VAST

Description

This is a single-user, non-commercial unlimited license. Not for Resale or Commercial Use.
For Commercial use please inquire. 

Overview: Soil water stable aggregates are formed and destroyed in relation to texture, mineralogy and man-made forces such as cropping and tillage.  The presence of aggregates indicates desired features like soil resistance to dispersion and erosion and correlates with positive traits like aeration and water infiltration. Solvita VAST enables rapid, visual recognition of the presence and relative quantity of these water stable aggregates by an innovative, volumetric wet dipping method that originate in Woods End Labs.

Application: This stand-alone procedure may be performed by anyone after basic instruction and without additional laboratory equipment. It is very suitable as a field test and teaching aid and for screening large numbers of plot and farm soil samples. It may also be employed under license arrangement in commercial soil labs which previously have had no means to represent viable aggregates in a cost-effective manner.

The process includes use of air-dried, sieved non-machine-ground soil. There is no reason why field moist soil could not also be used. VAST gives results in terms of soil volume occupied by aggregates, which is a different way then expressing it as percent of dry weight as used in other methods.  After running the steps of the test, requiring about 3 minutes, results are determined with assistance of a software utility that calculates relative volume surface areas and also determines replicate variance.

COMPARISONS: Studies have shown that VAST correlates positively with other wet-sieving gravimetric tests, some of which are considerably more laborious to obtain the level of precision suggested. These comparisons have been run by Land Grant Universities and include Eijkelkamp Wet-Dipping, OSU Comprehensive Wet Size-Sieving and Cornell simulated rainfall.

Contents: Solvita VAST Basic protocol includes the following components:

• Calibrated Volume soil scoop
• Standard Reference Soils with low and high VAST
• 20-MESH concave dipping sieve with calibration metric
• Volumetric moisture-proof scoring card
• Software to calculate results and print reports
• Instructional video on jump-drive
• 1-year free technical support, updates to method
• OPTIONAL: License Fee for Commercial Use –Please inquire