ISSN:
1572-9680
Keywords:
allelopathy
;
intercropping
;
nitrification
;
poplar
;
walnut
;
juglone
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Juglone (5-hydroxy-1,4-naphthoquinone), a chemical substance produced by black walnut (Juglans nigra L.), inhibits the growth and existence of some beneficial soil microorganisms, especially Frankia spp. isolate ArI3 and Rhizobium japonicum. However, no studies to date have reported on the effect of juglone on soil ammonification and nitrification. A field study and laboratory incubation study to investigate this were conducted. In the field, in situ soil ammonification and nitrification were measured within and outside of a 60-year-old black walnut plantation and a eight-year-old poplar (Populus spp. clone DN 177) plantation. In the lab, soil (Sandy Fox Loam), collected in the absence of black walnut trees, was incubated for periods of one to six weeks in the presence of varying concentrations of juglone. In the field, peak summer mean nitrate accumulation rates in soils within the black walnut and poplar plantation were 163 and 95 μg 100 g-1 dry soil day-1 respectively and in soils outside the plantations, 104 (black walnut) and 78 (poplar) μg 100 g-1 dry soil day-1 respectively. No accumulation of ammonium at the end of the incubation period was noted. Therefore, no inhibition effect of juglone on nitrification in the field was observed, and laboratory incubation results confirmed the results of the field study. Results from these studies should address concerns about nitrification inhibition under walnut based intercropping systems.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1006265620897
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