Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

FURTHER EVIDENCE FOR THE IMPORTANCE OF RESIDUAL LEAF PROTEIN COMPLEXES IN LITTER DECOMPOSITION AND THE SUPPLY OF NITROGEN FOR PLANT GROWTH

W. R. C. HANDLEY
Plant and Soil
Vol. 15, No. 1 (August 1961), pp. 37-73
Published by: Springer
Stable URL: http://www.jstor.org/stable/42931925
Page Count: 37
  • More info
  • Cite this Item
FURTHER EVIDENCE FOR THE IMPORTANCE OF RESIDUAL LEAF PROTEIN COMPLEXES IN LITTER DECOMPOSITION AND THE SUPPLY OF NITROGEN FOR PLANT GROWTH
Preview not available

Abstract

The nitrogen absorbed by birch seedlings grown in sand culture has been used as a measure of the resistance to decomposition of complexes formed in vitro by interaction between protein and water-extractable leaf constituents of Calluna vulgaris, Chamaenerion angustifolium and Circaea lutetiana. The resistance to decomposition of these complexes measured in this way is Calluna vulgaris > Chamaenerion angustifolium > Circaea lutetiana. This result seems to be in agreement with the soil-forming and field characteristics of these species and especially the raw humus-forming tendencies of Calluna vulgaris. The nitrogen released, as measured by the nitrogen absorbed by birch seedlings, from Calluna raw humus (H-layer material) and the model protein— Calluna leaf extractives complex is very nearly proportional to the widely different amounts of total nitrogen initially added to the root environment thereby suggesting that the organic nitrogen of the model complex and of the Calluna raw humus have similar properties. The amount of nitrogen absorbed by the birch seedlings when unaltered protein was added to the sand culture was less than when protein—Circaea lutetiana leaf extractives complex was added. This is ascribed to too rapid release and loss of nitrogen before it could be absorbed by the birch seedling roots and suggests a role for some leaf protein complexes in the conservation of litter nitrogen. Some possible effects of protein complexes in relation to the digestion of fresh and dry leaf material of various plant species by animals are discussed. Information from archeological observations and from investigations into the tanning of proteins is considered in relation to possible factors influencing the decomposition of protein complexes of litter and it seems probable that a less acid reaction, e.g. such as is brought about by the addition of adequate amounts of calcareous material, will assist the mobilization of the nitrogen of raw-humus-forming litter. The contention that the protein-precipitating substances of leaves are of fundamental importance in soil processes, especially raw humus formation and the supply of nutrients for plant growth, is considered to be supported by experimental approaches from different directions.

Page Thumbnails

  • Thumbnail: Page 
37
    37
  • Thumbnail: Page 
38
    38
  • Thumbnail: Page 
39
    39
  • Thumbnail: Page 
40
    40
  • Thumbnail: Page 
41
    41
  • Thumbnail: Page 
42
    42
  • Thumbnail: Page 
43
    43
  • Thumbnail: Page 
44
    44
  • Thumbnail: Page 
45
    45
  • Thumbnail: Page 
46
    46
  • Thumbnail: Page 
47
    47
  • Thumbnail: Page 
48
    48
  • Thumbnail: Page 
49
    49
  • Thumbnail: Page 
50
    50
  • Thumbnail: Page 
51
    51
  • Thumbnail: Page 
52
    52
  • Thumbnail: Page 
53
    53
  • Thumbnail: Page 
54
    54
  • Thumbnail: Page 
55
    55
  • Thumbnail: Page 
56
    56
  • Thumbnail: Page 
57
    57
  • Thumbnail: Page 
58
    58
  • Thumbnail: Page 
59
    59
  • Thumbnail: Page 
60
    60
  • Thumbnail: Page 
61
    61
  • Thumbnail: Page 
62
    62
  • Thumbnail: Page 
63
    63
  • Thumbnail: Page 
64
    64
  • Thumbnail: Page 
65
    65
  • Thumbnail: Page 
66
    66
  • Thumbnail: Page 
67
    67
  • Thumbnail: Page 
68
    68
  • Thumbnail: Page 
69
    69
  • Thumbnail: Page 
70
    70
  • Thumbnail: Page 
71
    71
  • Thumbnail: Page 
72
    72
  • Thumbnail: Page 
73
    73