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N 2 O fluxes from a Haplic Luvisol under intensive production of lettuce and cauliflower as affected by different N‐fertilization strategies
Author(s) -
Pfab Helena,
Palmer Iris,
Buegger Franz,
Fiedler Sabine,
Müller Torsten,
Ruser Reiner
Publication year - 2011
Publication title -
journal of plant nutrition and soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 1436-8730
DOI - 10.1002/jpln.201000123
Subject(s) - human fertilization , fertilizer , frost (temperature) , winter wheat , agronomy , chemistry , soil water , nitrogen , crop rotation , zoology , environmental science , horticulture , crop , biology , soil science , organic chemistry , geomorphology , geology
Vegetable‐production systems often show high soil mineral‐N contents and, thus, are potential sources for the release of the climate‐relevant trace gas N 2 O from soils. Despite numerous investigations on N 2 O fluxes, information on the impact of vegetable‐production systems on N 2 O emissions in regions with winter frost is still rare. This present study aimed at measuring the annual N 2 O emissions and the total yield of a lettuce–cauliflower rotation at different fertilization rates on a Haplic Luvisol in a region exposed to winter frost (S Germany). We measured N 2 O emissions from plots fertilized with 0, 319, 401, and 528 kg N ha –1 (where the latter three amounts represented a strongly reduced N‐fertilization strategy, a target value system [TVS] in Germany, and the N amount fertilized under good agricultural practices). The N 2 O release from the treatments was 2.3, 5.7, 8.8, and 10.6 kg N 2 O‐N ha –1 y –1 , respectively. The corresponding emission factors calculated on the basis of the total N input ranged between 1.3% and 1.6%. Winter emission accounted for 45% of the annual emissions, and a major part occurred after the incorporation of cauliflower residues. The annual N 2 O emission was positively correlated with the nitrate content of the top soil (0–25 cm) and with the N surpluses of the N balance. Reducing the amount of N fertilizer applied significantly reduced N 2 O fluxes. Since there was no significant effect on yields if fertilization was reduced from 528 kg N ha –1 according to “good agricultural practice” to 401 kg N ha –1 determined by the TVS, we recommend this optimized fertilization strategy.