title: Leaching and utilization of nitrogen during a spring wheat catch crop succession.
abstract: An experiment covering a 2-yr spring wheat (Triticum aestivum L.) catch crop succession was conducted in lysimeters to account for the losses of N due to leaching. We sought to relate these losses to the N uptake of the main crop and to integrate the estimated N loss and uptake into a balance. The non-winter hardy catch crops [yellow mustard (Sinapis alba L.), Phacelia (Phacelia tanacetifolia Benth), and sunflower (Helianthus annuus L.)] as well as bare soil fallow were studied at low and high N input levels of 4 and 29 g N m(-2) yr(-1), respectively. Catch crops allowed for an effective reduction of N leaching of 0.33 to 1.67 g N m(-2) yr(-1) compared to fallow. Reductions in N leaching were achieved mainly by avoiding the fallow period during autumn and winter while the catch crop species grown had little impact. During the spring wheat growing season, N leaching losses were highest after yellow mustard, the most effective catch crop for the entire crop succession. A balance of N indicated that the reductions in N leaching exerted by the catch crops did not result in a higher overall utilization of N by spring wheat. Thus, the efficacy shown by catch crops in reducing N leaching during growth is relatively lower when considering the entire crop succession. In addition, the N saved by growing catch crops does not increase N utilization by succeeding spring wheat.
authors.affiliation: Institute of Plant Sciences, Swiss Federal Institute of Technology (ETH) Zurich, Eschikon 33, CH-8315, Lindau, Zurich, Switzerland. juan.herrera@jpw.agrl.ethz.ch
authors.forename: Juan M
authors.initials: JM
authors.lastname: Herrera
authors.forename: Markus
authors.initials: M
authors.lastname: Liedgens
mesh_terms: D018556:Crops, Agricultural / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D012621:Seasons; D014908:Triticum / Q000378:metabolism*
chemical_list: D009584:Nitrogen