Between Soil Test And Food Production In Nigeria

The task of increasing food production to address the growing challenge of food insecurity in Nigeria remains enormous and complex that requires concerted efforts of all stakeholders including families and individuals.

Agriculture, particularly the cultivation of crops for food production needs the application of best practices, relevant implements and techniques which should not be limited to the use of improved seedlings, mere application of fertilisers and use of machinery alone.

In this regard, soil test must be given priority attention by farmers and gardeners to ensure high yield during harvest.

The significance of soil investigation before actual planting of crops during farming season across the nation therefore appears to be trivialised and benalised over the years.

This probably accounts for poor yield in both subsistence and commercial agriculture in parts of the country and Africa.

As a result, food security is threatened despite the application of supposedly right amount of fertilizer, use of extension field officers who enlighten local farmers on improved agriculture and provision of micro finance to medium scale farmers by government and intervention agencies.

No doubt, the inability to conduct soil investigation by most farmers and gardeners may well be traceable to ignorance, high cost of conducting such investigation and over dependence on subsistence agriculture.

There is also an erroneous impression among many that soil investigation is limited to construction industry alone where soil tests are conducted for analysis to ascertain state of soil before road construction, bridges and building of houses take place.

Nonetheless, soil test remains an integral part of modern and improved agriculture aimed at increasing food production.

Soil test or investigation as applied to farmers is concerned with investigation into soil properties to ascertain the quality and quantity of nutrients available for crops.  It involves the process by which plant nutrients, such as phosphorous, potassium, calcium, magnesium, sodium, sulfur, copper and zinc among others are chemically removed, added or measured for “plant available” content within a sample. This is because the quantity of available nutrients in a sample, for instance, determines the amount of fertiliser that may be recommended.

Soil test too helps to identify soil or piece of land with which to farm, and in addition, related crops that do well in that soil texture. Better still, it measures soil pH, homier matter and level of acidity.  Soil investigation and analysis, therefore, assist an enlightened farmer to adopt liming when necessary.

A soil expert in the Department of Crop and Soil Science Rivers State University of cience and Technology (RSUST), Professor Nnaemeka Isirima explains liming as the application of calcium and magnesium-rich materials to soil to neutralise soil acidity and in turn increase activity of soil.

Furthermore, soil pH represents a measurement of alkalinity or acidity of soil which is measured scientifically on a scale of one (1) to fourteen (14) with seven (7) considered as the neutral mark.

Scientists say when the measurement is below seven (7), the soil is said to be acidic while anything above seven (7) is considered alkaline soil.

One thing is clear: The rate of infiltration of water is an excellent indication of soil health.

Professor Isirima, in an interview, contended that soil is heterogeneous and not homogeneous and warned against application of fertilizer to crops without knowing the nutrients present or lacking in soil for cultivation, saying that such application of fertiliser could lead to what he called “Eutrophication”.

Eutrophication is dangerous because it makes a body of water to acquire high concentration of nutrients particularly phosphorus and nitrates that could lead to the growth of sea weeds called ALGAE.

Simply put, when fertiliser is applied without knowing the nutrient that is lacking, it may amount to waste of fertiliser because the piece of land could be “over rich” and in that case, the surplus overflows into surface water or water table beneath the earth.

Worse still, rather than being beneficial to plants the unnecessary addition of nutrients becomes detrimental.

Speaking during a recent plant tour of Notore Chemical Industries, formerly NAFCON, by stakeholders in agriculture, the chairman Agriculture Commission of Nigeria Economic Summit Group, Emmanuel Ijewere, stressed the need to conduct soil test in various zones of the country to ascertain the choice of fertilisers and applicable plants and crops, explaining that the use of fertilisers without soil test could be disastrous.

The overall benefits of soil investigation lies in the fact that farmers, growers and gardeners, as the case may be, appreciate the nature, and quality of soil in relation to plant nutrients, and this enables farmers to determine the type of crops to be planted, determines the right amount and type of fertilisers to be applied as well as whether or not to embark on liming if soil sample is acidic.

On the other hand, inability to conduct soil test may result in dumping of fertiliser that adds to pollution, leads to waste of money and resources that would otherwise have been spent on other in puts to increase food production through better yield.

In addition, Professor Bernard Onuegbu of the Department of Crops and Soil Science of Rivers State University of Science and Technology, Port Harcourt, says “soil test enables farmers to appreciate the chemical integrity of soil as it affects the presence of heavy metals” which he described as injurious and non essential elements because they are not required for the normal growth and development of plants.

Professor Onuegbu, a former Commissioner for Agriculture, Rivers State, contended that even when the heavy metals are needed, they are needed in minute quantities and when absorbed by plants the injurious elements form part of food chain and thus create havoc in animal and humans.

According to him, some heavy metals such as cadmium and sulfur dioxide are not caused by unnecessary application of fertiliser but said that they are common in some native soils that had had history of pollution by crude oil, adding that soils along major roads contaminated with sulfur dioxide and smoke from exhaust of automotive vehicles have been found to be susceptible to heavy metals.

In Japan, for instance, Professor Onuegbu said cadmium, an example of heavy metals, is known to have caused a disease in man called ITAI-TAIL in which there is disintegration of bones in human body.

In fact, GLANZE 1996 identified heavy metals to include antimony, cerium, chromium, arsenic, bismuth, cadmium, cobalt, manganese, copper, gallium, lead, gold, mercury, nickel, platinum, silver, iron and tin. Others are thallium, uranium, vanadium, tellurium, and zinc.

Given this background, food scarcity nationwide may not after all be attributed to use of primitive tools alone but the absence and inability to conduct soil investigation to determine the right application of fertiliser or undertake liming if need be.

To this end, it is pertinent to suggest to the authority concerned to include as a matter of necessity, soil analysis that may be beneficial to farmers, gardeners and agronomist in Environmental Impact Assessment (EIA) so that farmers within certain project sites could take advantage of such soil analysis to improve their agricultural practice.

Fertiliser manufacturing companies must collaborate with relevant stakeholders such as research institutes in agriculture to conduct soil analysis in the country to aid in the right use of available fertilisers as well as choose the right crops.

Farmers practising improved agriculture whether subsistence or commercial agriculture should begin to see the need to seek advice on crops to plant and type of fertiliser suitable for their soil and crop before actual cultivation.

Extension officers must be domiciled in their areas of operations to provide needed enlightenment to the teeming ignorant farmers wishing to embrace their services.

The media, particularly broadcast media ,should ensure that their programming accommodate coverage of a broad spectrum of fields of specialisation including agriculture where reasonable airtime is given to the practice of improved agriculture.

Perhaps, it will not be out of place to accommodate soil investigation and analysis in the call for thorough mapping and surveying of Nigeria in the quest to provide a holistic land cadastre system nationwide as canvassed by Nigeria Institute of Surveyors.

The importance of this lies in the fact that some industrialists wishing to embark on commercial agriculture in Nigeria can avail themselves of such scientific data to site industries for optimum productivity.

Research institutes and university laboratory services must be accessible to true farmers against the present trend where researches in various tertiary institutions are carried out as mere academic exercises designed to pass examination and obtain academic laurels.

Truly, the task to attain self-sufficiency in food production does not remain and end with mere planting crops but maintaining global best practices which encompass soil investigation, use of improved variety and right application of fertiliser among others.

The time to act is now.

Sika is of Radio Rivers, Port Harcourt.

Baridorn Sika