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Nitrous oxide emissions and dynamics of soil nitrogen under 15 N‐labeled cow urine and dung patches on a sandy grassland soil
Author(s) -
Wachendorf Christine,
Lampe Carola,
Taube Friedhelm,
Dittert Klaus
Publication year - 2008
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.200625217
Subject(s) - lysimeter , leaching (pedology) , chemistry , soil water , zoology , pasture , grazing , urine , nitrogen , agronomy , ammonia volatilization from urea , environmental chemistry , environmental science , biology , soil science , organic chemistry , biochemistry
Grazing animals highly influence the nutrient cycle by a direct return of 80% of the consumed N in form of dung and urine. In the autumn‐winter period, N uptake by the sward is low and rates of seepage water in sandy soils are high, hence high mineral‐N contents in soil and in seepage water as well as large losses of N 2 O are expected after cattle grazing in autumn. The objective of this study was the quanitfication of N loss deriving from urine and dung leaching and by N 2 O emission. Therefore the deposition of urine and dung patches was simulated in maximum rates excreted by cows by application of 15 N‐labeled cow urine and dung (equivalent to 1030 kg N ha –1 and 1052 kg N ha –1 , respectively) on a sandy pasture soil in N Germany. Leachate was collected in weekly intervals from free‐draining lysimeters, and 15 N‐NO $ _3^- $ , 15 N‐NH $ _4^+ $ , and 15 N‐DON (dissolved organic N) were monitored over 171 d. Furthermore, the 15 N‐N 2 O emission rates and the dynamics of inorganic 15 N in the upper soil layer were monitored in a field trial, adjacent to the lysimeters. After 10 d following the urine application, the urea was completely hydrolyzed, shown by a 100% recovery of urine‐N in the soil NH $ _4^+ $ . The following decrease of 15 N‐NH $ _4^+ $ in the soil was higher than the increase of 15 N‐NO $ _3^- $ , and some N loss was explained by leaching. Amounts of 51% and 2.5% of the applied 15 N were found in leachate as inorganic N, 2.4% and 0.7% as DON derived from urine and dung, respectively. Release of N 2 O from urine and dung patches applied to the pasture was low, with losses of 0.05% and 0.33% of the applied 15 N, respectively. Overall loss of dung‐derived N was very low, but as the bulk dung N remained in the soil, N loss after mineralization of the dung needs to be investigated.