Brief Summary of Minutes of Annual Meeting

The activities of the annual meeting primarily concerned committee business, termination of the project activities for FY 1995 - 2001 and protocols for project activities for FY 2001 - 2006.

Committee Business: The minutes for the 2000 Annual Meeting and the agenda for the 2001 Annual Meeting were reviewed, modified and approved. Committee officers for the coming year were selected and approved (Brouder - Chair, Dick - Secretary, Horwath - Member-at-Large). The location (Kansas City, MO), date (March 27-28, 2002) and time (8:00 AM on 3/27 through noon on 3/28) for the next annual meeting were established.

Termination of FY ‘95 - ‘01 Activities: The cumulative data sets for the project were reviewed. Preliminary analyses using several different approaches to the data were presented (Walters, time series data; Bundy, identification of the economically optimum N rate and yield responses to this rate) and discussed with the intent of developing strategies for the committee to proceed beyond a simple summary of the database. The committee determined that an overall manuscript was needed that described the justification and objectives of the current project and the extent and depth of the database including a general description of components and ranges in values and conditions and methodologies for field experiments, long-term lab incubation mineralization studies and soil characterization analyses. This overview paper would serve as the primary methodology reference for a minimum of four additional manuscripts detailing in-depth analyses of specific subsets of the database. The subjects of the four additional manuscripts were identified as (1) PMN quick-tests and thermal units, (2) Plant sensing of corn N status, (3) Characterization of soil C pools, and (4) Using testing techniques and N mineralization estimates in making N fertilizer recommendations. Writing teams and lead authors were identified for each paper and timeline for writing (1st drafts to all committee members prior to next year‘s meeting) was established.

Protocols for Project Activities for FY 2001 - 2006: The committee agreed to establish core experiments that all participating members would conduct in their own states. Protocols are to be defined during the coming year for final approval at next year‘s meeting with the 1st growing season of the new project to be 2002. Three types of core experiments were identified for the new project: 1) sites that have been previously used and have historic records of N management, 2) new sites having uniform crop/soil management where N rate studies would be established, and 3) small-sized plots where N15 would be used to evaluate available N pools in soils taken up by plants. The possibility of using "strip trial" experiments for some of these sites was discussed. A protocol writing committee of Randall*, Bundy, Hoeft, Schmidt and Walters was identified to meet in late July or August to develop the protocols for the core experiments. Horwath will provide an N15 protocol for this effort. Preliminary results for two enzyme assays of arylamidase and glucoseamidase, which provide organic N for mineralization to NH4-N and will be used for soils collect in the current project, were presented and discussed (Tabatabai).

Committee members completed field research on cropping systems and N management approaches to address the two project objectives (FY ‘95 - ‘01 project). The two objectives were (1) to determine the feasibility of using thermal units coupled with an appropriate measure of potentially mineralizable soil N to predict current season N availability, and (2) to characterize active N and C pools subject to mineralization in cropping systems. Systems examined included continuous corn or corn-soybean rotations with inorgranic and/or organic (crop residues, cover crops, manures, other biosolids) N sources. Laboratory analyses of plant and soil samples including long-term incubations of soil samples to quantify potentially available N were also completed. All field sites data have been compiled into two separate subsets that feature either summary harvest data with soil test data or timed measurements of soil N, temperature, water content and plant N uptake data throughout the season. A final draft of the databases compiling field and laboratory measurements on plant and soil samples collected from 74 experimental sites was made available to committee members for individuals to pursue the statistical analyses required for the manuscripts outlined above (Summary of Annual Meeting Minutes: Termination of FY ‘95 - ‘01 Activities).

Results from several North Central states field studies will be used to help agronomists better predict the amount of N released by mineralization of organic N present in soils during the growing season. This will allow producers to credit this mineralized N against fertilizer N recommendations, so excess N will not be applied and potential for losses of N from agricultural soils to surface and groundwater resources will be minimized. Specific examples of committee activities that can be directly incorporated into commercially-practiced N management strategies include demonstrating that (1) adjusting N applications based on PSNT results or N crediting should greatly reduce the risk of losing excess N to water resources and does not increase economic risk, (2) cover crop-based organic and low-input cropping systems that add C to soil have the potential for storing N and making it available for future crop use, while minimizing the risk of nitrate pollution, and (3) the Greenwood dilution curve provides a universal age-dependent N dilution curve that can be used to calibrate technologies designed to monitor N sufficiency of maize in a real-time fashion.

Acosta-Martinez, V., and M.A. Tabatabai. 2000. Arylamidase activity of soils. Soil Sci. Soc. Am. J. 64:215-221.

Acosta-Martinez, V., and M.A. Tabatabai. 2000. Enzyme activities in limed agricultural soil. Bio. Fertil. Soils 31:85-91.

Acosta-Martinez, V., and M.A. Tabatabai. 2000. Arylamidase activity of soils: effect of trace elements and relationships to soil properties and activities of amidohydrolases. Soil Biol. Biochem. (In Press).

Andraski, T.W., L.G. Bundy, and K.R. Brye. 2000. Crop management and corn nitrogen rate effects on nitrate leaching. J. Environ. Qual. 29:1095-1103.

Binder, D.L., D.H. Sander, and D.T. Walters. 2000. Irrigated maize response to time of nitrogen application as affected by level of nitrogen deficiency. Agron. J. 92(6) 1228-1236.

Brouder, S.M., and B. Hofmann. 2000. Environmentally friendly management of nitrogen in continuous and rotational corn in the eastern cornbelt. 2000. In Proceedings of the Symposium of the Japan Science-Promoting Society, Faculty of Agriculture, Iwate University, Morioka, Japan, Sept. 2nd , 1999. Pp. 85-93.

Brouder, S.M., D.B. Mengel, and B.S. Hofmann. 2000. Diagnostic efficiency of the blacklayer stalk nitrate and grain N tests for Corn. Agron. J. 92:1236-1247.

Bundy, L.G. 2000. Nitrogen recommendations and optimum nitrogen rates: How do they compare? In Proc. 30th North Central Extension?Industry Soil Fert. Workshop, St. Louis, MO, 15-16 Nov., 2000. 16:5-13.

Deng, S.P., and M.A. Tabatabai. 2000. Effect of cropping systems on nitrogen mineralization in soils. Biol. Fertil. Soils 31: 211-218.

Deng, S.P., and M.A. Tabatabai. 2000. Characterization of active N pools in soils under different cropping systems. Biol. Fertil. Soils 32: 302-309.

Eagle, A.J., J.A. Bird, W.R. Horwath, B.A. Linquist, S.M. Brouder, J.A. Hill, and C. van Kessel. 2000. Rice yield and nitrogen utilization efficiency under alternative straw management practices. Agron. J. 92:1096-1103.

Gilmour, J., Cogger, C., Jacobs, L.W., Wilson, S.A., Evanylo, G.K., Sullivan, D.M. 2000. Estimating plant-available nitrogen in biosolids. Project 97-REM-3, Water Environment Research Foundation, Alexandria, VA. 46 p.

Klose, S., and M.A. Tabatabai. 2000. Urease activity of microbial biomass in soils as affected by cropping systems. Biol. Fertil. Soils 31: 191-199.

Klose, S., and M.A. Tabatabai. 2000. Soil microbial biomass carbon and nitrogen as affected by cropping systems. Biol. Fertil. Soils 31: 200-210.

Poudel, D.D., W.R. Horwath, J. P. Mitchell, S.R. Temple. 2001. I Impacts of Cropping Systems on Soil Nitrogen Storage and Loss. Agricultural. Ecosystems. Environment Journal. Accepted.

Poudel, D.D., W.R. Horwath, S.R. Temple, W.T. Lanini, and A.H.C. van Bruggen. 2001. Potential of plant tissue nitrogen as an indicator of crop yield and soil nitrogen availability in farming systems. Agricultural. Ecosystems. Environment Journal. Accepted.

Randall,G. W., T. K. Iragavarapu, and M. A. Schmitt. 2000. Nutrient losses in subsurface drainage water from dairy manure and urea applied for corn. J. Environ. Qual. 29:1244-1252.

Ryan, K.E., E.J. Kladivco, M.V. Hickman, S.M. Brouder, C. Nakatsu, J.G. Graveel, and J. Santini. 2000. Soil quality improvement with cover crop mixtures. In Proceedings of the International Soil Tillage Research Organization (ISTRO) 2000 Conference, July 2-7, 2000, Fort Worth, Texas.

Schmidt, J. P., M. A. Schmitt, G. W. Randall, J. A. Lamb, J. H. Orf, and H. T. Gollany. 2000. Swine manure application to nodulating and nonnodulating soybean. Agron. J. 92:987-992.

Yamoah, C.F., D.T. Walters, C.A. Shapiro, C.A. Francis and M..J.. Hayes. 2000. Standardized precipitation index and nitrogen effects on yields and risk distribution of maize. Agr. Ecostys. Environ. 80:113-120.