GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 Root development and the performance of grapevines in response to natural as well as man‐made soil impediments

Root development and the performance of grapevines in response to natural as well as man‐made soil impediments

Abstract

Context and purpose of the study ‐ The majority of soils used for wine and table grape production in South Africa are notoriously shallow, i.e. they are restricting root penetration. The result of such shallow soils is uneven and poor vineyard performance that eventually lead to unprofitable vineyards. The purpose of this study was to investigate soil impediments to root growth, methods to detect such impediments, and practices to alleviate obstructions before planting, as well as in existing vineyards.

Material and methods ‐ Many investigations in South Africa have addressed the reasons for poor grapevine root development and methods to rectify this detrimental factor. This large body of knowledge is not only spread over different generations of researchers and experts, but also fragmented among many articles and journals. Starting with recommendations for “dynamite‐ ploughing” in 1912, all research on soil profile modification was reviewed and a synopsis made regarding soil conditions, root studies, grapevine response and corrective measures.

Results ‐Natural soil compaction is the main cause of root restriction in the majority of vineyard soils in the Western Cape, but man‐made compaction through vehicle traffic and implement use occurs. Acid soils, i.e. pHKCl< 5.5 are commonly found in the coastal areas of the Western Cape. Further impediments to grapevine root penetration include dense clay in the subsoil, various types of hardpan, water tables, rock and sharp transitions between soil layers of different textures. Plant holes incorrectly made can be a serious impediment to root distribution and poor growth of young vines. Penetrometer measurement of soil resistance is the most practical, easiest and quickest method to detect the degree, position and extent of soil compaction. Grapevine root penetration is drastically impeded above 2000 kPa penetrometer readings. The EM38 apparatus that measures the bulk electrical conductivity of the soil, is also increasingly used to determine root restricting layers in the soil. Grapevine root distribution is the most reliable, direct and accurate indicator of soil conditions. Root distribution of grapevines is generally shaped by soil conditions and cultivation practices and not by genetic traits of the rootstock. Scientific root studies in South Africa date back to the 1930’s and include the profile wall method, core sampling, glass wall methods, excavation methods. A recent novel technique employed, is the scanning of roots against the walls of chambers made of perspex. In addition to deep tillage, shallow soils can be improved by ridging while loosening of the inter‐row area is an option in existing vineyards that perform poorly. This should only be done when poor performance is due to soil compaction. Grapevine response to root pruning depends particularly on timing, severity of pruning and the presence or absence of roots in the inter‐row area. 

DOI:

Publication date: June 19, 2020

Issue: GiESCO 2019

Type: Article

Authors

Johan VAN ZYL and Eduard HOFFMAN

Soil Science Department, Stellenbosch University, Stellenbosch, 7602, Republic of South Africa

Contact the author

Keywords

soil compaction; penetrometer; root studies; re‐compaction; root pruning; plant holes

Tags

GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Rapid damage assessment and grapevine recovery after fire

There is increasing scientific consensus that climate changeis the underlying cause of the prolonged dry and hot conditions that have increased the risk of extreme fire weather in many countries around the world. In December 2019, a bushfire event occurred in the Adelaide Hills, South Australia where 25,000 hectares were burnt and in vineyards and surrounding areas various degrees of scorching and infrastructure damage occurred. The ability to coordinate and plan recovery after a fire event relies on robust and timely data. The current practice for measuring the scale and distribution of fire damage is to walk or drive the vineyard and score individual vines based on visual observation. The process is time consuming, subjective, or semi-quantitative at best. After the December 2019 fires, it took many months to access properties and estimate the area of vineyard damaged. This study compares the rapid assessment and mapping of fire damage using high-resolution satellite imagery with more traditional ground based measures. Satellite imagery tracking vineyard recovery in the season following the bushfire is being correlated to field assessments of vineyard productivity such as canopy health and development, fertility and carbohydrate storage. Canopy health in the seasons following the fires correlated to the severity of the initial fire damage. Severely damaged vines had reduced canopy growth, were infertile or had very low fertility as well as lower carbohydrate levels in buds and canes during dormancy, which reduced productivity in the seasons following the bushfire event. In contrast, vines that received minor damage were able to recover within 1-2 years. Tools that rapidly and affordably capture the extent and severity of damage over large vineyard area will allow producers, government and industry bodies to manage decisions in relation to fire recovery planning, coordination and delivery, improving the efficiency and effectiveness of their response.

Leaf vine content in nutrients and trace elements in La Mancha (Spain) soils: influence of the rootstock

The use of rootstock of American origin has been the classic method of fighting against Phylloxera for more than 100 years. For this reason, it is interesting to establish if different rootstock modifies nutrient composition as well as trace elements content that could be important for determining the traceability of the vine products. A survey of four classic rootstocks (110-Richter, SO4, FERCAL and 1103-Paulsen) and four new ones (M1, M2, M3 and M4) provided by Agromillora Iberia. S.L.U., all of them grafted with the Tempranillo variety, has been carried out during 2019. The eight rootstocks were planted in pots of 500 cc, on three soils with very different characteristics from Castilla-La Mancha (Spain). In the month of July, the leaves were collected and dried in a forced air oven for seven days at 40ºC. Then, the samples were prepared for the analysis determination, carried out by X-Ray fluorescence spectrometry. The results obtained showed that in the case of content in mineral elements in leaf, separated by soil type, we can report the importance of few elements such as Si, Fe, Pb and, especially, Sr. The rootstock does not influence the composition of the vine leaf for the studied elements that are the most important in determining the geochemical footprint of the soil. The influence of the soil can be discriminated according to some elements such as Fe, Pb, Si and, especially, Sr.

Current climate change in the Oplenac wine-growing district (Serbia)

Serbian autochthonous vine varieties Smederevka (for white wines) and Prokupac (for rosé and red wines) are the primary representatives of typical characteristics of wines and terroir of numerous wine-growing areas in Serbia. In the past, these varieties were the leading vine varieties, however, as the result of globalization of winemaking and the trend of consumption of wines from widely prevalent vine varieties, they were replaced by introduced international varieties. Smederevka and Prokupac vine varieties are characterized by later time of grape ripening, and relative sensitivity to low temperatures. Climate conditions can be a restrictive factor for production of high-quality grapes and wine and for the spatial spreading of these varieties in hilly continental wine-growing areas.
This paper focuses on the spatial analysis of changes of main climate parameters, in particular, analysis of viticultural bioclimatic indices that were determined for the purposes of viticulture zoning of wine-growing areas in the period 1961-2010, and those same parameters determined for the current, that is, referential climate period (1988-2017). Results of the research, that is, analysis of climate changes indicate that the majority of examined climate parameters in the Oplenac wine-growing district improved from the perspective of Smederevka and Prokupac vine varieties. These studies of climate conditions indicate that changes of analyzed climate parameters, that is, bioclimatic indices will be favorable for cultivation of varieties with later grape ripening times and those more sensitive to low temperatures, such as the autochthonous vine varieties Smederevka and Prokupac, therefore, it is recommended to producers to more actively plant vineyards with these varieties in the territory of the Oplenac wine-growing district.

Towards a regional mapping of vine water status based on crowdsourcing observations

Monitoring vine water status is a major challenge for vineyard management because it influences both yield and harvest quality. It is also a challenge at the territorial scale for identifying periods of high water restriction or zones regularly impacted by water stress. This information is of major importance for defining collective strategies, anticipating harvest logistic or applying for irrigation authorisation. At this spatial scale, existing tools and methods for monitoring vine water status are few and often require strong assumptions (e.g. water balance model). This paper proposes to consider a collaborative collection of observations by winegrowers and wine industry stakeholders (crowdsourcing) as an interesting alternative. Indeed, it allows the collection of a large number of field observations while pooling the collection effort. However, the feasibility of such a project and its interest in monitoring vine water status at regional scale has never been tested.

The objective of this article is to explore the possibility of making a regional map of vine water status based on crowdsourcing observations. It is based on the study of the free mobile application ApeX-Vigne, which allows the collection of observations about vine shoot growth. This information is easy to collect and can be considered, under certain conditions, as a proxy for vine water status. This article presents the first results obtained from the nearly 18,000 observations collected by winegrowers and wine industry stakeholders during 2019, 2020 and 2021 seasons. It presents the vine shoot growth maps obtained at regional scale and their evolution over the three vintages studied. It also proposes an analysis of the factors that favoured the number of observations collected and those that favoured their quality. These results open up new perspectives for monitoring vine water status at a regional scale but above they provide references for other crowdsourcing projects in viticulture.

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.