Impact of soil degradation on agricultural productivity in Iran

December 9, 2015 - 0:0

The commemoration of World Soil Day on 5 December marked the closure of the 2015 International Year of Soils, which throughout the past year had sought to raise awareness of the importance of healthy soils not only for sustaining our ecosystem but also in ensuring the well-being of humanity and in securing global food security through enhanced agricultural productivity.

According to a report released recently by FAO’s Intergovernmental Technical Panel on Soils (ITPS) on the ‘Status of the World’s Soil Resources in 2015’, most of the world’s soil resources are either in a “fair, poor or very poor condition”. The report further pointed out that global soil conditions are not getting any better with some 33 percent of land over the world manifesting worrying signs of deficiency due to erosion, salinization, compaction, acidification, and chemical pollution of soils.
Rapid deterioration of the world’s soil is undoubtedly aggravated by the global population growth which generates increasing demands for food and energy production as well as a rise in the amount of raw materials extracted from the land. What many may not be aware of is the fact that the natural area of productive soils is finite. Consequently, its loss and degradation is not recoverable within a human lifespan. It has therefore become imperative for urgent measures to be taken to value the role of soil biodiversity in natural terrestrial ecosystems, recognise the significance of healthy soils as a foundation of food and promote improved soil fertility as an essential step for successful cropping and the establishment of high-production agricultural systems.
In Iran, soil erosion resulting from both wind and water erosion constitutes one of the main causes of land degradation. Of the total land area in the country, approximately 75 million hectares (ha) are exposed to water erosion, 20 million ha to wind erosion, and the remaining five million to other types of chemical and physical degradation. As a result, over two million hectares in the country have been rendered infertile and equally large proportions of land surface have been afflicted by high levels of salinity.
Soil salinity constitutes in addition another major limiting factor in agricultural development in the country. Soil salinization is more severe particularly in arid and semi-arid areas of the country where an estimated 34 million hectares are affected by high levels of salt that hinder the land’s natural growth procedure.
As indicated in previous remarks earlier this year, the current annual rate of land loss due to waterlogging and salinity is about 0.5 million hectares per year. Increasing water shortages has led to digging of deeper wells resulting in water with higher levels of salinity. The annual economic losses due to salinization and land degradation have been estimated more than USD 1 billion.
Despite the ITPS report, there is also crucial evidence that the loss of the Earth’s vital soil resources and functions can be curtailed and even reversed. Erosion, which carries away 25 to 40 billion tonnes of topsoil every year, can be brought down to sustainable levels through the adoption of such measures as the reduction or eradication of tillage and use of crop residues and cover crops to protect the soil surface.
To achieve these aims, the Food and Agriculture Organisation of the United Nations (FAO) is seeking to assist its Member States, including the Islamic Republic of Iran, through research and development (R&D), capacity-building with a major emphasis on training the trainers, policy advice, technology transfer and technical support and assistance.