AS Stakeholders in the Soil sub-sector converge globally on Thursday, 5th December, 2019, for World Soil Day, it is pertinent to note that erosion is recognized as one of the world’s most serious environmental problems.
In Nigeria, especially the southeastern part, agricultural productivity, sustainability and management for food security/sustenance has been undermined by the menace posed by soil erosion.
This itself entails the danger of soil exhaustion, of which accelerated erosion is often only a symptom in Nigeria.
Soil erosion by definition, is a systematic removal of soil, including plant nutrients, from the land surface by the various agents of denudation which occurs in several parts of Nigeria under different geological, climatic and soil conditions.
But the degree of occurrence varies considerably from one part of the country to the other. Equally varied are the factors responsible for the inception and development of erosion, as well as the types that exist in several parts of the country.
It is believed that globally, about 80 per cent of the current degradation of agricultural land is caused by soil erosion.
In Northern Nigeria, desertification is one of the major environmental problems while the high torrential rainfall of the southern Nigeria creates enabling environment for catastrophic soil erosion in the region.
Erosion is particularly pronounced and ecologically vulnerable in areas of southeastern Nigeria where population densities and least land per capita ranks among the highest in rural Africa.
Dr Adewale Nafiu Head of Inspectorate and Education Department of Nigerian Institute of Soil Science (NISS) said the soil in Nigeria is very fragile, hence susceptible to erosion if not handled with care.
He activities like farming, road construction with poor drainage system, and other engineering constructions could lead to soil erosion if the soil is tampered without care.
The kind of soil we have in Nigeria is a fragile one, and when I say fragile, it means that we have to be very careful the way we handle it. If we don’t handle it well, it is like a life, when we don’t handle life well, there may be complications, the same thing happens to our soil.
African soil the way it is, is a very fragile one, which means it needs to be well taken care of. The climatic condition of our environment, the man made activities are some of the things that lead to a situation whereby we have soil erosion.
And when this man made activities like farming, when we are constructing roads without putting proper drainages or channels, or when you are constructing engineering structures and you don’t factor into it that one way or the other you are tampering with that fragile soil, there is tendencies for us to have soil erosion.
The menace of soil erosion represents a major ecological challenge facing most states in Nigeria especially Anambra, Imo, Ebonyi, Abia and other states in the humid tropical region, this is as a result of soils in those areas having high soil erodibility which are are said to be structurally unstable.
Also, the soils are naturally prone to erosion due to their fragile nature and ease of leaching being mainly ultisols and alfisols and that is the reason why gully erosion is prevalent in this southeastern zone.
Both physical, socioeconomic and anthropogenic factors as well as deficient agricultural production practices are believed to have aggravated and exacerbated the high erodibility of the soils in the region.
However, according to the policy brief of The Global Soil Partnership, soil is the main resource base and the most productive natural capital for many people in Sub-Saharan Africa (SSA), especially for the rural population. With an estimated population growth from the current 900 million to 1.4 billion in 2030, the region’s soil will experience increasing pressure to provide for the vital needs of its people.
The Brief further noted that with an estimated 65 per cent of arable lands, 30 per cent of grazing land and 20 per cent of forests already degraded, the region has the potential to position itself as champion in terms of increasing food production and security by achieving land restoration and increasing agricultural innovative practices that are resilient to climate change.
The best identified strategy to tackle these issues is through increased knowledge of the regional and national needs and priorities, and the subsequent implementation of projects and programs that address these issues, as well as working on the acknowledgment and strengthening of already existing projects programs and declarations.
Soil degradation in Sub-Saharan Africa is believed to be expanding at an alarming rate, accompanied by the lowest agriculture and livestock yield of any region in the world. While cereal production has increased marginally over the past two decades, more than 70 per cent of this growth is due to the expansion of cultivated area rather than to the yield increases.
According to an article by Barry-Chukwu Princess Kelechi titled: Are Our Actions Eroding the Earth?; it noted that soil erosion has continued to be a concept that is ever present as one of the major problems affecting agriculture in Nigeria where resource poor farmers follow extractive farming practices.
The article noted: “Simply put, soil erosion is the physical disaggregation and wearing away of the upper layers of the soil due to natural forces of wind and water or other man made activities such as tillage and urbanization.
“This relocation of the topsoil that is very rich in nutrient greatly reduces soil fertility and productivity and also results in blockage of water channels and pollution of water posies which may lead to eutrophication.
“Currently, soil erosion is happening faster than ever recorded and humans are at the driver’s seat causing more than 10 times the erosion that is due to natural forces.
The declining issues of land availability and increasing population density has intensified rapid urbanization, conversion of arable land to non-agrarian uses and intensive cropping/shorter fallow periods thereby exacerbating soil erosion.”
Barry-Chukwu further stated that high rate of erosion in Nigeria is of great concern because soil formation and degradation naturally take place in a balanced process whereby new soil forms at about the same rate at which it erodes.
She said as a result of human action, rate of soil erosion me than 10 to 20 fold faster, making nature unable to keep up with soil formation.
The article also cited a work by Scherr and Yadav, which said soil erosion will pose a major threat to food production, which is a major livelihood to poor rural dwellers in Nigeria.
“Evidence of this is already being seen in various parts of Nigeria for instance, it has been reported that in Calabar South, productivity of some lands have declined by 60 per cent due to erosion and nutrient loss,” Barry Chukwu added.
Man must take cognisance of the effects their actions in soil erosion and take actions to control it. Immediate appropriate actions must be taken by decision makers, farmers, and public at large to control erosion, improving food security and ensure the survival of the future generation.