Maize

Quick Facts

Maize can be grown as a cash crop for sale to livestock farmers. It is a high yielding quality forage crop that is transportable and can be ensiled.
While improved varieties cope better with our climate, maize yield and consequently its production cost per tonne are variable depending on seasonal weather variation.
While polythene mulch cover increases yield and starch levels, production is still better in southern and eastern areas.
Maize is a good break crop in rotations boosting subsequent cereal crop yields.
Contract maize production is restricted by the unavailability of well-defined feeding quality descriptors and associated contract payment systems.

Maize (Zea mays) is a monocot plant (cereals/grasses) which is native to central America but is now grown world wide from latitudes of 58N to 40S.
While maize is a C4 plant which is most efficient producing starch/sugars in hot dry climates, it has been the subject of intense breeding effort and is now well adapted to more temperate climates for forage production.
Maize is a high-input crop requiring high levels of fertiliser and appropriate weed control. Depending on climate and weather, pests and diseases can be problematic.

In the Irish climate, the conserved forage market is the only economic outlet for maize currently. Maize is grown as a forage crop, cut with a forage harvester and ensiled in anaerobic conditions to promote a stable acidic fermentation.
Forage maize is a high energy, low protein feed which can bring some synergistic performance benefits in diets when fed with grass silage.
While much of the maize crop is grown by livestock producers for consumption by their own stock, there is a market for maize produced by crop growers for subsequent sale to livestock producers. This allows livestock producers to import additional high quality feed onto their farms, effectively allowing expansion of their enterprise. As a forage, it is less expensive to harvest and transport than grass silage.

The continuing development of early maturing maize varieties makes economic production feasible in many areas of Ireland. Currently the geographical area south east of a line from Dundalk to Bandon is best suited for maize. While maize can be produced outside of this geographical area, the economics of production become more marginal.
Covering maize with a polythene mulch will accelerate early growth and improve yield, dry matter level and starch content. While expensive, it will cover the extra costs in most situations. While the use of polythene mulch in marginal areas will improve yields, because of its cost it may not improve the profitability of production in these areas.
Because of the somewhat marginal suitability of our climate for maize production, seasonal climate variations can impact significantly on maize yield and maturity with both polythene covered and open crops. This results in a variable production cost and creates challenges for feed budgeting.
The single annual harvest and better transport density than grass silage make a maize a suitable forage for importing onto expanding livestock farms with limited farm scale. This offers an opportunity for contract production.

While maize is a grass family plant similar to cereals, it is an effetive break crop for most diseases and gives the subsequent cereal a yield boost similar to other break crops.
In other European countries, where minimum tillage is practiced, there can be a carryover of fusarium from maize to cereal crops. However this is not considered a problem when plough establishment is used.
The different tap root type structure of maize may provide some small benefits to soil structure compared to continuous production of cereal roots.

There is considerable breeding activity internationally with maize. While forage maize in more marginal areas may not be the primary focus, there is a continuing development of cooler climate tolerant varieties; and maize production has expanded greatly in more northerly European countries. In Denmark, maize is largely displacing fodder beet as an annual forage crop.
Over the last two decades there has been a limited amount of production research and a more comprehensive programme of ruminant feeding research. The production research has largely focused on the use of polythene mulch.
There is considerable scope to improve the agronomy of forage maize in the Irish climate through studies on establishment systems, weed, pest and disease control, crop nutrition and harvest and storage technologies.
To facilitate the contract production of maize, rapid and accurate methods of defining feed quality are essential as are secure contracts and payment systems.
A more precise assessment of the role of maize in crop rotations would be beneficial.

Select a suitable site taking into account geographical region and local topography -south facing sites preferred.
Sow when soil temperatures are above 8 C. In most areas, sowing under polythene mulch can proceed from late March, whereas non-covered crops should not be sown before mid-April. Drill approximately 100,000 seeds/ha using a precision seeder.
Insect pests must be monitored post sowing.
Fertiliser requirement is based on soil index for the major elements with modest N but high P and K levels normally required.
Weed control is critical as maize competes poorly with weeds.
Fungal disease attacks can cause yield loss.
Harvest should be correctly timed to optimise yield and quality as the crop matures.