Brief Summary of Minutes of Annual Meeting

2005 MINUTES: It was agreed to strike from the minutes of the 2005 meeting the phrase "that labs can be certified to perform" found in the second paragraph of the section, "Popular Press Article". Subsequently the minutes were approved as amended. STATE REPORTS: State reports were presented by AK, CA, IA, MN, MO, NE, OH, SD, and WI. Little committee-related work was done this year, primarily because the data for this 5-year research phase have already been collected. Discussion topics included recent negative findings with the Illinois Soil N Test, the current status of soil N testing in states, administrative changes in the agricultural colleges at North Central universities, and the need to target educational efforts at the proper sector(s) of the agricultural community--landowner versus farm manager versus crop consultant. PROGRESS OF PUBLICATIONS FROM PREVIOUS PROJECT: L. Bundy will soon finish writing a manuscript that characterizes the indigenous soil N supply and N use efficiency in the North Central region. This manuscript will also touch on the topic of a second proposed manuscript regarding the use of soil testing techniques for predicting soil N mineralization and developing fertilizer recommendations. D. Walters presented statistical analysis of the relationship of rapid mineralization quick tests to long-term aerobic incubation. P. Scharf will soon receive galley proofs for a manuscript on plant sensing of N status. No progress has been made with a manuscript on the relationship of soil mineralizable C to mineralizable N. It was decided to not revisit these manuscripts at future annual meetings. PROGRESS OF PUBLICATIONS FROM CURRENT PROJECT: G. Randall discussed progress in coordinating a joint outreach publication on best management practices (BMPs) for nitrogen use in the North Central region. Committee members have finished writing half of the sections. He has received state-specific BMPs for many of the North Central states. The committee discussed options for obtaining BMPs from states with inactive or no committee representation. C. Laboski discussed progress in compiling data from the committee's evaluation of the Illinois Soil N Test. The majority of states have submitted their data. The sites represent a mix of corn-based rotations, manure application, irrigation, drainage, and duration of experimental treatments. It was decided to publish the results in one joint journal paper and to simultaneously issue press releases in each of the states. The press releases would preferably cite Powerpoint presentations or extension-like publications that would be posted on web sites of each state university. NEW PROJECT PLANNING: D. Walters, W. Horwath, and D. Olk presented some analytical components of the new project plan, which intends to develop a deeper process-level understanding of soil N cycling in corn-based rotations. D. Walters stressed the need to continue the committee's traditions of a common experimental protocol at all sites and centralized laboratory analyses. He discussed the respective goals of research in long-term plots at research stations versus on-farm plots. W. Horwath discussed the soil N cycle and the application of the A value and 15N studies to understanding soil N cycling. D. Olk discussed the extraction of active fractions of soil organic matter and analyses for their quantities and biochemical nature of N and C. D. Walters discussed application of the hybrid maize model toward understanding the relative effects on crop yield of N availability and other factors. It was emphasized that this phase of research is predicated upon obtaining external funding, given the declining amounts of CSREES funds that are designated for committee research. A grant proposal will be written and submitted to the National Research Initiative (NRI) later in 2006. The degree of participation by each state in the proposal remains to be determined. The committee decided to pursue these process-level investigations of N cycling within the context of field trials that will evaluate corn crop response to lowered application rates of N fertilizer. The escalating cost of N fertilizer has prompted calls for lowering the recommended N fertilizer rates. There is, however, concern that reduced fertilizer input would over the long-term deplete the reserves of native soil N. Hence the committee will measure crop growth parameters (yield, N uptake) and the quantity and quality (i.e. chemical nature) of active pools of native soil N at these lower fertilizer rates. D. Walters discussed various programs within the NRI to which the grant proposal could be submitted. He will visit Washington, D.C. in April to further discuss the committee's proposal with NRI program leaders. CSREES REPORT: None. CSREES advisor was not present. ADMINISTRATIVE ADVISOR'S REPORT: None. Administrative advisor was not present. BUSINESS: The committee thanked L. Bundy for 20 years of service to the committee; this was his final committee meeting. J. Sawyer was elected member-at-large. Committee leadership for 2006-2007 is D. Olk, chairman, P. Scharf, secretary, and C. Laboski, past chair. The next annual meeting will be March 7-8, 2007 in Kansas City. To continue the planning for the next 5-year research phase, a subcommittee will meet during June or July in Ames, IA to develop specific protocols for all proposed research activities. A second subcommittee meeting will be held in the autumn to organize the writing of the grant proposal so that it can be submitted to the NRI by the potential December deadline. A conference call will shortly be arranged to gauge the level of interest in the new project plan by new committee members who did not attend this annual meeting. A termination report will be written for the current 5-year phase, which finishes September 30, 2006.

In 2005-2006 research continued on assessing the Illinois soil nitrogen test (ISNT) for its use predict nitrogen (N) mineralization and fertilizer N requirement for corn. Results showed that ISNT values were not related to observed economic optimum N rates (EONR) in field corn N response experiments and that the ISNT had no ability to separate N responsive from non-responsive sites. ISNT values were strongly correlated with the soil organic matter content of the experimental sites suggesting that the ISNT is measuring a constant fraction of the soil organic N rather than the readily mineralizable N component. Soil organic N fractions were not related to corn N response (percent yield increase due to added N fertilizer relative to control plot yield) although these experiments included cropping systems ranging from first year corn following alfalfa to continuous corn and showed marked differences in yield response to N fertilizer additions. Specifically, results showed that the soil amino sugar-N fraction was not related to observed corn N fertilizer response. Likewise, relationships between corn N fertilizer response and other hydrolyzable N fractions including hydrolyzable ammonium-N, (amino sugar + ammonium)-N, amino acid-N, and total hydrolyzable-N were also poor. A strong correlation was found between ISNT results and amino sugar-N, but ISNT was also strongly related to soil organic matter, soil total N, and soil total C. These results confirm the conclusion that the ISNT is measuring a constant fraction of the soil organic N instead of the readily mineralizable fraction of soil N. Results from this work indicate that the ISNT or the soil organic N fractions studied are not reliable predictors of corn N response. Compilation of data from 2001-2005 across the multiple states was begun. This data will be placed into a database and further analysis of the ISNT and glucosaminidase tests as a means to predict N mineralization and corn response to N fertilizer on a regional basis will be performed.

Andraski, T.W., and L.G. Bundy. 2005. Cover crop effects on corn yield response to nitrogen on an irrigated sandy soil. Agron. J. 97:1239-1244. Bundy, L. 2005. How do we improve N application to increase N-use efficiency? In Annual meetings abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI. Bundy, L.G. 2005. Should soybean N credits be taken in 2005? Proc. Wis. Fert. Aglime and Pest Mgmt. Conf. 44:112-117. Bundy, L.G., and T.W. Andraski. 2005. Recovery of fertilizer nitrogen in crop residues and cover crops on an irrigated sandy soil. Soil Sci. Soc. Am. J. 69:640-648. Bundy, L. and C. Laboski. 2005. Optimum nitrogen rates for corn and the Illinois soil nitrogen test. Wisconsin Crop Manager. 12:212-213. Clay, D.E., N. Kitchen, C.G. Carlson. J. Kleinjan, 2006. SSMG- 42. A first step in precision nutrient management: Sampling old farmsteads separately from the rest of the field. Clay et al. (Ed) Site Specific Management Guidelines. Potash and Phosphate Institute. Norcross, GA. Chang, J., and D.E. Clay. 2006. Identifying factors for yield prediction models and evaluating model selection methods. Korean Crop Sci. Soc. J. Korean J Crop Science 50:268-275. Clay, D.E., C.G. Carlson, S.A. Clay, C. Reese, Z. Liu, and M.M. Ellsbury. 2006. Theoretical Derivation of New Stable and Non-isotopic Approaches for Assessing Soil Organic C Turnover. Agron. J. (In press). Clay, D.E., Ki-In Kim, J. Chang, S.A. Clay, and K. Dalsted. 2006. Characterizing water and N stress in corn using remote sensing. Agron. Journal. (In press). Clay, D.E., C.G. Carlson, S.A. Clay, J. Chang, and D.D. Malo. 2005. Soil organic C maintenance in a corn (Zea mays L.) and soybean (Glycine max L.) as influenced by elevation zone. Journal of Soil Water and Conservation. 60:342-348. Clay, D.E., S.A. Clay, D.J. Lyon, and J.M. Blumenthal. 2005. Can 13C discrimination in corn (Zea mays) grain be used to characterize intra-plant competition for water and nitrogen? Weed Sci. 53:23-29. Dobermann, A., D.T. Walters, F. Legoretta, T.J. Arkebauer, K.G. Cassman, R.A. Drijber, J.L. Lindquist, J.E. Specht, and H.S. Yang. 2005. Unlocking the secrets of carbon and nitrogen cycling in soil. Fluid J. 13:8-10. Ferguson, R., G. Hergert, D. Walters, C. Shapiro, A. Dobermann, K. Cassman, C. Wortmann and D. Tarkalson. 2005. Nitrogen Fertilizer Use in Nebraska Over the Past Fifty Years. Agronomy Abstracts of the American Society of Agronomy Annual Meeting, Salt Lake City, UT. Ferguson, R.B., A. Dobermann, C.S. Wortmann, D.T. Walters, C.A. Shapiro, D. Tarkalson, and D.D.Baltensperger.2004. Developing recommendations for site-specific nitrogen management of irrigated maize. In: Proceedings of the 7th International Conference on Precision Agriculture and Other Resource Management, July 25-28, 2004, Bloomington, MN. CD-ROM. . ASA, CSSA, SSSA, Madison, WI. Legoretta, F. 2005. Effect of cropping system and management on the storage and release of C and N from soil humic acid pools. PhD dissertation, University of Nebraska  Lincoln. Department of Agronomy and Horticulture. Lindquist, J.L., Arkebauer, T.J., Walters, D.W., Cassman, K.G., Dobermann, A. (2005, 10/20). Maize radiation use efficiency under optimal growth conditions. Agronomy Journal, 97 (2005): 72 -78. Mishra, U., D. Clay, T. Trooien. K. Dalsted, D.D. Malo, 2006. Using remote sensing based ET maps to assess landscape processes impacting soil properties. Geoderma (In review). Moran KK, J Six, WR Horwath, C van Kessel. 2005. Role of mineral-nitrogen in residue decomposition and stable soil organic matter formation. SOIL SCIENCE SOCIETY OF AMERICA JOURNAL 69 (6): 1730-1736. Onsoy YS, T Harter, TR Ginn, WR Horwath. 2005. Spatial variability and transport of nitrate in a deep alluvial vadose zone. VADOSE ZONE JOURNAL 4 (1): 41-54. Osterhaus, J., and L. Bundy. 2005. Soil organic nitrogen fractions measured by the Illinois soil nitrogen test. In Annual meetings abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI. Osterhaus, J.T., and L.G. Bundy. 2005. Determining economic optimum nitrogen rates with the Illinois soil nitrogen test and soil organic nitrogen fractions. p. 123-129. In Proc. North Central Ext. - Industry Soil Fertil. Conf., Des Moines, IA. Vol. 21, Potash and Phosphate Inst., Brookings, SD. Randall, G. W., and J. A. Vetsch. 2005. Nitrate losses in subsurface drainage from a corn-soybean rotation as affected by fall and spring application of nitrogen and nitrapyrin. J. Environ. Qual. 34:590-597. Randall, Gyles W., and Jeffrey A. Vetsch. 2005. Corn production on a subsurface-drained mollisol as affected by fall versus spring application of nitrogen and nitrapyrin. Agron. J. 97:472-478. Randall, Gyles and J. Sawyer. 2005.Nitrogen application timing, forms and additives. pp. 73-84. In Proc. Gulf Hypoxia and Local Water Quality Concerns Workshop. 26-28 Sept. 2005. Ames, Iowa. Sawyer, J, and G. Randall. 2005. Nitrogen rates. pp 59-71. In Proc. Gulf Hypoxia and Local Water Quality Concerns Workshop. 26-28 Sept. 2005. Ames, Iowa. Verma, S.B., A. Dobermann, K. G. Cassman, D.T. Walters, J.M. Knops, T.J. Arkebauer, A.E. Suyker, G.G. Burba, B. Amos, H. Yang, D. Ginting, K.G. Hubbard, A.A. Gitelson, E.A. Walter-Shea. 2005. Annual carbon dioxide exchange in irrigated and rainfed maize-based agroecosystems. Agricultural and Forest Meteorology. 131-77-96. Walters D.T. 2005. Fertilizer nitrogen source and management impacts on greenhouse gas emissions. Proc. 35th N.C. Extension industry Soil Fertility Conference., Des Moines, IA. Nov. 16-17, 2005.