ISSN:
1573-0867
Keywords:
ground water nitrate
;
irrigation N
;
N uptake
;
N use efficiency
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract In order to achieve efficient use of nitrogen (N) and minimize pollution potentials, producers of irrigated maize (Zea mays L.) must make the best use of N from all sources. This study was conducted to evaluate crop utilization of nitrate in irrigation water and the effect N fertilizer has on N use efficiencies of this nitrate under irrigated maize production. The study site is representative of a large portion of the Central Platte Valley of Nebraska where ground water nitrate-N (NO3-N) concentrations over 10 mg L−1 are common. Microplots were established to accommodate four fertilizer N rates (0, 50, 100, and 150 kg ha−1) receiving irrigation water containing three levels of NO3-N (0, 10, 20 mg L−1). Stable isotope15N was applied as a tracer in the irrigation water for treatments containing 10 and 20 mg L−1 NO3-N. Plots that did not receive nitrate in the irrigation water where tagged with15N fertilizer as a sidedress treatment. Sidedressed N fertilizer significantly reduced irrigation-N uptake efficiencies. When residual N uptake is added to first year plant usage, total irrigation NO3-N uptake efficiencies are similar to total sidedress N fertilizer uptake efficiencies for our cropping system over the two year period. Efficiency of irrigation-N use depends on crop needs and availability of N from other sources during the irrigation season.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00750252
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