Conservation Practices in Iowa: Historical Investments, Water Quality, and Gaps

t o g e t h e r a n d f o r me d a p a r t n e r s h i p t o s u p p o r t a n i n i t i a t i v e t o a s s e s s t h e " s t a t e o f questions: 1) What conservation practices are currently in place in Iowa, what is their coverage, and what is the cost of these practices? 2) What are (and have been) the effects of these practices on water quality? 3) What would it take to improve water quality to obtain specific standards? With datasets available from the U.S. Department of Agriculture and other sources, some economic models, and a hydrological simulation model, the Center for Agricultural and Rural Development (CARD) at Iowa State University undertook the task of answering these questions. To address the first question, CARD gathered county-level data for some major conservation practices with regard to their costs and coverage. A database of county average cost is established for terraces, grass waterways, land retirement, sediment control basins, grade stabilization structures, filter strips, wetland restoration, riparian buffers, contour buffer strips, and nutrient management. We estimated that the statewide cumulative annual cost was about $435 million for seven major conservation practices on 2 the ground and accounted for as part of 1997 and 2004 data-sets. ($37 million for terraces and grass waterways and $397 million for other five practices). [Directly related discussions can be found on pages 155 and 176.] Table 3. Cost of practices currently in place. P Pr ra ac ct ti ic ce e C Co os st t T Te er rr ra ac ce es s* * *annual average of total installation costs divided by the life span of the practice. The assumed life span is 25 years for terraces and 10 years for grass waterways. In order to answer the second question, a widely used biophysical model was utilized to estimate the water quality impacts of land use practices. We undertook the hypothetical experiment of removing all existing conservation practices from the landscape and performing a simulation with the calibrated Soil and Water Assessment Tool (SWAT) model. The resulting water quality values were then compared with the corresponding values of the current baseline results. The difference between these …

[1]  T. Veith,et al.  OPTIMIZATION PROCEDURE FOR COST EFFECTIVE BMP PLACEMENT AT A WATERSHED SCALE 1 , 2003 .

[2]  Marvin E. Jensen,et al.  Operational estimates of reference evapotranspiration , 1989 .

[3]  John R. Williams,et al.  LARGE AREA HYDROLOGIC MODELING AND ASSESSMENT PART I: MODEL DEVELOPMENT 1 , 1998 .

[4]  H. Varian.  A Solution to the Problem of Externalities When Agents Are Well-Informed , 1994 .

[5]  R. Ferguson.  River Loads Underestimated by Rating Curves , 1986 .

[6]  M. Jha,et al.  IMPACT OF WATERSHED SUBDIVISION LEVEL ON FLOWS, SEDIMENT LOADS, AND NUTRIENT LOSSES PREDICTED BY SWAT , 2002 .

[7]  George H. Hargreaves,et al.  Reference Crop Evapotranspiration from Temperature , 1985 .

[8]  V. Singh,et al.  Soil Conservation Service Curve Number (SCS-CN) Methodology , 2003 .

[9]  S. Nusser,et al.  The National Resources Inventory: a long-term multi-resource monitoring programme , 1997, Environmental and Ecological Statistics.

[10]  Timothy A. Cohn,et al.  Load Estimator (LOADEST): A FORTRAN Program for Estimating Constituent Loads in Streams and Rivers , 2004 .

[11]  John B. Braden,et al.  A Dynamic Programming Approach to a Class of Nonpoint Source Pollution Control Problems , 1990 .

[12]  Hayri Önal,et al.  Cost‐Effective Targeting of Land Retirement to Improve Water Quality with Endogenous Sediment Deposition Coefficients , 2003 .

[13]  Jeffrey G. Arnold,et al.  The Soil and Water Assessment Tool: Historical Development, Applications, and Future Research Directions , 2007 .

[14]  Robert M. Hirsch,et al.  Estimating constituent loads , 1989 .

[15]  S. Chiu,et al.  Loading functions for assessment of water pollution from nonpoint sources. Final report , 1976 .

[16]  M. Ribaudo,et al.  Targeting the Conservation Reserve Program to Maximize Water Quality Benefits , 1989 .

[17]  農業土木学会応用水文研究部会,et al.  応用水文 = Applied hydrology , 1991 .

[18]  R. W. Hann,et al.  Optimal Operation of Large Agricultural Watersheds with Water Quality Restraints , 1978 .

[19]  J. Arnold,et al.  SWAT2000: current capabilities and research opportunities in applied watershed modelling , 2005 .

[20]  J. Arnold,et al.  AUTOMATED METHODS FOR ESTIMATING BASEFLOW AND GROUND WATER RECHARGE FROM STREAMFLOW RECORDS 1 , 1999 .

[21]  Kalyanmoy Deb,et al.  A fast and elitist multiobjective genetic algorithm: NSGA-II , 2002, IEEE Trans. Evol. Comput..

[22]  An evaluation of alternative policies for controlling agricultural nonpoint source pollution , 1984 .

[23]  John B. Braden,et al.  An Efficient Algorithm for Non-Point Source Pollution Management Problems , 1994 .

[24]  Dorothea Heiss-Czedik,et al.  An Introduction to Genetic Algorithms. , 1997, Artificial Life.

[25]  C. Priestley,et al.  On the Assessment of Surface Heat Flux and Evaporation Using Large-Scale Parameters , 1972 .

[26]  John B. Braden,et al.  Optimal Spatial Management of Agricultural Pollution , 1989 .

[27]  Christopher L. Lant,et al.  Using GIS-Based Ecological-Economic Modeling to Evaluate Policies Affecting Agricultural Watersheds , 2005 .

[28]  Goldberg,et al.  Genetic algorithms , 1993, Robust Control Systems with Genetic Algorithms.

[29]  Silvia Secchi,et al.  The cost of cleaner water: Assessing agricultural pollution reduction at the watershed scale , 2007 .

[30]  F. P. Kapinos,et al.  Hydrologic Map Units , 1987 .

[31]  Mary Leigh Wolfe,et al.  Cost-effective BMP placement: Optimization versus targeting , 2004 .

[32]  W. H. Wischmeier,et al.  Predicting rainfall erosion losses : a guide to conservation planning , 1978 .

[33]  M. Ribaudo.  Consideration of Offsite Impacts in Targeting Soil Conservation Programs , 1985 .

[34]  Philip W. Gassman,et al.  Water Quality Modeling for the Raccoon River Watershed Using SWAT , 2006 .

[35]  Misgana K. Muleta,et al.  Decision Support for Watershed Management Using Evolutionary Algorithms , 2005 .

[36]  R. Bagnold.  Bed load transport by natural rivers , 1977 .

[37]  James M. Hamlett,et al.  Watershed optimization of best management practices using AnnAGNPS and a genetic algorithm , 2002 .

[38]  Misgana K. Muleta,et al.  Evolutionary algorithms for multiobjective evaluation of watershed management decisions , 2002 .

[39]  R. C. Schultz,et al.  Nutrient and sediment removal by switchgrass and cool-season grass filter strips in Central Iowa, USA , 1998, Agroforestry Systems.

[40]  Bobbi Harrison,et al.  Iowa City, Iowa , 2002 .

[41]  S. Batie,et al.  Using Spatial Information to Reduce Costs of Controlling Agricultural Nonpoint Source Pollution , 1998, Agricultural and Resource Economics Review.

[42]  Marco Laumanns,et al.  SPEA2: Improving the Strength Pareto Evolutionary Algorithm For Multiobjective Optimization , 2002 .

[43]  W. Green,et al.  Studies on Soil Phyics. , 1911, The Journal of Agricultural Science.

[44]  Philip W. Gassman,et al.  Alternative practices for sediment and nutrient loss control on livestock farms in northeast Iowa , 2006 .

[45]  John Duggan,et al.  Implementing the Efficient Allocation of Pollution , 2002 .

[46]  Lothar Thiele,et al.  Multiobjective evolutionary algorithms: a comparative case study and the strength Pareto approach , 1999, IEEE Trans. Evol. Comput..

[47]  V. Singh,et al.  The EPIC model. , 1995 .

[48]  M. Jha,et al.  The Designation of Co-benefits and Its Implication for Policy: Water Quality versus Carbon Sequestration in Agricultural Soils , 2005 .

[49]  W. Montgomery,et al.  Markets in Licenses and Efficient Pollution Control Programs" Journal of Economic Theory , 1972 .