CLIMATE CHANGE AND SOIL SALINITY: IMPACTS ON AGRICULTURE
The worrying influence of climate change on the build-up of soil salinity has recently gotten a lot of attention in the scientific community. Increased greenhouse gas (GHG) concentrations in the atmosphere, as well as the resulting increase in air temperature and decrease in relative humidity, as well as extreme rainfall events, are all possible indicators of climate change that have a significant impact on the rate at which soil salinity develops (IPCC, 2013; Haj-Amor and Bouri, 2019). Due to rising sea levels, climate change may hasten saltwater incursion into rich soils, and excessive groundwater extraction in arid places of the world may further exacerbate soil and groundwater salinity (Dasgupta et al., 2015).
Despite the fact that climate change and agriculture are closely intertwined, multiple studies have found that their interactions have had a negative influence on agricultural productivity (Coster and Adeoti, 2015; Ayinde et al., 2010; Apata et al., 2009; Mendelsohn et al., 2001). According to Ochieng et al. (2016), global agriculture is in jeopardy due to the threat of climate change in the agricultural sector; however, the impact on agricultural productivity is expected to deteriorate through time and vary by country and region (Food and Agriculture Organisation 2016). As a result, the phenomenon is projected to exacerbate the gap between developed and developing countries (Abdullahi, 2018; Coster and Adeoti, 2015), as well as wreak havoc on economic growth (Abdullahi, 2018).
Rising sea levels have been attributed to climate change by the Intergovernmental Panel on Climate Change (IPCC), which further accelerates the process of salinization. Due to rising sea levels, climate change may hasten saltwater incursion into rich soils, and excessive groundwater extraction in arid places of the world may further exacerbate soil and groundwater salinity (Dasgupta et al., 2015). Because of shifting climate variability, soil salinity is a serious problem in arid and semi-arid regions of the world, wreaking havoc on agricultural output (Mukhopadhyay et al., 2021; El hasini et al., 2019). Soil salinization refers to the concentration and flow of salts in agricultural landscapes (Kayode, Aizebeokhai and Odukoya 2021; Kamran et al. 2019). Soil salinity is a global environmental issue that has an impact on many aspects of human life, including the chemical composition of natural water resources (lakes, rivers, and groundwater), degrading the quality of domestic and agricultural water supplies, and contributing to biodiversity loss (Okur and Orcen, 2020; Vengosh, 2003). Soil salinity currently covers 20% of all cultivated lands and 33% of irrigated agricultural fields worldwide (Mukhopadhyay et al., 2021) and is anticipated to increase at a higher rate by 2050. Salt-infected soils cause nutritional problems, poor soil physical conditions, osmotic stress, poorer crop yield, toxicity, low agricultural productivity, and low economic returns (Kayode, Aizebeokhai, and Odukoya 2021).
CATEGORIES OF SOIL SALINITY
Soil salinization has been classified into two major categories according to its origins and production process as primary salinity and secondary salinity (Safdar et al., 2019; Wanjogu et al., 2001)
1. Primary salinity: This is also known as naturally occurring salinity and can be divided into three categories: pedological processes that deal with soil pedogenesis, climatic conditions that affect soil salinization, and water management
2. Secondary salinity: This form of salinization is caused by human factors, generally as a result of improper irrigation methods.
THE RELATIONSHIP BETWEEN SOIL SALINITY AND CLIMATE CHANGE
Long-term changes in weather conditions and climate systems, whether direct or indirect, are referred to as climate change. The world’s climate has warmed by 0.7 degrees Celsius on average, with the warmest years happening between the 1990s and 2000s (Watson, 2010); as a result, huge changes have already been noticed, with significant implications for soil salinity development. These adjustments, as proposed by Mukhopadhyay et al. (2021) and Corwin (2020), are as follows:
(i) Increased frequency of extreme weather events such as temperature rises, evaporation rates, excessive rain, and heat stress.
(ii) Increased concentrations of GHGs (e.g., CO2, N2O, CH4), which trap heat in the atmosphere to cause global warming.
(iii) The spatial and temporal variability of rainfall distribution that causes changes in soil moisture
(iv) Temperature rise that promotes transpiration and depletion of moisture from soil profile where precipitation increase leads to soil erosion, groundwater recharge, infiltration, and storage
(v) Rising sea levels and seawater intrusion limit their usage for irrigation in coastal areas.
IMPACT OF CLIMATE CHANGE AND SOIL SALINITY ON AGRICULTURE
Climate change and soil salinity are two universal environmental challenges with numerous human implications. Rising sea levels have been connected to climate change, which has hastened the salinization process, according to the Intergovernmental Panel on Climate Change (IPCC). Excessive groundwater extraction in arid places of the world may increase soil and groundwater salinity, while climate change may hasten saltwater invasion into rich soils due to rising sea levels. Excess salts impair crop growth by restricting their ability to absorb water, according to differing definitions of climate change and soil salinity. As a result, it is a concern to the populace since excess salts hamper crop growth by limiting their ability to absorb water. Ajala (2017) expressed that some professions and sectors (i.e. weather and climate-related vocations such as agriculture and tourism) may experience issues as a result of climate change. Climate change salinity implications in agriculture can be divided into three categories: social, economic, and environmental.
Social Impact
Human life has been harmed by climate change and soil salinity. According to Ajala (2017), human life is suited for current climate circumstances. Climate change will have an impact on food production around the world, and this will have an impact on people’s social lives. Food production is important in human culture but rising CO2 levels in the atmosphere are endangering it, and higher temperatures and extreme weather, which induce soil salinity, are a current concern that farmers must contend with. Health, overcrowding owing to migration, and conflicts among individuals and communities, as well as energy and water resources, are all aspects of people’s social lives that are significantly impacted by climate change and salinity effects.
Economic impact of climate change
Climate change and soil salinity both have a significant impact on society, making their effects intertwined. Climate change and salinity have impeded the expansion of many nations throughout the world, wreaking havoc on man’s daily activities, resulting in employment losses, agricultural production, and energy productivity, to name a few. Deressa et al. (2005) investigated the economic impact of climate change on South African agriculture, finding that temperature and precipitation have a considerable impact on net revenue per hectare across production seasons. Another economic impact of climate change and soil salinity is the cost of coping when society finds a way to minimize or cope with the threat, indicating that coping is likely to be a more expensive option than reducing climate change and soil salinity elements.
Environmental impact of climate change
Climate change and soil salinity have resulted in property and infrastructure damage, as well as a loss of production. Land degradation, which depletes the soil’s nutrients, is another major environmental impact of climate change. Salinization as a result of climate change will have an impact on ecosystems, recreation, and coastal areas, as some plant and animal species will become extinct.
SOLUTION TO CLIMATE CHANGE AND SALINIZATION IN AGRICULTURE
Saline soils can be turned into more productive croplands by controlling the influx of saltwater through appropriate farm management practices, correcting soil toxicities and nutrient deficiencies, and leaching the salts out of the root zone. Planting salt-tolerant cultivars, known as saline agriculture, can also help to reduce reclamation costs. These methods can be classified as follows:
1. Amelioration through fertilization
2. Saline agriculture
3. Leaching
4. Adoption of better farm management practices such as drip irrigation to maximize the use of water
CONCLUSION
This study shows that climate change is worsening the occurrence of extreme weather events, which increases soil salinity. It is a rising source of worry in agriculture, but its impact is felt throughout a wide range of plants and ecosystems, as well as human livelihood. Salinity causes a water shortage and ionic toxicity in plants, slowing or stopping major plant activities. Action must be taken to tackle these challenges and limit the consequences of climate change and soil salinity on people and property, as well as to sustain economic development, by proposing and accepting a solution.
REFERENCES
Ajala, S. B. (2017). Perceived effects of climate change on agricultural production of smallholder crop farmers in the Lowveld areas of Mpumalanga Province, South Africa. An MSc dissertation submitted to Department of Agriculture and Animal Health, College of Agriculture and Environmental Sciences, University of South Africa.
Apata, T.G., Samuel, K.D. and Adeola, A.O. (2009). Analysis of climate change perception and adaptation among arable food crop farmers in South Western Nigeria. Contributed Paper Prepared for Presentation at the International Association of Agricultural Economists’ Conference, Beijing, China, August 16–22, 2009.
Ayinde, O.E., Ajewole, O.O., Ogunlade, I., and Adewumi, M.O. (2010). Empirical analysis of agricultural production and climate change: A case study of Nigeria. Journal of Sustainable Development in Africa, Vol.5, №6.
Corwin, D.L. (2020). Climate change impacts on soil salinity in agricultural areas. European Journal on Soil Science, 72: 842–862
Coster, A.S., and Adeoti, A.I. (2015). Economic effect of climate change on Maize production and farmers’ adaptation strategies in Nigeria: A Ricardian approach. Journal of Agricultural Science, Vol. 7, №5.
Dasgupta, S., Hossain, M., Huq, M. and Wheeler, D. (2015). Climate change and soil salinity: The case of coastal Bangladesh. Ambio, 44:815–816
Deressa, T., Hassan, R. and Poonyth, D. (2005). Measuring the impact of climate change on South African agriculture: The case of sugarcane growing regions. Agrekon. Vol 44, No 4.
Food and Agriculture Organisation, FAO. (2010). Climate change adaptation and mitigation: New initiatives and update on agriculture, forestry and fisheries proceedings: Thirtieth FAO regional conference for the Near East. December 4th-8th, 2010, Khartoum, the Republic of Sudan.
Haj-Amor, Zied., Bouri, S. (2019). Use of HYDRUS-1D-GIS tool for evaluating effects of climate changes on soil salinization and irrigation management. Archives of Agronomy and Soil Science, 66 (2): 1–15
Intergovernmental Panel on Climate Change (IPCC) (2013). Summary of policymakers . In: Stocker, T.F., Quin, D., Plattner, G.K., Tignor, M., Allen, S.K., Boschung, J., Nauels, A., Xia, Y., Bex, V., Midgley, P.M. (Eds.), Climate Change 2013: The Physical Science. Contribution of Working Group to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge New York (CA, NY), pp 1535.
Kamran, M., Parveen, A., Ahmar, S., Malik, Z., Hussain, S. et al. (2020). An overview of hazardous impacts of soil salinity in crops, tolerance mechanisms and amelioration through selenium supplementation. Int. J. Mol. Sci. 21(1):148
Kayode, O.T., Aizebeokhai, A.P. and Odukoya, A.M. (2020) Soil salinity and its implications on sustainable agriculture in Southern and Northcentral States of Nigeria. International Conference on Science and Sustainable Development, Conference Series: Earth and Environmental Science 655.
Mendelsohn, R., Dinar, A., and Sanghi, A. (2001). The effect of development on the climate sensitivity of agriculture.
Mukhopadhyay, R., Sharkar, B., Sahay, Hanuman., Sharma, P. and Bolan, N. (2021). Soil salinity under climate change: challenges for sustainable agriculture and food security. Journal of Environmental Management, 280.
Okur, B. and Orcen, N. (2020). Climate change and soil interaction. Retrieved 6th December 2021. https://doi.org/10.106/B978-0-12-818032-7.00012-6. ISBN 978–0–12–818032–7
Wanjogu, S.N., Gicheru, P.T., Maingi, P.M. and Matolo, N. (2001). Saline and sodic soils in the drylands of Kenya.
Safdar, H., Amin, A., Shafiq, Y., Ali, A., Yasin, R., Shoukat, A., Hussan, M. and Sarwar, M (2019). A review: Impact of salinity on plant growth. Nature and Science, 17(1): pp 34–40
