Land Degradation in Rural Tanzania

Credit: ©2014CIAT/GeorginaSmith

By Nora Ririe

Published Spring 2022

Special thanks to Alyssa Augustus for editing and research contributions

Summary+

Land degradation is the primary environmental issue for the Eastern African country of Tanzania. Due to its effect on crop production, land degradation primarily affects farmers living in rural parts of the country. Unsustainable farming techniques, deforestation, and rainfall variation are the main drivers of land degradation. Victims of land degradation tend to struggle from increased undernutrition, decreased economic well-being, and regular environmental migration. Implementing the principles of conservation agriculture are essential to increasing crop yields and decreasing poverty and undernutrition in Tanzania.

Key Takeaways+

• More than 19 million people live in lands affected by land degradation in Tanzania.
• Contributing factors of land degradation include unsustainable farming practices, deforestation, and rainfall variability.
• Negative consequences of land degradation are undernutrition, economic decline, and environmental migration.
• 64% of adolescents in Tanzania experience stunted growth.
• 81% of rural Tanzanians reported having an income that is insufficient for their needs.
• Conservation agriculture has been shown to increase crop production in some areas of Tanzania by 200%.

Key Terms+

Adolescents—Children aged 10–19 years.

Conservation Agriculture—A method of agriculture focusing on minimizing soil disturbance (introducing full organic soil cover) and expanding crop diversification to help improve the food yield, soil health, and overall nutrition of the people it benefits.

Croppable Mosaic Vegetation—Areas within a natural vegetation mosaic which are croppable.

Deforestation—The process of removing natural forestry.

Fallowing—An agricultural technique characterized by leaving a piece of land unused for a period of time. ¹

Forced Migration—The involuntary removal of an individual from their home, generally caused by conflict or natural disaster.

Ground Cover—Any plant that grows over an area of land. Ground cover helps reduce soil erosion.

Labor Market Displacement—Wide-spread involuntary job loss due to economic factors. ²

Land Degradation—The process by which land becomes less useful for agricultural processes. ³

Land Degradation Hotspot—An area which has seen an Normalized Difference Vegetation Index (NDVI) decline for 20 or more years.

Malnutrition/undernutrition—A lack of basic nutrition caused by a lack of food or a lack of necessary food for the process of growth and health.

Natural Vegetation Mosaic—Lands with a mosaic of croplands, forest, shrublands, and grasslands in which no one component comprises more than 60% of the landscape. ⁴

Normalized Difference Vegetation Index (NDVI)—A common indicator of land degradation that uses remote sensing and reflects the visible and near-infrared radiation reflected by vegetation. ⁵

Over-Cultivation—The same plot of land being used for multiple consecutive growing periods without breaks for regeneration.

Overgrazing—Exposure of plants to grazing for extended periods of time without sufficient recovery periods.

Rainfall Variability—The change in the amount of precipitation is received in a given area over a period of time.

Salinization—The process by which soil goes from non-saline (that is, not containing salt) to saline (containing salt).

Soil Degradation—The detachment or removal of nutrients in the soil.

Soil Erosion—The removal of topsoil, or the layer of soil that holds nutrients for plant growth. ⁶

Stunting—An inability to grow caused by malnutrition, typically typified by a low height for age.

Unlined Canal—An irrigation system made of a material that allows for high leakage.

Wasting—Low weight compared to height caused by malnutrition.

Water Erosion—Detachment or removal of soil nutrient by water.

Context

Q: What is land degradation, and what does it look like in Tanzania?

A: Land degradation is the process by which land becomes less productive. This brief will measure land productivity by its ability to produce agricultural goods. Levels of land degradationThe process by which land becomes less useful for agricultural processes.³ are apparent through the amount of land that can produce agricultural goods and the actual amount of agricultural goods that are produced. Degraded land is less available for the agricultural processes which are necessary for the food production in rural areas of Tanzania. 120,000 square kilometers of land are degraded each year worldwide; the amount of land degraded each year in Tanzania specifically is unavailable.^{7, 8, 9} One form of land degradation, soil degradation, is the process by which soil loses nutrients that are necessary for crop growth. Even if agricultural processes are still possible, the yields they produce are not sufficient for necessary growth. Soil degradation may manifest itself through soil or water erosionDetachment or removal of soil nutrient by water..

Credit: ©2014CIAT/StephanieMalyon

Land degradation is especially harmful when it impacts cropland or croppable mosaic vegetationAreas within a natural vegetation mosaic which are croppable. because these are the types of lands that Tanzania uses to produce food. Mosaic vegetation is a term that is used to describe an area of land that has a mix of croplands, shrublands, and forests. Croppable mosaic vegetation is the area of land within mosaic vegetation that can be used for agricultural purposes. In Tanzania, 32% of cropland and 62% of croppable mosaic vegetation are in land degradation hotspotsAn area which has seen an NDVI decline for 20 or more years..¹⁰ These areas have seen a decline in the Normalized Difference Vegetation Index (NDVIThe Normalized Difference Vegetation Index. A common indicator of land degradation that uses remote sensing and reflects the visible and near-infrared radiation reflected by vegetation.⁵) for at least twenty years.¹¹ NDVI decline is a common indicator for land degradationThe process by which land becomes less useful for agricultural processes.³; in cropland and croppable mosaic vegetation, this sort of decline indicates a loss of plant productivity and characterizes lower plant health in the areas it affects.¹² For farmers, NDVIThe Normalized Difference Vegetation Index. A common indicator of land degradation that uses remote sensing and reflects the visible and near-infrared radiation reflected by vegetation.⁵ decline means lower agricultural productivity. Because research demonstrates that 51% of all land in Tanzania (around 450,000 sq. km. [173746 sq. mi.]) is covered by “land degradation hotspotsAn area which has seen an NDVI decline for 20 or more years.,” about half of the land in the country has seen long-term NDVI decline due to land degradation.^{13, 14} Over 43% of Tanzania’s population live in these areas, so a significant portion of Tanzanian citizens are affected by the decline in NDVI.¹⁵

Q: What does farming look like in Tanzania?

A: Agriculture is the central part of rural Tanzanians’ lives, as it is the occupation of most of those who live in agricultural areas. Nearly 65% of Tanzanians live in rural areas, and around 90% of those individuals are engaged in agriculture for their primary source of food and income.^{16, 17, 18} 65% of all people in Tanzania are employed in the agricultural sector.¹⁹ Of those, 83% are small family farmers, meaning that one family is engaged in all of the work for that farm. The average farm size for small family farmers is 3 acres, and 60% of farmers in Tanzania have farms under 5 acres.^{20, 21} For reference, the average farm size in the United States is 444 acres.²²

The labor required for farmers is strenuous, as only 1.4% of small family farmers have motorized equipment, and work without motorized equipment is done using livestock or by hand.²³ Of those that own farms, Tanzanians spend on average 5.8 hours a day working. Seventy-eight percent of that labor occurred on their own farms and the other 22% was devoted to work such as collecting water, keeping livestock, or attending school.²⁴ Farmers in Tanzania are mostly focused on a few crops, with the primary agricultural products from the country being maize, wheat, rice, sweet potatoes, bananas, beans, sorghum, and sugar cane.²⁵

Q: Who is affected by land degradation in Tanzania?

A: Farmers need arable land to farm, and land degradationThe process by which land becomes less useful for agricultural processes.³ makes farming more difficult and leads to inadequate crop yields. Because of this, farmers are the primary group affected by land degradation in Tanzania. The population of Tanzania has doubled within the past 25 years, greatly increasing the demand for agricultural goods in the country.²⁶ Because long-term land degradation persists in about half of the land in the country, land degradation reduces the ability of farmers to meet those needs.²⁷ It is common for people in rural areas to only farm for their own meals rather than yielding harvests to sell for profit.²⁸ Therefore, less domestic food is available for urban consumption, delineating how degradation-based food shortages affect both urban and rural citizens of Tanzania. Research from 2017 demonstrates that 78% of households in Tanzania reported having food shortages—84% of rural households and 64% of urban.²⁹

Q: How has land degradation in Tanzania changed over time?

A: Around 300 BCE, agriculture and ironwork introduced slow topsoil erosion and land degradationThe process by which land becomes less useful for agricultural processes.³ to the area that is now Tanzania.³⁰ In the early 19th century, increased caravan trade destroyed natural vegetation along trade routes to make way for walkways and settlements.³¹ The destruction of ground coverAny plant that grows over an area of land. Ground cover helps reduce soil erosion and removal of natural vegetation contributed to an increase in land degradation in the area. Additionally, as travelers moved along the caravan routes, they needed food and other agricultural goods; the caravan travelers would trade for food, making agricultural production an avenue for wealth. Because of this, farmers focused on quick crop yields rather than sustainable agricultural methods, quickly degrading the land they worked on.³² The decision by farmers to engage in inadequate agrarian exercises acted as a precursor to contemporary farming practices which have continued to affect land degradation.

Much of the increase in land degradationThe process by which land becomes less useful for agricultural processes.³ in Tanzania has happened in the last 70 years as farming techniques and trends have evolved in ways that have proved harmful to the land, largely due to the villagization of Tanzania. In late 1973, Tanzania passed the Rural Lands Planning and Utilization Act, which permitted the government to take the people in rural areas out of small and localized settlements and into centralized and consolidated villages.³³ The hope of this law was that it would make it easier for the government to provide water, electricity, and schooling to its citizens.³⁴ However, the law also allowed the expansion of unsustainable farming techniques (to be discussed in the Contributing Factors section of this brief). The extent to which the Rural Lands Planning and Utilization Act affected land degradation in Tanzania is difficult to measure because long-term NDVIThe Normalized Difference Vegetation Index. A common indicator of land degradation that uses remote sensing and reflects the visible and near-infrared radiation reflected by vegetation.⁵ studies, and thus measurements of land degradation hot spots, were not available after 1973.

Q: Within Tanzania, where is the problem most relevant?

A: Tanzania is more affected by land degradationThe process by which land becomes less useful for agricultural processes.³ than almost any country in the world. 51% of the land in Tanzania is affected by land degradation hot spots; only six countries in the world have a higher percentage of land affected by land degradation hot spots.³⁵ All of the countries in Eastern Africa but one have lower levels of land degradation hotspotsAn area which has seen an NDVI decline for 20 or more years., and more people in Tanzania live in land degradation hot spots than in any other country. The only country bordering Tanzania that has a higher percentage of land affected by degradation is Rwanda. However, Rwanda’s population is nearly only 1/5 the size of Tanzania’s population, and over four times as many people in Tanzania live in land degradation hot spots than in Rwanda.³⁶

The problem is most obvious in the northwestern part of the country, far outside the major city of Dar es Salaam. The areas closer to the coasts are less affected than the dryer inward areas of the country.³⁷ Generally, land degradationThe process by which land becomes less useful for agricultural processes.³ becomes worse as an area becomes more inland and rural.³⁸ Additionally, farmers in Tanzania are used to farming with rain-dependent crops.³⁹ As annual rainfall decreases, the problems associated with land degradation increase. The practices that contribute to land degradation (i.e. overgrazingExposure of plants to grazing for extended periods of time without sufficient recovery periods., poor irrigation techniques, etc.) are more severe in areas with less rainfall.

Q: What is the climate of Tanzania?

A: Due to its proximity to the equator, Tanzania is a relatively temperate area. The climate is split into four major areas: the coastal plains (along the eastern coast), the northern and southern highlands (in the northern and southern parts of the country), and the central plateau, which takes up most of the rural parts of the country.⁴⁰ The coastal areas are hot and humid, with temperatures ranging from 70–90 degrees year round, while temperatures in the rural areas within the highland and on the central plateau range between 59 and 75 degrees annually.⁴¹ Rainfall changes within different regions, but the rainfall differences between rural and urban areas is not abundantly evident. Rain tends to fall between November and May, with the majority of rain coming during April.⁴² Furthermore, the growing season for crops in Tanzania tends to begin in December for most regions and end in April.⁴³ Throughout the growing season, rainfall is between 100 and 200 mm per month for regions.⁴⁴ During the other months of the year, rainfall tends to stay below 25 mm per month for most regions, especially between May and October.⁴⁵ Understanding Tanzania’s climate is an important part of understanding how global climate change and rainfall variabilityThe change in the amount of precipitation is received in a given area over a period of time. have an effect on land degradation.

Contributing Factors

Inadequate Agricultural Practices

Overgrazing

OvergrazingExposure of plants to grazing for extended periods of time without sufficient recovery periods., or the practice of grazing land for a long period without allowing time for the soil to recover, contributes to land degradationThe process by which land becomes less useful for agricultural processes.³ in Tanzania because it reduces the ground coverAny plant that grows over an area of land. Ground cover helps reduce soil erosion that typically allows water to penetrate the soil. A study published in 2021 indicated that as land use has increased over the past century, soil erosionThe removal of topsoil, or the layer of soil that holds nutrients for plant growth.⁶ has proportionally increased with it.⁴⁶ The study showed that the largest change in land use during that time came from a larger amount of land being used as grazing for livestock.⁴⁷ Owning livestock helps farmers with financial security (as a mobile and reliable asset) and is a sign of prestige.^{48, 49} Livestock are used for wedding dowry and other cultural celebrations, and slaying livestock for food is usually only preserved for when the animal is sick, becomes less productive, or for cultural or familial festivals.^{50, 51} As farmers continually choose to keep their livestock instead of slaying it for food or trade, livestock population increases. The livestock population in Tanzania has grown 130% over the past 50 years. Additionally, reports in 2017 demonstrated that livestock densities have nearly tripled in that time—from 20 units per square kilometer to 55 units per square kilometer since 1970.⁵² Livestock overpopulation affects land degradation because over-grazing decreases ground coverAny plant that grows over an area of land. Ground cover helps reduce soil erosion.⁵³ Natural ground cover prevents erosion typically caused by wind and rain in the soil. When erosion removes soil, it is more susceptible to these types of erosion (which are a type of land degradation).⁵⁴ As soil is eroded, the ground loses nutrients and is thus susceptible to decreased food production.⁵⁵

Improper Irrigation Systems

Improper irrigation contributes to land degradationThe process by which land becomes less useful for agricultural processes.³ in Tanzania because it introduces salts into the soil, which limit water intake by crops. Because of central Tanzania’s semi-arid climate and decreasing rainfall, irrigating the soil is necessary to effectively plant crops.⁵⁶ However, irrigation systems in Tanzania leak due to unlined canalsAn irrigation system made of a material that allows for high leakage. or incomplete, broken, or weak pipes. Unlined canals are irrigation systems made of a material that does not block water from leaking into the soil. Most studies estimate that only 15% of water from unlined canals become available for crop use, therefore the other 85% of the water either leaked into unwanted parts of the soil or evaporated before it successfully irrigated an intended plant.⁵⁷ A macrostudy of Tanzania found that water delivery for crops was primarily transported using unlined canals.⁵⁸ When unlined canals and other irrigation systems leak, they introduce salts into the soil which disrupts the transfer of water from soil to plants.⁵⁹

When plants take up the water, the salt remains in the soil. When the salt concentration levels are elevated outside the plant, water inside the plant transfers to the high-saline soil through osmosis.⁶⁰ Essentially, the water stays outside the plant and in the soil because of the high concentration of salt in the soil. This dehydrates the plant, ultimately leading to lower yields for farmers. For crops planted on salinated soil, typical yields are only 20-50% of crops planted on soil with normal salt levels.⁶¹ In this way, 27% of irrigated land in Tanzania has been destroyed by salinizationThe process by which soil goes from saline to non-saline..⁶²

Over-Cultivation

When farmers reuse the same plot of land for multiple consecutive growing periods without breaks for regeneration, soil nutrients are removed from the soil, increasing land degradationThe process by which land becomes less useful for agricultural processes.³.⁶³ This process is known as over-cultivationThe same plot of land being used for multiple consecutive growing periods without breaks for regeneration.. Over-cultivation happens because the nutrients in the soil are received by the plant; the more consecutive growing seasons that crops are in a particular set of soil, the fewer nutrients exist in that soil. Areas where soil has a natural low fertility, such as Tanzania, are especially susceptible to soil degradationThe detachment or removal of nutrients in the soil. by over-cultivation.⁶⁴ Allowing the soil to rest from cultivation for a period of time allows nutrients in the soil to be regenerated. As the nutrients are replenished, the soil is ready to re-produce adequate crop yield.⁶⁵ Allowing soil to rest for any amount of time is called fallowingAn agricultural technique characterized by leaving a piece of land unused for a period of time.¹: the general recommended time frame for fallowing is a period of 1–5 years.⁶⁶ When farmers do not allow the soil to rest through fallowing, the soil they are using becomes over-cultivated, thus increasing land degradation. One study found that 25.6% of farmers in Tanzania practiced fallowing, and only 11.6% of farmers who had never learned sustainable agricultural activities engaged in the practice.⁶⁷

Over-cultivationThe same plot of land being used for multiple consecutive growing periods without breaks for regeneration. became a problem in Tanzania following the villagization campaign in the 1970s. Before the villagization campaign, fallowingAn agricultural technique characterized by leaving a piece of land unused for a period of time.¹ was a regular practice in Tanzania and farmers reported sustainable crop yields. Following the villagization campaign, farmers worked on smaller plots of land and were required to keep their home and the area they cultivated on the land they had been allotted by the government, further decreasing the amount of land they had to use for cultivation.⁶⁸ Having less land for farming, farmers began to see smaller crop yields. As this happened, they began to over-cultivate the land without fallowing periods.⁶⁹ Following villagization, the ratio of cultivated to regenerating land decreased from 0.54 acres of regenerating for every 1 acre of cultivating land to 0.27 acres of regenerating land for every 1 acre of cultivating land.⁷⁰ Additionally, cultivated land in rural Tanzania increased by 10 sq. km. (3.86 sq. mi.) per farming family.⁷¹ In spite of farmers planting more per growing season, they continue to bring in lower crop yields because the soil they use is constantly losing nutrients and is not given time to regain those nutrients. As farmers began to over-cultivate the land in the early 1980s, their crop yields decreased; at the same time, however, Roman Catholic Mission farms in Tanzania produced the same yields as before because they still had adequate land to practice fallowingAn agricultural technique characterized by leaving a piece of land unused for a period of time.¹.⁷² The effects of over-cultivation have also become obvious; areas without ground coverAny plant that grows over an area of land. Ground cover helps reduce soil erosion, known as soil erosionThe removal of topsoil, or the layer of soil that holds nutrients for plant growth.⁶ scars, have increased by an average of 5 sq. km. (1.9 sq. mi.) following the villagization campaign in Tanzania.⁷³

Deforestation

Deforestation, the act of removing trees and other forms of natural forestry, is one contributor to land degradationThe process by which land becomes less useful for agricultural processes.³ in Tanzania. Rates of deforestationThe process of removing natural forestry. have increased in Tanzania over the past 20 years. The deforestation in Tanzania happens primarily in 2 parts of the country; 3 of the top 5 regions causing deforestation are southeastern coastal regions, and the other 2 are in the semi-arid central part of the country.⁷⁴ Between 2001 and 2020, 27,000 sq. km. (10,425 sq. mi.) of forest area were lost—equal to about 10% of the total forested area in the country.⁷⁵ The Food and Agriculture Organization of the United Nations ranked Tanzania as having the 5th-highest deforestation rate in the world from 2010–2020, below Brazil, the Democratic Republic of the Congo, Indonesia, and Angola.⁷⁶

Deforestation contributes to land degradationThe process by which land becomes less useful for agricultural processes.³ in Tanzania because forests can help create a barrier against water erosionDetachment or removal of soil nutrient by water.. Without natural vegetation, hydrological increases deplete natural soil nutrients and increase soil erosionThe removal of topsoil, or the layer of soil that holds nutrients for plant growth.⁶.⁷⁷ Farmers in rural Tanzania often cut down trees because it provides them with tracts of land to plant food on. With trees out of the way, farmers can plant more and thus hope to produce higher yields. Data from Northeast Tanzania indicates that as areas of natural vegetation decrease, farmland has increased.⁷⁸ During the last 2 decades, the primary driver for deforestationThe process of removing natural forestry. in Tanzania has been land clearing for small and medium-scale agriculture.⁷⁹

In 2019, 1,370 sq. km. (529 sq. mi.) of land, 96% of the forestry removed in that year, were removed for this purpose.⁸⁰ Despite the hope to use deforested land for farming, deforestation causes more harm to the land. When water runs through the deforested soil, the plants put in place of the removed trees cannot hold on to the soil because those plants have diminished root strength.⁸¹ This leads to a decrease in nutrients in the soil, which are essential to plant growth.⁸² Therefore, the crops planted on previously-forested soil are less likely to survive until harvesting. Data from Madagascar, an East African country with similar deforestation trends to Tanzania, found that after 2–4 years, farmers would leave previously-forested lands due to decreases in crop yields.⁸³ Migration trends for farmers on deforested land in Tanzania presently unavailable.

Rainfall Variability

Rainfall variabilityThe change in the amount of precipitation is received in a given area over a period of time. leads to land degradationThe process by which land becomes less useful for agricultural processes.³ because farmers in Tanzania rely on rainfall for their crops to receive water.⁸⁴ Variability becomes a problem when rainfall decreases to the point where evaporation happens faster than precipitation.⁸⁵ Whenever rainfall decreases in an area, that area becomes more susceptible to land degradation. Research has demonstrated that when a growing-season month has fewer rainfall days, the crops for that growing season are more meager.⁸⁶ Arid and semi-arid areas, which stretch throughout the center of Tanzania, are at higher risk to land degradation when rainfall decreases. In the Dodoma region of central Tanzania (a semi-arid region), research has demonstrated that the number of days receiving rainfall in a particular month during the growing season (January–March) have decreased between 1980 and 2015.⁸⁷ Dodoma’s primary crop, maize, needs at least 500 mm. (20 in.) of rain during the growing season; a secondary crop of the region, cassava, requires 1200–1500 mm. (47–59 in.) of rain for adequate crop yields.^{88, 89, 90} Research has demonstrated that the probability of receiving more than 1000 mm. (40 in.) of rain annually in the Dodoma region is 0%.⁹¹ During the growing season, Dodoma receives less than 400 mm. (16 in.) of rainfall.⁹² Changes in rainfall over the past several decades may explain the long-term NDVIThe Normalized Difference Vegetation Index. A common indicator of land degradation that uses remote sensing and reflects the visible and near-infrared radiation reflected by vegetation.⁵ decline that consumes over half of Tanzanian land, as plants are dependent on water to receive the nutrients needed for growth.⁹³

As rainfall variabilityThe change in the amount of precipitation is received in a given area over a period of time. increases, the productivity of the land decreases; this is measured through the ability of the land to produce food. The agricultural products produced by rural Tanzanian farmers are often rain-fed crops, such as maize and sorghum.⁹⁴ If there is no rain to help provide nutrients into the soil, the land becomes less productive and produces fewer crops and vegetation. This further causes degradation as improper irrigation systems are implemented in order to reduce the consequences of the decreasing rainfall, which results in poor irrigation and salinizationThe process by which soil goes from saline to non-saline..

Consequences

Undernutrition

Land degradation leads to undernutrition because farmers are dependent on adequate crop yields for food, and when the ground cannot produce those yields, rural families suffer. Therefore, farmers in those areas cannot produce ample food to provide the necessary nutrients for growth and survival.⁹⁵ When land is not arable, farmers lose the ability to plant crops. Research shows that 39.3% of Tanzanians were undernourished and 75% of the undernourished came from the rural communities where land degradationThe process by which land becomes less useful for agricultural processes.³ was a problem.⁹⁶ Not only are farmers in Tanzania not producing enough food, but the type of food they are producing does not provide the necessary nutrients for a well-balanced diet. One study in southeastern Tanzania demonstrated that over 75% of individuals in that area had medium diet diversity—consuming protein, fats, oils, and cereals but not consuming fruits and vegetables necessary for growth.⁹⁷ Another study shows that deforestationThe process of removing natural forestry. led to Tanzanians consuming 14 fewer grams of fruits and vegetables a day.⁹⁸ As overall food and variety in diet decrease, undernutrition increases.

Photo by Elliot PARIS on Unsplash

Without proper nutrition, rural Tanzanians suffer from an array of malnutritionA lack of basic nutrition caused by a lack of food or a lack of necessary food for the process of growth and health.-related problems. For example, children in rural Tanzania struggled from stunted growth. In agrarian areas, 64% of adolescentsChildren aged 10–19 years. and 34% of children under the age of 5 experience stunted growth. In addition, 10.2% of adolescentsChildren aged 10–19 years. experience wastingLow weight compared to height caused by malnutrition., which is a type of malnutrition characterized by low weight compared to height. Malnourishment among adolescents is especially concerning, as improper growth during adolescence spreads into adulthood and prompts further health problems.⁹⁹

Economic Decline

Land degradation leads to economic decline for rural Tanzanians because farmers invest in the land they plant on; when that land is degraded, it creates a financial burden for the farmers and for Tanzania’s overall economy. The primary economic sector of Tanzania is agriculture—65% of the population of the country relies on agriculture for their main source of income.¹⁰⁰ In many cases, that source of income is not viable because of land degradationThe process by which land becomes less useful for agricultural processes.³. A 2015 study demonstrated that the cost of degraded land per year is $223 billion (USD).¹⁰¹ For each person engaged in agriculture in Tanzania, this is equal to over $5,000.00 per year.^{102, 103} This problem is worse for Tanzanians in rural areas. The Morogoro region in central Tanzania had an estimated annual cost of $297 million for land and degradation-related issues. In contrast, Dar es Salaam—the largest city in Tanzania—had an annual cost of only $6.4 million.¹⁰⁴

Absent the cost of land degradation-related costs, individuals in rural areas are also more likely to experience poverty in general, demonstrating that economic degradation runs parallel to land degradationThe process by which land becomes less useful for agricultural processes.³ in Tanzania.¹⁰⁵ One study demonstrates that 81% of individuals in rural Tanzania express that their income does not fit their needs.¹⁰⁶ The respondents for this survey reported that a daily income meeting individual needs is $0.68 per person and $4.62 per household.¹⁰⁷ According to data from the Bank of Tanzania, 1 kg. of rice cost $0.78 in January of 2022.¹⁰⁸ One kilogram of rice is equal to about 5 cups, and the average household in rural Tanzania is 4.9 people, meaning that 1 kg. of rice affords a household 1 cup of rice per person.¹⁰⁹ A daily income of $4.62 would mean that each person could afford to eat 6 cups of rice in a day, and that the household would be able to afford nothing else (including a diversified diet). A rural Tanzanian’s regular expenses go beyond food and include the costs of land upkeep, farming materials, and livestock livelihood; data from 2018 indicates that 48% of Tanzanian consumption goes towards goods besides food.¹¹⁰ As Tanzanians must continue to invest in land in a situation where they cannot afford food, a cycle of economic decline ensues making it difficult for farmers to find a new set of land where they can hope to produce high agricultural yields.

Environmental Migration

Environmental migration refers to any migration that happens because of environmental-related factors. Land degradation leads to environmental migration because in order to avoid lasting poverty and possible starvation due to inadequate crop yields, farmers will often move from degraded land to arable land. Evidence from the Hanang district in central Tanzania demonstrates that 81.3% of farmers had responded to climatic stresses via migration.¹¹¹ Research has demonstrated that every 1% decrease in agricultural income for a Tanzanian farming family results in a 9–13% increase in the probability of that family migrating.¹¹² Rural farmers in Tanzania often lack the resources to improve their situation where they are, and so they are forced to migrate to different parts of the country in order to improve their situation elsewhere.¹¹³ Data demonstrates that, as a trend, rural Tanzanians are moving to the northwest and southeast parts of the country; these two areas have more favorable weather conditions for farmers (such as higher rainfall).¹¹⁴ Environmental migration spreads the effects of land degradationThe process by which land becomes less useful for agricultural processes.³ to new areas as rural farmers transport unsustainable farming and irrigation activities from one area to another until the new area is also degraded.¹¹⁵ As less land becomes arable, farmers crowd on the remaining arable land, which only makes the land degrade more quickly. As land degrades quicker, migration occurs more often. Because of land degradation, environmental crises are the leading factors for migration both within and out of Tanzania.¹¹⁶

Due to increasing land and soil degradationThe detachment or removal of nutrients in the soil., many younger migrants travel away from the rural areas and towards urban cities such as Dar es Salaam or Zanzibar.¹¹⁷ Most of these migrants are trained in farming for their livelihoods, but the most prominent industries in the urban areas of Tanzania are mining and tourism.¹¹⁸ Due to large-scale competition in the cities, migrants lack the ability to learn new trades, leaving them without an opportunity to provide necessities like food, water, and shelter. Thus, competition for resources prompts labor market displacementWide-spread involuntary job loss due to economic factors.² throughout urban areas, which disrupts the economic flow of the city.¹¹⁹

Best Practice

Conservation Agriculture

One intervention that has begun to gain traction in Eastern Africa is conservation agricultureA method of agriculture focusing on minimizing soil disturbance (introducing full organic soil cover) and expanding crop diversification to help improve the food yield, soil health, and overall nutrition of the people it benefits..¹²⁰ Conservation agriculture is a set of practices that farmers can choose to implement. It focuses on three principles to help improve the food yield, soil health, and overall nutrition of the implemented areas. Conservation agriculture requires farmers to adhere to all three principles: minimizing soil disturbance, introducing full organic soil cover, and expanding crop diversification.¹²¹

Minimizing soil disturbance requires farmers to abandon mechanical tilling. When tilling decreases, the disturbance of the soil decreases alongside it.¹²² In theory, an absence of mechanical tilling should minimize soil degradationThe detachment or removal of nutrients in the soil., which is the most prominent type of land degradationThe process by which land becomes less useful for agricultural processes.³ in Tanzania. Implementing organic soil cover requires farmers to plant cover crops during fallowingAn agricultural technique characterized by leaving a piece of land unused for a period of time.¹ periods so that the land does not become salinized, overgrazed, or over-cultivated.¹²³ This allows the soil to be fully rejuvenated when it is not under cultivation, increasing soil quality and controlling unwanted weeds and pests.¹²⁴ The final principle of conservation agricultureA method of agriculture focusing on minimizing soil disturbance (introducing full organic soil cover) and expanding crop diversification to help improve the food yield, soil health, and overall nutrition of the people it benefits., expanding crop diversification, involves the introduction of crop rotation. Crop rotation is the process of changing which crops are planted on a plot of land over different times.¹²⁵ Much like fallowing, crop rotation increases and preserves soil fertility, ultimately leading to longer-sustained food production in the areas that use conservation agriculture.¹²⁶ Crop rotation allows for different crops to be planted at the same time, which expands the nutritional intake of small family farmers and curtails the existence of stuntingAn inability to grow caused by malnutrition, typically typified by a low height for age., wastingLow weight compared to height caused by malnutrition., and other types of malnutritionA lack of basic nutrition caused by a lack of food or a lack of necessary food for the process of growth and health..¹²⁷

Impact

To understand the impact of conservation agricultureA method of agriculture focusing on minimizing soil disturbance (introducing full organic soil cover) and expanding crop diversification to help improve the food yield, soil health, and overall nutrition of the people it benefits., it is important to understand what effect the practice has on both land degradation and its consequences. It is also important to note that because different studies have focused on different measurements (some focus on the consequences of land degradation while others focus on land degradation as a whole), much of the literature disagrees on the efficacy of conservation agriculture; however, most research agrees on what parts of the impact assessments are statistically significant.¹²⁸

Photo credit: Peter Lowe/CIMMYT.

Much of the existing literature on conservation agricultureA method of agriculture focusing on minimizing soil disturbance (introducing full organic soil cover) and expanding crop diversification to help improve the food yield, soil health, and overall nutrition of the people it benefits. focuses on its efficacy on food production. While this is an important measurement, it does not focus on the consequences of low agricultural yields such as undernutritionA lack of basic nutrition caused by a lack of food or a lack of necessary food for the process of growth and health. or economic decline. One study found that conservation agriculture in Tanzania tripled food production and elevated maize production from 12,000–20,000 kg. (26455.471–44092.452 lbs.) of food per acre.¹²⁹ For impact assessments which have studied the relationship between conservation agriculture and better nutrition, the results have been promising. One study found that in Tanzania, conservation agriculture not only significantly increased total agricultural yield, but also increased nutrition measures such as food security and number of meals per day. Families who engaged in conservation agricultureA method of agriculture focusing on minimizing soil disturbance (introducing full organic soil cover) and expanding crop diversification to help improve the food yield, soil health, and overall nutrition of the people it benefits. ate (on average) 1.728 more meals a day than those who were not.¹³⁰ However, these nutrition measurements are imperfect because nutrition is about receiving both enough nutrients and a diversity of nutrients.¹³¹ This study also found that conservation agricultureA method of agriculture focusing on minimizing soil disturbance (introducing full organic soil cover) and expanding crop diversification to help improve the food yield, soil health, and overall nutrition of the people it benefits. assisted in reversing economic decline by leading to increased income, more assets, and decreased production costs.¹³² Another study demonstrated that for farmers who adopt conservation agriculture, the amount of work required reduces from 3–4 days for land preparation, seeding, and weeding to 1 day and 5 hours; the labor force decreases from 14 people for these three jobs to 6.¹³³ This could possibly lead to a decrease in labor-intensive jobs performed by individuals who are weakened due to undernutritionA lack of basic nutrition caused by a lack of food or a lack of necessary food for the process of growth and health..

Gaps

So far, studies of conservation agricultureA method of agriculture focusing on minimizing soil disturbance (introducing full organic soil cover) and expanding crop diversification to help improve the food yield, soil health, and overall nutrition of the people it benefits. have focused more on increasing agricultural yields than on decreasing undernutritionA lack of basic nutrition caused by a lack of food or a lack of necessary food for the process of growth and health., environmental migration, or economic decline. Much of the existing literature does not agree on the efficacy of conservation agriculture overall.¹³⁴ Most of the problems surrounding conservation agriculture happens when insufficient application of the practice occurs. For those who do adopt conservation agricultureA method of agriculture focusing on minimizing soil disturbance (introducing full organic soil cover) and expanding crop diversification to help improve the food yield, soil health, and overall nutrition of the people it benefits., many only adopt one of the necessary practices; of those who adopt one of the three practices, 43% adopted 2 or more and 27% adopted all 3 practices.¹³⁵ Several studies have indicated that when minimizing soil disturbance is implemented but introducing full ground coverAny plant that grows over an area of land. Ground cover helps reduce soil erosion and expanding crop diversification are ignored, crop yields decrease when compared to conventional agricultural practices.¹³⁶ In order for farmers to receive the full impact of the practice, it must be implemented completely.

Last of all, conservation agricultureA method of agriculture focusing on minimizing soil disturbance (introducing full organic soil cover) and expanding crop diversification to help improve the food yield, soil health, and overall nutrition of the people it benefits. only accounts for the production of food and not the accessibility or transportation of food. Production of food does not equal access to food; for an intervention to be completely effective, it requires that the larger food yields are properly distributed and consumed.¹³⁷ For the practice to be effective, steps must be taken to ensure that more people receive the food produced by increased and diversified crop yields. At that point, any researchers can measure the nutrition levels of the people using conservation agriculture and identify changes in migration patterns or economic decline to more fully determine how effective conservation agriculture addresses the issue of land degradationThe process by which land becomes less useful for agricultural processes.³.

Preferred Citation: Ririe, Seth. “Land Degradation in Rural Tanzania.” Ballard Brief. May 2022. www.ballardbrief.byu.edu.

Viewpoints published by Ballard Brief are not necessarily endorsed by BYU or The Church of Jesus Christ of Latter-day Saints