Terroir 2020 banner
IVES 9 IVES Conference Series 9 Soil variability effects on vine rootzones and available water

Soil variability effects on vine rootzones and available water

Abstract

Aim: The aim of this work is educating people about soil variability, vine rootzone depth and readily available water holding capacity. The concept of terroir is readily discussed in the wine industry but many people involved are unable to describe a soil profile and interpret its limitations that impact on vine growth, fruit quality and wine produced. This paper discusses soil physical characteristics important to vine root growth and readily available water holding capacity (RAW).

Background and Results: Identification of the soil texture, structure and coarse fragment content is required to determine a vine rootzone depth and readily available water holding capacity (RAW).  Vine rootzone depths are dependent on soil texture and structure. For example vine roots will penetrate 50 cm into a friable sub-angular or angular blocky clay, but only 30 cm into prismatic, columnar or lenticular clay.  Vine rootzone depths are used to calculate the RAW value (mm) of the soil profile and consequently irrigation management units and design.  Water retention curve data used to calculate RAW values uses the relationship between water content and matric potential (Childs, 1940), which is dependent on soil texture and structure (Hillel, 1982). The predicted rootzone depth and RAW values will therefore be dependent on the changes in a landscape which is part of the concept of terroir.

Three examples of soil profile characteristics from a 40 ha property located on the Fleurieu Peninsula of South Australia are presented:

  • Soil 1 is a yellow Sodosol (Isbell, 1996) with deep sand over massive sandy clay.  The predicted rootzone depth is 70 cm and the RAW value 36 mm.  Vine roots are limited by the massive yellow sandy clay at 40 cm;
  • Soil 2 is a red Chromosol (Isbell, 1996) with shallow sandy clay loam topsoil over friable angular blocky clay and clay soil carbonate in the lower subsoil.  The predicted rootzone depth is 60 cm and the RAW value 36 mm.  Vine roots will colonise 50 cm of the friable clay and will penetrate the soil carbonate in the lower subsoil;
  • Soil 3 is a Calcarosol (Isbell, 1996) with sandy clay loam and 50% calcareous rock fragments to 50 cm, below which is un-weathered calcareous shale rock.  The predicted rootzone depth is restricted by the calcareous rock and the high percentage of coarse fragments reduces the RAW value to 18 mm. 

Conclusions: 

The volume of soil utilised by vine roots and the RAW value are governed by soil physical properties which change with position in the landscape, the concept of terroir.  

Significance and Impact of the Study: Soil profile characterisation is essential to all forms of agriculture and horticulture.  Understanding how soil variability impacts on vine root growth, fruit quality and wine production is the essence of terroir.

DOI:

Publication date: March 17, 2021

Issue: Terroir 2020

Type: Video

Authors

Geoff Kew1*

1Kew Wetherby Soil Survey Pty Ltd, Second Valley, South Australia, Australia, 5204

Contact the author

Keywords

Soil monolith, soil variability, soil profile description, soil horizon, field hand texture, soil structure

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

‘Cabernet Sauvignon’ (Vitis vinifera L.) berry skin flavonol and anthocyanin composition is affected by trellis systems and applied water amounts

Trellis systems are selected in wine grape vineyards to mainly maximize vineyard yield and maintain berry quality. This study was conducted in 2020 and 2021 to evaluate six commonly utilized trellis systems including a vertical shoot positioning (VSP), two relaxed VSPs (VSP60 and VSP80), a single high wire (SH), a high quadrilateral (HQ), and a guyot (GY), combined with three levels of irrigation regimes based on different crop evapotranspiration (ETc) replacements, including a 25% ETc, 50% ETc, and 100% ETc. The results indicated SH yielded the most fruits and accumulated the most total soluble solids (TSS) at harvest in 2020, however, it showed the lowest TSS in the second season. In 2020, SH and HQ showed higher concentrations in most of the anthocyanin derivatives compared to the VSPs. Similar comparisons were noticed in 2021 as well. SH and HQ also accumulated more flavonols in both years compared to other trellis systems. Overall, this study provides information on the efficacy of trellis systems on grapevine yield and berry flavonoid accumulation in a currently warming climate.

Bioclimatic shifts and land use options for Viticulture in Portugal

Land use, plays a relevant role in the climatic system. It endows means for agriculture practices thus contributing to the food supply. Since climate and land are closely intertwined through multiple interface processes, climate change may lead to significant impacts in land use. In this study, 1-km observational gridded datasets are used to assess changes in the Köppen–Geiger and Worldwide Bioclimatic (WBCS)

Analysis of Cabernet Sauvignon and Aglianico winegrape (V. vinifera L.) responses to different pedo-climatic environments in southern Italy

Water deficit is one of the most important effects of climate change able to affect agricultural sectors. In general, it determines a reduction in biomass production, and for some plants, as in the case of grapevine, it can endorse fruit quality. The monitoring and management of plant water stress in the vineyard

Analysis of some environmental factors and cultural practices that affect the production and quality of the Manto Negro, Callet and Prensal Blanc varieties

45 non irrigated vineyards distributed in the DO (Denomination) Pla i Llevant de Mallorca and the DO Binissalem Mallorca were used to investigate the characteristics of production and quality and their relationships certain environmental factors and cultural practices. The grape varieties investigated are autochthonous to the island of Mallorca, Manto Negro and Callet as red and Prensal Blanc as white. All plants were measured for four consecutive years in the main production and quality parameters. Among the environmental factors, the type of soil has been studied, more specifically its water retention capacity, the planting density, the age of the vineyard and the level of viral infection. The presence or absence of virus seems to have no effect on any component studied in the varieties studied. For the white variety Prensal Blanc age is negatively correlated with production and the number of bunches, nevertheless it does not cause any effect on the required quality parameters. However, for the red varieties Callet and Manto Negro, the age of the plantation is the variable that best correlates with the quality parameters, therefore the old vines should be the object of preservation by the viticulturists and winemakers in order to guarantee its contribution to the quality of the wines made with these varieties.

Climate ethnography and wine environmental futures

Globalisation and climate change have radically transformed world wine production upsetting the established order of wine ecologies. Ecological risks and the future of traditional agricultural systems are widely debated in anthropology, but very little is understood of the particular challenges posed by climate change to viticulture which is seen by many as the canary in the coalmine of global agriculture. Moreover, wine as a globalised embedded commodity provides a particularly telling example for the study of climate change having already attracted early scientific attention. Studies of climate change in viticulture have focused primarily on the production of systematic models of adaptation and vulnerability, while the human and cultural factors, which are key to adaptation and sustainable futures, are largely missing. Climate experts have been unanimous in recognising the urgent need for a better understanding of the complex dynamics that shape how climate change is experienced and responded to by human systems. Yet this call has not yet been addressed. Climate ethnography, coined by the anthropologist Susan Crate (2011), aims to bridge this growing disjuncture between climate science and everyday life through the exploration of the social meaning of climate change. It seeks to investigate the confrontation of its social salience in different locations and under different environmental guises (Goodman 2018: 340). By understanding how wine producers make sense of the world (and the environment) and act in it, it proposes to focus on the co-production of interdisciplinary knowledge by identifying and foreshadowing problems (Goodman 2018: 342; Goodman & Marshall 2018). It seeks to offer an original, transformative and contrasted perspective to climate change scenarios by investigating human agency -individual or collective- in all its social, political and cultural diversity. An anthropological approach founded on detailed ethnographies of wine production is ideally placed to address economic, social and cultural disruptions caused by the emergence of these new environmental challenges. Indeed, the community of experts in environmental change have recently called for research that will encompass the human dimension and for more broad-based, integrated through interdisciplinarity, useful knowledge (Castree & al 2014). My paper seeks to engage with climate ethnography and discuss what it brings to the study of wine environmental futures while exploring the limitations of the anthropological environmental approach.