Soil Salinity: Historical Perspectives and a World Overview of the Problem

Abstract

Soil salinity is not a recent phenomenon, it has been reported since centuries where humanity and salinity have lived one aside the other. A good example is from Mesopotamia where the early civilizations first flourished and then failed due to human-induced salinization. A publication 'Salt and silt in ancient Mesopotamian agriculture' highlights the history of salinization in Mesopotamia where three episodes (earliest and most serious one affected Southern Iraq from 2400 BC until at least 1700 BC, a milder episode in Central Iraq occurred between 1200 and 900 BC, and the east of Baghdad, became salinized after 1200 AD) have been reported. There are reports clearly revealing that 'many societies based on irrigated agriculture have failed', e.g. Mesopotamia and the Viru valley of Peru. The flooding, over-irrigation, seepage, silting, and a rising water table have been reported the main causes of soil salinization. Recent statistics of global extent of soil salinization do not exist, however, various scientists reported extent differently based on different data sources, such as there have been reports like, 10% of the total arable land as being affected by salinity and sodicity, one billion hectares are covered with saline and/or sodic soils, and between 25% and 30% of irrigated lands are salt-affected and essentially commercially unproductive, global distribution of salt-affected soils are 954 million ha, FAO in 1988 presented 932 million ha salt-affected soils, of almost 1500 million ha of dryland agriculture, 32 million ha are salt-affected. Precise information on the recent estimates of global extent of salt-affected soils do not exist, many countries have assessed their soils and soil salinization at the national level, such as Kuwait, United Arab Emirates, Middle East, and Australia etc. Considering the current extent of salt-affected soils the cost of salt-induced land degradation in 2013 was $441 per hectare, a simple benefit transfer suggests the current annual economic losses could be $27 billion.

A GmSIN1/GmNCED3s/GmRbohBs Feed-Forward Loop Acts as a Signal Amplifier That Regulates Root Growth in Soybean Exposed to Salt Stress

“…High salt concentrations in soils strongly reduce crop performance (Munns and Tester, 2008) , and salt-affected soils currently account for 10% of the world's total arable land area (Shahid et al, 2018). Soybean (Glycine max) is a major agricultural crop for oil and protein resources, and its production is reported to decrease by 40% with increasing salt stress (Papiernik et al, 2005) .…”

Correlation between Spectral Characteristics and Physicochemical Parameters of Soda-Saline Soils in Different States

“…Approximately 932 million ha of soil worldwide suffers from primary salinization, and another 77 million ha from secondary salinization [1,2]. Soil salinization severely impacts the environment and reduces the grain yield.…”

Comparative studies of reproductive biology, seed morphology and anatomy of new salt tolerant accessions of Quinoa (Chenopodium quinoa Willd.) introduced in Kur-Araz lowland (Azerbaijan)

“…The ability of quinoa to produce high-quality proteins under extreme environmental conditions makes it an important crop not only for Andean communities but also for the diversification of future agricultural systems over the world [Rao et al, 2019]. Certain varieties grow well in difficult conditions because they are drought-and salt-resistant; plants grow in mountainous areas and lowlands, which confirms its universality as a crop that adapts to the surrounding climatic conditions [Zaman et al, 2018;Toderich et al, 2013;Rao et al, 2019]. Due to its high adaptability to different climatic conditions and effective water consumption, quinoa is an excellent alternative grain cash crops under ongoing climate change.…”