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Prairie strips improve biodiversity and the delivery of multiple ecosystem services from corn–soybean croplands

  1. Chris Wittec
  1. aDepartment of Natural Resource Ecology and Management, Iowa State University, Ames, IA 50011;
  2. bDepartment of Statistics, Iowa State University, Ames, IA 50011;
  3. cDepartment of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA 50011;
  4. dDepartment of Agronomy, Iowa State University, Ames, IA 50011;
  5. eDepartment of Sociology, Iowa State University, Ames, IA 50011;
  6. fNational Laboratory for Agriculture and the Environment, US Department of Agriculture Agricultural Research Service, Ames, IA 50011;
  7. gNorthern Research Station, US Department of Agriculture Forest Service, Grand Rapids, MN 55744;
  8. hDepartment of Entomology, Iowa State University, Ames, IA 50011;
  9. iDepartment of Natural Resources and the Environment, University of New Hampshire, Durham, NH 03824;
  10. jNeal Smith National Wildlife Refuge, US Fish and Wildlife Service, Prairie City, IA 50228;
  11. kLeopold Center for Sustainable Agriculture, Iowa State University, Ames, IA 50011;
  12. lVan Ryswyk Farms, Mitchellville, IA 50169
  1. Edited by David Tilman, University of Minnesota, St. Paul, MN, and approved August 1, 2017 (received for review December 9, 2016)

  1. Fig. S1.

    Three of the 12 catchments comprising the STRIPS experiment at Neal Smith National Wildlife Refuge showing three of the four treatments: 100% crop (Interim 3), 90% crop and 10% prairie at the footslope (Interim 2), and 90% crop and 10% prairie in multiple contour strips (Interim 1). All runoff within catchments flows to a single outlet that is instrumented with an H-flume (Inset) and automated water sampler (ISCO 6712 with integrated pressure transducer) used to collect surface water measurements. The crop in the year of the photograph is soybean, which is planted in odd-numbered years in this experiment, alternating with corn in even-numbered years.

  2. Fig. 2.

    Multiplicative effects (circles) or their reciprocals (triangles) comparing prairie and no-prairie treatments in the STRIPS experiment. Bars represent 95% CIs. Dashed lines at 1.1 and 1.2 respectively represent the expected response levels for 10% and 20% conversions of annual row cropland to prairie if effects were area proportional.

  3. Fig. S2.

    Multiplicative effects (circles) or their reciprocals (triangles) with 90% (thick line) and 95% (thin line) CIs of prairie versus no-prairie (Top Row), 20% versus 10% prairie (Middle Row), and prairie located in strips versus prairie located in the footslope (Bottom Row) on catchment responses in the STRIPS experiment at the Neal Smith National Wildlife Refuge. The hydrological category includes components that move with water. Reciprocals of the measured responses were used so all beneficial effects appear as larger values. Responses with 90% and 95% CIs crossing y = 1 are not significant at the P = 0.10 and P = 0.05 levels, respectively. Dashed lines at 1.1 and 1.2 represent the expected response levels for 10% and 20% conversions, respectively, of annual row cropland to prairie if effects were area-proportional.

  4. Fig. 3.

    Iowans’ ranked priorities for agricultural programs and policies. Bar length indicates differences in mean responses between populations who live on a farm (n = 130) and do not live on a farm (n = 1,033). Differences significant at the P < 0.05 level are indicated by asterisks.

  5. Fig. 4.

    Distribution of row-crop fields in Iowa with an area ≥10 ha and with a 4–10% slope; boundaries of USDA Natural Resource Conservation Service Major Land Resource Areas (MLRA) (Table S7) are also shown.

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