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Availability of Nitrogen in 15N‐Labeled Ruminant Manure Components to Successively Grown Crops
Author(s) -
Jensen B.,
Sørensen P.,
Thomsen I. K.,
Christensen B. T.,
Jensen E. S.
Publication year - 1999
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/sssaj1999.03615995006300020021x
Subject(s) - straw , lolium perenne , manure , agronomy , hordeum vulgare , hay , feces , chemistry , ruminant , mineralization (soil science) , poaceae , dry matter , perennial plant , zoology , liquid manure , crop residue , fertilizer , crop , nitrogen , biology , agriculture , paleontology , organic chemistry , ecology
To improve crop N use efficiency of animal manures, the availability of N in individual manure components must be better understood. This microplot field study quantifies crop offtakes of N in four similar batches of ruminant manure containing 15 N‐labeled urine, feces, or straw, or unlabeled components only. The urine and feces were from a sheep first fed unlabeled hay and then 15 N‐labeled hay. Manures (≈ 19 g total N m ‐2 ) were incorporated into two coarse‐textured soils before planting to spring barley ( Hordeum vulgare L.) undersown with perennial ryegrass ( Lolium perenne L.). Manures with one 15 N‐labeled component were supplemented with unlabeled NH 4 NO 3 (7.3 g N m ‐2 ), while unlabeled manure was given 15 NH 4 15 NO 3 . Labeled and unlabeled N were determined in the spring barley at maturity and in six cuts of ryegrass taken during the succeeding 2.5 yr. The homogeneity of feces and urine 15 N‐labeling was high. Dry matter yields and crop N offtakes were similar in all treatments. Barley (grain and straw) recovered 40, 26, 10, and 6%, respectively of 15 N added with mineral fertilizer, urine, straw, and feces. Weighted mean recovery of the combined manure and fertilizer dressing was 22% of the added 15 N. Crop recovery of urine and feces 15 N was smaller and that of straw 15 N higher than reported in previous studies on individual components, indicating that the N mineralization‐immobilization turnover (MIT) of the manure components interacted. In the second and third growth seasons, 2.7 to 4.4% and 1.1 to 2.0% of the 15 N was recovered in grass cuts, respectively. Total recovery ranged from 84 to 95% of the added 15 N, suggesting small N losses from this cropping system.