Conservation refers to actions that humans take to manage, preserve and protect something — in particular, natural resources — to prevent its exploitation, destruction or neglect. Natural resources include the air, land, water and animals — all of which are threatened by climate change.

In agriculture, conservation refers to farming practices that are designed to prevent the destruction of arable land or to regenerate land that has deteriorated or been overused or has been damaged by climate change. They help to ensure that there is:

• permanent soil cover,
• minimum soil disturbance, and
• diversification of plant species.

Conservation practices mitigate climate change by increasing carbon sequestration. Plants and other types of vegetation absorb CO2 from the atmosphere and store it in the soil, which helps to reduce GHG emissions. In the long term, this improves crop production, which helps to increase food security.

Traditional conservation practices

Here are some of the main traditional conservation practices in agriculture:

• Using organic soil cover and permanent soil cover: These natural materials sit on the soil surface and protect the land from erosion. Rain droplets can cause the soil surface to become compact, which increases runoff and reduces water infiltration. Organic or natural soil materials include crop residues, hay, animal manure, compost, sawdust, ground pine bark, wood chipping, leaves and peat moss.

• Combining crop residue with less tillage or zero tillage: This reduces the amount of water evaporation from the soil and can reduce the amount of irrigation that is needed.
• Practising crop rotation: planting different crops in the same field at different times means the soil does not become exhausted. When soil is exhausted, it can lead to lower yields, which in turn can reduce food security. (See FAO, 2022, for more information.)
• Intercropping: Planting two or more crops together in the same field at the same time.
• Practising one of the many variations of crop diversification/polyculture, such as having a mixture of different crops and livestock, practising agro-forestry, or having a combination of tree crops and pastures.
• Reforestation: Replanting trees and preserving biodiversity in forests.
• Contour farming/terracing: Planting across a slope along the contours instead of up and down. This practice reduces runoff and soil erosion and increases the amount of water that infiltrates the soil, which in turn prevents flooding from intense rains caused by climate change.
• Destroying infected crop residues: Crop residue is burned after harvesting to destroy pests and weeds that interfere with agricultural yields. Climate change is creating temperatures and moisture levels that encourage pests and weeds.

Traditional IPM also involves mechanical pest control in which some of the soil-infesting larvae or adult insects are controlled by tillage. The subterranean insects are exposed to sunlight, which harms them, or predators, such as birds or other insects.

• Windbreaks: A line of planted trees or plants designed to reduce wind speed and protect crops, livestock and soil from wind erosion. They can also help sequester carbon.
• Grassed waterways: Wide, shallow channels that are dug where there is a concentration of water runoff in an agricultural field. Permanent vegetation is planted in the channels, and the roots help slow the flow of water, which holds the soil in place and prevents erosion. The vegetation also reduces the amount of GHGs in the atmosphere.
• Traditional rainwater harvesting: Water from the roofs of buildings is channelled into covered barrels or containers and stored for use when water is scarce.

As noted in Unit 3, many modern innovations in agriculture and food production are only suitable for large-scale production. (See Dahlin & Svensson, 2021, for more information.)

Some women-led businesses in the eco-tourism industry have successfully used traditional practices to conserve natural resources while creating and sustaining decent livelihoods. (See Akhter et al., 2013, for more information.)

The complexities of conservation: Bangladesh

The situation in Bangladesh illustrates the complexities that can arise when a particular area requires a mix of conservation practices to mitigate the impacts of climate change. For example, while rice production has increased over the years, it has required increasing reliance on ground water. Dry season irrigation systems use a lot of ground water and energy. The heavy use of ground water means the water table has gone down to dangerous levels. There has also been a switch from local low-yielding varieties to high-yielding varieties of rice, as well as for many other crops. The new varieties of rice are heavily dependent on fertilisers applied via controlled water management and on pesticides and other chemicals. The ecosystem has been damaged by leaching of agro-chemicals from the overuse of pesticides and other chemicals.

In addition, certain naturally occurring phenomena create problems for agricultural crop production and threaten food security. These natural problems include increased salinity in parts of the country, arsenic in ground water finding its way into the food chain, acidic soil and soil erosion in hilly areas due to deforestation. Altogether, the effect is a deterioration in the quality of the land in some places due to degradation of soil fertility, soil erosion, soil and water pollution, depletion of soil organic matter, water logging, increased soil salinity, pan formation (or hardening of the soil), acidification and deforestation.

In response, the government has made some commitments to a wide range of actions to support agriculture in its National Conservation Strategy 2021-2036 policy document.

Adapted from: Ministry of Environment, Forest and Climate Change Government of the People’s Republic of Bangladesh. (2021). Bangladesh National Conservation Strategy 2021-2036. https://faolex.fao.org/docs/pdf/BGD219210.pdf
Licence: Open data (https://www.fao.org/contact-us/terms/en/)

Water conservation: Sri Lanka

In Sri Lanka — especially in the Dry Zone — thousands of small irrigation tanks of varying shapes and sizes provide water for paddy cultivation. The tanks are usually made by building a dam across a flowing stream or river. A complex system of dams, canals and tanks traps and moves the water from different rivers.

Adapted from: Agriculture in Sri Lanka. (2023, 8 December). In Wikipedia. https://en.wikipedia.org/wiki/Agriculture_in_Sri_Lanka#References
Licence: CC BY-SA 4.0 DEED Attribution-ShareAlike 4.0 International License

Reading

Akhter. S., Alamgir, M., Sohel, S. I., Parvez, R., Ahmed, M., & Chowdhury, M. S. H. The role of women in traditional farming systems as practiced in home gardens: A case study in Sylhet Sadar Upazila, Bangladesh. Tropical Conservation Science, 3(1),17-30. https://doi.org/10.1177/194008291000300103
Licence: CC BY 3.0 Deed

Dahlin, J., & Svensson, E. (2021). Revitalizing traditional agricultural practices: Conscious efforts to create a more satisfying culture. (2021). Sustainability, 13(20), 11424. https://doi.org/10.3390/su132011424
Licence: CC BY

Food and Agriculture Organization of the United Nations. (2022). Conservation agriculture. https://www.fao.org/conservation-agriculture/overview/what-is-conservation-agriculture/en/
Licence: CC BY-NC-SA 3.0 IGO