The Potential for LISA -Type Nitrogen Use Adjustments in Mainstream U.S. Agriculture

Concern about environmental impacts of nitrogen fertilizer use is increasing. Mainstream agriculture is dependent on nitrogen fertilizer and use patterns are polluting water resources. A five cent tax on nitrogen fertilizer is shown to have three benefits. National nitrogen fertilizer use is estimated to decline about 10 percent. Use of legume-produced nitrogen increases and crop use of nitrogen declines only 5 percent. A reduction in wasted legume-produced nitrogen equal to 2.5 percent of nitrogen application in the baseline occurs due to more growing of legumes and other crops in rotation. The nitrogen tax is not without costs. Soil erosion and pesticide use are estimated to increase 2.2 and 1.7 percent, respectively, in response to the tax

Comparison of steer behavior when housed in a deep-bedded hoop barn versus an open feedlot with shelter

The use of hoop barns as an alternative housing system for beef cattle has not been widely researched. The objectives of this study were to determine the main effects of behavior of steers 1) over winter and summer, 2) when housed in either a hoop barn or a conventional feedlot, and 3) interactions between season and housing system. A total of 960 crossbredBos taurus steers were used [August 2006 to April 2008 (2 winter and 2 summer trials)]. Steers were housed in either 1 deep-bedded hoop barn (n = 12 pens; 4.65 m2/steer) or 1 open feedlot with shelter (n = 12 pens; 14.7 m2/steer). Steers were ear tagged, implanted, and weighed (414 ± 36 kg) on arrival and allotted to treatments that were balanced for source, BW, and hide color. Behavioral data (3 postures and 2 behaviors) were collected using a 10-min live scan. The experimental unit for behavior was a pen of steers. Behavioral data were arcsine transformed to achieve a normal distribution. There were no (P \u3e 0.05) differences for time spent at bunk or waterer for steers between housing treatments. Steers housed in an open feedlot with shelter spent less time lying and more time standing and walking (P \u3c 0.05) compared with steers housed in a hoop barn. There were no (P = 0.32) differences between seasons for standing. Steers spent more time at the bunk (P \u3c 0.0001) and waterer (P \u3c 0.0001) in the summer compared with the winter. In the winter, steers engaged in more lying (P = 0.0002) and walking (P \u3c 0.0001). Overall, steers stood less (P = 0.006) and spent more time lying (P = 0.024) when housed in a hoop barn than in the open feedlot with shelter regardless of season. Steers housed in the open feedlot with shelter walked more (P \u3c 0.0001) than steers housed in the hoop barn and walked more (P \u3c 0.0001) in winter than in summer months (6 vs. 3%). There were no (P \u3e 0.05) differences in time spent at bunk and waterer between housing systems within season, but time spent at the waterer and bunk decreased (P \u3c 0.05) for both housing systems during the winter. In conclusion, housing 40 steers per pen in a cornstalk-bedded hoop barn at 4.65m2/steer does not result in adverse behavioral alterations and can be considered as a housing alternative for finishing steers in the Midwestern United States when compared with steers fed in an open feedlot with shelter provided

Sow and Litter Performance for Individual Crate and Group Hoop Barn Gestation Housing Systems: A Progress Report II

The effects of swine gestation housing on sow and litter performance were evaluated at the Iowa State University Lauren Christian Swine Research and Demonstration Farm near Atlantic, IA. The gestation systems were 1) individual gestation crates in a mechanically ventilated, partially slatted floor, manure flush confinement building (CRATE); and 2) group pens in deep-bedded, naturally ventilated hoop structures (HOOP). The HOOP sows were fed with individual feed stalls. The sows were artificially inseminated in a confinement breeding barn with slatted floors and were later moved to their assigned gestation housing treatment. Sows included in the study continued in the same gestation housing their entire time at the farm. All first-litter gilts were gestated in individual gestation crates to minimize sow size differential in the groups. There were 35 sows per group in the HOOP barns. Farrowing occurred every 2 weeks on a year-round basis. All sows were fed 4.5 lb/day and increased to 6 lb/day during the last trimester of gestation. During the winter, HOOP sows were fed 25% more and CRATE sows were fed 5% more. Reproductive performance was summarized for 493 litters during the period March 2001 to September 2003. This is a progress report of a continuing study. Preliminary trends were a shorter wean-to-breed interval, 0.5 more live pigs born per litter, and 0.5 more pigs weaned/sow/year for HOOP sows compared with CRATE sows. Higher percentages of stillborn and mummied pigs were observed in the HOOP sows compared with the CRATE sows. Slightly lower pre-wean mortality and sow culling rates occurred in the CRATE sows as compared with HOOP sows, with similar sow mortality rates for both groups. The preliminary data suggests that gestating sows can be housed in deep-bedded hoop barns equipped with individual feeding stalls and achieve results comparable to individual crated gestation systems

High porosity metallic glass foam: A powder metallurgy route

A powder metallurgy route to the fabrication of metallic glass foam is introduced. The method involves consolidating metallic glass powder blended with blowing agent particulates to produce expandable precursors, capable of yielding foams with porosities as high as 86%. The foams are found to inherit the strength of the parent metallic glass and to be able to deform heavily toward full densification absorbing high amounts of energy

Analysis of 1990 Farm Bill Conservation Options

This report summarizes the ARIMS analysis for the 1990 Farm Bill Conservation Initiatives Work Group. Three major tasks were completed. First, ARIMS was updated to reflect the short-run nature of possible 1990 farm bill policies. Specifically, ARIMS now incorporates a more differentiated set of land resources and crop production technology to match the requirements of the 1985 Food Security Act. Second, baseline solutions for 1990, 1995, and 2000 were estimated. The solutions included the conservation titles of the 1985 Food Security Act. The baselines differed in the specification of acres in the Conservation Reserve Program (CRP) and in conservation compliance provisions. The 1990 baseline had a 40-million-acre CRP requirement; the 1995 baseline has a 40-million-CRP plus conservation compliance; and the 2000 baseline has an eight-million CRP with conservation compliance. Third, two alternative farm bill policy options were evaluated. The water quality option involved adding 10 million acres to the 40-million-acre CRP enrollment in the 1995 baseline. The selection of the 10 million acres was based on potential water quality impacts. The Trees for the U.S. program evaluated the conversion to tress of 37 million targeted acres of cropland and marginal pasture land

Compromise Solution for Economic-Environmental Decisions in Agriculture

Least cost production versus the environmental on- and off-site erosion damage of agriculture is evaluated in a policy context for a major Corn Belt watershed. Compromise programming, previously utilized in firm-level multi-criteria decision making problems is applied to a regional agricultural production model with environmental policy goal trade-offs. The crop sector model allocates land, water, labor, capital, and commodity-program base acres to crop production. Production options include four conservation practices, three tillage methods, and several crop rotations. Crop yield and fertilizer levels are dependent upon erosion. Cropping options selected allow for both wind and water erosion. The vector of objectives include three minimization functions: current production cost, future value of productivity loss, and sediment damage. Vector optimization technique was used to generate the payoff matrix containing efficient but simultaneously unobtainable solutions. Given the ideal but infeasible solution vector we generated efficient solutions in the compromise subset corresponding to the L1. L2. and Loo metrics. Trade-off relations were developed using the noninferior set estimation technique

National and Regional Implications of Conservation Compliance

Soil erosion as an on-site problem received much attention in the 1985 Food Security Act (FSA), which established programs for the Conservation Reserve and conservation compliance. The 1985 FSA explicitly linked farmers\u27 resource use and conservation activities to benefits received from commodity programs. Much debate has ensued on erosion standards for compliance and farm income trade-offs. Farm-level uncertainties about meeting conservation compliance standards and about the trade-offs between limiting soil loss and maintaining farm income are evident. The objective of the analysis described herein was to provide information on national and regional implications of conservation compliance