Sustainable viticultural production, optimising soil resources

Abstract

A set of soil sustainability criteria relating to vine performance was sought by this project which was able to describe soil constraints to vine performance and suggest management systems for groups of soils with similar implications for production.

Summary

The fundamental interest of the investigation was how soil physical and chemical properties affected root growth, examining available water, soil texture, soil strength, aeration, drainage, chemical barriers and nutrient deficiencies, salinity, sodicity, nutrient status, organic matter and other factors. Field trials covered long-established and newly-planted vineyards, various vineyard floor management regimes and soil types ranging from rendzinas and duplexes to sands and dark cracking clays.

Compaction exacerbated by vineyard practices plus naturally hard-to-penetrate B layers were found to be major root-limiting factors while sodicity and waterlogging could work against healthy root performance during the growing season. Another limitation could be excessive summer heat, found to inhibit growth near the surface in vertisols (cracking clays). Assessment of different practices revealed that location and type of soil were very important. Deep ripping of compacted horizons and use of gypsum to improve structure were widely justified but high evaporation from mounding meant a recommendation to not mound in warm climates particularly where irrigation water was limited. Another strong recommendation was to care for cracking clays by limiting tillage and traffic to lessen the risk of reducing storage of available water.

Valuable outcomes from the project for vineyard managers have been categorisation of vineyard soils and guidance for sustainable management.