A terrible year for maize?

Published 10 August 12

John Morgan from the Maize Growers Association talks about the effect this summer's bad weather has had on the maize crop and what you can do about it.

2012 is turning out to be a truly terrible year for maize, with several individual problems presenting real challenges to both crop yields and quality.

An exceptionally warm March tempted many to drill very early and it was all we could do to hold folk off until April in many cases. The wonderful weather of late March and early April was followed by a wet and cold May, June and to a lesser extent July, with the only weather breaks - in the South West of England anyway - being a week in late May and one in late July.The breaks have allowed grass silage to be made in most cases but have done little to boost struggling maize.

The issues with early drilled maize crops were primarily linked to heavy rain falling on over cultivated seedbeds, with the result that surface capping reduced final plant populations to the extent that some growers were forced to re drill.

All the maize, whether drilled early or late, has suffered from lack of heat and the wet cold soils in which its sits. Crops have struggled all through, looking yellow and hungry. Yield assessments and forage plans have been the order of the day, particularly while the option of making wholecrop cereal silage to fill the forage gap remains available.

The warmer and thankfully drier weather of late has at last started to make a difference. However the significant leaching of nitrogen during the cold wet weather and lower than normal nitrogen mineralisation due to the low soil temperatures is still causing problems. Crops are now yellowing as their roots are not sufficiently developed to get to the deep nitrogen within the soil. 

So what is to be done? First off it is time to work out what your crops are likely to yield. Plant population tables are available and using these, alongside an allowance for weather-related yield reductions, a total crop yield can be estimated.

Options to fill this gap are wholecrop cereal silages or other moist feeds. It is generally far better to identify and sort out forage shortages now rather than during the winter when they will be a lot more expensive to rectify.

The next step is to assess what can be done to boost maize yields. As previously noted, the issue is lack of nutrient as a result of leaching and low mineralisation.  One obvious option therefore is to fertilise the crop. 

But there are risks involved.Nitrogen applied now will take a day or two to become available which, with some crops starting to tassel already, may have limited impact. Further complications arise when the risk of nitrogen scorch is considered. The scorch risk is least with liquid nitrogen. You could alternatively consider a small application of slurry!

Whatever route you take it is likely that the maize silages harvested this autumn will either be late or, if harvested on time, immature. Late harvest of maize presents challenges in relation to what to feed cows in the interim as well as the potential soil structure damage issues.

Immature maize has the potential to be low in starch and quite acidic. Care needs to be taken when drawing up rations to consider these characteristics.

All in all, 2012 is year that maize growers will want to forget, a year to put behind them but also one to learn from. The lessons are primarily to do with over cultivation of seedbeds, early yield estimation and the impact of nitrogen leaching.