Forage-based livestock production is a vital component of the agricultural economies of states in the North Central Region (NCR). This region accounts for 33% of the nation's beef cow herd. The states of Kansas, Missouri, Nebraska, North Dakota and South Dakota alone have 7.5 million head of beef cows, which comprise over 25% of the nation's beef cows; adding the remaining states in the NCR brings that number to over 10 million. This region finishes over 50% of cattle marketed for meat (NASS, 2013). Forages account for 80% of the feed resources consumed by beef cattle and, therefore, represents an extremely important resource to the industry (Bula et al., 1981).

Production of ethanol from corn, oil and oilseed co-products from soybeans, increased worldwide demand for wheat, and high crude oil prices have caused a shift in land use in the NCR. As recently as 1997, perennial forages occupied approximately 106 million acres, or 31% of land classified as farmland in the NCR (NASS, 1997). During the time period of 1997-2013, the acres planted to corn and soybeans in the states of ND, SD, NE and KS increased from 33.6 million to 42.2 million (NASS, 2013), an increase of 25.6%. Much of the increase in land use for corn and soybeans has resulted from the conversion of acres producing perennial forages. Recently, Wright and Wimberly (2013) estimated that 1.3 million acres of rangeland in the western cornbelt region of ND, SD, NE, MN and IA have been converted to corn and soybeans during the time period of 2006 to 2011 (Figure 1 in Appendix A).

In addition to perennial native grasslands and grazinglands with introduced species broken out for grain production, other perennial grasslands with potential for grazing are also being converted to row crop production. Conservation Reserve Program (CRP) lands seeded to perennial native and introduced grasses have been used for conservation and wildlife habitat for almost 30 years; however, recent commodity prices have enticed producers to either remove acres from CRP or to place CRP acres back into row crop production once contracts expired. Reports from the USDA (USDA 2009, 2013) showed that 12.8 million acres of CRP in 14 north central states (Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Montana, Nebraska, North Dakota, Oklahoma, South Dakota, Wisconsin and Wyoming) were set to expire between 2007 and 2012. Out of those 12.8 million acres, only 3.2 million acres were immediately reenrolled, meaning 9.6 million of those acres exited the CRP program when their contracts expired and were eligible for conversion back to row crop production. Some of these acres in Nebraska, South Dakota, North Dakota, Iowa and Minnesota are surely included in the land conversion highlighted by Wright and Wimberly (2013), and the same process is likely occurring in neighboring states. Therefore, summer grasslands with excellent potential to support the north central US cattle herd are shrinking, while croplands with grazable crop residues are increasing. This land conversion process then indicates that greater production or greater harvest efficiency is required of perennial grazinglands in this region to support or enhance the size of the regions cattle herd during the growing season.

Concomitant with the decrease in acres of perennial forages is a decrease in the size of the US beef cow herd. Using the same time period of 2006-2011 as investigated by Wright and Wimberly (2013), the US cow herd declined from 33,253,000 head to 30,864,000 head, a loss of 2,389,000 head (NASS 2006, 2011). During the same period, beef cows in the 12 states of the NCR declined from 11,148,000 to 10,024,000, a loss of 1,124,000 head (NASS 2006, 2011). Therefore, 47% of the beef cows lost in the US during the period of 2006 to 2011 were lost in the NCR. We hypothesize that the reduction in cows in the NCR is directly related to the loss of forage resources in the NCR due to land conversion to row crops such as corn and soybeans. Since 2011, the US cow herd has further been reduced to 29,295,300 (NASS, 2013; Figure 2, Appendix A). The rapid decline during the last two years can be partially attributed to severe drought in the central and southern plains. Any attempt to increase the number of cows in the US will depend on the availability of forage resources.

A major limitation to rebuilding the cow herd in the NCR is increased prices of livestock feeds and forages from hay and pasture. These increases in commodity prices for grain crops have pushed agricultural land values and rental prices to all-time highs. For example, from 2006 to 2013 the price indices for feed grains and hay prices have increased over 200%, whereas the price index for meat animals has increased 41% (NASS, 2013). During this same period, rental rates per animal unit month have increased 24% in the states of ND, SD, NE and KS (NASS, 2013).

In order to maintain or increase the size of the US beef cow herd, improving the use of forage resources in a sustainable manner is essential. We propose to 1) investigate strategies to optimize the sustainable use of the remaining range and pastureland, and 2) expand the use of alternative forages such as crop residues and annual forage crops.

The loss of range and pastureland to cropland will increase the production pressure on the remaining land mass now producing perennial forages. These lands must be managed to efficiently capture the available forage resource, but in a sustainable manner so that long-term degradation does not occur. Harvest efficiency will increase linearly as grazing pressure is increased on pastures; however, individual animal performance will generally decrease with increased grazing pressure (Smart et al., 2010). To maintain animal production, strategies need to be explored to either increase available forage on grazinglands or to mitigate depressed animal gains as grazinglands receive greater grazing pressure. Greater forage production may potentially be attainable on the same land area by methods to shift species composition toward more productive species (Smart and Owens, 2008). Alternatively, strategies that alter the timing and density of animal stocking may enable an increase in animal production without increasing land area used (Owensby et al., 2008; Harmoney and Jaeger, 2011). Furthermore, use of supplements (Griffin et al., 2012; Stalker et al., 2012) and crop residues (Warner et al., 2011) may mitigate any expected decline in individual performance or may enable the capture of greater production other than during the main growing season.

Capturing the expanding forage resources that are available with increased cropping systems is critical to the future of the US beef industry, especially in the NCR. As crop yields increase, so does the non-grain biomass (residues) because the proportion of grain to plant (harvest index) for corn is generally 0.50 or less (DeLougherty and Crookston, 1979), meaning there is at least as much residue produced as grain. However, removal of the residue biomass, whether by grazing or harvest, must be optimized so that land productivity is not compromised long term. It has previously been demonstrated that removal of residue decreases subsequent crop yield (Wilhelm et al., 1986). However, grain yields and residue biomass production have increased dramatically over the past three decades. More recent research demonstrates that removal of residue positively impacts subsequent yields (McGee et al., 2013b), but the response of residue removal on subsequent crop yields differs in irrigated and non-irrigated fields (Weinhold et al., 2013). Therefore, different crop residue management practices may be required depending on environmental and management conditions. Additionally, the use of cover crops is known to improve soil characteristics while producing high quality forage. However, little is known about the impacts of partial biomass removal from cover crops in an integrated cropping-livestock system. Finally, as grain prices change with time, some producers may find it beneficial to integrate annual forages for livestock production into their production system to maximize profit.

Our project addresses priority research objectives established under the guidelines for Multi-State Research Projects of the North Central Regional Association under two broad areas: 1) agriculture production, processing and distribution, and 2) natural resources and the environment. This project will specifically meet the regional objectives to 1) design economically and environmentally sound methods to convert biomass and secondary products into food and nonfood uses, 2) develop alternative agricultural production systems to enhance economic competitiveness in the rural landscape, and 3) develop guidelines for optimal economic, social and environmental management of non-cropped farm and natural ecosystems and for restoration of damaged ecosystems.

This research is critical to the long-term viability of the beef industry because it strives to expand the forage base for beef production both by efficiently utilizing existing grazinglands and by capturing forage resources currently underutilized in crop residues and annual forages such as cover crops. If this research were not conducted, the number of beef cows in the NCR may continue to decline because of limited forage availability. Beef producers would be forced to pay more for forage resources, thereby experience greater expenses, and less profit, until they could no longer compete. Ultimately, forage availability will play a major role in determining the economic impact of the beef industry in rural communities.

This project will be conducted at research stations throughout the Great Plains. Participants have access to experimental pastures, livestock handling and feeding facilities, and laboratories at their respective institutions. The 5-year project will allow for adequate time for an initial investigation into the interaction of biomass removal from cropping systems for livestock production. In addition, researchers at the participating institutions have a history of successful collaborative research through previous committees. The advantages of a multi-state effort include synergistic relationships among multi-disciplinary colleagues at the different institutions, ability to evaluate biomass removal over wide north-to-south and east-to-west climatic gradients, and the ability to disseminate research findings to a broad regional audience. Several project faculty members have cooperative extension appointments and will assist with the dissemination of research findings. The conversion of range and pasturelands to cropland is widespread in these states, and the potential to incorporate beef production into crop production systems is high in each state. The opportunity to expand beef production is great in the states of the NCR because of the biomass resulting from expanding cropping systems. Furthermore, perennial grass forages still encompass a major portion of the NCR; the land area potentially affected by effective management of rangeland and the number of producers benefitted is extensive. Collaborative extension efforts will aid in reaching this broad audience.

The likely impacts from successfully completing perennial grassland work include 1) development of management strategies to increase animal production on fewer grassland acres, 2) knowledge of grazing and management strategies to shift pastures to more productive species, 3) implementation of animal management systems that match timing of forage supplies, and 4) retention of the NCR beef cattle herd on fewer grazed perennial grass acres. Likely impacts from successfully completing crop residue research will include 1) development of guidelines for utilizing low quality crop residues in conjunction with feeding of co-products, 2) implementation of annual forages to increase the forage base and enhance use of crop residues, 3) determination of the sustainable level of use of crop residue for animal and crop production, 4) widespread adoption of feeding co-products and utilizing crop residues by producers, and 5) improved profitability of producers throughout the Great Plains. The economic impact of beef production has been estimated from $1850 to $5200 per cow, depending on whether or not the economic impact of the feeder and finishing sector is separated from the cow/calf sector. If the cow herd were expanded from 29 million head to 33 million head as a result of improved utilization for forage resources through the strategies proposed herein, the economic impact would be estimated at $7.4 billion for the cow-calf sector, and over $20 billion for the beef industry as a whole. Much of the potential to expand the cow herd exists in the NRC because of the potential use of traditional and non-traditional forages in the region.