Articles
NITROGEN NET MINERALIZATION UNDER FIELD CONDITIONS IN AN IRRIGATED SOIL.
Article number
335_8
Pages
81 – 94
Language
Abstract
Samples of a soil of known N-mineralization rates, previously determined under controlled moisture and temperature in the laboratory, were periodically collected from two plots that had been differently N fertilized for five years, receiving one twice as much N fertilizer as the other.
Within each plot, sampling area was restricted to four microplots which were plantless and covered with black polyethylene sheet in a furrow irrigated potato field.
Sampling at 20 or 30 cm depth increments was carried out to 120 cm depth.
Moist and refrigerated samples were analyzed for mineral N and moisture.
The plastic cover kept approximately constant soil moisture.
Soil mean daily temperature was measured by thermistors, connected to a data logger equipment, placed at 2, 10, 30 and 50 cm depth.
Within each plot, sampling area was restricted to four microplots which were plantless and covered with black polyethylene sheet in a furrow irrigated potato field.
Sampling at 20 or 30 cm depth increments was carried out to 120 cm depth.
Moist and refrigerated samples were analyzed for mineral N and moisture.
The plastic cover kept approximately constant soil moisture.
Soil mean daily temperature was measured by thermistors, connected to a data logger equipment, placed at 2, 10, 30 and 50 cm depth.
Net organic N mineralization in the whole soil profile sampled for a 74 day-summer period were 131 kg N/ha and 113 kg N/ha for the normal and low fertilized plots, respectively.
Contribution to those figures of the corresponding soil surface layer (0–20 cm) were 71% and 82%. Calculated field net N mineralization rates for the same period and surface soil ranged between 0.33 and 0.58 mg N/kg soil x day as compared to 0.37 to 0.42 mg N/kg soil x day obtained in soil samples in laboratory incubation experiment.
Authors
R. Llorca, I. Bautista, J. Oliver, G. Cruz-Romero
Keywords
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