price across alternative technology equations for Model I appear to reflect perceived productivity/-
profitability and field-level cost (or productive capacity) effects. Normalized nitrogen prices were
positively correlated with corn acres planted on fields with no structural practices, but with a
smaller and negative effect on corn field acres with either infield or perimeter-field conservation
structures present. Together with the significance of the nitrogen price coefficients for the case with
no structural practices and significant but smaller when infield structures are present, these results
suggest that corn producers recognize field-level productivity/profitability effects of adopting
conservation structures. That is, infield conservation structures are more likely to be adopted on
smaller-sized corn fields, while the scale-effect of nitrogen productivity maintains larger field sizes
for the case with no structural practices present. These results are not surprising given that infield
structures (specifically grassed waterways, terraces, and filter strips) account for nearly 70 percent
of the conservation structure acres on corn fields across the study area. Grassed waterways alone
account for 48 percent of structure acres adopted by conservation program non-participants (fig. 3).
For program non-participants, Model I results imply that higher relative nitrogen prices will
likely result in reduced adoption of conservation structural practices.10 For program participants,
the nitrogen price effect appears to be the opposite of that for non-participants. In other words, for
these producers higher relative nitrogen prices will likely encourage greater program participation,
resulting in an increase in corn-producing acres associated with producer adoption of conservation
structural practices. Even though fewer of the estimated coefficients for program participants are
statistically significant, there individual effects remain important as part of a jointly estimated
9 Phase III CEAP-ARMS data, which included farm-household, operator, and farm economic data, was not used
because of its limited sample size (only 212 observations). This sample size was determined to be insufficient to
estimate the three acreage supply equations for both conservation program participants and non-participants.
10 For program non-participants, the negative nitrogen price coefficients for the infield and perimeter-field equations
indicate the marginal reduction effect in corn-producing acres (associated with a nitrogen price increase) for fields
with the respective conservation technology. At the same time, the positive nitrogen price coefficient (for fields with
no structural practices) implies an increase in corn-producing acres for these fields with a nitrogen price increase.
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