SMAF Case Studies

The effectiveness and applicability of the Soil Management Assessment Framework (SMAF) was tested by applying it to numerous research results. The results from four case studies are shown here. Each of the case studies differs in region, climate, soil, land-use practice, and management goals. The sites were: the 1996 Natural Resource Inventory (NRI) MLRA 9 spanning parts of Idaho, Washington and Oregon; the Deep Loess Research Station near Treynor, IA; the Sustainable Agriculture Farming Systems (SAFS) project near Davis, CA; and two experiment stations in Georgia near the cities of Calhoun and Farmington.

Property	NRI	Treynor	SAFS	GA Exp Station
Scale	MLRA 9	watersheds	large plot	small plot
State(s)	ID, WA, OR	IA	CA	GA
Treatment	multi	conservation tillage	system	compost
Data type	chemical, biological	chemical, biological	mostly chemical	chemical, biological and physical
Published	yes	no	yes	some
Soil suborder	Xerolls, Albolls	Udolls, Orthents	Fluvents, Orthents	Udults, Udalfs
Management goal	environment	production	production	manure management

The inherent properties and management goals (and the available data) for each study site dictated the choice of indicators:

Assay	NRI	Treynor	Treynor	GA Exp Station
Available water capacity				X
Bulk density		X		X
Electrical conductivity			X
Microbial biomass C		X		X
Mean weight diameter	X	X
Soil reaction (pH)	X	X	X	X
Potentially mineralizable N	X	X
Metabolic quotient	X
Sodium adsorption ratio			X
Soil test P	X		X	X
Total organic C	X	X	X	X

Each of these was compared with end point data as available.