title: Dissolved free and combined amino acids in surface runoff and drainage waters from drained and undrained grassland under different fertilizer management.
abstract: Organic matter is a valuable resource on which the sustainability and productivity of soils relies heavily. Thus, it is important to understand the mechanisms for the loss of organic compounds from soil. It is also essential to determine how these losses can be minimized, especially those resulting from anthropogenic activity. Grazed grassland lysimeters (1 hectare) were used to examine the contribution and distribution patterns of dissolved free and combined amino acids to dissolved organic nitrogen and carbon in surface runoff and drainage waters from a grassland soil over three winter drainage periods. The waters were collected from soils beneath drained and undrained permanent ryegrass swards, receiving 0 and 280 kg ha(-1) year(-1) mineral nitrogen (N) input. Total dissolved free amino acid (DFAA) and dissolved combined amino acid (DCAA) concentrations ranged between 1.9 nM and 6.1 microM and between 1.3 and 87 microM, respectively. Although addition of mineral N fertilizer increased both DFAA and DCAA concentrations in waters, there was no detectable effect of soil hydrology or fertilizer addition on distribution patterns.
authors.affiliation: Institute of Grassland and Environmental Research, Okehampton, Devon, United Kingdom. jane.hawkins@bbsrc.ac.uk
authors.forename: Jane M B
authors.initials: JM
authors.lastname: Hawkins
authors.forename: David
authors.initials: D
authors.lastname: Scholefield
authors.forename: Jim
authors.initials: J
authors.lastname: Braven
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D002244:Carbon / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D005308:Fertilizers; D015233:Models, Statistical; D009584:Nitrogen / Q000032:analysis*; D011891:Rain; D012987:Soil; D014867:Water / Q000032:analysis*; D014872:Water Movements; D014873:Water Pollutants / Q000032:analysis*; D014881:Water Supply
chemical_list: D000596:Amino Acids; D005308:Fertilizers; D012987:Soil; D014873:Water Pollutants; D014867:Water; D002244:Carbon; D009584:Nitrogen