Author
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Karlen, Douglas |
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Hunt, Patrick |
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Matheny, Terry |
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Submitted to: Crop Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/5/1995 Publication Date: N/A Citation: N/A Interpretive Summary: An improved understanding of how crop and soil management practices affect N cycling is needed to develop sustainable agricultural production practices. We measured the amount of labeled N fertilizer that was removed by the harvested portions of corn, wheat, and cotton crops to obtain this information for a major Coastal Plain Soil. Disked and non-disked tillage comparisons were included in the study but had only a slight effect on the recovery of labeled fertilizer, and this was attributed to differences in crop yield. Tillage did not appear to have an effect on how N was cycled in the soil and taken up by these crops. Total recovery by the crops ranged from 22 to 35% of the applied fertilizer, with most being taken up by the crop that received the labeled material. However, labeled fertilizer continued to be cycled from crop to crop and from year to year. When sampling was ended, 27 to 31% of the labeled fertilizer was still present in the top 90 cm of the soil profile. This information will help improve management practices and the overall sustainability of agriculture. Technical Abstract: This research was conducted to determine the fate of 15N fertilizer that was applied to corn, wheat, or cotton in a 2-year rotation on Norfolk loamy sand. A urea and ammonium nitrate solution that had a 5 atom percent (ATM%) label was applied to each of 48 microplots. Surface tillage effects were statistically significant (P |
