ownership perceptions, where farms with higher ownership rates are hypothesized to be more likely
to allocate smaller parcels of cropland to working-land conservation structures. Field management,
specifically the use of a crop rotation plan for the field, is hypothesized to capture the marginal
effects of farm operator concerns with longer-term crop productivity for the field.
Four covariates were included in Model II to capture the influence of site-specific
environmental attributes, including the use of surface drainage structures, the occurrence of gully
erosion on the field, whether the field was adjacent to a water body, intermittent stream or wetland,
and whether the farm operator expressed a concern with improving the quality of nearby fish or
wildlife habitat. Surface drainage and gully erosion are likely indicators of field-level soil fragility.
Covariates identifying the proximity of a field to nearby water sources and producer concerns for
fish and wildlife are likely indicators of conservation structures installed to improve offsite
environmental benefits.
Both models were estimated using the integrated Phase II/NRI 2005 CEAP-ARMS data for
corn (380 field/farm observations representing 39 million planted corn acres across the 4 surveyed
States).9 Weights were provided by USDA’s National Agricultural Statistics Service.
Empirical Results
Estimated GEE coefficients for Model I and their significance tests indicate that relative
prices do explain producer choices in allocating field acres between corn production, and infield and
perimeter-field conservation structural practices (table 2). It is not surprising that estimation results
demonstrate stronger statistical significance across coefficients for conservation program non-
participant equations, since these producers accounted for 86 percent of the farms growing corn
across the study area in 2005. For program non-participants, estimated coefficients for nitrogen
8 State-level average input/output prices for 2005 were USDA National Agricultural Statistics Service statistics
acquired through the Market & Trade Economics Division, ERS, USDA.
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