23 August 1996

Control your contractor…

Seminars at this years event are looking at Managing the Maize Harvest: the mechanics and the product. Our preview starts with some advice from MGA member Norman Light on how to get the most out of contractors.

MAIZE is a crop that has a wide harvesting window. Compared with grass, it is a matter of weeks not days before the D value starts to drop.

Only after a frost is there a rapid reduction in quality. It is important the clamp is filled fast to stop the on-set of aerobic spoilage. For this reason alone, it is a crop best harvested by contractor, so that long days are worked, with high output.

We have been clearing about 16ha (40 acres) a day, yielding 45t/ha (18t/acres) – a total of 80 trailer loads a day. Our contractor has now purchased a larger machine, averaging over 24ha (60 acres) a day. This means a 10t load is arriving at the clamp every five minutes.

With over 162ha (400 acres) to harvest, we have often thought of buying our own machinery to do the harvesting. But getting a return on the capital required, and extra labour needed for such a short time, would prove uneconomical for us.

What do you want your contractor to do?

On a small farm with very little labour it is best to get him to do the whole job.

Tell him where the field is, where the clamp is and where he can find the sheet to cover it down before he leaves the farm. That is the highest cost an acre, but the least trouble.

When you have tractors and trailers that can be spared for full days at harvest, these can be used and reduce the price. If you have an industrial loader, you could use that on the clamp.

On our farm we do the carting, getting neighbours to help, then we help them in return. We do the covering down and provide a tractor for rolling on the clamp as it is being filled.

What is the area to be harvested?

This is where trouble starts. Is it the area on the map, the area claimed for IACS, or the area recorded on the drill?

As the IACS area and the drilled area tend to be the same, it makes sense to agree that before the start. Farmers have a reputation for making fields smaller when a contractor is doing the work. If you cheat them on this, they will get their own back before they leave.

When do you want the crop harvested?

It helps both the farmer and the contractor to have some idea. We try to give at least a weeks notice of when we want to start.

We grow some early varieties of maize, to be followed by grass, which is harvested first. Late varieties are harvested after we have got the grass seed and winter cereals sown. When you are on heavy soil, it is better to get the crop in the clamp than have tractors stuck in the field.

Who is paying for the fuel?

Are the contractors filling up from your tanks, or bringing their own? It takes about 18 litres in total to harvest an acre of maize. This can make £2-£35/acre difference in what is charged.

Chop length

This is the most important part of harvesting. It has more effect on clamp management and animal performance than all the other points put together.

A contractor can reduce this cost and save fuel by not chopping the crop well. Indeed, they can increase the output of their machine by 15% a day, just by chopping it longer. Research in France on chop length has shown that 90% of the crop being chopped to less under 2.5cm (1in) will increase milk yield by 9% and also improve quality.

The difference a contractor can make on chop length will cover the cost of harvesting the maize crop.

My contractor sharpens and resets his cutting blades three-times-a-day, and turns his shear bar regularly. He pays £5 if you can find a whole grain in a trailer load of maize. Will your contractor offer you the same?

What height do you want the crop cut

The higher it is cut, the faster a contractor can go. Research work completed by the Maize Growers Association has shown that raising the cutting height from 10cm (4in) to 38cm (15in) increases the dry matter and starch by 4% but reduces the yield by 5%. The stubble left behind had a feed value equal to straw. So when short of food cut the lot, when you want quality cut a bit higher.

Missing the trailer

Some forage harvester drivers seem to take delight in missing the trailer to show how far they can blow the crop. It is annoying to see all you effort for the year being wasted.

Mud on the road

It is the responsibility of the person who put it there, to clear it up. Is your contractor well insured to cover any claims should there be an accident?

Soil erosion is a problem on sloping fields, and all wheel tracks lead to the gate. It is the farmer who is responsible to stop soil getting into the road. To avoid a £20,000 fine, as soon as the crop is off, cultivate across slope or plough the headland inside the gate.

When very wet it helps to clear only a bit of headland at a time. Fields drain much better with the crop on them, than after having driven over it.

Filling the clamp

Spreading the maize thinly over the clamp all the time, not in waves or lumps, helps consolidation. Roll, roll, roll all the time. That is important.

Aim to walk over the clamp in your shoes, and not sink in far enough for the cap to go inside them. One machine filling the clamp, and a tractor rolling is a must. This will reduce aerobic spoilage once the clamp is opened. The face should be so hard that you cannot get a finger into it. The best additive is your neighbours biggest tractor.n


You want your contractor to:

&#8226 Turn up when agreed

&#8226 Chop the crop small

&#8226 Roll the clamp tight

MGA member and Hampshire farm manager Norman Light takes care to ensure his maize is drilled into the right seedbed. He is also careful to see the mature crop is harvested correctly. "I want a contractor who will come when he says he is coming, chop the crop small, and roll it tight. If he will not give me the chop I want, then I will give him the chop."

Spreading the maize thinly over the clamp all the time, not in waves or lumps, helps improve consolidation.

Are you getting the chop length you want. Its the most important part of harvesting and it could make a big difference to milk yields and profit.