Optimum Plant Population in Iowa, 2007

As a result of higher seed prices, improved planters and weed management programs, soybean growers are more aware of the importance of seeding rates and optimal plant populations at harvest. A harvest population of approximately 100,000 uniformly distributed plants per acre will maximize economic return in Iowa regardless of row spacing. There appears to be no economic advantage to harvest populations greater than, or less than, 100,000 plants per acre. Economics, however, should be considered carefully when striving for higher harvest populations since seed is expensive. Timely management, such as weed management, is more critical at low plant populations.

Optimum Plant Population in Iowa, 2007

Planting soybeans in rows narrower than 30 inches can improve yield potential. Most Midwest research documents that narrow rows (less than 30 inches) yield greater than wide rows (30 inches or greater). On average in Iowa a 4.5 bu./acre yield increase can be expected using 15-inch row spacing, compared to 30-inch row spacing. These data have been fairly consistent for the past 20 years.

Optimum Plant Population in Iowa, 2007

As a result of higher seed prices, improved planters and weed management programs, soybean growers are more aware of the importance of seeding rates and optimal plant populations at harvest. A harvest population of approximately 100,000 uniformly distributed plants per acre will maximize economic return in Iowa regardless of row spacing. There appears to be no economic advantage to harvest populations greater than, or less than, 100,000 plants per acre. Economics, however, should be considered carefully when striving for higher harvest populations since seed is expensive. Timely management, such as weed management, is more critical at low plant populations.

Soybean Planting Date, 2007

The planting date for soybeans should be based on seedbed conditions and calendar date rather than soil temperature. The optimum time to plant soybeans in Iowa is the last week of April for the southern two thirds of Iowa and the first week of May for the northern one third of Iowa.

Soybean Planting Date, 2007

The planting date for soybeans should be based on seedbed conditions and calendar date rather than soil temperature. The optimum time to plant soybeans in Iowa is the last week of April for the southern two thirds of Iowa and the first week of May for the northern one third of Iowa.

Thermoplastic Starch-based Composites Reinforced with Rape Fibers: Water Uptake and Thermomechanical Properties

Fully biodegradable composite materials were obtained through reinforcement of a commercially available thermoplastic starch (TPS) matrix with rapeseed fibers (RSF). The influence of reinforcement content on the water sorption capacity, as well as thermal and thermo-mechanical properties of composites were evaluated. Even though the hydrophilic character of natural fibers tends to favor the absorption of water, results demonstrated that the incorporation of RSF did not have a significant effect on the water uptake of the composites. DSC experiments showed that fibers restricted the mobility of the starch macromolecules from the TPS matrix, hence reducing their capacity to crystallize. The viscoelastic behaviour of TPS was also affected, and reinforced materials presented lower viscous deformation and recovery capacity. In addition, the elasticity of materials was considerably diminished when increasing fiber content, as evidenced in the TMA and DMTA measurements

Business Sphere, Vol. 20, no.2

With its central U.S. location, access to a plethora of agricultural raw materials, a highly educated and skilled workforce, and a supportive state government; food and ingredient manufacturers find many advantages to locating in Iowa. Another major plus for Iowa’s food makers is access to one of the strongest food science and human nutrition programs in the nation, located on the campus of Iowa State University (ISU). At ISU, you will find scientists who will assist your organization in bringing food related innovations in plant, animal and microbial products to commercialization. The Department of Food Sciences and Human Nutrition (FSHN) is jointly administered by the Colleges of Agriculture and Life Sciences and Human Sciences. Our mission is to generate new knowledge around food and human nutrition and to promote health through food.

Hydrologic Simulations of the Maquoketa River Watershed Using SWAT Working Paper 09-WP 49,June 2009

This paper describes the application of the Soil and Water Assessment Tool (SWAT) model to the Maquoketa River watershed, located in northeast Iowa. The inputs to the model were obtained from the Environmental Protection Agency’s geographic information/database system called Better Assessment Science Integrating Point and Nonpoint Sources (BASINS). Climatic data from six weather stations located in and around the watershed, and measured streamflow data from a U.S. Geological Survey gage station at the watershed outlet were used in the sensitivity analysis of SWAT model parameters as well as its calibration and validation for watershed hydrology and streamflow. A sensitivity analysis was performed using an influence coefficient method to evaluate surface runoff and base flow variations in response to changes in model input hydrologic parameters. The curve number, evaporation compensation factor, and soil available water capacity were found to be the most sensitive parameters among eight selected parameters when applying SWAT to the Maquoketa River watershed. Model calibration, facilitated by the sensitivity analysis, was performed for the period 1988 through 1993, and validation was performed for 1982 through 1987. The model performance was evaluated by well-established statistical methods and was found to explain at least 86% and 69% of the variability in the measured stream flow data for the calibration and validation periods, respectively. This initial hydrologic modeling analysis will facilitate future applications of SWAT to the Maquoketa River watershed for various watershed analysis, including water quality.

Iowa Aviation System Plan, 2004-2024

The Iowa Department of Transportation (DOT), working closely with the Federal Aviation Administration (FAA), strives to ensure that Iowa’s system of public airports is positioned to meet the needs of businesses, residents, and visitors to our state. Airports must be accessible and positioned to safely meet different levels of aviation activity. In partnership with the FAA and various cities, counties, and airport authorities, the Iowa DOT helps to direct the systematic development of public airports. This report is a summary of a more comprehensive technical report that outlines a strategic plan for improving the performance of airports in Iowa over the next 20 years. More information on the technical report and on individual reports prepared for each of the public airports can be obtained from the Iowa DOT, Office of Aviation website at www.iawings.com. The Iowa Aviation System Plan provides the Iowa DOT with an important tool to monitor the ability of airports to meet customer needs. The plan also provides a means to measure the effects of investment on the performance of the Iowa Aviation System. Over the next 20 years, federal, state, local, and private funding will be needed to ensure that the aviation system meets goals established in this study. It is estimated that at least $821 million will be needed over the next 20 years if airports in Iowa are to respond to objectives set by the system plan. In future years, the plan will enable the Iowa DOT to measure system performance. By tracking key indicators for the airport system, it will be possible for the Iowa DOT and the FAA to formulate strategies for responding to Iowa’s air transportation needs. The Iowa Aviation System Plan provides a guide for the state and its communities to ensure that the vision established for the Iowa Aviation System can be achieved.

Reading, Translating, Rewriting: Angela Carter's Translational Poetics

In "Reading, Translating, Rewriting: Angela Carter's Translational Poetics", author Martine Hennard Dutheil de la Rochère delves into Carter's The Fairy Tales of Charles Perrault (1977) to illustrate that this translation project had a significant impact on Carter's own writing practice. Hennard combines close analyses of both texts with an attention to Carter's active role in the translation and composition process to explore this previously unstudied aspect of Carter's work. She further uncovers the role of female fairy-tale writers and folktales associated with the Grimms' Kinder- und Hausmärchen in the rewriting process, unlocking new doors to The Bloody Chamber. Hennard begins by considering the editorial evolution of The Fairy Tales of Charles Perrault from 1977 to the present day, as Perrault's tales have been rediscovered and repurposed. In the chapters that follow, she examines specific linkages between Carter's Perrault translation and The Bloody Chamber, including targeted analysis of the stories of Red Riding Hood, Bluebeard, Puss-in-Boots, Beauty and the Beast, Sleeping Beauty, and Cinderella. Hennard demonstrates how, even before The Bloody Chamber, Carter intervened in the fairy-tale debate of the late 1970s by reclaiming Perrault for feminist readers when she discovered that the morals of his worldly tales lent themselves to her own materialist and feminist goals. Hennard argues that The Bloody Chamber can therefore be seen as the continuation of and counterpoint to The Fairy Tales of Charles Perrault, as it explores the potential of the familiar stories for alternative retellings. While the critical consensus reads into Carter an imperative to subvert classic fairy tales, the book shows that Carter valued in Perrault a practical educator as well as a proto-folklorist and went on to respond to more hidden aspects of his texts in her rewritings. Reading, Translating, Rewriting is informative reading for students and teachers of fairy-tale studies and translation studies.

Evaluation of Electronic Speed Limit Signs on US 30, September, 2011

This study documents the speed reduction impacts of two dynamic, electronic school zone speed limit signs at United Community Schools between Ames and Boone, Iowa. The school facility is situated along US Highway 30, a rural four-lane divided expressway. Due to concerns about high speeds in the area, the Iowa Department of Transportation (DOT) decided to replace the original static school zone speed limit signs, which had flashing beacons during school start and dismissal times (Figure 1), with electronic speed signs that only display the reduced school speed limit of 55 mph during school arrival and dismissal times (Figure 2). The Center for Transportation Research and Education (CTRE) at Iowa State University (ISU) conducted a speed evaluation study one week before and 1 month, 7 months, and 14 or 15 months after the new signs were installed. Overall, the new dynamic school zone speed limit signs were more effective in reducing speeds than the original static signs with flashing beacons in the 1 month after period. During the 7 and 14 month after period, speeds increased slightly for the eastbound direction of traffic. However, the increases were consistent with overall speed increases that occurred independent of the signs. The dynamic, electronic signs were effective for the westbound direction of traffic for all time periods and for both start and dismissal times. Even though only modest changes in mean and 85th percentile speeds occurred, with the speed decreases, the number of vehicles exceeding the school speed limit decreased significantly, indicating the signs had a significant impact on high-end speeders.

Inter-relation between soybean yield and soil compaction under degraded pasture in Brazilian Savannah

The Cerrado (Brazilian Savannah) plays an important economic and financial role in the nation, since the pastures of this biome feed cattle for half of the domestic bovine meat productivity, and its agricultural fields produce a third of the country's grain. The variability and spatial dependence between the soil physical attributes and soybean yield were evaluated in a crop rotation planted on a degraded brachiaria pasture, on a dystroferric Red Latosol of an experimental farm of the State University of São Paulo (UNESP), in the 2005/2006 growing season. The linear and spatial correlations between these attributes were also studied, to determine conditions that would allow increased agricultural productivity. In the above pasture area, a grid was installed with 124 plots, spaced 10.0 x 10.0 m and 5.0 x 5.0 m apart, in a total area of 7,500 m². From the linear and spatial point of view, the high grain yield can be explained by the number of grains per plant and soil macroporosity. The high variability observed for most soil properties indicated that the crop - livestock integration system results in environmental heterogeneity of the soil.

A Laboratory Investigation into the Effects of the Aggregated Related Facts of Critical VMA in Asphalt Paving Mixtures, June 2000

This report summarizes research conducted at Iowa State University on behalf of the Iowa Department of Transportation, focusing on the volumetric state of hot-mix asphalt (HMA) mixtures as they transition from stable to unstable configurations. This has raditionally been addressed during mix design by meeting a minimum voids in the mineral aggregate (VMA) requirement, based solely upon the nominal maximum aggregate size without regard to other significant aggregate-related properties. The goal was to expand the current specification to include additional aggregate properties, e.g., fineness modulus, percent crushed fine and coarse aggregate, and their interactions. The work was accomplished in three phases: a literature review, extensive laboratory testing, and statistical analysis of test results. The literature review focused on the history and development of the current specification, laboratory methods of identifying critical mixtures, and the effects of other aggregate-related factors on critical mixtures. The laboratory testing involved three maximum aggregate sizes (19.0, 12.5, and 9.5 millimeters), three gradations (coarse, fine, and dense), and combinations of natural and manufactured coarse and fine aggregates. Specimens were compacted using the Superpave Gyratory Compactor (SGC), conventionally tested for bulk and maximum theoretical specific gravities and physically tested using the Nottingham Asphalt Tester (NAT) under a repeated load confined configuration to identify the transition state from sound to unsound. The statistical analysis involved using ANOVA and linear regression to examine the effects of identified aggregate factors on critical state transitions in asphalt paving mixtures and to develop predictive equations. The results clearly demonstrate that the volumetric conditions of an HMA mixture at the stable unstable threshold are influenced by a composite measure of the maximum aggregate size and gradation and by aggregate shape and texture. The currently defined VMA criterion, while significant, is seen to be insufficient by itself to correctly differentiate sound from unsound mixtures. Under current specifications, many otherwise sound mixtures are subject to rejection solely on the basis of failing to meet the VMA requirement. Based on the laboratory data and statistical analysis, a new paradigm to volumetric mix design is proposed that explicitly accounts for aggregate factors (gradation, shape, and texture).

Kinetic parameters of silicon uptake by rice cultivars

Silicon is considered an important chemical element for rice, because it can improve tolerance to biotic and abiotic stress. However, in many situations no positive effect of silicon was observed, probably due to genetic factors. The objective of this research was to monitor Si uptake kinetics and identify responses of rice cultivars in terms of Si uptake capacity and use. The experiment was carried out in a greenhouse of the São Paulo State University (UNESP), Brazil. The experiment was arranged in a completely randomized, factorial design with three replications. that consisted of two rice cultivars and two Si levels. Kinetic parameters (Vmax, Km, and Cmin), root morphology variables, dry matter yield, Si accumulation and levels in shoots and roots, uptake efficiency, utilization efficiency, and root/shoot ratio were evaluated. Higher Si concentrations in the nutrient solution did not increase rice dry matter. The development of the low-affinity silicon uptake system of the rice cultivar 'Caiapó' was better than of 'Maravilha'.

Handbook of Simplified Practice for Traffic Studies, November 2002

The Iowa Highway Research Board has identified the development of a simplified handbook of transportation studies as a high priority for the state of Iowa. The Center for Transportation Research and Education (CTRE) at Iowa State University was chosen to develop such a handbook. A well-executed, well-documented study is critical in the decision-making process for many transportation-related projects and in reporting to elected officials and members of the community. As more research is conducted in the area of transportation, study procedures in many cases have become more complex. It is often difficult for local jurisdictions with limited staff, training, experience, and time availability to perform these studies. The most commonly used publication for traffic studies is geared toward transportation professionals and professional engineers. That defining document, Manual of Transportation Studies (Institute of Transportation Engineers, 2000), is over 500 pages and includes several dozen types of transportation studies. Many of the transportation studies described in the manual are rarely (if ever) used by local jurisdictions. Further, those studies that are frequently used are at times very complex and possibly very costly to perform exactly as described. Local jurisdictions without the staff expertise to understand and apply the manual’s various studies have a need for a simplified handbook of procedures to perform common traffic studies themselves or properly define a scope of work to hire a consultant to perform the studies. This handbook describes simplified procedures that are easy to apply and are written for all potential users (civil engineers and traffic engineers, public works mangers, city managers and attorneys, and the general public).