Evaluating Forage Quality Predictors and Grazing Calendars for Restored Prairies In Iowa.

As native ecosystems are under increasing pressure to be brought into crop production due to rising crop prices, making native plants and ecosystems profitable becomes essential to maintaining native plants and corresponding ecosystems services on the Iowa landscape.  Grazing native plants provides an economic incentive to keep native plants on the landscape, but also has the potential to provide forages during the summer when cool-season pastures are less productive.  Currently, little agronomic information exists for farmers and land-managers that are interested in grazing native plants in Iowa.  To address the lack of available information, we are creating a grazing calendar for mixed forb and warm-season grass prairie, warm season grassland, and oak-savannah restorations.  The grazing calendars for each ecosystem are being compiled based on bi-monthly forage sampling for dry matter yield and quality in 2010 and data that will be collected in 2011.  To assess the agronomic and livestock production viability of grazing cattle on native plant communities, livestock nutrition calendars will be estimated for possible livestock scenarios and compared to the forage quality and availability calendar.  To better understand quality changes throughout the growing season, quality parameters will be correlated with day of year and growing degree days in 2010 and 2011.  We hypothesize that the forage quality and availability calendar will not meet season long livestock nutrition needs, but that at one or more weeks during the season grazed native plants will meet nutrition needs.  We also hypothesize that growing degree days will be a significant predictor for forage quality parameters.