Introduction and Rationale
The most significant change in crop production has been the more intensive use of organic and inorganic fertilizers and the consequent heavier load of grain bearing on the stem of the cereal plant.
Where there are adequate water supplies and sunshine, the plant has a good chance of absorbing large amounts of fertilizer, but, as is well-known, successfully concluded application of such quantities is inhibited by the limited ability of the stem of existing varieties to remain upright until harvesting time.
This has led to the breeding of fertilizer responsive varieties thus heightening the yield ceiling. What is not always appreciated is the fact that our present usage of fertilizer is so meagre that great strides can be made in areas with adequate soil moisture to raise yields of traditional cereal varieties by means of this single improvement in crop production.
Conversely where there is insufficient soil moisture the adoption of increased quantities of fertilizers, let alone of the new response potential varieties, would prove unproductive.
A clear instance of raising yields through the greater usage of fertilizer, in the absence of any significant change of other inputs and prior to the advent of high yielding varieties
(HYVs), is that of rice output in India since 1950. Between 1950 and 1964 (the period of widespread introduction of HYVs of rice, millet, sorghum wheat and corn) total food grain output rose by about 80 percent while area under cultivation rose only about 22 percent. On the other hand the amount of nitrogen fertilizer distributed in Indian agriculture increased about ten fold over the same period.
Even so this enormous increase barely lifted India out of the category of countries unacquainted with the practice of concentrated use of fertilizers. In the early 1960s an average application of plant nutrients of 7 kg. per hectare of cultivated land was recorded for India compared with 180 kg. for Britain, 250 kg. for Taiwan, and 250 kg. for the Netherlands.
For the same period the wheat yield in India was 800 kg. per hectare against Britain’s 4,000 kg/ha. India’s average rice yield was then about 1,400 kg./ha. while Taiwan’s was 3,200 kg./ha. These differences accounted for the varying levels of development indicators for the four countries.
Since fertilizer is a substitute for land, its application is likely to be more profitable in areas where the culture of poverty and subsistence farming are the lot of the producers.
To target poverty reduction and economic growth in an agrarian society where 60 - 65% of the population are resource-poor farmers and where fertilizer usage is less than 20 kgs./ha. is tantamount to trying to carry water in a basket.
No continent and/or country has ever shaken off subsistence production culture, hunger, poverty, efficient farm and non-farm rural employment without ensuring adequate and timely fertilizer usage for soil fertility improvement and productivity growth.
One must, of course, question whether, in spite of the very low fertilizer usage, economic growth and poverty reduction can take place in a society where 60 - 70 percent of the population are dependent on agriculture and where fertilizer usage is, on the average, less than 20 kgs./ha.
There is adequate empirical evidence confirming that no country has ever shaken off subsistence farming culture, hunger and poverty without ensuring adequate fertilizer usage for soil fertility improvement and productivity growth.
Can organic sources of crop nutrients solve Africa’s problems?
In an ideal world, all sources of nutrients are combined in an approach called integrated plant nutrient management.
Farmers start with on-farm sources of nutrients such as manures, crop residues and legumes and then supplement them with fertilizers. In Africa’s case available, available organic materials are limited, and there is always a competing demand to use them for other purposes, such as fuel for the fire and for reinforcing mud buildings.
Fertilizers can provide the missing nutrients, which will also improve the balance among the required elements and thus enhance the plants’ uptake of nutrients from existing organic sources. Higher yields (except for groundnuts) mean there is more organic matter to be introduced into the soil, thus allowing farmers to enrich their soils to increase the chances of successful crop production in subsequent years.
Feeding the crops that feed people
Agriculture and the spread of cities both require large land areas. Although the population density of Africa is relatively low, most of the good agricultural land is already being used.
Ironically, new settlements are often built on the best lands for food production. As a result increased agricultural production often requires higher yields on existing agricultural lands, or the conversion of fragile lands and precious wild life habitats to cultivation.
Because many people have moved to the cities and other growth centers and many others have been affected by diseases, Africa’s agricultural work force is shrinking. This is another reason why it is important to grow more and harvest more from each plot of land through appropriate and timely fertilizer usage.
Without adequate and timely fertilizer usage, farmers often cannot meet the food needs of their own families, much less tose of a rapidly growing population. To feed themselves and their countries, farmers will need to shift from low-yielding, extensive land practices to more intensive, high-yielding practices, with increased and sustained use of fertilizers.
The farmer’s currency is his yield per hectare which is determined by increased and sustained use of fertilizer. There are no short-cuts. Balanced and healthy diets for all
By contributing to greater soil fertility and improved productivity, fertilizers help farmers produce more food, feed, fibre and bio-energy per unit of land. The main nutrients that help raise yields nitrogen (N) phosphate (P) and potassium (K) and sulphur (S), although others are important. Calcium (Ca) is also critical.
Even if people consume enough calories, human health and well being can suffer from a lack of important vitamins and minerals. By some estimates, as many as one-half of the global population is not getting enough of at least one nutrient.
The varied foods, such as fruits and vegetables, that are an essential part of a healthy, balanced diet require significant quantities of as many as 16 different nutrients. But the crop can only contain these elements if they are available in the soil, or from an external source like fertilizers.
Among the nutrients we require to be healthy, nitrogen has a particularly important role in the formation of protein. Phosphate and calcium contribute to strong bones. Potassium provides energy and vitality.
Crops also provide micronutrients that benefit human health. Targeted fertilization can help raise food’s content of some of this trace elements in order to improve public health in aq cost-effective way.
Fighting soil degradation
Healthy soils are fertile and retain moisture well. Many of our soils contain few nutrients and little organic matter. Not many plants can grow under such conditions, so these soils are exposed to erosion.
As farmers remove more and more nutrients from the soil without replenishing them, nutrient mining, this cycle can worsen, causing an extreme form of damage to the land called desertification. Once the situation has reached this, it is hard to repair the damage, and food or other crops can be grown ai a very high cost.
By making healthy crop covers possible, fertilizers help protect fragile lands from erosion. Higher yields and more plentiful crop residues gradually increase the organic matter in soils, so they are better able to retain moisture. Fertilizers are therefore an important part of the fight to stop desertification.
Conclusion: Getting from scarcity to abundance
In the face of an appropriate understanding of the prime role of fertilizers in agricultural and national development, the starting point in discussing the challenges that Africa face is to brush aside the web of fantasy we have woven around “development” and decide more precisely what we mean by it.
Only then will we be able to devise meaningful targets or measures of progress to judge the relative importance of various problems which arise in the process of development, and thus to help improve policy, national and international.
We cannot avoid what the positivists often disparagingly refer to as value “judgment”.
“Development” is inevitably treated as a normative concept, as almost a synonym for improvement. To pretend otherwise is just to hide one’s value judgment.
What is clear to us now is that, as an agrarian continent, we cannot expect growth, increased production, productivity, food security, poverty reduction - as a matter of fact attainment of the millennium development goals as well as the vision of the New Partnership for Africa’s Development without the sustained incremental usage of recommended fertilizer use-rate and use-efficiency across the continent.
The adoption of recommended fertilizer use-rates and use-efficiency, in combination with other efficient use of other farm inputs, could trigger an African Green Revolution, give new hope to millions of poor farmers and free them from the shackles of food insecurity and hunger.
This is the only strategy that would contribute to Africa’s ability to meet the Millennium Development Goal on hunger that targets a 50 percent reduction in food insecurity by 2015 as well as the 2015 vision of the New Partnership for Africa’s Development (NEPAD).
As a matter of fact, the New Partnership for Africa’s Development has declared that the vision of economic development in the continent must be based on raising and sustaining higher rates of economic growth (7 percent per year).
To realize this vision, the African Heads of State and Government adopted the Comprehensive Africa Agricultural Development Programme (CAADP) as a framework for the restoration of agricultural growth, food security and rural development in Africa. Stakeholders have identified that addressing the fertilizer crisis will help accelerate agricultural growth, food security and income for farmers and, hence, the entry point for the socio-economic development of the continent.
This suggests putting in place a supporting framework for fertilizer use in Africa. A framework has been developed for the Gambia in 2005 in what is known as the “provision of agriculture support services.” Our future depends on recommended fertilizer use-rate and use-efficiency.