Black walnut nitrogen-fixing plants

Allelopathic Interference of Black Walnut Trees with Nitrogen-Fixing Plants in Mixed Plantings... 

To gain more understanding of the European alder decline and because of our concern about the future growth of black walnut planted with nitrogen-fixing species, a study was initiated to measure soil juglone concentration and to estimate the number of Nitrobacter and Nltrosomonas bacteria in a black walnut plantation containing plots of black walnut alone and in mixture with European alder and autumn-olive. 

Table I. Juglone Concentration in Soil According to Depth and Treatment in a Mixed Planting of Black Walnut and Nitrogen-fixing Species...

Table III. Mean Total and Nitrate Nitrogen, Organic Matter, and pH in Soil Beneath Black Walnut Planted in Mixture with Nitrogen-fixing Species...

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