المنتدى العالمي المعني بالأمن الغذائي والتغذية

On Guidelines to Embody a Sound Code of Conduct in Policies Pertaining to Sustainable Soil Fertility

Should suggestions given here are adopted, it must be borne in mind that they are not universal in that some of them may be already included in relevant policies, or they are not relevant due to the type of crop, existing state of the soil, economic constraints, or other factors. Thus, it may be seen as a bag of options from which one may select those best suited to the circumstances involved.

Let us not forget the logical order of our task. Its overall purpose is to enhance sustainable global nutrition by “maintaining or increasing global food production.” Its successful achievement depends in part, on having a sustainable soil fertility. I think there will be a general agreement on the argument thus far.

Now, the use of fertilisers is perhaps the most important means of achieving this objective while its inappropriate application will have the opposite effect as shown by the ruins of the soil in vast tract of land near the now defunct Aral Sea. Thus, our efforts are concerned with a sub-set of  means in use to enhance soil fertility in a sustainable way, and our efforts are concerned with the point 2 to 5 specified in the document on our purpose. I think now I have placed the discussion within a holistic framework, from which to take my point of departure.

Before proceeding, may I point out the last two points, 4 and 5 have a causal link, for certain concentrations of heavy metal and other organic extraneous materials in artificial fertilisers are taken up by food crops and their subsequent consumption is known to have adverse health effects, hence undesirable. I think these two points may be united owing to their causal connection to our health.

The purpose of the code then, has two dimensions. The first would be to identify how the use of fertilisers may enhance soil fertility, i.e., what policy could promote the optimal use of them. Next, it is important to identify what uses of fertilisers would have an adverse effect on soil fertility, environment and health. Together, these will consititute an inclusive code that may be fruitfully embodied in a set of relevant policies.

It would be reasonable to suggest that the possibility of successful agriculture depends on having an adequate and sustainable ecosystem services and the use of crops suitable to an area. Those services include the concentration of carbon dioxide in the air, water supply, air and soil temperatures and indeed soil fertility that depends on its mineral content, general composition and structure. It is established beyond reasonable doubt that the well-being of our environment is essential for an adequate supply of ecosystem services mentioned earlier. Therefore, the use of fertilisers represents a supplementation of a particular ecosystem service to enhance one aspect of soil fertility, viz., its mineral content in a manner that does not adversely affect its other content or structure. Some may argue that as the use of mulch enhances soil porosity, and hence its overall fertility, it may also be included. If this is desired, such fertility enhancements should also be subjected to the same requirements as will be described below.

At this point, let us recall that it is axiomatic that a region’s food culture represents the culture of plants best suited for its soil, climatic and geographic conditions through a long trial and error over a period. Next, well-being of our environment on which ecosystem services depend, have a qualitative and a quantitative dimension. While the former represents its biodiversity, the latter indicates the optimal sustainable population of each individual species in the area. Thus, supplementation of soil fertility should not be undertaken at the risk of diminishing an area’s biodiversity or those optimal populations. Otherwise, one runs into an evil chain of gradually diminishing natural ecosuystem services leading to an increased need for their supplementation that ends in salination and soil ruins as in the areas around the Aral Sea.

So, the proposed code of conduct ought to  ensure that the use of fertilisers pay careful attention to the following considerations:

1. Maintain or enhance the ecosystem services of the area with reference to an optimal as governed by its climate, geography and soil composition so that the crops best suited for the location may thrive. This objective may be achieved in part by ---
2. Using fertilisers to achieve the natural levels for a given soil type the micro-nutrients required for a given crop. Whenever it is possible, one should prefer the use of compost, green manure and similar organic fertilisers.
3. As its counterpart, do not use fertilisers to supplement those micro-nutrients already present in adequate quantities in order to avoid salination and environmental damage
4. Whenever it is possible, undertake soil. Micro-nutrient assays to ascertain the relevant qualitative and quantitative needs of supplementation for the crops involved prior to the use of fertilisers.
5. Ensure that the fertilisers used do not run off out of the cultivated area to avoid their adverse effects on the environment like biodiversity imbalance due to species predomination like algal blooms in water ways andeventually  the sea. Sequential slow-release of fertilisers is often useful in achieving this goal.
6. It would not be sustainable to use fertilisers to increase the soil fertility to cultivate a crop that is unsuitable to be grown in the virgin soil of an area. It is this error that has rendered many areas of once tree-clad Amazons barren and bare today.
7. Whenever possible, it is highly desirable to monitor soil status on a regular basis to ascertain the availability of micro-nutrients required, soil composition and structure (porosity, distribution of larger elements, etc.) as well as soil biology with a view to adjusting supplementation as required.
8. A careful distinction should be made between the use of fertilisers to enhance soil fertility and an ‘increased crop yield’, because the latter will legitimize the use of plant growth accelerators which are known to be endocrine disruptors whose intake poses a very serious threat to human and environmental health.

Here, I will devote a little time to how one may avoid making  the use of fertilisers a possible threat to human and environmental health. While the importance of the former is obvious, the latter may not only directly affect our health (global warming), but could indirectly do so by reducing the availability of ecosystem services, resulting in food shortages. So, in order to “maximise the efficient use of plant nutrients to enhance sustainable agriculture,” the following conditions should obtain:

1. Strict regulation of what each inorganic fertiliser contains with a view to exclude them from containing heavy metals, growth accelerators or any other compound whose effects are known to be injurious to the living, and whose long term effects on the same are not yet known. Such higher standards of purity should be obligatory.
2. In addition to their loss by run-off and causing polution, surface application of dry chemical fertilisers are easily dispersed by the wind especially when they are followed by dry spells. This can pose a health hazzard to people and upset the ecology of the surroundings. Therefore, this practise is to be deprecated. It would be far more effective if inorganic fertilisers in suitably inert depots are ploughed into the soil so that the nutrients they contain are slowly released into the substrate, thus enhancing their effect. As an alternative, the required quantity of inorganic fertilisers may be mixed with organic ones and applied.
3. Inorganic fertilisers are prone to cause leaching, i.e., fertiliser displacing a less reactive metal element from small rock particles in the soilwhile making less nutrientsavailable from the fertiliser and increasing the concentration of some metal whose higher concentration is not desirable. How to deal with this issue is discussed in 1.I to 1.III above. It must not be forgotten that an adequate soil analysis needed here may be undertaken in a fairly simple laboratory for a reasonable cost even though very expensive more sophisticated ones are available.

These are some of the essential actions to be undertaken in the field in real life. The question then is how to motivate the fertilizer users and those who connected with their production and sales as well as  those who control the latter to undertake appropriate actions. Naturally, it is the last group who lays down the norms needed for the purpose and facilitate or hinder their adequate application. So, let us begin with them whose responsibility is to formulate and implement policies that ensures prudent use of fertilisers.

Some useful steps in this direction may involve inclusion of sound use of fertilisers in the curriculum of agriculture education and training, legal instruments to enforce the quality of inorganic fertilisers both with reference to manufacture and sale, trade policy that excludes the import of fertilisers that do not meet those standards, financial and technical support to promote the guidelines given above including more wide spread use of organic fertilisers as much as possible, and particularly practical research into combined farming where maximum amount of ‘crop remainders’ can be re-cycled within a farm. This last is not a suggestion concerned with the ‘cutting edge stuff’, rather it is a request for an enquiry into how the existing good local farm practices may be combined in  some new combinations for a greater food yield with less cost in fertilisers.

As mentioned at the outset, this is only a skeleton to be fleshed out according to what relevant for a given locale. What is applicable to all is the importance of knowing soil structure and chemistry as well as its biology before one decides on crops and fertilisers to be used. Traditional food culture despite its shortcomings often represents this knowledge in its pragmatic manifestation, and should serve as a sound point of departure for further work and gradual improvement.

Hope this would be of some use.

Cheers!

Lal Manavado.