ISSN:
1435-0661
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
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 15N-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 15N-labeled component were supplemented with unlabeled NH4 15NO3 (7.3 g N m-2), while unlabeled manure was given 15NH4 15NO3. 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 15N-labeled 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 15N added with mineral fertilizer, urine, straw, and feces. Weighted mean recovery of the combined manure and fertilizer dressing was 22% of the added 15N 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 15N was recovered in grass cuts, respectively. Total recovery ranged from 84 to 95% of the added 15N, suggesting small N losses from this cropping system.
Type of Medium:
Electronic Resource
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