Wednesday, February 21, 2018

Soil Biological Responsiveness

Soil respiration represents the biological energy inherent in soil systems. While it has become customary to ignore soil biology in fertilizer and fertility budgets, this recurring cycle of respiration represents the absorption and release of massive amounts of carbon which is increasingly recognized to be tied to the productivity of flora and vegetation.

By accurately measuring the magnitude of the CO2 pulse, the Solvita test infers microbial biomass and nutrient delivery potential. By factoring this information into nutrient budgets, it is possible to both reduce chemical inputs and to improve yield sustainability – hence improve net economic yield.

With the new Solvita DCR (Digital Colour Reader), soil test values can be as precisely determined as conventional laboratory CO2-base trap titrimetry or IRGA, without the cost and fussy chemistry of these techniques.

Two procedures to evaluate soil respiration are available:

GROWER TEST: Measurement of a volume of as-is (field moist) soil and reading the results visually by the colorimetric colour chart; the result provides a good estimate of soil quality and the supply of available carbon. Order as Solvita Soil Life test kit (uses lower cost polystyrene incubator jars).

HANEY-BRINTON TEST: The Woods End-USDA quantitative protocol uses pre-dried, weighed soil which is re moistened and immediately measured for 24-hr CO2 burst. The hand-held Solvita spectrophotometer (DCR) is required. The result provides a ppm reading of CO2 release and represents a close approximation of soil microbial biomass. It directly correlates to mineralized nitrogen and phosphorus. The methods of calculation are provided with the procedure. Order as Solvita Pro Soil C+N+P Burst Test Kit (Requires DCR to analyse and uses glass jars).