Cotton farming in the Thabazimbi environment recently received a tremendous boost with new mechanised harvesting methods as well as a new cotton mill but, in spite of these advances, a new challenge emerged for the cotton grower: Cotton stubble that remains on the land after harvesting is a different kettle of fish to that of mealies, wheat and even barley rests. These the Thaba farmers are used and can cope with.

However, a cotton plant grows into a virtual small tree in one season and the hard stalk that remains after picking is no friend of any tractor tyre. When doing any form of cultivation after cotton harvesting on lands under irrigation, it is almost a given that a new set of tyres will be necessary. But there is a solution – the Orthman Stalk Puller.

“Apart from hand labour, there is nothing else that can be used to get rid of the cotton stalks,” says Johan de Klerk, a farmer with a few thousand hectares cotton fields.”

“Earlier I tried to remove the stalks with a ripper, but that is actually soil cultivation and demands a powerful tractor which sends your fuel costs sky-high. Then you still have to follow up with a disc before you can really start preparing your land for planting. But the Orthman works fast and is easy on tractor power.”

How the system works

Johan says immediately behind the combine comes a slasher which cuts the dry cotton stalks. He then uses his smallest tractor to tow the 6-row Orthman directly behind the slasher in the irrigation circle. The tractor wheels run between the rows causing no damage.

Johan plants 91 cm (3 ft.) rows because it gives a higher yield en limits boll rot. The Orthman is fitted with a set of paired 61 cm (24”) discs which run on the top of the soil. The pairs are fitted at an angle so that they turn against each other and form a V at the bottom where they run on the top of the soil. They follow the plant rows and the machine sets itself with the aid of the discs. The stalk puller features adjustable row unit down pressure allowing for reliable ground contact, even in rough conditions, and which ensures continuous disc revolutions.

“It is a beautiful sight to see this machine in operation pinching and pulling the residue from the ground, then cutting it – from behind it more or less resembles the wake of a fast motor boat skimming over the water.

“Initially we worked at low speed as you are unsure of what the result will be. Then we found that the higher the speed, the more efficient the action became. The machine works at its best at 12 km/h because it then prevents clogging. When you find that the discs in one row do not pull the stalks properly, it is normally because of wear and tear on the discs preventing them to run tightly against each other at the bottom. This is rectified with a simple re-adjustment. The pulling angle can also be adjusted from straight to an angle with the ground level.”

Johan is using the machine for its second season and says maintenance is minimal. “Orthman use thick extra strong carbon steel for the beams and top quality bearings, a combination that ensures a low incidence of breakages.”

Orthman is known for its strip cultivation equipment aimed at conservation tilling. Because the stalk puller does not disturb the soil, it is an ideal tool in any conservation cultivation system.

AFGRI is the distributor of Orthman equipment in the area. To find the nearest distributorship, or to obtain any further technical information, talk to Brian Nieuwoudt on 076-283-0766 or 012-940-2155 (landline). Also visit the www.orthman.com website to see the stalk puller and other Orthman products in action. There is also a video that can be viewed on www.proagri.co.za.