ECOLOGICALLY-BASED SOIL AND CROP MANAGEMENT SYSTEMS FOR SUSTAINABLE AGRICULTURE
Location: North Central Agricultural Research Laboratory
Title: Soil, Maize Crop, and Kernel Composition Responses to Rotation and N Fertilizer Treatments
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 3, 2008
Publication Date: October 7, 2008
Citation: Riedell, W.E., Pikul Jr, J.L., Schumacher, T., Osborne, S.L., Jaradat, A.A. 2008. Soil, Maize Crop, and Kernel Composition Responses to Rotation and N Fertilizer Treatments. Agronomy Abstracts #672-6.
Interpretive Summary: Long-term experiments conducted at eastern US corn-belt locations have demonstrated 10 to 17 % greater yield in corn grown in rotation with other crops than when grown in monoculture. Improved yield under rotation is related to both soil and crop parameters. Crop rotations that include legumes increase soil nitrogen levels. Various scientific studies have concluded that much of the yield benefit observed from crop rotation with legumes, however, was due to factors other than increased soil nitrogen. Crop rotation improves soil structural stability, increases crop water use efficiency, increases soil organic matter levels, improves nutrient use efficiency, provides better weed control, and disrupts insect and disease cycles. Research conducted previously at the Eastern South Dakota Soil and Water Research Farm has demonstrated that mineral nutrient accumulation and grain yield were greater in corn grown under annual rotation with soybean than in corn grown in monoculture. We were interested in determining whether a corn-soybean-wheat/alfalfa-alfalfa rotation would have similar beneficial effects on soil fertility and crop mineral nutrition. Our experimental objectives were to investigate the effects of complex crop rotation on soil fertility and corn mineral nutrient composition. Understanding the complex interactions of soils, plants, and management practices is a first step towards development of agricultural systems that sustain food and fiber production.
Maize can utilize nitrogen (N) from inorganic fertilizers as well as from mineralized organic sources. We were interested in how maize responds to rotations that contain legumes. The objective of this 2-yr field investigation conducted on a long-term field study (started in 1990) was to measure effects of crop rotation (CC, continuous corn; CS, corn-soybean; CSWA, corn-soybean-wheat/alfalfa-alfalfa) and N fertilizer applications (based on yield goals of 8.5 or 5.3 Mg/ha, or no N fertilizer) on soil and crop characteristics. Planting-time soil samples (0-30 cm) revealed greater CEC, P (Bray-P1), K, S, and Ca (DTPA extraction) concentrations with increasing N fertilizer application rates. Soil nitrate N and Mn concentration increased while pH and P decreased with increasing rotation complexity. When measured at the VT stage, rotation treatments had no effect on plant height or LAI under high N fertilizer while CC plants had decreased height and LAI compared to other rotations under no N fertilizer. Grain yields across all N fertilizer rates were similar in the CS and CSWA rotations (about 7 Mg/ha). Yield under the CC rotation dropped (from about 6 Mg/ha at the high N to about 4 Mg/ha under no N) with decreased with N fertilizer rates. There were no differences in kernel protein across N fertilizer treatments for the CSWA rotation (105 g/kg), but kernel protein dropped (from about 95 g/kg under high N to about 75 g/kg under no N) in the CC and CS rotations. Oil was greater (about 37 g/kg) under CSWA rotation than under CC and CS rotations (about 33 g/kg). In conclusion, maize growth, yield, and kernel composition were more consistent under CSWA rotation than CC and CS across the three N fertilizer rates used in this study. Additionally, the CSWA rotation essentially replaced the need for inorganic N fertilizer applications.