Integrated Dryland Crop and Livestock Production Systems on the Great Plains: Extent and Outlook

Soil organic carbon levels have declined 24 to 60% on many Great Plains soils since initial cultivation. Integrated crop and livestock systems could help reverse this trend, therefore we examined the extent of use, the factors affecting use, and the potential for this system. The 1992 U.S. Department of Commerce data indicate that land in integrated systems is limited to less than 10% of the agricultural land. However, expiration of the USDA Conservation Reserve Program (CRP) has created interest in integrated systems. Economists report that after CRP contracts expire, perennial forages and livestock systems may be the most profitable; however, a survey of growers indicates that 63% of all CRP acres will go back to crop production. Recent research in Wyoming shows that returning CRP land to production using wheat (Triticurn aestivum L.)-fallow practices quickly degrades soil quality. A doubling of grazing fees would mean an 18% reduction in demand for public land, which could mean more options for CRP acreage after contract expiration. Exemplified successful systems are the Australia wheat-sheep (Ovis aries L.) system, perennial legume-wheat rotation in southern Alberta, grass community establishment on marginal Wyoming cropland, and an alternative (organic) farming system in South Dakota. Benefits include the opportunity for soil quality improvement, economic diversity, and pest control. However, tradition, lack of managerial experience, and necessary alteration in farm-ranch infrastructure may slow adoption. Generally, dryland integrated systems are agriclimatic zone specific, and represent a potential ecologically and economically sustainable form of agriculture. Scientists and producers have to identify and develop appropriate integrated systems that fit the natural resource base. Research QuestionSoil organic carbon levels have declined on Great Plains soils since initial cultivation. Integrating crop and livestock production systems may be one of the ways to halt or reverse this trend. Our objective is to examine the extent, factors limiting more widespread use, and the potential of integrated crop and livestock production systems in the Great Plains. Literature SummaryA 1957 review documented the effects of cultivation on soil carbon and N from 24 Great Plains Research Stations and reported losses of 24 to 60% from soils cultivated for 30 to 43 yr. More recent studies from the Great Plains report similar losses of soil organic carbon with cultivation. The desire to reverse this continuing soil degradation led to the establishment of the USDA Conservation Reserve Program (CRP) and motivated a greater interest in alternative cropping systems. Integrating crop and livestock production systems has been successful in Australia, as revealed by examining the benefits of management alternatives on Australian wheat yields from 1860 to 1980. The decline in wheat production, starting in 1860 continuing until 1900, went from an average of 12.8 to 7.5 bu/acre. The use of superphosphate, fallow, and new varieties, brought production back to previous levels by 1950. The use of legume pasture-wheat rotation systems improved soil quality and mechanization brought production up to 19 bu/acre by 1980. Study DescriptionWe reviewed the literature to share with you information on: (i) the current extent of integrated crop and livestock production systems across the Great Plains; (ii) reasons for renewed interest in these systems; (iii) some examples of integrated crop and livestock production systems; and (iv) limitation and benefits of these systems. Applied QuestionsWhat is the status of integrated dryland crop and livestock enterprise systems on the Great Plains? Based on land census data, if we assume pastured cropland and dryland forages to be part of the integrated production system, they comprise an estimated 6.5% of agricultural land. Some land devoted to dryland perennial forages is probably also rotated to annual crops; therefore, land in integrated dryland crop and livestock production systems may account for about 10% of the agricultural land area in the region. What are reasons for renewed interest in these systems? Expiration of the CRP has created interest in and offered opportunity for integrating livestock management into typical cropland agriculture. Economists report that after expiration of CRP contracts, perennial forages and livestock systems may be the most profitable use of these lands; however, a survey of landowners and operators indicates that 63% of all CRP acres will go back to crop production when contracts expire. A recent study in Wyoming shows that returning CRP land to production using winter wheat-fallow practices will degrade soil quality quickly. A doubling of grazing fees on public lands will Full scientific article from which this summary was written begins on page 187 of this issue. mean an 18% reduction in demand for these lands, which could mean more options for owners of CRP acreage after contract expiration. What are some examples and benefits of integtated dryland crop and livestock systems? Some successful systems are exemplified by the wheat-sheep system of Australia; perennial legume-wheat rotation in southern Alberta; establishment of productive grass communities on marginal, highly erodible cropland in Wyoming; and alternative (organic) farming in South Dakota. Benefits include an opportunity for soil quality improvement, economic diversity, and pest control that result fiom crop rotation, What are the limitations of integrated systems? Tradition, lack of managerial experience, and infrastructure may slow adoption on the Great Plains. Wells, ponds, and fences for pasture systems may have to be upgraded or installed. Existing paradigms will require modification: less transportation to move feed to livestock and more transportation to move livestock to forage producing lands. SummaryIn general, dryland integrated crop and livestock production systems appear to be agriclimatic zone specific and they represent a potential ecologically and economically sustainable form of agriculture. However, land devoted to these production systems is currently on the Great Plains. Scientists and innovative Great Plains producers should cooperate to identify appropriate systems and then develop integrated systems that fit the variable natural resource base encountered across the Great Plains.