred in the soil, with red soil being the result of iron
oxidation, and yellow soil being the result of aluminum oxidation.
s in the soil. The high temperatures and low humidity in arid regions means that salinization often accompanies irrigation.
) requirement for a certain number of hours of daylight before they will grow, flower
, or produce fruit
. Without this they will not complete their life-cycle
and will not produce fruit and seeds. For this reason seeds brought from the temperate zones may not perform as expected, or at all in the tropics. Some plants are genetically keyed to only start producing when a certain number of hours of daylight is reached, the same number of hours as is found in their native habitat. With the shorter daylight hours experienced in the tropics, that switch never gets thrown.
, and certain South-East Asian Countries, a lot of forest is being cleared to produce food. Major examples are the oil palm
plantations in Indonesia and the dry rice farming techniques using slash and burn
-method in Southeast Asia. This of course adds to global warming
(as trees collect CO2 in life and release it in death) and increases the decline in biodiversity. It has been argued that although tropical crops should be grown, it should be done in regions under threat (e.g., regions at risk of desertification, salination, ...)
Although tropical crops have high value at supermarkets, most crops are not sold at all or have very limited supply because of the small amounts and fluctuating supply. At normal markets (not supermarkets), these food items are available, but only local crops within season. Of course because the availability meets demand in these places, prices are lower and the returns are lower than they would be in the West.
This availability of inexpensive foreign food is not only damaging to the indigenous economy, but also for the health
of the people themselves (sparking obesity, heart problems, and a lack of certain vitamins and minerals). This is believed to be because certain Western food (not only hamburgers but also the main staple food) is not qualified for them (as strange as it may seem). Because of these problems, the traditional African food is again slowly being distributed within the continent (e.g. in Nairobi
, the Tusker Supermarket
).
has been entirely lost to erosion, or where desertification
has started. The intent is not to grow food or cash crops, but to repair and reinvigorate the soil in order to prepare the way for the later planting of food or cash crops. Nitrogen fixing plants and trees normally form the basis of such a reclamation
project.
has been consumed, and the next harvest is still some time away. Even in normal years, many households face an annual
reduction in the amount of food they have available. Typically the hunger season will coincide with the start of planting the new crop, or shortly thereafter. So farmers are faced with a shortage of food at the very time they are expected to perform their heaviest labor.
One way of mitigating the effects of the hunger season is growing some non-seasonal crops close to the family home, such as banana
s in humid areas, or cassava where it is arid. As an example, a family that has ten banana plants producing fruit during the hunger season is unlikely to experience excessive hardship. Sweet potato
, pigeon pea
, and Moringa oleifera
should also be considered.
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
than any other endeavor; the majority are self-employed subsistence farmer
Farmer
A farmer is a person engaged in agriculture, who raises living organisms for food or raw materials, generally including livestock husbandry and growing crops, such as produce and grain...
s living in the tropics
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
. While growing food for local consumption is the core of tropical agriculture, Cash crop
Cash crop
In agriculture, a cash crop is a crop which is grown for profit.The term is used to differentiate from subsistence crops, which are those fed to the producer's own livestock or grown as food for the producer's family...
s (normally crops grown for export
Export
The term export is derived from the conceptual meaning as to ship the goods and services out of the port of a country. The seller of such goods and services is referred to as an "exporter" who is based in the country of export whereas the overseas based buyer is referred to as an "importer"...
) are also included in the definition.
When people discuss the tropics, it is normal to use generalized labels to group together similar tropical areas. Common terms would include the humid-tropics (rainforest
Rainforest
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...
s); the arid-tropics (desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...
s and dry areas); or monsoon
Monsoon
Monsoon is traditionally defined as a seasonal reversing wind accompanied by corresponding changes in precipitation, but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea...
zones (those areas that have well defined wet/dry season
Season
A season is a division of the year, marked by changes in weather, ecology, and hours of daylight.Seasons result from the yearly revolution of the Earth around the Sun and the tilt of the Earth's axis relative to the plane of revolution...
s and experience monsoons). Such labeling is very useful when discussing agriculture, because what works in one area of the world will normally work in a similar area somewhere else, even if that area is on the opposite side of the globe.
Most temperate zone agricultural techniques are inappropriate for tropical areas. The second half of the 20th century saw many attempts to duplicate in the tropics farming practices that had been successful in temperate climates. Due to differences in climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
, soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
s, and patterns of land ownership, these largely failed. When they did succeed they tended to heavily favor farmers with substantial land holdings, as a high percentage of temperate agricultural practices are economically "scale-based" and favor large scale production. This in turn pushed many small-scale farmers on to ever more marginal land, as the better quality land was consolidated into larger farms.
Green Revolution
The "Green RevolutionGreen Revolution
Green Revolution refers to a series of research, development, and technology transfer initiatives, occurring between the 1940s and the late 1970s, that increased agriculture production around the world, beginning most markedly in the late 1960s....
" is the name given to the most successful agricultural improvement program ever undertaken in the tropics. Funded initially by the Rockefeller Foundation
Rockefeller Foundation
The Rockefeller Foundation is a prominent philanthropic organization and private foundation based at 420 Fifth Avenue, New York City. The preeminent institution established by the six-generation Rockefeller family, it was founded by John D. Rockefeller , along with his son John D. Rockefeller, Jr...
, it aimed to improve corn
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
, rice
Rice
Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...
, and other cereal
Cereal
Cereals are grasses cultivated for the edible components of their grain , composed of the endosperm, germ, and bran...
cultivators – breeding
Plant breeding
Plant breeding is the art and science of changing the genetics of plants in order to produce desired characteristics. Plant breeding can be accomplished through many different techniques ranging from simply selecting plants with desirable characteristics for propagation, to more complex molecular...
plants that would produce more grain for the same amount of effort.
From that point it expanded out to improved basic farming practices, particularly for rice farmers. The growth of crop yields was such that agriculture was able to outstrip population growth — per capita production increased every year following 1950 - with Asia leading the way. One of the more remarkable aspects of the Green Revolution is that the total cost of the program by 1990 was approximately US$100 million, less than what a single Boeing 747
Boeing 747
The Boeing 747 is a wide-body commercial airliner and cargo transport, often referred to by its original nickname, Jumbo Jet, or Queen of the Skies. It is among the world's most recognizable aircraft, and was the first wide-body ever produced...
airliner costs in 2005.
It can be concluded that the Green Revolution
Green Revolution
Green Revolution refers to a series of research, development, and technology transfer initiatives, occurring between the 1940s and the late 1970s, that increased agriculture production around the world, beginning most markedly in the late 1960s....
was a success, with only a minor flaw: although the crops gave more yield, they were more subject to disease since this was not a primary concern in the program.
In order to address this problem together with an approach to more small-scale farming crops, there is today substantial interest in creating a second Green Revolution, based on sustainable
Sustainable agriculture
Sustainable agriculture is the practice of farming using principles of ecology, the study of relationships between organisms and their environment...
agricultural practices and geared towards (small-scale) farmers with limited financial
FINANCIAL
FINANCIAL is the weekly English-language newspaper with offices in Tbilisi, Georgia and Kiev, Ukraine. Published by Intelligence Group LLC, FINANCIAL is focused on opinion leaders and top business decision-makers; It's about world’s largest companies, investing, careers, and small business. It is...
resources.
The Humidtropics CGIAR Research Program on Integrated Systems in the Humid Tropics, called Humidtropics (www.humidtropics.org) is a new initiative (2010) that progresses the "Green Revolution
Green Revolution
Green Revolution refers to a series of research, development, and technology transfer initiatives, occurring between the 1940s and the late 1970s, that increased agriculture production around the world, beginning most markedly in the late 1960s....
" approach by considering research for development (R4D) for complex agricultural livelihood systems.
Plant propagation
Many tropical food plants are propagated by cuttingCutting
Cutting is the separation of a physical object, or a portion of a physical object, into two portions, through the application of an acutely directed force. An implement commonly used for cutting is the knife or in medical cases the scalpel...
s. Seeds are necessary for plant embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
s to survive the winter and other harsh conditions such as drought
Drought
A drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region...
. However, where the weather is normally conducive to growth year-round, it is often advantageous for plants to reproduce through means other than seeds. By bypassing the seed stage plants can greatly accelerate their reproductive cycle. Despite this, anyone who wishes so, may still grow tropical crops (e.g. fruit, ...) from seed. To do so, some special seed germination techniques to germinate it more quicker may be best used.
Plant defenses
A particularly good description of plant defenses can be found at How and why do plants defend themselves? that states in part:- "Plants are faced with a dilemma; while they need to attract beneficial pollinators and seed dispensers, they must also minimize the damage caused by the marauding army of herbivores. Without some form of protection the trees would be stripped bare and smaller plants would be completely devastated, and because plants stand still, they cannot run away. This is as true in Amazonian rainforest as it is in Northern coniferous forest." - Marcus Wischik.
Many (tropical) plants use toxin
Toxin
A toxin is a poisonous substance produced within living cells or organisms; man-made substances created by artificial processes are thus excluded...
s to protect themselves. Cassava
Cassava
Cassava , also called yuca or manioc, a woody shrub of the Euphorbiaceae native to South America, is extensively cultivated as an annual crop in tropical and subtropical regions for its edible starchy tuberous root, a major source of carbohydrates...
, one of the most important tropical food crops, produces cyanide
Cyanide
A cyanide is a chemical compound that contains the cyano group, -C≡N, which consists of a carbon atom triple-bonded to a nitrogen atom. Cyanides most commonly refer to salts of the anion CN−. Most cyanides are highly toxic....
upon ingestion
Ingestion
Ingestion is the consumption of a substance by an organism. In animals, it normally is accomplished by taking in the substance through the mouth into the gastrointestinal tract, such as through eating or drinking...
if improperly processed. Other plants are high in oxalate
Oxalate
Oxalate , is the dianion with formula C2O42− also written 22−. Either name is often used for derivatives, such as disodium oxalate, 2C2O42−, or an ester of oxalic acid Oxalate (IUPAC: ethanedioate), is the dianion with formula C2O42− also written (COO)22−. Either...
s (the agent that binds calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
to form kidney stone
Kidney stone
A kidney stone, also known as a renal calculus is a solid concretion or crystal aggregation formed in the kidneys from dietary minerals in the urine...
s); castor beans are the source of ricin
Ricin
Ricin , from the castor oil plant Ricinus communis, is a highly toxic, naturally occurring protein. A dose as small as a few grains of salt can kill an adult. The LD50 of ricin is around 22 micrograms per kilogram Ricin , from the castor oil plant Ricinus communis, is a highly toxic, naturally...
, one of the most powerful poison
Poison
In the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....
s in existence; and velvet beans
Mucuna pruriens
Mucuna pruriens is a tropical legume known as velvet bean or cowitch and by other common names , found in Africa, India and the Caribbean. The plant is infamous for its extreme itchiness produced on contact, particularly with the young foliage and the seed pods...
contain 7-10% L-DOPA. The list of toxic plants is long, but toxicity does not always mean a particular plant should be avoided, the knowledge needed to render toxic plants safe to use already exists in most communities.
Slash/mulch
The contents of a bag of commercialCommerce
While business refers to the value-creating activities of an organization for profit, commerce means the whole system of an economy that constitutes an environment for business. The system includes legal, economic, political, social, cultural, and technological systems that are in operation in any...
fertilizer
Fertilizer
Fertilizer is any organic or inorganic material of natural or synthetic origin that is added to a soil to supply one or more plant nutrients essential to the growth of plants. A recent assessment found that about 40 to 60% of crop yields are attributable to commercial fertilizer use...
is described in terms of NPK -nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
(N), phosphorus
Phosphorus
Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...
(P) and potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
(K); with nitrogen being the main component of most commercial fertilizers.
Oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
is only a small part of the air; the largest component of air is nitrogen. Nitrogen is the main building block of protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
; muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
in mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s and plant tissue
Tissue (biology)
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
in plants. If the level of nitrogen in the soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
is increased, plant growth can be significantly increased. Legumes are a group of plants that interact with bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
(rhizobia
Rhizobia
Rhizobia are soil bacteria that fix nitrogen after becoming established inside root nodules of legumes . Rhizobia require a plant host; they cannot independently fix nitrogen...
) in the soil to fix nitrogen
Nitrogen fixation
Nitrogen fixation is the natural process, either biological or abiotic, by which nitrogen in the atmosphere is converted into ammonia . This process is essential for life because fixed nitrogen is required to biosynthesize the basic building blocks of life, e.g., nucleotides for DNA and RNA and...
from the air, and deposit the nitrogen into the soil where it is available for other plants to use. The nitrogen deposited by legumes can be readily converted into larger harvests.
Green manure
Green manure
In agriculture, a green manure is a type of cover crop grown primarily to add nutrients and organic matter to the soil. Typically, a green manure crop is grown for a specific period of time , and then plowed under and incorporated into the soil while green or shortly after flowering...
s are plants grown to improve the soil, suppress weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
s, limit erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
, and — when legumes are used — to increase the nitrogen content of the soil. The most common type of green manure used in the tropics is Velvet bean. It produces a thick blanket
Blanket
A blanket is a type of bedding, generally speaking, a large piece of cloth, intended to keep the user warm, especially while sleeping. Blankets are distinguished from sheets by their thickness and purpose; the thickest sheet is still thinner than the lightest blanket. Blankets are generally used...
of vine
Vine
A vine in the narrowest sense is the grapevine , but more generally it can refer to any plant with a growth habit of trailing or scandent, that is to say climbing, stems or runners...
s and leaves
Leaves
-History:Vocalist Arnar Gudjonsson was formerly the guitarist with Mower, and he was joined by Hallur Hallsson , Arnar Ólafsson , Bjarni Grímsson , and Andri Ásgrímsson . Late in 2001 they played with Emiliana Torrini and drew early praise from the New York Times...
that in addition to infusing the soil with nitrogen also smother most weeds. In addition it has reasonable tolerance to drought, low soil fertility, and highly acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...
ic soil. Alternatives to the Velvet bean include the Lablab bean, the Jack bean, and for use above 500 m altitude, the Scarlet runner bean.
Once the blanket is several centimeters thick, it is chopped down with a machete
Machete
The machete is a large cleaver-like cutting tool. The blade is typically long and usually under thick. In the English language, an equivalent term is matchet, though it is less commonly known...
, and the vines are chopped up. This produces thick mulch
Mulch
In agriculture and gardening, is a protective cover placed over the soil to retain moisture, reduce erosion, provide nutrients, and suppress weed growth and seed germination. Mulching in gardens and landscaping mimics the leaf cover that is found on forest floors....
on top of the ground that both inhibits weed growth and adds vital nutrient
Nutrient
A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment. They are used to build and repair tissues, regulate body processes and are converted to and used as energy...
s to the soil. Corn or other crops are then planted directly into this mulch.
Slash/mulch is popular in southern Mexico, Guatemala
Guatemala
Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...
, and Honduras
Honduras
Honduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...
; and in recent years has gained a following in many areas of the tropics, from Brazil to central Africa. Where it has been embraced it has pushed aside slash and burn
Slash and burn
Slash-and-burn is an agricultural technique which involves cutting and burning of forests or woodlands to create fields. It is subsistence agriculture that typically uses little technology or other tools. It is typically part of shifting cultivation agriculture, and of transhumance livestock...
agriculture, and allowed farmers to utilize the same land continuously for many years.
Cornell University
Cornell University
Cornell University is an Ivy League university located in Ithaca, New York, United States. It is a private land-grant university, receiving annual funding from the State of New York for certain educational missions...
has taken a leading role in research
Research
Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...
ing the effects of mulches and slash/mulch practices in the tropics.http://ppathw3.cals.cornell.edu/mba_project/moist/home2.html
Small-scale irrigation
In most places in the tropics sufficient precipitationPrecipitation (meteorology)
In meteorology, precipitation In meteorology, precipitation In meteorology, precipitation (also known as one of the classes of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation...
occurs to grow enough food to feed the local population; however, it many not fall in a timely or convenient manner. Making maximum use of the water that does fall is an ongoing challenge.
Water is a particularly important issue in dryland farming
Dryland farming
Dryland farming is an agricultural technique for non-irrigated cultivation of drylands.-Locations:Dryland farming is used in the Great Plains, the Palouse plateau of Eastern Washington, and other arid regions of North America, the Middle East and in other grain growing regions such as the steppes...
. The ability to collect and store water at a low cost and without damaging the environment, is what opens up deserts and other arid
Arid
A region is said to be arid when it is characterized by a severe lack of available water, to the extent of hindering or even preventing the growth and development of plant and animal life...
regions to farmers. When it rains in dryland areas, the rain storms are normally heavy, and the soil unable to absorb the large amounts of rain that comes down. This leads to excessive surface run-off that needs to be captured and retained.
Commercial farms growing cash crops often use irrigation techniques similar to or identical to what would be found on large scale commercial farms located in temperate regions; as an example, the Israeli drip-irrigation lines.
Water harvesting pits
One of the simplest forms of irrigationIrrigation
Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...
- the farmer digs bathtub
Bathtub
A bath , bathtub , or tub is a large container for holding water in which a person may bathe . Most modern bathtubs are made of acrylic or fiberglass, but alternatives are available in enamel over steel or cast iron, and occasionally waterproof finished wood...
sized pits into his fields and lines them with plastic sheets to collect rainwater. Then once the dry season
Dry season
The dry season is a term commonly used when describing the weather in the tropics. The weather in the tropics is dominated by the tropical rain belt, which oscillates from the northern to the southern tropics over the course of the year...
sets in the farmer uses the collected water to irrigate his crops. The technique is especially useful in mountainous areas, where rapid run-off
Surface runoff
Surface runoff is the water flow that occurs when soil is infiltrated to full capacity and excess water from rain, meltwater, or other sources flows over the land. This is a major component of the water cycle. Runoff that occurs on surfaces before reaching a channel is also called a nonpoint source...
would otherwise occur.
During years with normal precipitation the growing season can be increased by an extra month or more by using harvesting pits. An extra month in many places means an extra crop can be grown. For instance if the local growing season
Growing season
In botany, horticulture, and agriculture the growing season is the period of each year when native plants and ornamental plants grow; and when crops can be grown....
is 5 months long, and the farmers main crop takes 3 or 4 months to grow, an extra month may be enough time to grow a secondary crop. During times of drought, what rain does fall can be collected in the pits and used to secure the farmer's main crop.
Bucket drip irrigation
An irrigation system consisting of a bucketBucket
A bucket, also called a pail, is typically a watertight, vertical cylinder or truncated cone, with an open top and a flat bottom, usually attached to a semicircular carrying handle called the bail. A pail can have an open top or can have a lid....
hung from a pole
Utility pole
A utility pole is a pole used to support overhead power lines and various other public utilities, such as cable, fibre optic cable, and related equipment such as transformers and street lights. It can be referred to as a telephone pole, power pole, hydro pole, telegraph pole, or telegraph post,...
, with a hose
Hose (tubing)
A hose is a hollow tube designed to carry fluids from one location to another. Hoses are also sometimes called pipes , or more generally tubing...
coming out of the bottom, and holes punched into the hose. The bucket is filled, and gravity feeds the water to the plants. As a rule about 40 litres of water per day are needed for every 100 plants, although this can vary depending upon what is being grown.
Treadle pumps
The treadleTreadle
A treadle [from OE tredan = to tread] is a part of a machine which is operated by the foot to produce reciprocating or rotary motion in a machine such as a weaving loom or grinder...
pump
Pump
A pump is a device used to move fluids, such as liquids, gases or slurries.A pump displaces a volume by physical or mechanical action. Pumps fall into three major groups: direct lift, displacement, and gravity pumps...
is a human-powered pump designed to lift water from a depth of seven meters or less. A treadle is lever device pressed by the foot to drive a machine, in this case a pump. The treadle pump can do most of the work of a motorized pump, but costs considerably less to purchase, and needs no fossil fuel
Fossil fuel
Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years...
as it is driven by the operators body weight and leg muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
s. It can lift five to seven cubic meters of water per hour from wells
Water well
A water well is an excavation or structure created in the ground by digging, driving, boring or drilling to access groundwater in underground aquifers. The well water is drawn by an electric submersible pump, a trash pump, a vertical turbine pump, a handpump or a mechanical pump...
and borehole
Borehole
A borehole is the generalized term for any narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water or other liquid or gases , as part of a geotechnical investigation, environmental site...
s up to seven meters deep and can also be used to draw water from lakes and rivers. Most treadle pumps used are of local manufacture, as they are simple and inexpensive to build.
Standard treadle pumps are suction
Suction
Suction is the flow of a fluid into a partial vacuum, or region of low pressure. The pressure gradient between this region and the ambient pressure will propel matter toward the low pressure area. Suction is popularly thought of as an attractive effect, which is incorrect since vacuums do not...
pumps, and where first developed in the early 1980s in Bangladesh
Bangladesh
Bangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
. Most treadle pumps manufactured in Africa are pressure
Pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
treadle pumps; a modification to the original design that means water is forced out of the pump under pressure. Pressure treadle pumps are more versatile as they allow farmers to pump water uphill, or over long distances, or fill elevated tanks.
Crop rotation
Crop rotationCrop rotation
Crop rotation is the practice of growing a series of dissimilar types of crops in the same area in sequential seasons.Crop rotation confers various benefits to the soil. A traditional element of crop rotation is the replenishment of nitrogen through the use of green manure in sequence with cereals...
is the cornerstone pest control
Pest control
Pest control refers to the regulation or management of a species defined as a pest, usually because it is perceived to be detrimental to a person's health, the ecology or the economy.-History:...
in the tropics. When a single crop is planted repeatedly in the same soil, insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s and disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
s that attack that crop are allowed to build up to unmanageable levels, greatly reducing the farmer's harvest
Harvest
Harvest is the process of gathering mature crops from the fields. Reaping is the cutting of grain or pulse for harvest, typically using a scythe, sickle, or reaper...
.
The most basic form of crop rotation is also the simplest: never plant the same thing in the same place twice. This results in naturally breaking the cycles
Biological life cycle
A life cycle is a period involving all different generations of a species succeeding each other through means of reproduction, whether through asexual reproduction or sexual reproduction...
of weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
s, insects and diseases that attack food crops. Rotations are used to prevent or at least partially control several pests and at the same time to reduce the farmer's reliance on chemical pesticide
Pesticide
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...
s. Crop rotations often are the only economically feasible method for reducing insect and disease damage.
Crop rotation replaces a crop that is susceptible to a serious pest with another crop that is not susceptible. Each food crop comes with its own set of pests that attack that particular crop. By planting a different crop each time, the farmer is able to starve out those pests. Often a set of three or four crops are planted on a rotating basis, ensuring that by the time the first crop is replanted, the pests that attack it are substantially reduced.
Another side benefit of crop rotation is it improves the soil. Constantly growing the same crop in the same location will strip the soil of the nutrient
Nutrient
A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment. They are used to build and repair tissues, regulate body processes and are converted to and used as energy...
s that particular crop requires. Rotating to a different crop will reduce the pressure placed on the soil. Or if a green manure is used as part of the rotation sequence, the soil can actually be improved.
Integrated pest management
Integrated Pest ManagementIntegrated Pest Management
Integrated pest management is an ecological approach to agricultural pest control that integrates pesticides/herbicides into a management system incorporating a range of practices for economic control of a pest...
(IPM) was developed as an alternative to the heavy use of chemical pesticides. Eliminating all insect pests requires the extensive use of chemical pesticides, which over time can become self-defeating. Farmers end up using more and more chemicals with diminishing effect as pests quickly adapt –while at the same time natural predator insects are eliminated from the farm. Under IPM chemicals should be a secondary line of defense, while building up the number of natural predators on a farm is the main goal. The IPM approach calls for keeping the pest populations below the levels at which they cause economic injury, not total eradication.
IPM in its pure form is extremely complex, and beyond the ability of most farmers to manage; however, the underlying principals have gained widespread acceptance in the tropics, with most governments sponsoring IPM educational programs.
Non-indigenous crops
Most crops grown in the developing world are crops imported from Europe and North America (wheat, maize, ...). These crops are -as they come from other regions- not adapted to the new environment in which they are grown. This causes decreased yields (when compared to other similar (yet indigenous) crops) and makes the plant less capable of fending off pests. A new project called Crops for the Future, started by the International Centre for Underutilised CropsInternational Centre for Underutilised Crops
The International Centre for Underutilised Crops has been an independent nonprofit scientific research institute that investigated, coordinated and supported research programmes towards increasing the productivity and use of what are termed underutilised crops—crops that have a potential to...
is momentarily researching indigenous alternatives to western crops.
Mild winters
Winters are mild in the tropics; there is no frost, no snow, and no ice, so the insect population flourishes year-round. In temperate areas winter eliminates most insect pests prior to the emergence of new crops, so plants coming up in the spring have a chance to take hold and grow prior to being attacked. In the tropics plants enter a world already full of hungry adult insects.Acidic soils
Soils in the humid tropics are normally highly acidic and nutrient poor; decompositionDecomposition
Decomposition is the process by which organic material is broken down into simpler forms of matter. The process is essential for recycling the finite matter that occupies physical space in the biome. Bodies of living organisms begin to decompose shortly after death...
is rapid because of high temperatures, high humidity
Humidity
Humidity is a term for the amount of water vapor in the air, and can refer to any one of several measurements of humidity. Formally, humid air is not "moist air" but a mixture of water vapor and other constituents of air, and humidity is defined in terms of the water content of this mixture,...
, and frequent heavy rains. Heavy rains, especially monsoon rains, lead to rapid nutrient leaching
Leaching (agriculture)
In agriculture, leaching refers to the loss of water-soluble plant nutrients from the soil, due to rain and irrigation. Soil structure, crop planting, type and application rates of fertilizers, and other factors are taken into account to avoid excessive nutrient loss.Leaching may also refer to ...
, and chemical weathering of the soil. Standard temperate strategies for improving nutrient poor soil, such as composting, have limited application in such an environment due to rapid leaching.
Aluminum is the most common metal found in the Earth's crust
Crust
Crust may refer to:* Crust * The Crust, television seriesPhysical sciences:* Crust , at least continent-wide structure* Soil crust, local biology-sensitive structureFood:* Crust, dense surface layer of bread...
. It is found in all soils and in all environments, from temperate to tropical. In a soluble state it is highly toxic to plant life, as it inhibits root
Root
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...
growth; however, in neutral
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
and alkaline soils common to the temperate zones it is insoluble and therefore inert
Inert
-Chemistry:In chemistry, the term inert is used to describe a substance that is not chemically reactive.The noble gases were previously known as inert gases because of their perceived lack of participation in any chemical reactions...
. Soil fertility
Fertility
Fertility is the natural capability of producing offsprings. As a measure, "fertility rate" is the number of children born per couple, person or population. Fertility differs from fecundity, which is defined as the potential for reproduction...
is directly influenced by how acidic it is, as the more acidic the higher the level of aluminum toxicity; in areas where the pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
drops below 5, aluminum becomes soluble and can enter into plant roots where it accumulates.
Approximately a third of all tropical soils are too acidic to support traditional food crops. These highly acidic tropical soils represent the largest untapped arable land
Arable land
In geography and agriculture, arable land is land that can be used for growing crops. It includes all land under temporary crops , temporary meadows for mowing or pasture, land under market and kitchen gardens and land temporarily fallow...
left in the world, and therefore more productive utilization of these lands is key to expanding the world food supply.
Winrock International states "In the humid tropics, the relative importance of acid soils is greatest in Latin America (81%), but also significant in Africa (56%) and Asia (38%)" http://www.winrock.org/forestry/FACTPUB/AIS_web/AIS10.html.
Traditionally on commercial farms aluminum toxicity is countered by adding lime
Agricultural lime
Agricultural lime, also called aglime, agricultural limestone, garden lime or liming, is a soil additive made from pulverized limestone or chalk. The primary active component is calcium carbonate...
to the soil, which neutralizes the acid and renders the aluminum inert. However, many small land holders and resource-poor farmers cannot afford lime, and instead rely on slash-and-burn agriculture. As the original plant life is burnt, the ash acts to neutralize the acidic soil and makes the area acceptable for food plants. In time acidity increases and only native plants will grow, forcing the farmer to move on and clear a new area.
Soil color in humid areas is related to the level of oxidation that has occurred in the soil, with red soil being the result of iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
oxidation, and yellow soil being the result of aluminum oxidation.
Salinization
Salinization occurs naturally in arid areas where not enough rain falls to wash soluble salts down and out of the root zone. Irrigation makes the situation worse, since surface water and groundwater contain more salt than rainwater does. Salt tends to build up in the soil as water is added through irrigation. As water is used by plants and evaporates from the soil surface, the salt in the water concentrateConcentrate
A concentrate is a form of substance which has had the majority of its base component removed. Typically this will be the removal of water from a solution or suspension such as the removal of water from fruit juice...
s in the soil. The high temperatures and low humidity in arid regions means that salinization often accompanies irrigation.
Day-length sensitive plants
Some plants have a photoperiod (photoperiodismPhotoperiodism
Photoperiodism is the physiological reaction of organisms to the length of day or night. It occurs in plants and animals.Photoperiodism can also be defined as the developmental responses of plants to the relative lengths of the light and dark periods...
) requirement for a certain number of hours of daylight before they will grow, flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
, or produce fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
. Without this they will not complete their life-cycle
Biological life cycle
A life cycle is a period involving all different generations of a species succeeding each other through means of reproduction, whether through asexual reproduction or sexual reproduction...
and will not produce fruit and seeds. For this reason seeds brought from the temperate zones may not perform as expected, or at all in the tropics. Some plants are genetically keyed to only start producing when a certain number of hours of daylight is reached, the same number of hours as is found in their native habitat. With the shorter daylight hours experienced in the tropics, that switch never gets thrown.
Logging of rainforest/tropical forests to produce food
Throughout the tropics and predominantly in IndonesiaIndonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
, and certain South-East Asian Countries, a lot of forest is being cleared to produce food. Major examples are the oil palm
Oil palm
The oil palms comprise two species of the Arecaceae, or palm family. They are used in commercial agriculture in the production of palm oil. The African Oil Palm Elaeis guineensis is native to West Africa, occurring between Angola and Gambia, while the American Oil Palm Elaeis oleifera is native to...
plantations in Indonesia and the dry rice farming techniques using slash and burn
Slash and burn
Slash-and-burn is an agricultural technique which involves cutting and burning of forests or woodlands to create fields. It is subsistence agriculture that typically uses little technology or other tools. It is typically part of shifting cultivation agriculture, and of transhumance livestock...
-method in Southeast Asia. This of course adds to global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
(as trees collect CO2 in life and release it in death) and increases the decline in biodiversity. It has been argued that although tropical crops should be grown, it should be done in regions under threat (e.g., regions at risk of desertification, salination, ...)
Low economic input in Africa, constraining the export of tropical crops
In Africa, there are very few registered African companies that sell their products through a commercial distributor' into Supermarkets. This phenomenon can be clearly seen if one walks into a supermarket (not a normal market, where this isn't the case); almost all products come from Western companies.Although tropical crops have high value at supermarkets, most crops are not sold at all or have very limited supply because of the small amounts and fluctuating supply. At normal markets (not supermarkets), these food items are available, but only local crops within season. Of course because the availability meets demand in these places, prices are lower and the returns are lower than they would be in the West.
Availability of inexpensive Western crops and food
Western food, as it is subsidized by the EU and the USA, is for certain products, such as chicken, cheaper than its counterparts in the developing world. Besides the matching food products being cheaper, the availability of Western surrogates for certain food has also proven disastrous. At least in certain continents as Africa, Western surrogate foods are thought to be 'better' and more modern by African people, who thus switch from their traditional ingredients and meals to Western counterparts (see article below).This availability of inexpensive foreign food is not only damaging to the indigenous economy, but also for the health
Health
Health is the level of functional or metabolic efficiency of a living being. In humans, it is the general condition of a person's mind, body and spirit, usually meaning to be free from illness, injury or pain...
of the people themselves (sparking obesity, heart problems, and a lack of certain vitamins and minerals). This is believed to be because certain Western food (not only hamburgers but also the main staple food) is not qualified for them (as strange as it may seem). Because of these problems, the traditional African food is again slowly being distributed within the continent (e.g. in Nairobi
Nairobi
Nairobi is the capital and largest city of Kenya. The city and its surrounding area also forms the Nairobi County. The name "Nairobi" comes from the Maasai phrase Enkare Nyirobi, which translates to "the place of cool waters". However, it is popularly known as the "Green City in the Sun" and is...
, the Tusker Supermarket
Supermarket
A supermarket, a form of grocery store, is a self-service store offering a wide variety of food and household merchandise, organized into departments...
).
Pioneering crops
Pioneering crops are used in places where the land has been striped bare, and the topsoilTopsoil
Topsoil is the upper, outermost layer of soil, usually the top to . It has the highest concentration of organic matter and microorganisms and is where most of the Earth's biological soil activity occurs.-Importance:...
has been entirely lost to erosion, or where desertification
Desertification
Desertification is the degradation of land in drylands. Caused by a variety of factors, such as climate change and human activities, desertification is one of the most significant global environmental problems.-Definitions:...
has started. The intent is not to grow food or cash crops, but to repair and reinvigorate the soil in order to prepare the way for the later planting of food or cash crops. Nitrogen fixing plants and trees normally form the basis of such a reclamation
Land reclamation
Land reclamation, usually known as reclamation, is the process to create new land from sea or riverbeds. The land reclaimed is known as reclamation ground or landfill.- Habitation :...
project.
Hunger season
The hunger season is that period of time when all the food from the previous harvestHarvest
Harvest is the process of gathering mature crops from the fields. Reaping is the cutting of grain or pulse for harvest, typically using a scythe, sickle, or reaper...
has been consumed, and the next harvest is still some time away. Even in normal years, many households face an annual
Year
A year is the orbital period of the Earth moving around the Sun. For an observer on Earth, this corresponds to the period it takes the Sun to complete one course throughout the zodiac along the ecliptic....
reduction in the amount of food they have available. Typically the hunger season will coincide with the start of planting the new crop, or shortly thereafter. So farmers are faced with a shortage of food at the very time they are expected to perform their heaviest labor.
One way of mitigating the effects of the hunger season is growing some non-seasonal crops close to the family home, such as banana
Banana
Banana is the common name for herbaceous plants of the genus Musa and for the fruit they produce. Bananas come in a variety of sizes and colors when ripe, including yellow, purple, and red....
s in humid areas, or cassava where it is arid. As an example, a family that has ten banana plants producing fruit during the hunger season is unlikely to experience excessive hardship. Sweet potato
Sweet potato
The sweet potato is a dicotyledonous plant that belongs to the family Convolvulaceae. Its large, starchy, sweet-tasting, tuberous roots are an important root vegetable. The young leaves and shoots are sometimes eaten as greens. Of the approximately 50 genera and more than 1,000 species of...
, pigeon pea
Pigeon pea
The pigeon pea , also known as tropical green pea, toor dāl or arhar dāl , ತೊಗರಿ ಬೇಳೆ kadios , or Congo pea or gungo pea , pois Congo , gandul , gunga pea, or no-eye pea, [Cajanus...
, and Moringa oleifera
Moringa oleifera
Moringa oleifera, the word Moringa probably came from dravidian language Tamil and commonly referred to as "Shojne" in Bengali, "Munagakaya" in Telugu,"Shenano" in Rajasthani,...
should also be considered.
Common tropical horticulture crops
- papayaPapayaThe papaya , papaw, or pawpaw is the fruit of the plant Carica papaya, the sole species in the genus Carica of the plant family Caricaceae...
- rubber tree
- coconutCoconutThe coconut palm, Cocos nucifera, is a member of the family Arecaceae . It is the only accepted species in the genus Cocos. The term coconut can refer to the entire coconut palm, the seed, or the fruit, which is not a botanical nut. The spelling cocoanut is an old-fashioned form of the word...
- BananaBananaBanana is the common name for herbaceous plants of the genus Musa and for the fruit they produce. Bananas come in a variety of sizes and colors when ripe, including yellow, purple, and red....
- PalmsArecaceaeArecaceae or Palmae , are a family of flowering plants, the only family in the monocot order Arecales. There are roughly 202 currently known genera with around 2600 species, most of which are restricted to tropical, subtropical, and warm temperate climates...
(mainly oil palm)
Common agricultural crops
- CassavaCassavaCassava , also called yuca or manioc, a woody shrub of the Euphorbiaceae native to South America, is extensively cultivated as an annual crop in tropical and subtropical regions for its edible starchy tuberous root, a major source of carbohydrates...
- MaizeMaizeMaize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
(corn) - RiceRiceRice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...
- SorghumSorghumSorghum is a genus of numerous species of grasses, one of which is raised for grain and many of which are used as fodder plants either cultivated or as part of pasture. The plants are cultivated in warmer climates worldwide. Species are native to tropical and subtropical regions of all continents...
- barleyBarleyBarley is a major cereal grain, a member of the grass family. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods...
- WheatWheatWheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...
- buckwheatBuckwheatBuckwheat refers to a variety of plants in the dicot family Polygonaceae: the Eurasian genus Fagopyrum, the North American genus Eriogonum, and the Northern Hemisphere genus Fallopia. Either of the latter two may be referred to as "wild buckwheat"...
- Sweet potatoSweet potatoThe sweet potato is a dicotyledonous plant that belongs to the family Convolvulaceae. Its large, starchy, sweet-tasting, tuberous roots are an important root vegetable. The young leaves and shoots are sometimes eaten as greens. Of the approximately 50 genera and more than 1,000 species of...
- TaroTaroTaro is a common name for the corms and tubers of several plants in the family Araceae . Of these, Colocasia esculenta is the most widely cultivated, and is the subject of this article. More specifically, this article describes the 'dasheen' form of taro; another variety is called eddoe.Taro is...
- milletMilletThe millets are a group of small-seeded species of cereal crops or grains, widely grown around the world for food and fodder. They do not form a taxonomic group, but rather a functional or agronomic one. Their essential similarities are that they are small-seeded grasses grown in difficult...
- yamYam (vegetable)Yam is the common name for some species in the genus Dioscorea . These are perennial herbaceous vines cultivated for the consumption of their starchy tubers in Africa, Asia, Latin America and Oceania...
- tobaccoTobaccoTobacco is an agricultural product processed from the leaves of plants in the genus Nicotiana. It can be consumed, used as a pesticide and, in the form of nicotine tartrate, used in some medicines...
- sugarcaneSugarcaneSugarcane refers to any of six to 37 species of tall perennial grasses of the genus Saccharum . Native to the warm temperate to tropical regions of South Asia, they have stout, jointed, fibrous stalks that are rich in sugar, and measure two to six metres tall...
- kidney beans
- soybeanSoybeanThe soybean or soya bean is a species of legume native to East Asia, widely grown for its edible bean which has numerous uses...
s - teaTeaTea is an aromatic beverage prepared by adding cured leaves of the Camellia sinensis plant to hot water. The term also refers to the plant itself. After water, tea is the most widely consumed beverage in the world...
- cottonCottonCotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
- CoffeeCoffeeCoffee is a brewed beverage with a dark,init brooo acidic flavor prepared from the roasted seeds of the coffee plant, colloquially called coffee beans. The beans are found in coffee cherries, which grow on trees cultivated in over 70 countries, primarily in equatorial Latin America, Southeast Asia,...
- cocoa
- morus alba
External links
- Humidtropics CGIAR Research Program
- Global Horticulture Initiative
- International Institute of Tropical Agriculture
- Benefits of traditional vegetables, over Western food
- Article on the effects of Western food to Africans
- Crops of Africa: Vol 1 Grains
- Lost Crops of Africa: Vol 2 Vegetables
- Organic Farming Worldwide