Opportunities and Challenges of Agriculture
This pages provides resources and lesson ideas on opportunities and challenges of agriculture, in extreme environments, predominantly hot arid environments. It develops a broad range of place examples, skill-based activities and multi-media resources to cover the challenges of irrigation and environmental problems such as salinization and irrigation. Students are introduced to a number of ways of mangaging arid environments, not all of which are pro-poor. Resources include graphs and photographs,unequal access to resources are looked at through gender differences. Video resources on benefits of permaculture are included in this lesson.
What are the opportunities and challenges for management of agriculture in arid environments?
Lesson Time: 2-3 Hours
- To examine the opportunities and challenges of agriculture in arid environments
- To explain the causes of desertification and salinization
- To describe more effective and sustainable solutions to irrigation
Starter Activity_Processes and Possibilities_ Mind Map
Working in pairs mind map the challenges of agriculture in extreme environments that you have seen in the course so far. Think about your key headings and then identify specific examples for each heading.
Student Notes on Agriculture
Arid regions are complex environments that pose many challenges for the management of agriculture. With rapidly growing population, climate change and uncertain rain patterns many arid environments are at risk of desertification and other regions are witnessing the migration of desert dunes. However, there are many successful examples of countries greening the desert for agriculture. These include intensive rain fed schemes like those found in Egypt and Saudi Arabia, to small scale permaculture projects such as those found in the arid and savannah regions of Kenya. Soil management and ecology are increasingly becoming more sophisticated and through shared knowledge, cooperatives and the work of NGO networks to share good practice, the knowledge of simple and appropriate solutions such as stone lines, fencing, reforestation programs is spreading. Excellent examples include tassa construction through women's cooperatives in Niger.
Arid soils lack moisture while infertile soils lack vital nutrition such as nitrogen, phosphorous and potassium. However these two problems are often closely associated.
The causes of increasing aridity are complex and can be both natural and man-made. Arid environments and their location are determined by their climate and so experience intense periods of heat and short but often intense rain in a seasonal climate known as Tropical Wet and Dry. What rain that falls often lands on sparsely vegetated soils and quickly evaporates away. Arid and semi-arid areas have a negative water balance meaning that evapotranspiration and stores of water exceed the inputs of precipitation.
Infertility is caused by low organic content and biomass decay, thin soils and therefore limited mineral content, and weak leaching leading to a build-up of salt from transpiration. However interference through population pressure, over cultivation, deforestation and overgrazing. These factors increase the fragility of soils and threaten agricultural practice in hot and arid environments.
Student Activity_Processes_Aridity vs Fertility
Read the following text on the challenges of aridity and fertility and summarise the text as a 140 character tweet
Access to Irrigation
Student Activity_Place and Processes_ Photo Discussion
Examine the photo of irrigated crop circles in Saudi Arabia below and discuss
- Where you think the water comes from?
- The impacts of this
- Who is doing the farming
Student Activity_Place and Possibilities_How Sustainable is Wheat Production in Saudi Arabia?
- Describe the trend in wheat production shown in the graph below
- Why do think the government is closing farms?
There are many examples of turning the desert green and fertile. Irrigation is used to bring water to the desert and artificial fertilizers bring fertility. Today massive greening projects are underway all over the world from the USA to China and across North Africa and the Middle East. These intensive greening projects produce, cotton, date palms, wheat and even potatoes through the modern irrigation and use of artificial fertilizers and herbicides. The image to the right shows irrigated crop circles seen from satellite imagery over Saudi Arabia. These are formed from the use of specialized center pivots. However this method of irrigation is not without its problems.
Irrigated crop circles in Saudi Arabia
The main problem with this type of irrigation is that no level of technology can prevent water loss if the climate is simply too hot. It is thought that over 90% of the water released from Egyptian and Saudi Arabian center pivots is evaporated before it even reaches the ground. This unsustainable use of water from aquifers has a very short lifespan with wheat farming in Saudi Arabia now considered completely unprofitable, with rising costs and depleting water.
Student Activity_Place and Processes_Center Pivot Irrigation
Watch the following animated clip on how modern center pivot irrigation works and write notes on how center pivot irrigation systems can help grow more food with less water.
Discuss whether you think this is an opportunity for all people and places?
Student Activity_Power_Unequal Access to Irrigation
Read the following handout featuring an adapted Al Jazeera article on unequal access to irrigation and write a summary of your own on the reasons for the gender divide in terms of access to water.
Student Activity_Place and Possibilities_ Greening the Desert in Jordan
Watch the following clip on the use of permaculture in Jordan
Student Activity_Place and Possibilities_ Zai Pits in Burkina Faso
Watch the following explanation of zai construction (tassa in Niger) and complete the worksheet provided.
Starter Activity_Power_ Press Release Dafur Genocide
Watch the press release on Dafur and discuss why this genocide links to the course
Student Activity_Place, Power and Possibilities_ Access to Land
Discuss why you think land tenures (legal right to land) is so important to increasing field production in extreme environments
Watch the following video to 4.15, which documents the complex land/resource conflicts in the Dafur region of Sudan from 2003.
Answer the questions on the worksheet provided.
The following article provides further reading into the complex nature of land rights in Dafur
Student Activity_ Place, Power and Possibilities_Gender Conflict over Land Rights in Niger
Watch the following video based in Niger to do with with cooperatives and gender conflct over land rights
- Describe the location and the tassa agricultural system?
- Why are tassa's successful?
- What are the route causes to the problems in this excample?
- How do you think the conditions of extreme environments exacerbates the problem?
Salinisation is the accumulation of soluble salts, such as sodium, magnesium and calcium in soil, to the extent that soil fertility is severely reduced. It is regarded as a major cause of soil degradation and is therefore a leading factor in the process of desertification. There are a number of causes of salinisation in hot arid environments, principally increased salinity is caused by the evapotranspiration of water from the surface, which leaves deposits of soluble salt in the soil. The heat of the sun draws water and salts upwards and it crystalizes in the upper layers.
This can impede root growth and infiltration rates that in turn increases surface run-off or can cause surface waterlogging where impermeable crystal layers form. In hot arid environments where vegetation cover is limited and under pressure, infiltration rates can be increased, which leads to a rising of the water table. This in turn increases salinity through a process of capillary rise. In addition, waterlogging due to excessive irrigation practices and leaching methods also increase salinity in soils.
Student Activity_Place and Processes_Saline and Sodic Soils in Australia
Watch the following clip and make notes on the causes and signs of salinity in soils.
Student Activity_Processes_Explaining the Process of Salinisation
Complete the worksheet activities based on salinisation
Study the following maps and describe the pattern of salinisation in Western Australia
Increasing salinisation in Western Australia
Salinisation Processes, adapted from Dept of conservation, forests and Land 1987
Student Assessment - Mind Map on the Opportunities and Challenges of Agriculture in Extreme Environments
Students should create a one page mind map of the agricultural opportunities and challenges, to include place examples covered in class. This can be a full extension of the opening starter activity or they can begin again.
The mind map should be full of the located examples developed in the course. It should be on A3 paper and as result becomes the revision resource for the topic area.
Full explanation and evaluation of a broad range of opportunities and challenges in a variety of extreme environments