Premium
Nitrous oxide emissions from grassland in an intensive dairy farm in the Basque Country of Spain
Author(s) -
Merino M.P.,
Estavillo J.M.,
Pinto M.,
Rodríguez M.,
Duñabeitia M.K.,
GonzálezMurua C.
Publication year - 2001
Publication title -
soil use and management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.709
H-Index - 81
eISSN - 1475-2743
pISSN - 0266-0032
DOI - 10.1111/j.1475-2743.2001.tb00017.x
Subject(s) - fertilizer , slurry , nitrous oxide , environmental science , ammonium , agronomy , nitrogen , ammonium nitrate , nitrate , soil water , zoology , chemistry , soil science , environmental engineering , biology , organic chemistry
. Intensively managed grasslands are potentially a large source of N 2 O in the North Coast of Spain because of the large N input, the wet soil conditions and mild temperatures. To quantify the effect of fertilizer type and management practices carried out by farmers in this area, field N 2 O losses were measured over a year using the closed chamber technique. Plots received two types of fertilizer: cattle slurry (536 kg N ha –1 ) and calcium ammonium nitrate (140 kg N ha –1 ). N 2 O losses were less in the slurry treatment than after mineral fertilizer. This was probably due to high, short‐lived peaks of N 2 O encountered immediately following mineral N addition. In contrast, the seasonal distribution of N 2 O losses from the slurry amended plot was more uniform over the year. The greater N 2 O losses in the mineral treatment might have been enhanced by the combined effect of mineral fertilizer and past organic residues present from previous organic amendments. Weak relationships were found between N 2 O emission rates and soil nitrate, soil ammonium, soil water content and temperature. Better relationships were obtained in the mineral treatment than in the slurry plots, because of the wider range in soil mineral N. Water filled pore space (WFPS) was a key factor controlling N 2 O emissions. In the > 90% WFPS range no relationships were found. The best regressions were found for the mineral treatment in the 40–65% WFPS range, 49% of the variance being explained by soil nitrate and ammonium content. In the 65–90% WFPS range, 43% of the variance was explained by nitrate only, but the inclusion of soil ammonium did not improve the model as it did in the 40–65% WFPS range. This fact indicates that nitrification is likely to be an important process involved in N 2 O emissions at the 40–65% WFPS.