|
Following each
measure on this table are three symbols indicating the availability
of data for the measure, the degree of definition or agreement among
project participants on the measure, and whether there are legal, regulatory,
or other thresholds against which the measure can be compared.
Data availability
ratings (  ,
 ,
or  )
indicate whether there are data that are national in scope and provide
historical trends (),
whether there are data with either geographic limitations or a lack
of historical data ("data with significant gaps" - )
or no data ().
The introduction and summary of findings includes additional discussion
on data availability.
Definition or
agreement ratings ( ,
or  )
indicate whether project participants believe the measure is clearly
defined or whether additional concept development is needed. In addition,
there were some cases in which project participants did not reach agreement
on a specific measure. Measures requiring additional conceptual development
or which are the subject of disagreement are marked with a ;
others with a .
The final rating
(
or  )
indicates whether a measure has a societally-recognized threshold against
which a measure may be compared. The only such measure for croplands
is nitrate in streams, for which there are drinking water standards.
Most measures have no such reference point, and are marked with a zero
().
| |
Property
|
Measures
|
Data
Availability
|
Data
Quality
|
Societal
Threshold
|
| System
Dimensions |
Extent |
Total
cropland area |
|
|
|
| Area
of prime farmland |
|
|
|
| the
Cropland Landscape |
Rapid
development and high quality farmland
|
|
|
|
| Cropland
areas planted to grass or trees |
|
|
|
| Wetlands
on croplands |
|
|
|
| Average
size of farm fields |
|
|
|
| Conservation
buffer strips |
|
|
|
| Government
Programs Affecting Cropland Use |
Acreage
idled by various federal programs |
|
|
|
| Lands
subject to soil conservation restrictions |
|
|
|
| State
and local farmland preservation programs |
|
|
|
| Human
Use |
Food
and Fiber Production |
Dollar
value of national agricultural output |
|
|
|
| Value
of agricultural production per acre |
|
|
|
| Agricultural
output per unit of inputs |
|
|
|
| Recreation
(and Other Uses) |
Acreage
of land where recreation is allowed |
|
|
|
| Percentage
of farm income from recreation |
|
|
|
Ecosystem
Condition
|
Crop
and Livestock Yield |
Yields
of major crops |
|
|
|
| Calories
produced per acre of harvested land |
|
|
|
| Feed
used per pound of livestock produced |
|
|
|
| Satellite
measurements of overall productivity |
|
|
|
| Soil
and Water |
Soil erosion
|
|
|
|
| organic
matter |
|
|
|
| compaction |
|
|
|
| acidity |
|
|
|
| salinity |
|
|
|
| Irrigated
acreage |
|
|
|
| Water
use per acre of irrigation |
|
|
|
| Acreage
drained |
|
|
|
| Nutrients |
Phosphorous
in agricultural soils |
|
|
|
| Nitrogen
in agricultural streams and ground water |
|
|
|
| Fertilizer
applications and local crop needs |
|
|
|
| Manure
production and local crop needs |
|
|
|
| Pesticides |
Pesticides
in streams, ground water, and fish |
|
|
|
| Biological
Community Condition |
See
Cropland Extent; Landscape Patterns; Native Species |
| Native
Species |
Status
and trends in: |
| Waterfowl |
|
|
|
| Grassland
birds |
|
|
|
| Upland
game |
|
|
|
| Pollinators |
|
|
|
| Biological
Invasions, Outbreaks and Disease |
Pest
and disease losses |
|
|
|
| Non-native
agricultural pests |
|
|
|
| Pesticide
resistance |
|
|
|
|
