Indiana Farm Research Articles

Risk Assessment of Cattle Handling on Pasture Using Work Environment Screening Tool

ABSTRACTWorking with beef cattle in an open area or while on pasture has been shown to expose workers to a high risk of work-related injury. Prior research on this problem has been conducted using mail surveys, interviews, self-reporting of work practices and injury experiences, and summaries of published injury data, including media reports. Prior research on injury prevention has largely focused on worker education in a specific cultural or geographical setting. A pilot study was conducted to test the cross-cultural usability of the Working Environment Screening Tool in Agriculture (WEST-AG), a modification of the WEST, developed for Swedish industrial applications, to assess risk factors associated with farmers working with cattle being raised largely on pasture as compared with cattle raised in confined feeding operations. Swedish and English language versions of WEST-AG were developed and pilot-tested on a convenient sample of eight Swedish and eight Indiana farms that raise beef cattle primarily on pasture. On-site observations were conducted independently by Swedish and US agricultural safety professionals and documented using photography and a 15–risk-of-injury component on an 11-degree linear scale. Comparisons were made between independent observations documented from the Swedish and Indiana application of the WEST, including collective assessment of photographic record, and the results reported. Key findings included (a) a higher level of observed risks on Indiana farms studied as compared with their Swedish counterparts; (b) high levels of worker exposure to cattle, especially mature breeding bulls, on both sets of farms; (c) a higher frequency of self-reported farm-related injuries than anticipated on both Swedish and Indiana farms; (d) substantially different economic, social, cultural, and regulatory forces that influence small-operation Swedish and Indiana beef producers’ decisions regarding adoption of safer work practices, including use of new and safer technology; and (e) differences between the interpretations of the levels or severity of risks observed between the Swedish and US researchers conducting the assessments based upon regulatory and cultural context. Recommendations for enhancing the methodology of applying the WEST-AG to beef production are discussed, along with utilizing the findings to recommend steps to enhance worker safety on small beef farms, regardless of cultural setting. The most significant contribution of this study was to explore the viability of an assessment tool for agricultural workplaces that could be used internationally to enhance worker safety and health regardless of cultural and political differences.

Comparison of export dynamics of nutrients and animal-borne estrogens from a tile-drained Midwestern agroecosystem

Concentrated animal feeding operations (CAFOs) are known to be a source of nutrients and hormones found in surface water bodies around the world. While the fate and transport of nutrients have been studied for decades, much less research has been conducted on the fate and transport of hormones. To facilitate a comparison of nutrient and hormone export dynamics from farm fields, nitrate + nitrite (N), dissolved reactive phosphorus (DRP), 17α- and 17β-estradiol (E2), estrone (E1), and estriol (E3) were monitored in a tile drain and receiving ditch for one year on a working farm in north central Indiana. Repeated animal waste applications led to high frequency detection of hormones (>50% in tile drain; >90% in the ditch) and nutrients (>70% for DRP; 100% for N). Hydrologic variability was found to be a dominant factor controlling export of N, DRP, and E1 to the drain and ditch. Of the estrogens, the temporal trend in E1 export was most similar to that of DRP. Differences in temporal export between P and the other estrogens likely were due to differences in the biogeochemical processes that affect their fate and transport within the agroecosystem. During short periods when the flowrate exceeded the 80th percentile for the year, over 70% of the total mass export of DRP and E1 occurred for the year in both the tile drain and ditch, demonstrating the importance of high-flow events. Therefore, best management practices must be effective during large flow events to substantially reduce transport to downstream locations.

Synergies between cover crops and corn stover removal

The potential harvest of corn stover as a feedstock for biofuels to meet government mandates has raised concerns about the agronomic impacts of its removal from fields. Furthermore, in order to meet these mandates, larger quantities of stover will be required. As a result, increased attention has been placed on sustainable agronomic practices, such as cover crops. While cover crops may offer desirable benefits, adoption comes at a cost. The objective of this study was to determine the extent to which cover crop costs could be compensated by additional stover removal and additional agronomic benefits from the use of cover crops.To meet the objective, we took three distinct approaches: (1) benefit-cost analysis, (2) integrated model analysis, and (3) representative farm analysis using the linear programming model PC-LP. Each approach was a different take on the same issue; however, each provided different information. First, we estimated cover crop costs and agronomic benefits and employed benefit-cost analyses, including stochastic analysis in @RISK. Second, we tested cover crops with stover removal for 24 Indiana farms using PC-LP. Cover crop costs ranged from $81.76/ha to $172.50/ha, with variability being driven by differences in the seeding rate and seed cost. Agronomic benefits included reduced erosion, which was calculated using a newly created integrated modeling system.The mean estimated reduced soil erosion with a cover crop and no residue removal was 0.72metric tons/ha. An analysis of cover crop agronomic benefits resulted in private benefits (on-site) ranging from $91.45/ha to $192.07/ha, and $97.63/ha to $198.27/ha from society’s perspective. These benefits were highly influenced by added or scavenged nitrogen (N) from the cover crop. For sensitivity we eliminated the benefit from added N and reevaluated the results. Without the N credit, benefits ranged from $74.72/ha to $134.62/ha. Benefit-cost analyses when considering the agronomic benefits of cover crops resulted in a range of a net loss of $11.09/ha to a net benefit of $87.32/ha for the private perspective.The integrated modeling system results indicated that, on average, while holding soil erosion constant, an additional 4.01metric tons/ha of stover could be removed if a cover crop were used. Accounting for cover crop costs and stover removal, a benefit-cost analysis suggested that at a farm-gate stover price of $66.14/metric ton, net benefits ranged from a loss of $3.78/ha to a net benefit of $86.93/ha. At a farm-gate stover price of $88.18/metric ton, mean net benefit ranged from $158.81/ha to $249.52/ha.Results from the farm model (PC-LP) indicated that cover crops, along with increased stover removal, impacted crop rotations, increased the total amount of stover harvested, and had the potential to increase farm profits.

Isolation and Characterization of Porcine Epidemic Diarrhea Viruses Associated with the 2013 Disease Outbreak among Swine in the United States

Porcine epidemic diarrhea virus (PEDV) was detected in May 2013 for the first time in U.S. swine and has since caused significant economic loss. Obtaining a U.S. PEDV isolate that can grow efficiently in cell culture is critical for investigating pathogenesis and developing diagnostic assays and for vaccine development. An additional objective was to determine which gene(s) of PEDV is most suitable for studying the genetic relatedness of the virus. Here we describe two PEDV isolates (ISU13-19338E and ISU13-22038) successfully obtained from the small intestines of piglets from sow farms in Indiana and Iowa, respectively. The two isolates have been serially propagated in cell culture for over 30 passages and were characterized for the first 10 passages. Virus production in cell culture was confirmed by PEDV-specific real-time reverse-transcription PCR (RT-PCR), immunofluorescence assays, and electron microscopy. The infectious titers of the viruses during the first 10 passages ranged from 6 × 10(2) to 2 × 10(5) 50% tissue culture infective doses (TCID50)/ml. In addition, the full-length genome sequences of six viruses (ISU13-19338E homogenate, P3, and P9; ISU13-22038 homogenate, P3, and P9) were determined. Genetically, the two PEDV isolates were relatively stable during the first 10 passages in cell culture. Sequences were also compared to those of 4 additional U.S. PEDV strains and 23 non-U.S. strains. All U.S. PEDV strains were genetically closely related to each other (≥99.7% nucleotide identity) and were most genetically similar to Chinese strains reported in 2011 to 2012. Phylogenetic analyses using different genes of PEDV suggested that the full-length spike gene or the S1 portion is appropriate for sequencing to study the genetic relatedness of these viruses.

Divergent Picornavirus from a Turkey with Gastrointestinal Disease

A novel picornavirus, turkey avisivirus (TuASV), was identified from the feces of turkeys (Meleagris gallopavo) with gastrointestinal disease from a farm in Indiana. Its genome organization is as follows: 5′ untranslated region (UTR)IRES-II [VP0, VP3, VP1, 2A, 2B, 2C, 3A, 3B, 3Cpro, 3Dpol] 3′ UTR-poly(A). TuASV shares only 34% (P1), 36% (P2), and 35% (P3) amino acid identities with avihepatoviruses, indicating that it potentially represents a novel picornavirus genus.

Wild Bees Visiting Cucumber on Midwestern U.S. Organic Farms Benefit From Near-Farm Semi-Natural Areas

Wild bees that provide pollination services to vegetable crops depend on forage resources, nesting sites, and overwintering sites in the agricultural landscape. The scale at which crop-visiting bees use resources in the landscape can vary regionally, and has not been characterized in the Midwestern United States. We investigated the effects of seminatural land cover on wild bee visitation frequency to cucumber (Cucumis sativus L.) and on wild bee species richness on 10 organic farms in Indiana. We estimated the spatial scale at which the effects of land cover were strongest, and also examined the effects of nonlandscape factors on wild bees. The visitation frequency of wild bees to cucumber was positively related to the proportion of seminatural land in the surrounding landscape, and this relationship was strongest within 250 m of the cucumber patch. The species richness of wild cucumber visitors was not affected by land cover at any spatial scale, nor by any of the nonlandscape factors we considered. Our results indicate that wild, crop visiting bees benefit from seminatural areas in the agricultural landscape, and benefit most strongly from seminatural areas within 250 m of the crop field. This suggests that setting aside natural areas in the near vicinity of vegetable fields may be an effective way to support wild, crop-visiting bees and secure their pollination services.

Field fertility of frozen boar semen: A retrospective report comprising over 2600 AI services spanning a four year period

Worldwide, greater than 90% of sows are inseminated with fresh semen. Less than 1% is inseminated using frozen semen. Albeit, frozen semen is an effective technology for the transfer of genes between breeding pyramids and also to reliably provide semen for planned matings. Little information exists on the long term use of frozen boar semen in commercial pork production operations. The objective in the present study was to assess application of frozen semen throughout a 4 year period comprising more than 2600 AI services. The frozen semen sourced from a boar stud in Manitoba, Canada. All artificial insemination (AI) occurred on a single 1800 sow farm in Indiana, USA. The sperm-rich fraction was collected and only those collections having ≥80% motility and ≤15% abnormalities were further processed. Semen was prepared for cryopreservation using Androhep® CryoGuard™, packaged in 0.5mL French straws (average 500 million total sperm per straw) and frozen using a programmable freezer (IceCube™). For each frozen ejaculate, a post-thaw quality check was performed. Ninety eight percent of the ejaculates that were frozen showed at least a 50% post-thaw motility and were approved for shipment. For AI, eight straws were thawed (to achieve at least 2.0×109motile sperm) and diluted with 60mL of extender pre-warmed to 26°C. Within 2–5min of thawing, the sows or gilts were inseminated via intra-cervical deposition using a standard AI pipette. Sows and gilts were inseminated three times PM/AM/PM and AM/PM/AM, respectively. Of 2696 recorded services, 2122 (78.7%) of the females farrowed. The mean (±SD) total number piglets born were 12.5 (±3.9). A progressive improvement of fertility over time was observed mainly due to adaptive procedures associated with an introduced technology. In summary, acceptable fertility is possible with frozen semen and has merit for application as a reproductive management tool.

Impacts of drainage water management on subsurface drain flow, nitrate concentration, and nitrate loads in Indiana

Drainage water management is a conservation practice that has the potential to reduce drainage outflow and nitrate (NO₃) loss from agricultural fields while maintaining or improving crop yields. The goal of this study was to quantify the impact of drainage water management on drain flow, NO₃ concentration, and NO₃ load from subsurface drainage on two farms in Indiana. Paired field studies were conducted following the paired watershed statistical approach modified to accommodate autocorrelation. Annual NO₃ load reductions ranged from 15% to 31%, with an overall reduction of 18% to 23% over the 2-year period, resulting from reductions in both flow and NO₃ concentration. Although the study revealed weaknesses in using the paired statistical approach for a dynamic practice like drainage water management, the results of this study support the use of drainage water management as a conservation practice and provide information for decision-makers about the level of benefits that can be anticipated.

Field evaluation of biofilters in reducing aerial pollutant emissions from a commercial pig finishing building

Two elevated-bed, wood-chip biofilters were tested at a commercial pig finishing farm in Indiana for effectiveness in mitigating aerial pollutant emissions. Three wooden sampling chambers were installed to contain and redirect two biofilter-treated and one untreated exhaust streams. Two trials were conducted to test the effects of biofilter thickness, which included 127-mm and 254-mm of media depths. The two biofilters with 127-mm media thickness reduced concentrations of ammonia (NH 3 ) by 31.2% ( p < 0.05) and 18.1% ( p > 0.05), and hydrogen sulfide (H 2 S) by 26.6% ( p < 0.05) and 23.6% ( p < 0.05) in the pit fan exhaust air, respectively. Insignificant reductions of methane concentrations were observed. The biofilters with 254-mm media thickness significantly ( p < 0.05) reduced concentrations of NH 3 by 45.8% and 18.0%, and H 2 S by 42.2% and 27.9%, respectively. Significant reductions ( p < 0.05) of particulate matter (PM 10 ), and total suspended particulate were 62.0% and 89.7% for the 127-mm biofilters, and 62.9% and 96.3%, for the 254-mm biofilters, respectively. Very low inlet PM 2.5 concentrations were detected. Average pressure drops of the biofilters ranged from 29.6 to 57.2 Pa. The empty bed residence times (EBRTs) were 0.3 s and 0.6 s for the 127-mm and 254-mm biofilters, respectively. Frequent maintenance checks to minimise compaction and ensure uniform moisture content were required to ensure minimal pressure drops and maximal aerial pollutant removal efficiency. The biofilters were relatively simple and inexpensive to install. Although the EBRT was relatively short, the biofilters exhibited low to medium mitigation effectiveness. Higher mitigations would be obtained using biofilters with greater media volumes corresponding to longer EBRTs. ► Two elevated-bed, wood-chip biofilters were tested at a commercial pig farm. ► The biofilters were small, but exhibited low to medium mitigation effectiveness. ► Emissions of NH 3 , H 2 S, PM 10 , and TSP were reduced, but not CH 4 and PM 2.5 . ► Average pressure drops of the biofilters ranged from 29.6 to 57.2 Pa ► Performance was affected by media compaction and moisture content.

Cerebral Phaeohyphomycosis due to Cladophialophora bantiana in a Huacaya Alpaca ( Vicugna pacos)

Cerebral phaeohyphomycosis, caused by Cladophialophora bantiana, was diagnosed in a Huacaya alpaca (Vicugna pacos). An 8-year-old, intact male Huacaya alpaca from a farm in Indiana was found dead at pasture and submitted to the Animal Disease Diagnostic Laboratory at Purdue University for necropsy examination. Gross lesions were limited to the cerebrum, which had a 2×2.5×5 cm, well-demarcated, firm, mottled, pale grey to brown-red mass with a granular texture, centered on the left and right cingulate gyri. Microscopically, granulomatous and necrotizing meningoencephalitis with intralesional pigmented fungal hyphae effaced the cerebral grey and white matter of the cingulate gyri. The hyphae were 4-6 μm in diameter and septate, with non-parallel walls and occasional branching. Polymerase chain reaction for the internal transcribed spacer-1 of the nuclear small-subunit ribosomal RNA genes was performed on extracts from formalin-fixed and paraffin wax-embedded sections of cerebrum. Nucleotide sequence analysis of the amplified fragment identified the fungal agent as C. bantiana. This is the first report of cerebral phaeohyphomycosis attributable to C. bantiana in a camelid.

Silk &amp; Venom: Searching for a Dangerous Spider (review)

Reviewed by: Silk & Venom: Searching for a Dangerous Spider Elizabeth Bush Lasky, Kathryn . Silk & Venom: Searching for a Dangerous Spider; illus. with photographs by Christopher G. Knight . Candlewick, 2011. [64p]. ISBN 978-0-7636-4222-8 $16.99 Reviewed from galleys R Gr. 4-7. The title may be worthy of a YA romance novel, but Lasky’s account of arachnologist Greta Binford is actually a closer cousin to the Scientists in the Field entries. After an opening chapter on the characteristics of spiders, readers meet Binford and learn how her childhood on an Indiana farm awakened her interest in nature, how a college trip to Peru honed that interest into a scholarly pursuit, and how a spider infestation at the Indiana statehouse drew her deeper into the the study of the Loxosceles genus. Binford’s effort to trace the migration of Loxosceles from South American to North America (that, at least, is the theory, which she acknowledges might not pan out) leads her to field exploration in the Dominican Republic, where she and her small team of colleagues crawl around market stalls, investigate abandoned buildings, and turn over rocks in search of the elusive Loxosceles taino. Since the book comes to a screeching halt with their success, readers may wonder exactly what will happen with the specimens they bring back to their Oregon lab. Many readers, though, will be so pleased to follow the hunt for the creepy little venomous critter that they may not miss the scientific follow-through at all. Knight’s photographs, a satisfying balance of spider close-ups and working-scientist documentation, are certain to lure browsers. A “Glossary of Spiders” with thumbnail [End Page 283] photos and page references is included, along with an index and list of print and online sources for further reading. [End Page 284] Copyright © 2011 The Board of Trustees of the University of Illinois

Survey on management practices related to the prevention and control of bovine viral diarrhea virus on dairy farms in Indiana, United States

The objective of this cross-sectional study was to describe the application of management practices known to be associated with the prevention of bovine viral diarrhea virus (BVDV) infection on Indiana dairy farms and to determine the extent of BVDV vaccine use within Indiana dairy herds. The population in this study was Indiana dairy producers enrolled under the Indiana Premise ID list by the Indiana State Board of Animal Health ( n = 1600). During the fall of 2008 a questionnaire was mailed to Indiana dairy producers. Returned questionnaires were entered into a database and descriptive statistics were performed. A total of 208 questionnaires were found useful for analysis. Small herds (<100 head) constituted 60% of the sample population, 33% farms were categorized as medium herds (100–499 head) and finally 7% were large herds (>500 head). Most of the herds (68%) acquired their replacements from external sources (open herds); however, preventive measures against the introduction of BVDV into the farm such as purchased animal history, quarantine and BVDV testing were not commonly performed. Even though producers commonly reported the use of BVDV vaccines, not all animals groups were vaccinated within herds. This study highlights the aspects of management practices of BVDV control on Indiana dairy farms that need reinforcement. In particular, dairy producers should be made aware that vaccination should be complementary to a comprehensive biosecurity program.

Chicago Made: Factory Networks in the Industrial Metropolis (review)

Reviewed by: Chicago Made: Factory Networks in the Industrial Metropolis Damon Yarnell (bio) Chicago Made: Factory Networks in the Industrial Metropolis. By Robert Lewis. Chicago: University of Chicago Press, 2008. Pp. xii+351. $40. In 1929, Campbell Soup completed a new 800,000-square-foot plant in an industrial development on the outskirts of Chicago. Each day, the facility took in tons of tomatoes from nearby farms in Illinois and Indiana and shipped out 3.6 million cans of soup to retailers across the Midwest. The factory’s most interesting trading partner, however, may have been just next door. The Continental Can Company not only built a factory on a neighboring lot, it delivered its cans via a conveyor belt that stretched between the two sites. In the simplest possible form, the relationship between Campbell and Continental encapsulates the two major themes of this important new work by one of North America’s leading urban geographers. First, Campbell and Continental chose industrial sites outside Chicago’s old industrial core. The new location altered existing social and economic patterns, and, by luring workers and other industrial firms to the urban fringe, helped fuel a process of industrial “decentralization.” Second, the two companies forged a commercial link that—because similar links multiplied at every point along the production chain—formed part of an industrial network. To make his case, Robert Lewis uses the tools of economic geography. In the first half of his book he documents changing patterns of industrial location between 1860 and 1940, offering both useful conceptual tools and a wealth of quantitative analysis. The industrial metropolis is best understood as a “localized production system” (p. 13). Industrialists don’t simply [End Page 932] build factories; they cultivate and exploit unique combinations of infrastructures, institutions, and practices that Lewis dubs “locational assets” (p. 15). Drawing on census records, business directories, and a variety of trade literature, he tracks variables such as firm size, product specialization, factory additions, and company relocations. The result is both nuanced and comprehensive. Most industrial growth occurred on the fringe, but certain industries tended to remain in the core, and different industries manifested different “location quotients,” or degrees of geographic concentration. Throughout, Lewis garnishes his empirical findings with lively anecdotes about individual firms, leading industrialists, and urban boosters. In the second half of Chicago Made, Lewis shifts his attention from factory to network. He uses an extraordinary database of bankrupt firms (97 businesses selected from four historical periods yielded 7,196 creditors) to trace flows of money and material. Here again, Lewis’s deft analysis offers both breadth and detail. The majority of creditors were manufacturers, for example, but financial institutions lent the most capital. Firms borrowed from both local and non-local creditors, but non-local manufacturers outnumbered other non-local sources nearly two to one: in certain circumstances, goods proved more mobile than bank loans or other services. Lewis makes clear that the vital importance of supply networks would not have been news to his actors. In chapters 6 and 7, he follows industrial boosters and developers as they used spatial proximity to promote and plan industrial districts such as Calumet, Pullman, and the Central Manufacturing District, America’s “first operating planned industrial district” (p. 167). Subsequent chapters probe the implications of networked space in broader terms, emphasizing not only geographic and economic consequences, but also deep, class-based social repercussions. Industrial networks reinforced particular social formations and alliances, and decisions about the built environment always carry a high degree of path dependency. Make room on your shelves. This is a major work by a leader in his field about processes of interest to many T&C readers. That the book will fit nicely in a variety of places is evidence of Lewis’s achievement. Urbanists may want to tuck it next to Bill Cronon’s Nature’s Metropolis (1991, because it complements agricultural flows from the hinterland with industrial flows in the city) or alongside Sam Warner’s Streetcar Suburbs (1962, because it contributes to the ongoing revision of the history of suburbanization). Scholars of “regional advantage” and “high technology” may choose to place it between AnnaLee Saxenian’s Regional Advantage: Culture and...

Conservation pioneer Melville H. Cohee

M elville H. Cohee was born April 17, 1909, and grew up on a crop and livestock farm in Indiana. He earned his bachelor and master's degrees from Purdue University before studying as a PhD student in agricultural economics and land use at the University of Wisconsin-Madison. Mel Cohee was one of Hugh Hammond Bennett's important partners in the early days of the Soil Erosion Service and Soil Conservation Service (now the Natural Resources Conservation Service) and in establishing the Soil Conservation Society of America (now the Soil and Water Conservation Society). In 1933, an angry Bennett had stormed the office of the Assistant Secretary of Agriculture Rexford G. Tugwell and argued, “Why on earth shouldn't we go about this problem [soil erosion] the right way by building terraces properly on the right kind of land and by supporting them with other needed practices, such as strip cropping, contour plowing, crop rotations, and grassed waterways?” Tugwell said he would look into it, but he told Bennett to be prepared, for Bennett would have to take a leading part in whatever program was agreed upon. Shortly thereafter, Secretary of Agriculture Harold Ickes informed Bennett that he had been selected to set up …

Conservation pioneer Melville H. Cohee

Melville H. Cohee was born April 17, 1909, and grew up on a crop and livestock farm in Indiana. He earned his bachelor and master's degrees from Purdue University before studying as a PhD student in agricultural economics and land use at the University of Wisconsin-Madison.

Background and Importance of Troyer Reid Corn

Corn (Zea mays L.) history and American westward expansion were intertwined when several hundred newer, better adapted, open‐pollinated corn varieties were developed by human and natural selection. Chester E. Troyer was a pioneer corn breeder who bred ‘Troyer Reid’, an improved ‘Reid Yellow Dent’ variety. We relate how Chester got to the particular Indiana farm whose pervious, river‐bottom soil affected natural selection. Better, deeper rooting probably helped Troyer Reid obtain more nutrients and water. Chester's formative years were spent as a teacher, and his later achievements included being honored four times as Corn King of the World and also as a successful corn breeder of productive corn varieties and proprietary hybrids. He was first to produce and sell hybrid seed corn in Indiana in 1925, received the Purdue University Certificate of Distinction and was a successful seed corn businessman and employer, successful gladiolus (Gladiolus × gandavensis Van Houtte) breeder of award winning varieties, successful banker, and beloved civic philanthropist. Troyer Reid accounts for about 15% of the background of documented U.S. Corn Belt hybrid corn through inbreds developed by Purdue University, Pioneer Hi‐Bred International, University of Minnesota, and Iowa State University corn breeders.

A model of decision-making and information flows for information-intensive agriculture

This paper describes the development of a systems based model to characterise farmers’ decision-making process in information-intensive practices, and its evaluation in the context of Precision Agriculture (PA). A participative methodology was developed in which farm managers decomposed their process of decision-making into brief decision statements along with associated information requirements. The methodology was first developed on a university research farm in Denmark and further revised during testing on a number of research and commercial farms in Indiana, USA. Twenty-one decision-analysis factors were identified to characterise a farm manager’s decision-making process. Then, a general data flow diagram (DFD) was constructed that describes the information flows “from data to decision”. Illustrative examples of the model in the form of DFDs are presented for a strategic, a tactical and an operational decision. The model was validated for a range of decisions related to operations by three university farm managers and by five commercial farmers practicing PA for cereal, corn and soybean production in Denmark and in Indiana, USA.

Profitability of On-Farm Precipitation Data for Nitrogen Management Based on Crop Simulation

The purpose of this study was to determine the utility of on-farm precipitation measurement for nitrogen management decisions on an Indiana farm. Site-specific farming has led some producers to measure on-farm precipitation at multiple sites, but the profitability of such intense sampling for non-irrigated agriculture is not clear. The CERES-Maize model in Decision Support System for Agrotechnology Transfer (DSSAT) version 3.5 was used to simulate corn yield for a farm in east-central Indiana for 20years of weather data from three precipitation data sources—an on-farm station, the nearest non-urban National Weather Service (NWS) station, and the weighted mean of the three nearest such stations. Stochastic dominance and descriptive statistics were used to compare simulated yield and profitability for four nitrogen strategies: variable-rate versus whole-field fertilizer application and split application (starter urea-ammonium nitrate mixture at planting and sidedressed ammonia 37days later) versus sidedress application only. Off-farm data never led to a different choice of nitrogen strategy than on-farm data, but the ability to categorize a choice as risk averse or risk neutral depended on the precipitation data source used. This suggested that although on-farm precipitation measurement could be useful for risk management decisionmaking, it might not be profitable on average. The nearest NWS station would be the most profitable source of precipitation data, if it leads to the same management strategy as on-farm data.

Mitigating the Compliance Cost of a Phosphorus-Based Swine Manure Management Policy

Regulatory changes by federal and state agencies portend a switch from nitrogen-based livestock manure disposal policies to phosphorus-based policies. This paper estimates the compliance costs of such a policy change for a hypothetical hog-grain farm in North Central Indiana. The farm includes 1,500 acres of cropland and has the capacity to raise 11,970 grow-finish hogs annually. The farm model also has the potential to produce four different crops on six different land types. A nonlinear math-programming model was developed to determine the optimal mix of management activities for a phosphorus-based regulation. The model allows mitigation of compliance costs via the choice between four different pig diets, three alternative methods of manure disposal, changes in timing of manure application, and crop pattern adjustments. This analysis concludes that the new regulation will result in a decrease in whole-farm returns above variable costs, the use of phytase enzyme in pig diets, and an increase in wheat acreage. The model also reveals that it is optimal for the farmer to hire a custom hauler to assist in application of manure in an effort to reduce the degree to which available field days constrain farming activities and land application of manure. The estimated cost to the farmer, as a result of the policy change, ranges between $0.56 and $21.74 per unit of pig production capacity.

Use of CERES-Maize to study effect of spatial precipitation variability on yield

The objective of this study was to determine the usefulness of on-farm precipitation measurement, through determining spatial and temporal precipitation variability and its effect on corn yield. CERES-Maize (DSSAT version 3.5) was used with three precipitation data sources, for an Indiana farm—an on-farm National Weather Service (NWS) station, the nearest non-urban NWS station with electronic reporting (27 km from the farm), and a weighted mean of the three nearest such stations (27–35 km away)—to simulate 31 years of crop yield on 1-ha grid cells. Described as a percentage of the mean, spatial precipitation variability among the three data sources by corn phenological phase was 21–104%, while temporal (year-to-year) variability was 20–49%. The difference in simulated yield based on spatial precipitation variability was 15.8%, while year-to-year yield variability was 21.5%. The apparent yield difference based on spatial precipitation variability was of the same order as year-to-year variability, which suggests having on-farm precipitation data may be necessary for accurate yield modeling.