Concepts and Rationale for Regional Nitrogen Rate Guidelines for Corn, April 2006

Nitrogen (N) is typically one of the largest corn fertilization expenses. Nitrogen application is critical because it signifi cantly improves corn yield in many crop rotations. When choosing N rates, producers need to carefully consider both achieving most profi table economic return and advancing environmental stewardship. In 2004, university agronomists from the Corn Belt states began discussions regarding N rate use for corn production. The reasons for the discussions centered on apparent differences in methods for determining N rates across states, misperceptions regarding N rate guidelines, and concerns about application rates as corn yields have climbed to historic levels. An outcome of those discussions was an effort with the objectives to: ▪ develop N rate guidelines that could be applicable on a regional basis and ▪ identify the most profi table fertilizer N rates for corn production across the Corn Belt. This publication provides an overview of corn N fertilization in regard to rate of application, investigates concepts for determining economic application rates, and describes a suggested regional approach for developing corn N rate guidelines directly from recent research data.

Iowa's Leadership in Research and Development, 2010

Pentagon-classified navigation systems are designed and tested. Genetically-superior, drought resistant triple-stacked corn hybrids exponentially improve corn and soybean yields. Scientists discover a simple flower, the marigold, unlocks astonishing potential as a change agent to improve the world’s health. All achieved or discovered in Iowa, the common denominator among all of these extraordinary activities is the intensive research and development efforts involved in bringing them to market. For businesses heavily dependent on research and development, one of their strategic advantages of conducting that world-changing research in Iowa is the state’s Research Activities Credit, commonly referred to as the Research and Development tax credit. Whether a company’s specific strategy is planting a stake into emerging markets, expanding its market leadership position, or paving technological inroads to gain market share, the success of those efforts is largely dependent on the company’s preceding work in research and development. Iowa recognizes how significant these resulting innovations are to long-term business growth and stability. Even though the federal research credits have fluctuated with intermittent expiration dates and reinstatement periods, Iowa has remained consistent in its support for the Research Activities Credit over theyears.

The Iowa Grain Flow Survey: Where and How Iowa Grain Producers and Country Elevators Shipped Corn and Soybeans During September 1, 1999 - August 31, 2000, 2001

In September 1996, a grain flow survey consisting of two parts was completed and published. One part was a farm-to-market survey from a sample of Iowa grain producers, and the second was a survey of all Iowa country elevators. An updated survey for the crop year September 1, 1999 -August 31, 2000, was initiated in September 2000. The results of the two updated surveys are presented in this report. The purpose of the surveys is to estimate the amount of Iowa corn and soybeans that are shipped from each crop reporting district to each major market. Copies of the two questionnaires are presented in the appendices.

Annual Report of Highway Division Highway Research and Development in Iowa, 2003

Annual report for Iowa Department of Transportation.

Research News, December 2002

Newsletter for Iowa Department of Transportation

Annual Report of Highway Division, Highway Research and Development in Iowa, November 2002

Annual report for the Iowa Department of Transportation

Research News, Fall 2003

Newsletter for Iowa Department of Transportation

Research News, Spring 2003

Newsletter for Iowa Department of Transportation

Iowa Corn Promotion Board, August 31, 2001 & August 31, 2002

State Agency Audit Report

Iowa Corn Promotion Board, August 31, 2002 & August 31, 2003

State Agency Audit Report

Iowa Corn Promotion Board, Independent Auditor's Reports Financial Statements and Supplemental Information, August 31, 2003 & 2004

State Agency Audit Report

Annual Report of Highway Division Highway Research and Development in Iowa, 2004

Annual report for Iowa Department of Transportation

Research News, Summer 2005

Newsletter for research news at the Iowa Department of Transportation

Assessment of Dowel Bar Research, August 2002

This report presents the latest technological gaps in dowel bar research based upon completed and ongoing dowel bar research from across the nation. In order to obtain this collection of information about dowel bars, a search was conducted on a nationwide level. The technological gaps and duplications of the research were then determined. In addition, this report also provides a brief annotated bibliography of all sources used to determine the gaps in technology and knowledge for dowel bar and alternative dowel bar topics as applied to highway pavements.

Stochastic Dynamic Northern Corn Rootworm Population Model, January 2000

A complete life cycle model for northern corn rootworm, Diabrotica barberi Smith and Lawrence, is developed using a published single-season model of adult population dynamics and data from field experiments. Temperature-dependent development and age-dependent advancement determine adult population dynamics and oviposition, while a simple stochastic hatch and density-dependent larval survival model determine adult emergence. Dispersal is not modeled. To evaluate the long-run performance of the model, stochastically generated daily air and soil temperatures are used for 100-year simulations for a variety of corn planting and flowering dates in Ithaca, NY, and Brookings, SD. Once the model is corrected for a bias in oviposition, model predictions for both locations are consistent with anecdotal field data. Extinctions still occur, but these may be consistent with northern corn rootworm metapopulation dynamics.