Winetech Technical Yearbook 2022

JUNE

LET YOUR TERROIR GUIDE YOUR FARM PLANNING

IN THE VINEYARD Let your terroir guide your farm planning

MANY FACTORS INFLUENCE THE CHOICES WE MAKE DURING FARM PLANNING. SOME MAY BE A TRADITION, OTHERS COULD BE THE MARKET TREND AND THE MOST POPULAR BY FAR IS WHETHER THE NEIGHBOUR IS DOING IT. UNFORTUNATELY, THESE ANECDOTAL APPROACHES CAN COST THE FARMER DEARLY SINCE THESE CHOICES MAY NEGATIVELY AFFECT THE LONG-TERM PERFORMANCE OF YOUR 20- TO 30-YEAR VINEYARD INVESTMENT. Many factors influence the choices we make during farm planning. Some may be a tradition, others could be the market trend and the most popular by far is whether the neighbour is doing it. Unfortunately, these anecdotal approaches can cost the farmer dearly since these choices may negatively affect the long-term performance of your 20 to 30-year vineyard investment. By Heinrich Schloms, Vinpro Soil and GIS Scientist BY HEINRICH SCHLOMS

WINETECH TECHNICAL YEARBOOK 2022 account when recommending these amendments. Specific amendments and fertilisers, such as lime, phosphate and gypsum, must be calculated and applied Detailed scientific information about your farm’s soil, climate and terrain (natural terroir resources) is a skilled viticulturist’s essential decision support tools, and should not be omitted during farm planning. To achieve a healthy, balanced and homogeneous vineyard block without factors limiting growth and production, you need to take the proper steps and obtain the right advice at least a year before establishment. The following surveys are required to obtain this information: Soil classification will determine the inherent physical properties, limitations and suitability of the soil. This information is vital during vineyard planning decisions, such as choosing rootstock, cultivar, clone, inter-vine planting distance, type and size of trellis system, soil preparation actions, irrigation, subsoil drainage, ridging, mulching and most important, block layout. Consult your local pedologist to assist you with a once-off soil classification survey, ideally for the whole farm to acquire important physical soil information that will guide farm planning for generations to come. This information can also assist significantly before purchasing a farm. Soil sampling and chemical analysis will determine the fertility status of your soil. In addition, the soil scientist will identify nutrient deficiencies, toxicities and antagonisms through chemical soil analysis. Based on this analysis, the soil scientist will prescribe the correct amount of suitable fertilisers to rectify any nutrient deficiencies directly affecting plant growth. Soil amendments, like lime and gypsum, indirectly affect plant growth by improving soil structure, soil pH or helping leach toxic salts out of the soil. The soil scientist should take soil physical characteristics into DETAILED SCIENTIFIC INFORMATION about your farm’s soil, climate and terrain (natural terroir resources) is a skilled viticulturist’s essential decision support tools, and should not be omitted during farm planning. To achieve a healthy, balanced and homogeneous vineyard block without factors limiting growth and production, y u need to take th proper steps and obtain the right advice at least a year before establishment. The following surveys are required to obtain this information: Soil classification will determine the inherent physical properties, limitations and suitability of the soil. This information is vital during vineyard planning decisions, such as choosing rootstock, cultivar, clone, inter-vine planting distance, type and size of trellis system, soil preparation actions, irrigation, subsoil drainage, ridging, mulching and ost important, block layout. Consult your local pedologist to assist you with a once-off soil classification survey, ideally for the whole farm to acquire important physical soil information that will guide farm planning for generations to come. This information can also assist significantly before purchasing a farm. Soil sampling and chemical analysis will determine the fertility status of your soil. In addition, the soil scientist will identify nutrient deficiencies, toxicities and antagonisms through chemical soil analysis. Based on this analysis, the soil scientist will prescribe the correct amount of suitable fertilisers t rectify any nutrie t deficiencies directly affecting plant growth. Soil amendments, like lime and gypsum, indirectly affect plant growth by improving soil structure, soil pH or helping leach toxic salts out of the soil. The soil scientist should take soil physical characteristics into account when recommending these amen ments. Specific amendments a d fertilisers, such as lime, phosphate and gypsum, must be calculated and applied before soil preparation. During soil preparation, these amendments and fertilisers will be worked mechanically into the soil. They are basically insoluble and will not work if applied after soil preparation. The uptake and leaching of certain nutrients cause the soil chemistry to change over short periods of time. Chemical analyses older than three years are deemed useless. Variable-rate application technology (VRT) helps the spreader apply only the prescribed amount of costly fertilisers and amendments in the right place using a GPS. This technology decreases the total amount of fertilisers and amendments needed and reduces the chemical variability of your block. Soil health or microbial diversity is often overlooked, but is essential for healthy vineyards. Most of these microbes occur in the topsoil. Therefore, preserving the topsoil is of utmost impo tance. Improper soil preparation can inve t th s il causing the organic, microbe-rich topsoil to be lost in the subsoil, while the chemical unfavourable, organic poor subsoil is brought up to the surface. Planting inter-row cover crops and adding compost can significantly boost soil health. However, manure additions must be made carefully to avoid the toxic build-up of salts. Analysing topsoil and fine-root s mples for nematode and other pathogens is a wise investment and can influence factors such as rootstock choice. Climate analysis of your location can be done by studying long-term data obtained from the closest weather station. However, the climate varies over short distances due to altitude and proximity to water bodies. Interpolated climate grids consider these factors and better estimate your farm’s climate. Important climate indices, such as growing degre days, mean diurnal temperature range, annual rainfall, rainfall seasonality and maximum growing season temperatures, are essential when choosing suitable cultivars. Combined climate and soil data of the farm will also provide a base for realistic yield estimates for a specific vine/rootstock combination. T rrain analysis maps show visual terrai variability on your farm, which influences the microclimate, soil variability and water movement. Using Geographic Information Systems (GIS), a terrain analysis helps grasp this complex and obscured part of terroir. Digital Elevation Modelling (DEM) uses precise contours to create nd visualise the following seven t rr i elements: 89