boom sprayer

Lightweight boom sprayer prevents compacting wet soil

The successful farmer is one that can do the right thing at the right time. But this gets complicated when you need to spray fields that are too wet to handle a tractor with a boom sprayer.

For some large commercial farmers the answer is to rent an aeroplane or helicopter to spray the lands.
To prevent this, Mr. Dirk Lesch from the Western Cape in South Africa, built a lightweight boom sprayer with which he could spray his fields and vineyards with herbicide and fungicides in wet conditions, saving his soil and money. The sprayer is drawn by a quad bike.

“The grain sprayer and quad bike is much lighter than a tractor so you don’t have the same problems with compacting the soil that you get when you drive a tractor through wet fields,” he says.

The implement isn’t that different from a traditional grain sprayer that is drawn by a tractor. The cross bar of 10 m has a double frame with nozzles that sit about 500 mm from another. The double frame is to strengthen the hinges, and there are Volkswagen Golf wheels either side of the framework to balance it.

The implement has a tank of 200 L. “You can’t really use a bigger one, since that would make it too heavy for the quad bike,” says Dirk.

Mr. Dirk Lesch’s custom built sprayer and quad bike is lighter than a tractor and doesn’t cause compaction. The sprayer folds so that it is easier to transport and store.

The numbers

Dirk built the sprayer back in 2009 for about ZMK 6900. He bought the metal at a scrap yard and the engine, pump and tank he bought new. The sprayer is oiled annually, the engine is serviced and the nozzles are replaced every second year.

At the moment the cost of using the quad bike and sprayer amounts to about ZMK 15 per hectare. If he had to rent a plane, it would cost him ZMK 75 per hectare. There are farmers who need to use planes twice. That means that Lesch saves about ZMK 30 000 per year when he avoids using a plane for his 200 hectare land.

This is how it works

Corrugated ‘saucers’ are used either side of the sprayer to cause it to push away should it bump into anything. The saucers are about 1,5 m from the framework.

Dirk says this bar can be made wider if you’d like a wider sprayer, but it would make the hinges weaker. Then you’ll need something stronger for a breakaway-action. The sprayer is equipped with a Imovilli-pump which is responsible for the spraying. A Honda petrol engine of about 4 kW moves it forward in the same manner that a power take-off (PTO) would do if a tractor was used (picture below).

The engine and the Imovilli-pump are connected to a gearbox to keep the speed of the engine in line with that of the pump (picture below). “The engine moves at 2 000 r/min to 2 500 r/min, while the pump’s maximum is about 750 r/min,” says Dirk.

A Bertoline flow control system is used to control the sprayer. The control panel sits right behind the quad bike so that it can easily be adjusted. The frame is divided into three – the left, the middle and the right – and valve levers that feed to each of these parts can be opened and closed from the control panel (picture below).

The nozzles spray at 110 kPa to get flow up to about 50 l per hectare. At the moment Dirk can spray about 4 hectares with one tank (picture below).

The framework on which the engine, pump and tank is built, is only 2,5 m wide in order to be able to use the device in vineyards as well. The load is carried by two 15 inch pickup truck tyres that sit about 2 m from another. All the wheels are on springs to minimise bouncing during the spraying process.

Mudguards were attached to the back of the bike to prevent mud splatters onto the. Dirk uses an EZ Guide 250 to monitor the spraying process. It uses satellite technology and shows exactly where the spraying has been done.

Contact: Mr. Dirk Lesch, whatsapp + 2783 655 8274

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