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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)

Significance

Prairie strips are a new conservation technology designed to alleviate biodiversity loss and environmental damage associated with row-crop agriculture. Results from a multiyear, catchment-scale experiment comparing corn and soybean fields with and without prairie vegetation indicated prairie strips raised pollinator and bird abundance, decreased water runoff, and increased soil and nutrient retention. These benefits accrued at levels disproportionately greater than the land area occupied by prairie strips. Social surveys revealed demand among both farm and nonfarm populations for the outcomes prairie strips produced. We estimated prairie strips could be used to improve biodiversity and ecosystem services across 3.9 million ha of cropland in Iowa and a large portion of the 69 million ha under similar management in the United States.

Abstract

Loss of biodiversity and degradation of ecosystem services from agricultural lands remain important challenges in the United States despite decades of spending on natural resource management. To date, conservation investment has emphasized engineering practices or vegetative strategies centered on monocultural plantings of nonnative plants, largely excluding native species from cropland. In a catchment-scale experiment, we quantified the multiple effects of integrating strips of native prairie species amid corn and soybean crops, with prairie strips arranged to arrest run-off on slopes. Replacing 10% of cropland with prairie strips increased biodiversity and ecosystem services with minimal impacts on crop production. Compared with catchments containing only crops, integrating prairie strips into cropland led to greater catchment-level insect taxa richness (2.6-fold), pollinator abundance (3.5-fold), native bird species richness (2.1-fold), and abundance of bird species of greatest conservation need (2.1-fold). Use of prairie strips also reduced total water runoff from catchments by 37%, resulting in retention of 20 times more soil and 4.3 times more phosphorus. Corn and soybean yields for catchments with prairie strips decreased only by the amount of the area taken out of crop production. Social survey results indicated demand among both farming and nonfarming populations for the environmental outcomes produced by prairie strips. If federal and state policies were aligned to promote prairie strips, the practice would be applicable to 3.9 million ha of cropland in Iowa alone.

Footnotes

  • ?1To whom correspondence should be addressed. Email: lschulte{at}iastate.edu.

Freely available online through the PNAS open access option.

Online Impact

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