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Production of Nitrogen‐15‐Labeled Pig Manure for Nitrogen Cycling Studies
Author(s) -
Sørensen Peter,
Thomsen Ingrid K.
Publication year - 2005
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2004.0364
Subject(s) - feces , manure , zoology , urine , incubation , nitrogen cycle , sativum , chemistry , mineralization (soil science) , nitrogen , biology , agronomy , biochemistry , ecology , organic chemistry
Nitrogen‐15 labeled pig ( Sus scrofa ) manure was produced to study the homogeneity of labeled pig manure prepared for soil N cycling studies. Growing pigs were fed with a diet consisting of mainly 15 N‐labeled barley ( Hordeum vulgare L.) and peas ( Pisum sativum L.) during a period of 11 d. Labeled feces and urine were collected separately. The 15 N enrichment of urine N was lower than that of fecal N except for the first 2 d of the 15 N feeding period. After 11 d of 15 N feeding, the 15 N enrichment of fecal N was 7% lower and urine N 28% lower than the enrichment of feed N. The homogeneity of 15 N‐labeling of feces N, sampled at different times during the 15 N feeding, was tested by an incubation test in quartz sand and soil. After 12 wk in soil at 20°C, 25 to 27% of the feces N was in inorganic form, and the N mineralization rate declined after this period. The test indicated that the 15 N‐labeled pig feces had a satisfactory labeling homogeneity even though the feed ingredients had variable 15 N enrichments. We recommend the collection of urine and feces separately and the use of labeled feces in combination with unlabeled urine and vice versa in studies of the fate of pig manure N in agroecosystems. If feces and urine with a similar 15 N enrichment can be obtained the two components can be mixed in the same manure.