If you need an accessible version of this item please contact JSTOR User Support

Effects of Excessive Natural Mulch on Development, Yield, and Structure of Native Grassland

J. E. Weaver and N. W. Rowland
Botanical Gazette
Vol. 114, No. 1 (Sep., 1952), pp. 1-19
Stable URL: http://www.jstor.org/stable/2472855
Page Count: 19
  • Download PDF
  • Cite this Item

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.

If you need an accessible version of this item please contact JSTOR User Support
Effects of Excessive Natural Mulch on Development, Yield, and Structure of Native Grassland
Preview not available

Abstract

1. An upland prairie, undisturbed by mowing, grazing, or burning for 15 years, was studied. About 80% was covered with a nearly pure stand of Andropogon gerardi. Similar stands of Panicum virgatum and Sporobolus heterolepis each occupied about 9%. 2. A dense natural mulch, 4.5-8 inches deep and weighing 6-9 tons per acre, covered the deep loam soil. The mulch intercepted much precipitation but promoted more rapid infiltration of water which reached the soil and greatly retarded evaporation. It increased the organic matter of the surface soil 1.5-2% and nitrogen content 0.1% of its oven-dry weight. 3. Roots and rhizomes grew thickly below the mulch and mellowed the surface soil. Pore space was 61.7%, and volume-weight was 0.97. 4. Soil temperatures 22⚬-28⚬ F. lower under the mulch in May delayed growth about 3 weeks compared with plants where the mulch had been removed. Production of flower stalks was considerably later in all mulched grasses and also less in Andropogon. Flower stalks were abundant on all unmulched grasses. 5. Yields in June, July, and August were 53, 26, and 29% less from mulched stands of Andropogon, and 57, 55, and 26% less in Panicum than those from unmulched stands. 6. Consequences of the effects of the mulch upon the environment were the production of a nearly pure, but some-what thinner than normal, stand of Andropogon. The understory characteristic of upland prairie had all but disappeared. The usual mid grasses of upland were few or none. Only a few of the taller forbs remained. 7. Dense stands of Panicum with forbs characteristic of very moist sites were typical. Between the large bunches of prairie dropseed the deeply mulched soil was usually free of vegetation.

Page Thumbnails

  • Thumbnail: Page 
1
    1
  • Thumbnail: Page 
2
    2
  • Thumbnail: Page 
3
    3
  • Thumbnail: Page 
4
    4
  • Thumbnail: Page 
5
    5
  • Thumbnail: Page 
6
    6
  • Thumbnail: Page 
7
    7
  • Thumbnail: Page 
8
    8
  • Thumbnail: Page 
9
    9
  • Thumbnail: Page 
10
    10
  • Thumbnail: Page 
11
    11
  • Thumbnail: Page 
12
    12
  • Thumbnail: Page 
13
    13
  • Thumbnail: Page 
14
    14
  • Thumbnail: Page 
15
    15
  • Thumbnail: Page 
16
    16
  • Thumbnail: Page 
17
    17
  • Thumbnail: Page 
18
    18
  • Thumbnail: Page 
19
    19