Submitted to: ASA-CSSA-SSSA Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/7/2003
Publication Date: 11/7/2003
Citation: GOLDSTEIN, W., WOOD, A., WANDER, M., CAMBARDELLA, C.A., BARBER, W., JENSEN, K., MULCAHY, J. ORGANIC CORN PRODUCTION, ORGANIC MATTER MANAGEMENT, AND ROOT HEALTH. ASA-CSSA-SSSA PROCEEDINGS. 2003. CD-ROM. MADISON, WI.
Technical Abstract: Organic farmers depend on the mineralization of N from soil organic matter and organic manures for growing corn. We developed an organic matter and nutrient budgeter and a field-result-based budgeting system for N and tested them on 35 farms (1/2 organic, 1/2 conventional) in Wisconsin, Iowa, and Illinois in 2001 and 2002. Soil, crop, and weed N were monitored on field trials with and without mineral fertilizer or manure. Corn root disease was evaluated at anthesis. The budgeter predicted that soils in cash-grain conventional grain systems and alternative green manure systems would equilibrate at a soil organic matter content of about 2 percent, while soils in systems with perennial forages and animal manure applications would equilibrate at higher levels. The fraction of N mineralized from organic matter sources was negatively proportional to the total content of N in the topsoil. Mineralization was considerably higher in N poor soils and unfertilized plots than is generally considered or predicted. Amino sugar N did not correlate well with N uptake or the quantity or fraction of N mineralized. Corn seemed to be driving the mineralization of N from the topsoil. The effects of fertilization on corn were generally lower than expected, but were higher on low yielding sites. Corn grown in conventional systems or in transitional, green manure systems had twice as much root disease as corn grown in systems with a history of perennial forages and animal manure applications.