The fate of slurry-N fractions in herbage and soil during two growing seasons following application

Abstract

Farmers are under increasing pressure to use slurry-nutrients more efficiently in order to maximise crop utilisation and minimise losses to the environment. The objective of this field experiment was to quantify the fate of three N fractions (urine-N [U], rapid faecal-N [FR] and slow faecal-N [FS]) from cattle slurry in herbage and soil. The recovery of the three slurry-N fractions was measured in the first and second year after application on a permanent grassland in Ireland. Urine and faeces were collected from cows fed with 15 N-labelled herbage, or unlabelled herbage with added 15 N-labelled urea and these were recombined to produce differentially labelled experimental slurries. Slurries were applied to plots, and 15 N-enrichments of the herbage and three soil layers were determined. The initial recovery of 15 N (6 weeks after application) in herbage was 18%, 13%, 2%, while the residual recovery (12-63 weeks) was 4%, 6% and 7% for U, FR and FS, respectively. The total slurry-N recovery in the plant-soil system was estimated to range from 45% for urine-N to 72% for faecal-N. These results increase our mechanistic understanding of slurry-N dynamics in soil-plant systems and will inform models used to predict the fate of cattle slurry applied to grassland.

Impact of chemically amended pig slurry on greenhouse gas emissions, soil properties and leachate

“…It would appear in the current study that a large amount of volatilization occurred from both amended and unamended slurry treatments with little unvolatilised inorganic N remaining, which is in agreement with previous studies (Morvan et al, 1997;Hoekstra et al, 2010;Hoekstra et al, 2011). Indeed, these rates of volatilization may represent a loss of 50-80% of total ammoniacal nitrogen from landspread slurry over a 10-d period (Misslebrook et al, 2005a(Misslebrook et al, , 2005bMeade et al, 2011).…”

Effects of Dietary Protein Concentration on Ammonia Volatilization, Nitrate Leaching, and Plant Nitrogen Uptake from Dairy Manure Applied to Lysimeters

“…Thomsen (2001) reported total recovery of 15 N-labeled sheep manure in winter wheat of 8.1 to 9.6% (anaerobically stored vs. composted manure) with slightly higher recovery for urinary (10.1 and 8.5%) vs. fecal N (7.2 and 7.6%, respectively). In a more recent study with 15 N-labeled cattle urine and feces, Hoekstra et al (2011) reported an initial recovery of urinary-15 N 6 wk after application in permanent grassland herbage of 18% vs. 13 and 2% for rapidly degradable (primarily non-neutral detergent fiber-bound N) and slowly degradable (neutral detergent fiber-N) fecal N, respectively.…”

The interactive effects of fertiliser nitrogen with dung and urine on nitrous oxide emissions in grassland

“…Although the ammonification of water-soluble organic N compounds in dung is rapid, the remaining N is resistant to mineralisation (Hoekstra et al, 2011). Consequently, mineralisation of the organic N in dung may take months to years (Ball and Ryden, 1984;Hoekstra et al, 2011).…”