WINETECH Technical Yearbook 2019

PHOTO 4. Johan evaluates the preparation action.

FIGURE 1. Example of a satellite image.

FIGURE 2. Example of an NDVI image.

• To evaluate the effect of the fertilisation programme on the nutrient status of the grapevine. • To evaluate the relationship between the soil nutrient status and the plant’s reaction as an aid to fertilisation management/adjustments. • To d i a g n o s e p r o b a b l e n u t r i e n t deficiencies during the growing season. • It is probably not necessary to sample all the blocks annually. Identify a number of monitoring blocks that are representative of the farm and sample these regularly.

This enables one to build up a history/ norm for the farm. New analyses should then be interpreted in the light of “farm norms”. This will also help producers to understand seasonal variations in analyses. All the above-mentioned aspects impact on the profitability of the farming enterprise, either with regard to production volumes, fruit quality, lifespan of a block or production cos t . Fur thermore these cont r i bute to the ecological sustainability of the farming system, especially by preventing

mismanagement of fertilisation (excessive application). Soil and leaf analyses are a useful tool in the hand of the fertilisation consultant. Based on scientific and economic principles, said analyses should combine the vineyard’s nutrient requirements and production goals in a practical and manageable programme. It is very important to know the physical nature of the soil in addition to its chemical composition in order to give optimal advice about fertilisation. Therefore it is of cardinal importance to make profile pits.

Fertilisation is not spot input, in other words the environment, climate and management system should be taken into account when the programme is drawn up. The programme should also include management of the cover crops. Cover crops play an important role in the accumulation of organic matter in the soil, the improvement of soil health and the conservation of biodiversity. Several local analytical laboratories comply with high standards and provide good service. Also note that the norms being used to interpret the analyses are based