Why do we persist with planting costly maize on marginal sites?
As planning for the upcoming spring cropping programme is taking place, one of the crops that seems to be in a state of uncertainty is maize. Maize grew very well in 2013 but 2012 was a disaster.
Given that it's a tropical crop trying to grow to potential on a rock in the middle of the North Atlantic, it is only to be expected that results will vary from year to year.
Maize has the potential to produce big yields of very high quality material, and those in other sectors know a lot more about the added benefit of adding maize to a finishing diet. However, it is a very expensive crop to grow and has a very late harvest. It can also be very detrimental to soil structure if harvested in very wet conditions and the build of up problem weeds as a result of continuous maize production is a growing problem.
The general trend in maize production is to cover the crop with plastic. There is a line of thought that maize can be grown in any site, in any location and under any conditions, as long as it's covered with plastic. While plastic covering can have its merits, the environmental footprint of this practice has often perplexed me.
Covering the land with such an energy intensive and non-renewable material such as plastic in order to feed cows is very questionable at the best of times, but using the technology to attempt to overcome a natural impediment for the crop such as poor site selection seems to me to be looking at the problem from the wrong way round.
I looked at the maize variety results from the Department of Agriculture crop variety evaluation trials from 2008 to 2013 and compared the results between the covered and uncovered trials.
The first point to make is that these are completely different trial programmes and really are not comparable at all. They have different protocols, sowing dates, locations and different varieties are used.
That said, these trials are planted in optimum sites and in optimum conditions using optimum varieties for each respective system, so a rough comparison can be made.