Planned versus Actual Outcomes As a Result of Animal Feeding Operation Decisions for Managing Phosphorus
- Perry E. Cabota and
- Pete Nowak *b
- a Department of Biological Systems Engineering and Nelson Institute for Environmental Studies, University of Wisconsin-Madison, 420 Agriculture Hall, 1450 Linden Drive, Madison, WI 53706
b Department of Rural Sociology and Nelson Institute for Environmental Studies, University of Wisconsin-Madison, 420 Agriculture Hall, 1450 Linden Drive, Madison, WI 53706
The paper explores how decisions made on animal feeding operations (AFOs) influence the management of manure and phosphorus. Variability among these decisions from operation to operation and from field to field can influence the validity of nutrient loss risk assessments. These assessments are based on assumptions that the decision outcomes regarding manure distribution will occur as they are planned. The discrepancy between planned versus actual outcomes in phosphorus management was explored on nine AFOs managing a contiguous set of 210 fields in south-central Wisconsin. A total of 2611 soil samples were collected and multiple interviews conducted to assign phosphorus index (PI) ratings to the fields. Spearman's rank correlation coefficients (r S) indicated that PI ratings were less sensitive to soil test phosphorus (STP) levels (r S = 0.378), universal soil loss equation (USLE) (r S = 0.261), ratings for chemical fertilizer application (r S = 0.185), and runoff class (r S = −0.089), and more sensitive to ratings for manure application (r S = 0.854). One-way ANOVA indicated that mean field STP levels were more homogenous than field PI ratings between AFOs. Kolmogorov–Smirnov (K–S) tests displayed several nonsignificant comparisons for cumulative distribution functions, S(x), of mean STP levels on AFO fields. On the other hand, the K–S tests of S(x) for PI ratings indicated that the majority of these S(x) functions were significantly different between AFOs at or greater than the 0.05 significance level. Interviews suggested multiple reasons for divergence between planned and actual outcomes in managing phosphorus, and that this divergence arises at the strategic, tactical, and operational levels of decision-making.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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