321-3 Pedogenetic Indicators of Terroir.

Poster Number 1037

See more from this Division: S05 Pedology
See more from this Session: General Pedology
Wednesday, November 3, 2010
Long Beach Convention Center, Exhibit Hall BC, Lower Level
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James Fisher, Soil Solutions LLC, Malvern, PA
Viticultural production systems are highly dependent on the nature of a site's solum and regolith, as well as the intrinsic permeability of the parent material.  Winegrape varieties - especially those of Vitis vinifera parentage - produce higher quality berries when grown in deep, well-drained soils, therefore we use field indicators to detect variance of depth and permeability within blocks.

These characteristics are of notable interest from the perspective of various weathering systems, as the soil production function favors site conditions which promote an abundant flux of weathering reagents supplied to primary minerals.  A mutual significance results from these concomitant criteria, ranging from mesoscale vineyard site selection to global scale weathering systems which can effectually be augmented by vineyard development practices, as follows.

Restrictive horizons such as fragipans can impede soil water flux, leading to reduced flux of reagents to primary minerals; additionally the resultant supersaturated soil solution further reduces the weathering rate due to the relationship between intrinsic permeability of a regolith and the greater ionic strength of the soil solution (White, 2000).

Vertical tillage is an effective means to shatter a fragipan, as well as prepare a vineyard soil for planting; for example the winged tine has become a standard tool in vineyard site development.  When a fragipan is detected in a pre-plant pedology analysis, a ripping depth can be targeted to shatter a restrictive horizon.  While fragipan reformation may be problematic in some instances, a vineyard may provide long-term fragipan prevention due to grapevine morphology and typical vineyard senescence.  Deep grapevine roots can impede fragipan reformation.  Replanting a block every 30 years allows an opportunity to shatter reforming fragipans.  Vertical tillage improves permeability of water and penetration of the grapevine roots.  Weathering rates of the parent material will be enhanced by allowing permeability through a fragipan.  By this logic, viniculture can improve global gas cycling by enhancing weathering systems.

See more from this Division: S05 Pedology
See more from this Session: General Pedology