Terroir 2020 banner
IVES 9 IVES Conference Series 9 Soil monoliths, soil variability and terroir

Soil monoliths, soil variability and terroir

Abstract

Aim: The aim of this work is educating people about soil variability and terroir. Soil monoliths are used to educate the wine industry about how to describe a soil profile, interpret the soil formation processes operating in a particular soil profile and consequently the impact of soil properties on vine growth, fruit quality and wine production. Soil monoliths are a permanent artistic tool for educating, research and management of soil variability.  

Method and Results: Soil profiles have a unique genetic combination of layers resulting from physical, chemical and biological processes in a landscape. Soil monoliths are permanent intact visual artistic examples of the changes in a landscape and reflect the history of soil development in unique locations. Three examples are presented from a property on Western Fleurieu Peninsula South Australia. The property is 40 ha, has average rainfall 500 mm, no water supply and elevation ranging from 80 m to 140 m above sea level. It is proposed to establish a portion of the property to bush vines.  Soil monoliths and one open soil pit show the key soil types.  

Soil 1 consists of 40 cm sand over massive yellow-brown sandy clay (Sodosol – Australian Soil Classification).  Soil 2 consists of sandy clay loam over red structured clay mixed with soil carbonate (calcic Red Chromosol – Australian Soil Classification).  Soil 3 consists of dark sandy clay loam over soil carbonate and calcareous weathered shale (Calcarosol – Australian Soil Classification). Planting of bush vines is being considered for Soil 2. This soil is at 90-100 m elevation above sea level with a north-west aspect. There is no water supply and the vines will need to be established dry grown. Readily available water holding capacity (RAW) for the soil is 45 mm and rootzone 60 cm.  This site has a friable angular blocky structured B horizon allow water and vine root penetration. There is no saline soil or major soil carbonate limitation that occurs with Soil 1 and Soil 3 respectively.     

Conclusions: 

Soil monoliths are a permanent intact section of soil that can be used for education, artistic display, research and management of soil changes over time. They can be collected from all parts of a landscape to show soil variability and 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.  Soil monoliths are a permanent, intact representation of soil variability and are useful for education, research and management of soil.  They are artistic and can convey the importance of soil properties in a visual, tactile manner.

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…

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.

Effect of the commercial inoculum of arbuscular mycorrhiza in the establishment of a commercial vineyard of the cultivar “Manto negro

The favorable effect of symbiosis with arbuscular mycorrhizal fungi (AMF) has been known and studied since the 60s. Nowadays, many companies took the chance to start promoting and selling commercial inoculants of AMF, in order to be used as biofertilizers and encourage sustainable biological agriculture. However, the positive effect of these commercial biofertilizers on plant growth is not always demonstrated, especially under field conditions. In this study, we used a commercial inoculum on newly planted grapevines of a local cultivar grafted on a common rootstock R110. We followed the physiological status of vines, growth and productivity and functional biodiversity of soil bacteria during the first and second years of 20 inoculated with commercial inoculum bases on Rhizophagus irregularis and Funeliformis mosseaeAMF at field planting time and 20 non-inoculated control plants. All the parameters measured showed a neutral to negative effect on plant growth and production. The inoculated plants always presented lower values of photosynthesis, growth and grape production, although in some cases the differences did not reach statistical significance. On the contrary, the inoculation supposed an increase of the bacterial functional diversity, although the differences were not statistically significant either. Several studies show that the effect of inoculation with AMF is context-dependent. The non-favorable effects are probably due to inoculation ineffectiveness under complex field conditions and/or that, under certain conditions, AMF presence may be a parasitic association. This puts into question the effectiveness of its application in the field. Therefore, it is recommended to only resort to this type of biofertilizer when the cultivation conditions require it (e.g., very low previous microbial diversity, foreseeable stress due to drought, salinity, or lack of nutrients) and not as a general fertilization practice.

Effects of graft quality on growth and grapevine-water relations

Climate change is challenging viticulture worldwide compromising its sustainability due to warmer temperatures and the increased frequency of extreme events. Grafting Vitis vinifera L.

Amino nitrogen content in grapes: the impact of crop limitation

As an essential element for grapevine development and yield, nitrogen is also involved in the winemaking process and largely affects wine composition. Grape must amino nitrogen deficiency affects the alcoholic fermentation kinetics and alters the development of wine aroma precursors. It is therefore essential to control and optimize nitrogen use efficiency by the plant to guarantee suitable grape nitrogen composition at harvest. Understanding the impact of environmental conditions and cultural practices on the plant nitrogen metabolism would allow us to better orientate our technical choices with the objective of quality and sustainability (less inputs, higher efficiency). This trial focuses on the impact of crop limitation – that is a common practice in European viticulture – on nitrogen distribution in the plant and particularly on grape nitrogen composition. A wide gradient of crop load was set up in a homogeneous plot of Chasselas (Vitis vinifera) in the experimental vineyard of Agroscope, Switzerland. Dry weight and nitrogen dynamics were monitored in the roots, trunk, canopy and grapes, during two consecutive years, using a 15N-labeling method. Grape amino nitrogen content was assessed in both years, at veraison and at harvest. The close relationship between fruits and roots in the maintenance of plant nitrogen balance was highlighted. Interestingly, grape nitrogen concentration remained unchanged regardless of crop load to the detriment of the growth and nitrogen content of the roots. Meanwhile, the size and the nitrogen concentration of the canopy were not affected. Leaf gas exchange rates were reduced in response to lower yield conditions, reducing carbon and nitrogen assimilation and increasing intrinsic water use efficiency. The must amino nitrogen profiles could be discriminated as a function of crop load. These findings demonstrate the impact of plant balance on grape nitrogen composition and contribute to the improvement of predictive models and sustainable cultural practices in perennial crops.

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.