ISSN:
1435-0661
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Triticum aestivum L.) experiments were selected for use of 15N to evaluate fertilizer recovery in the grain, straw, and soil. Each experiment included variable nitrogen rates that had been incorporated preplant each year for 〉 20 yr. In 1988, ammonium nitrate enriched with 11.888 atom % 15N (15NH4 15NO3) was applied to microplots within the main plots of these long-term experiments. Conventional ammonium nitrate (0.366% 15N) was added to the microplots the following 2 yr to allow measurement of residual effects of the enriched fertilizer. Three years after the 15N microplots were established, soil cores (0.025 m in diam.) were taken to a depth of 1.20 m and partitioned into 0 to 0.15, 0.15 to 0.30, 0.30 to 0.45, 0.45 to 0.60, 0.60 to 0.90, and 0.90 to 1.20 m. From all microplots, percentage 15N recovered in the grain and straw at harvest and in the soil was determined and expressed as atom % excess corrected for background abundance. Total fertilizer N recovery (15N removed in the grain and straw plus that remaining in the soil) decreased with increasing N application at both locations. Results from this study combined with previously published findings from these locations suggest that fertilizer N recovery was greater where there was: (i) no evidence of priming (increased net mineralization of organic N pools when low rates of fertilizer N are applied); and (ii) reduced soil-plant buffering (N that can be applied in excess of the amount needed for maximum yield without resulting in increased soil profile inorganic N accumulation).
Type of Medium:
Electronic Resource
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