Soil salinity management for eradicating hunger, nutrition deficiency

Soil salinity refers to the presence of excess soluble salts in the soils. The salts include sodium, magnesium and calcium.

The accumulation of these salts in high concentrations leads to nutrient imbalance, loss of soil fertility and eventual desertification of arable lands when the situation persists.

Saline soil is a term used to describe excessive levels of soluble salts in the soil water.

The level is high enough to negatively affect plant growth, resulting in reduced crop yields and even plant death under severe conditions.

Salinity becomes a problem when enough salts accumulate in the root zone to negatively affect plant growth.

Excess salts in the root zone hinder plant roots from withdrawing water from surrounding soil.

This lowers the amount of water available to the plant, regardless of the amount of water actually in the root zone.

This forms the basis of the 2021 World Soil Day (WSD) celebration with the theme "Halt Soil Salinisation, Boost Soil Productivity".

WSD is commemorated annually on December 5 to raise awareness on importance of healthy soil and its management.

Prof. Victor Chude, Registrar, Nigeria Institute of Soil Science (NISS) noted that if everyone focused on reclaiming and promoting sustainable practices on saline soils especially on semi- arid and arid soils, attaining food security would be possible.

According to Chude, recent statistics shows that the global annual cost of salt-induced land degradation in irrigated areas is estimated to be $27.3 billion in relation to lost crop production.

The Registrar advocated the use of sustainable farming systems adapted to saline and sodic environments.

He further called for investment in gathering better knowledge on salt affected soils at national, regional and global levels.

Chude called for awareness on the importance and impacts of preventing unsustainable practices that led to salinization of soils.

"Productivity of agricultural lands must be improved and sustained in order to meet the demands of increasing world population.

"Salt affected soils are increasingly becoming widespread and threatening agricultural production in hitherto productive farmlands especially in irrigated areas," he said.

Mr Monday Adiaha, Academic Researcher/Scientist, Department of Planning, Research Extension and Statistics of NISS noted that the endpoint of salinity was desertification contaminated land adding that it could lead to migration.

"With the presence of salt in the soil, you cannot go sustainable because you will not have money and your standard of living will go down," Adiaha said.

He identified practices to halt soil salinity as agroforestry, application of compost, leaching of the soil, surface flushing, and application of fertiliser at the right dose and right time.

The scientist noted that sustainability in the management of saline soil is the key word for future generations unborn to enjoy what "you have enjoyed today".

He further identified genetic engineering as a key tool to combat salinisation.

"For you to go sustainable in salinity, you need to have a clear understanding of the crops you are planting, crops that can resist toxicity to a certain limit of the toxicity nature of the soil," Adiaha said.

The scientist noted that sustainability in saline soil was necessary due to the concept of the Sustainable Development Goals (SDGs) of agricultural practices and environmental management.

According to him, it encompasses conservation and restoration strategies with the application of natural resources on food production to satisfy the need of both present and future generations.

"So, the key word is, if we take care of our environment in agroforestry, organic amendment, control your source of irrigation water so that it does not form salt, you will have a sustainable agriculture.

"And sustainable agriculture will bring increased standard of living as well as export, we will be able to export and get money.

"The farmer will be able to smile and have enough food and the overall effect is that there will be something in the soil which will be left conserved for the next people that are yet to come to the planet," Adiaha said.

Prof. Bashiru Raji, President, Soil Science Society of Nigeria (SSSN) laments that $27.3 billion is lost annually to salinity-induced soil degradation globally .

Raji describes soil salinisation as a major land degradation process that reduces soil fertility and promotes desertification processes in dry land areas.

"The World Bank estimates that soil salinisation due to inappropriate irrigation practices affects about 60 million hectares of land.

"Salinisation accounts for 50 per cent of irrigated land in Africa, almost 35 per cent of the agricultural land in Egypt and is a growing problem in India, Pakistan, China, and Central Asia.

"The annual cost in crop production loss due to salinity induced soil degradation is estimated at $27.3 billion," he said.

Raji specifically noted that some states like Nasarawa, Kano and Kebbi among others might experience the problem.

He called for urgent action against soil salinisation, adding that SSSN had joined the rest of the world to also call for conscious actions to limit the expansion of saline soils.

According to Raji, soil scientists all over the world are calling on governments, organisations, communities and individuals to commit proactively to maintaining healthy ecosystem and improving soil health by conscious actions to limit soil salinisation.

The don, who says that human life is organically linked to the soil, stressed that whatever reduces the productive potential of the soil diminishes human welfare.

"Therefore, soil salinisation must be halted to boost soil productivity," he said.

"I advocate for the adoption of sustainable farming systems adapted to saline and sodic environments, while encouraging people to avoid unsustainable practices that could lead to soil salinisation," Raji said.

Dr Mohammed Abubakar, the Minister of Agriculture and Rural Development, urged soil scientists to prevent soil salinisation through information dissemination on the prevention of destructive practices that lead to soil salinisation.

Abubakar identified other measures to mitigate soil salinisation as, sustainable farming systems adapted to saline and sodic environment, and development of early warning systems on the precursors of salinity in the soil.

"Our agriculture suffers from many limitations and most of these limitations are environmental in nature while others are anthropologic.

"Major soil constraints which include soil erosion, salinity, acidity, low soil fertility, desertification, leaching and fixation of nutrients are responsible for the declining productivity and degradation of our soils.

"Our scientists need to work closely with other stakeholders to carry out focused research that would address the soil-related problems affecting our agriculture," the Minister said.