Winetech Technical Yearbook 2022

PHOTO 10. Finger delve plough on one side and ripper on the other side.

of the lime, phosphate and/or gypsum occurs. An additional tillage action is then required to break the clods, leading to recompaction. • Direction of tillage : The first action is the deepest and must be applied from the highest to the lowest point. This action promotes internal drainability, and sometimes, a cross-action is also required, which must be executed at an angle of approximately 30 - 45° on the first action. • Furrow width and depth : Experience and obs e r va t i ons hav e shown that, where the soils allow it, the maximum movement depth of a toe of most implements is about 900 - 1 200 mm from the surface. It has also been observed that when a toe of an implement moves 1 200 mm deep, for example, the effective mixing of ameliorants only occurs at about 800 - 900 mm from the surface, and not at the total 1 200 mm, despite the toe reaching so deep. Not all implements offer effective downward mixing of ameliorants; a ripper movement without wings achieves no downward mixing – only mix-rip and finger delve plough implements, and to a lesser extent, the rippers with wings or swing-wings (wings on top or behind the toe which can be extended to expand the upward breaking action (“V action”), and more downward mixing takes place). If there is undesirable shallow clay in the subsoil that should not be brought to the

surface, the choice of implements moves more towards the mix rip and rippers with wings and away from implements that offer maximum mixing, like the finger-delve plough, delve plough and excavator. A rule of thumb is that the furrow width should be approximately two-thirds of the cultivation depth. This means a furrow width of 400 - 500 mm should be used if the cultivation depth is 600 - 700 mm. When the soil only has to be loosened, the maximum recommended furrow width is 750 mm (and never further), but if large amounts of lime have to be applied and the cultivation depth is 1 200 mm, the furrow width has to be adjusted not to exceed 550 - 650 mm, as to enable proper downward mixing of ameliorants. A too narrow furrow width is, however, too expensive. If the furrow width and the soil water status during preparation are correct, the soil should be even enough after preparation, so no further levelling is necessary. To prevent compaction after soil preparation, no tractor traffic should occur until after the vineyard has been established. After that, tractor traffic should be limited to the centre of the work row. Correct soil preparation before vineyard establishment is essential to the long-term success of the vineyard. There is no one size-fits-all approach; soil preparation choices should be made in conjunction with a soil scientist who has the necessary knowledge and information at their

disposal. Given the establishment costs per hectare, incorrect soil preparation actions for even one or two hectares can lead to massive potential financial losses over time. Therefore, an investment in correct soil management is an investment in your future. REFERENCE https://www.wineland.co.za/soil-preparation-think before-you-do/

For more information, contact Johan de Jager at johan@vinpro.co.za.

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WINETECH TECHNICAL YEARBOOK 2022