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@PHDTHESIS{Rist:46949,
      author       = {Rist, Roland},
      title        = {{T}he impact of nutrient heterogeneity on maize plants},
      volume       = {70},
      school       = {Universität Düsseldorf},
      type         = {Dr. (Univ.)},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
      reportid     = {PreJuSER-46949},
      isbn         = {3-89336-464-1},
      series       = {Schriften des Forschungszentrums Jülich. Reihe Umwelt /
                      Environment},
      pages        = {XII, 74 S.},
      year         = {2006},
      note         = {Record converted from VDB: 12.11.2012; Universität
                      Düsseldorf, Diss., 2006},
      abstract     = {In this work the impact of heterogeneously distributed
                      nutrients on plants was examined. In splitroot experiments
                      Zea mays plants (Zea mays hybrid Helix) received the same
                      amounts of nutrients, with different fractions supplied to
                      each root compartment (0.5/0.5, 0.6/0.4, 0.7/0.3, 0.8/0.2,
                      0.9/0.1, 1.0/0.0). The amounts of nutrients were adapted to
                      the relative growth rate (RGR) of this species in order to
                      achieve a nutritional supply adapted to demand. Two
                      different experiments were run. In one experiment the amount
                      of nutrients was adapted to 1.5*RGR, in another experiment
                      to 0.5*RGR. With this experimental design, it was possible
                      to measure at what level of nutrient heterogeneity plants
                      responded and if these responses were influenced by the
                      total amounts of given nutrients. In addition, the impact of
                      nutrient heterogeneity on structural and functional
                      parameters was measured. The experiments indicated that
                      plants responded locally to nutrient heterogeneity by
                      changes in biomass, and that this response depended on the
                      nutrient status of the plants. Well fertilized plants
                      responded with different root biomass at a ratio of nutrient
                      supply of 0.6/0.4. In contrast to this, plants with a lack
                      of nutrients responded to an unequal supply of nutrients in
                      the 0.7/0.3 treatment. The ratio of given nutrients in the
                      root compartments were probably not responsible for this
                      different reaction, however, because the response was
                      possibly caused by a minimum difference of supplied nitrate
                      concentrations in the split root sides within the
                      treatments. If this difference in concentration was exceeded
                      long enough (> 4 days), plants responded. Nutrient
                      heterogeneity had no impact on the total plant, total root
                      and shoot biomass. But the nutrition status of the plants
                      influenced the shoot biomass. Well fertilized plants had
                      higher shoot biomass than plants under nutrient deprivation.
                      This was detectable in different shoot/root ratios, too. In
                      this work different functional parameters of plants with
                      heterogeneous nutrient supply were measured. Neither the
                      rate of photosynthesis nor the sugar and starch
                      concentrations in leaves and roots were influenced. On the
                      other hand with increasing heterogeneity, the concentration
                      of nitrogen in the above ground part of the plants as well
                      as in the total plant increased. In contrast to this, the
                      sulphur concentrations in the plants were not influenced.
                      This could be explained with different uptake systems for
                      nitrogen and sulphate and their distribution in the roots.
                      Furthermore the amino acid concentration in the leaves was
                      influenced by the heterogeneous distribution of supplied
                      nutrients. Irrespective of the nutritional status of the
                      plants, the control treatments (0.5/0.5) showed lower total
                      amino acid concentrations compared to the 1.0/0.0 treatment.
                      In this work it was demonstrated that the amount of supplied
                      nutrients had a stronger impact on plant behaviour than
                      their distribution. If plants responded structurally as well
                      as functionally to nutrient heterogeneity, these responses
                      were partly influenced by the nutritional status of the
                      plants, occurred locally and at the whole plant level.},
      cin          = {ICG-III},
      ddc          = {333.7},
      cid          = {I:(DE-Juel1)VDB49},
      pnm          = {Terrestrische Umwelt},
      pid          = {G:(DE-Juel1)FUEK407},
      typ          = {PUB:(DE-HGF)11 / PUB:(DE-HGF)3},
      url          = {https://juser.fz-juelich.de/record/46949},
}