Incorporating Native Prairies into Working Farm Landscapes

View the project final report

• 2010 annual report

Commodities

• Agronomic: general hay and forage crops, grass (misc. perennial), hay

Practices

• Animal Production: feed/forage
• Education and Training: demonstration, extension, workshop
• Energy: bioenergy and biofuels
• Natural Resources/Environment: biodiversity, carbon sequestration, grass waterways, riparian buffers, wetlands
• Sustainable Communities: sustainability measures

Prairies were historically the dominant land use in Iowa, yet today less than 0.1% remain. Examining profit-gaining uses for prairies, in addition to highlighting their environmental benefits, may be an effective means of reincorporating prairie back into the landscape. In this project, we conducted a study that examined prairie plants managed for bioenergy production, wrote an extension publication that described the opportunities and benefits of using prairies in farm landscapes, and helped farmers to establish prairies on their farms that can be used as demonstration sites for other farmers. We found that there is great interest among farmers and landowners to learn more about prairies.

Introduction:

Before European settlement, more than 85% of Iowa’s landscape was tallgrass prairie (Sampson & Knopf 1994). Today, it is estimated that less than 0.1% of Iowa remains as either virgin or restored prairie (Sampson & Knopf 1994). The primary reason for this dramatic decline in prairie is conversion into cropland (Kurtz 2001), the majority of which is currently used to grow two annual crops: corn and soybean (USDA NASS 2008). Environmental advantages of prairies over annual crops include decreased soil erosion (Kort et al. 1998; McLauchlan 2006), decreased nutrient leaching (Donner & Kucharik 2008), more efficient use of soil nutrients through complementary patterns of resource use among diverse species (Skinner et al. 2006), increased wildlife habitat (Parrish & Fike 2005), and increased native plant species richness.

Potentially dramatic changes in agriculture are likely to occur in the foreseeable future. Inexpensive fossil energy will likely become less available as fossil fuel reserves diminish (Deffeyes 2006) and global demand for fossil energy increases (US EIA 2008a). This will necessitate changes in most of Iowa’s agriculture, which is heavily reliant on large inputs of externally derived nutrients and requires large inputs of herbicides or physical weed management (Liebman et al. 2008). Greater development of the carbon trading market will also provide strong incentives to reduce the carbon footprint of crops. The carbon footprint of crops can be reduced both by decreasing the amount of external industrial inputs used to produce the crops and growing crops that are better able to sequester carbon belowground (Tilman et al. 2006). In addition to becoming more environmentally benign, our agriculture will also be expected to produce more products, especially liquid transportation fuels (US House 2007). These changes in agriculture provide a great opportunity to develop cropping systems that are both environmentally beneficial and economically viable. Prairies grown as feedstocks for cellulosic biofuel production are one type of cropping system that can capitalize on these opportunities.

The primary objective of this project was to work with farmers, prairie conservation and farm organizations, and Iowa State University (ISU) Extension personnel to demonstrate and assess the opportunities and challenges of incorporating native tallgrass prairies into working farm landscapes.

The project had five short-term outcomes:

1) determine the effects of prairie functional group identity and diversity and nitrogen fertilization on productivity of prairies grown as biomass feedstocks,

2) disseminate knowledge of prairies grown as biomass feedstocks to farmers and ISU Extension field agronomists statewide through existing extension workshops,

3) inform farmers of the opportunities and challenges of applied uses for prairies on working landscapes through an extension publication,

4) provide tangible demonstration of prairies managed for multiple applied uses through field days, and

5) aid farmers in establishing prairies within their farms.

In the intermediate-term this research was to increase awareness among farmers of the opportunities that are available to incorporate prairies into working landscapes and the compositions of prairies that are best suited to different applied uses. In the long-term we expect that greater exposure to prairies used in working landscapes will prompt farmers to grow prairies on more of the landscape.