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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Root-to-shoot communication in response to drought a comparison of four central hardwood tree species /

Loewenstein, Nancy J., January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 185-200). Also available on the Internet.
12

The effects of sugar maple (Acer saccharum Marsh.) and black walnut (Juglans nigra L.) on soil fertility : preliminary assessment of their agroforestry potential

Kipkech, Francis Chepkonga January 1995 (has links)
Two studies were carried out in the Morgan Arboretum of McGill University to explore the agroforestry potential of some native tree species of Southern Quebec. In the first study, soil chemical characteristics under basswood (Tilia americana L.), white ash (Fraxinus americana L.) and bitternut hickory (Carya cordiformis Wang. K. Koch) in relation to sugar maple (Acer saccharum Marsh.) were assessed in natural stands. Soil pH was highest under white ash and was lowest under bitternut hickory. Soil NO$ sb3 sp-$ was low under basswood compared to white ash. Soil pH and exchangeable soil Ca$ sp{2+}$ and Mn$ sp{2+}$ decreased with an increase in basal area and exchangeable soil K$ sp+$ decreased (p = 0.07) with an increase in the proportion of sugar maple relative to total basal area. / In the second study, the effects of black walnut (Juglans nigra L.) on growth and nutrient content of lettuce (Lactuca sativa L.), kale (Brussica oleracea L.), parsley (Petroselinum crispum) and Swiss chard (Beta vulgaris L.) in an alley cropping system were determined. The experiment was carried out in a randomized complete block design with repeated measures. All vegetables survived in the black walnut plantation and in the open field. The order of sensitivity to growth under black walnut was Swiss chard $>$ kale $>$ lettuce $>$ parsley. Low light intensity in the plantation likely decreased plant dry weights and nutrient content. Generally plant N, P and K concentrations were higher in the plantation while Ca, Mg and Mn concentrations were higher in the open field, possibly due to an antagonistic effect of high soil K$ sp+$ content in the plantation and to inhibitory effects of black walnut.
13

The effects of sugar maple (Acer saccharum Marsh.) and black walnut (Juglans nigra L.) on soil fertility : preliminary assessment of their agroforestry potential

Kipkech, Francis Chepkonga January 1995 (has links)
No description available.

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