Barley [photo] 


Challenges and opportunities in maize production

By Kobus van Zyl (Senior Agronomist: North West)

Maize is the most important grain crop in Southern Africa and prices are dramatically influenced by any indication of under or over production. The crop is just as important in other parts of the world, and a considerable amount of it is produced if climatic conditions are favourable. This leads to a global over-production, which impacts negatively on the maize price. A case in point is what happened with the South African maize price last year as a result of the drought which affected large parts of the maize producing areas. There was a shortage of maize and this caused havoc. Fortunately, enough maize could be imported to make up the shortages and prevent the so-called “yellow porridge” fear.

The maize price is determined by supply and demand. Both yield and grain prices are drivers in the farmer’s business. Marketing of grain always sounds easy on paper, but it is a lot more complicated in practice. There can also be a substantial cost involved, depending on the marketing channel used. Therefore, the producer’s challenge is still to get the best possible prices for his produce, and to produce as much grain as possible with the resources at his disposal. This sounds easier said than done, but if we are not attuned to change, it will be difficult to achieve.

Increases in grain prices or yields will not always happen in large increments. However, it is not only the large improvements that matter, but the small, constant changes in crop prices and yield also make a difference. Any increases in grain price or yield should never be at the expense of long-term sustainability.

Thanks to new genetics, maize yield increases are easier to achieve, provided that none of the factors contributing to yield are limited in any way. This is very seldom the case in practice. Environmental conditions such as soil moisture, timely rainfall, waterlogged soils, nutrient deficiencies, weed pressure, plant disease and pests are often reasons why the crop’s genetic potential is not reached. Even in a more controlled environment, for instance under irrigation, it is not always possible to reach the genetic potential.

The potential profitability of maize production is indicated in Table 1. These figures are only meant for illustration purposes.

Table 1: Potential profitability of maize production.

The green figures indicate a profit of 40% or more above production cost. Table 1 clearly shows the impact the grain price and yields have on profitability. A maize yield of 4 tonnes per hectare (t/ha) at a price of R2 250/tonne will earn a profit of 28.6% (at a production cost of R7 000/ha). If the maize price goes up with a mere R250 per tonne (R2 500/ton), profitability will increase by 14.3%. If the price remains the same, but the yield increases with 1 t/ha with an increased production cost of R1 000/ha more, therefore R 8 000/ha, profitability will improve by 12%. It does not necessarily cost R1 000 per hectare more to produce an extra tonne of grain. If the producer succeeds in achieving a tonne per hectare yield increase, as well as a R250 per tonne better maize price, the total profitability can improve by 26.3%.

The grain market (Safex) does offer options to put maize price management into place. Use the opportunities offered by the market, but do this with the advice of a good grain marketer.

Being able to manage yields is the ideal for many farmers, since management practices influences it directly. The value of good and correct advice is often underestimated. But the value of advice that is not limited to just fertilization but which focuses on all agronomic aspects, usually exceeds the value of the fertilizer costs per hectare. The Omnia agronomist is the cornerstone of this process. Agronomic approaches are not only based on assumptions, but on research and development conducted and confirmed over time.

Without research and development, the rate of progress will decline rapidly and this could lead to a situation where more food will have to be imported, which will have negative consequences for the South African economy. To ensure that we do not get behind the rest of the world, Omnia will continue to develop and produce world class products. The primary focus of our research and development is to reduce the farmer’s risk and to ensure that sustainability is not left behind.

Which agronomic aspects can be addressed to ensure that maize reaches its full environmental potential?
Fertilization and liming

Fertilizer can be used with care to manipulate a plant into a certain direction. One of the most important aspects of plant nutrition is to ensure that the right fertilizer product is used. The correct placement of the fertilizer is critical to ensure that plant roots will be able to use the nutrients and convert them into grain. The amount of fertilizer applied has to compliment the potential of the soil and environment. Don’t over or under fertilize, as both are detrimental. Fertilize according to the potential and apply the necessary nutrients at the right time so that the plant can utilise it efficiently.

Addressing the above aspects regarding fertilization should improve the nutrient use efficiency. This means that the amount and type of fertilizer is used optimally and the maximum quantity of grain per unit nutrient produced. If the right type of fertilizer is used, the water use efficiency should also improve. The plant will produce more grain per millimetre of water under dry-land conditions, as well as under irrigation.

Increasing sub-soil acidification is a concern, as it could be detrimental to the long term profitability of maize, especially on sandy soils, unless it is corrected.

Graph 1: shows an example of sub-soil acidification.

Graph 1 gives an indication of the impact sub-soil acidity can have on maize production. Optimal root growth and development can be restricted at a pH (KCl) of lower than 5.5. A low soil pH is also associated with a high acid saturation percentage (aluminium toxicity), but often also with a low calcium and magnesium supply. In the specific example the pH (KCl) levels were changed to 5.8 in the topsoil (0-200 mm) and 4.7 in the sub-soil (300-500 ml) one year after the correct type and quantities of lime were applied.

Sub-soil acidity is seldom corrected after a short period and it has to be monitored regularly. Nitrogen fertilizer has to be applied with care as band placing large quantities could promote sub-soil acidity, depending on the nitrogen source. Decrease the pre-plant application and try to apply a portion of the nitrogen fertilizer as a topdressing. This will also improve nitrogen use efficiency.

Crop rotation

Crop rotation is definitely an important component of successful grain farming. It is, however, not always possible as the crops which could be used in rotation are not always suited to the soil type or cultivation system. To realise the extra tonne of yield referred to earlier in this article, crop rotation is one of the essential practices to consider. Choose the rotation crop carefully to ensure a positive reaction on the subsequent maize yield. Crop rotation can also be beneficial in reducing disease or weed pressure.


Soil should be cultivated just enough to ensure maximum yields for a particular season. Soils vary, and an operation that is successful in one place will not necessarily work on the next farm. Therefore, first examine the soil and then determine how it should be cultivated. Cultivation should primarily promote moisture conservation and good root development, but without exposing the soil to erosion, for example.

To ensure that the soil on your farm reaches its full potential, please contact your nearest Omnia agronomist.

Best wishes for the 2016-2017 season. May it be a blessed one!