|
|
||||||||
ABSTRACT
Humic substances have been reported to increase plant growth. A stimulating effect on the growth of legumes may improve biological nitrogen fixation in soils. The present investigation studied dry matter production, nodulation and N content in nodules of soybean (Glycine max L., Bragg), peanut (Arachis hypogaea L., Florunner), and clover (Trifolium vesiculosum, Arrow leaf), grown in sand cultures containing a fertilizer mixture and 0 to 800 mg kg–1 (ppm) of fulvic acid (FA) or humic acid (HA). The results indicated that FA and HA were capable of stimulating dry matter production in the plants. Dry weights of roots and nodules showed a tendency to increase over the control at 100 to 400 mg kg–1 (ppm) of FA or HA. The increases in total dry matter production were statistically significant at 800 mg kg–1 (ppm) of FA or HA, and a positive correlation was noticed between increases in dry weights of shoots, roots, and nodules and FA and HA concentrations. Fewer nodules were produced by plants receiving FA and HA treatments than the control, but the nodule mass was greater with the FA and HA treatments. The N content of nodules was little affected by the treatments, although a tendency can be noticed that 100 mg kg–1 (ppm) of FA had decreased the N content in the nodules of both soybean and peanut plants.
1 Contribution of the University of Georgia, College Agric. Exp. Stn., College Station, Athens, GA. This research was supported by State and Hatch funds allocated to the University of Georgia Agric. Exp. Stn. and conducted at the College Station, Athens, GA.
2 Professor and former Graduate Student, respectively, Dep. of Agronomy, University of Georgia, Athens, GA 30602.
Received for publication December 9, 1982. Accepted for publication July 27, 1983.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Crop Science | |||
| Vadose Zone Journal | Journal of Plant Registrations | ||||
| Journal of Natural Resources and Life Sciences Education |
Journal of Environmental Quality |
||||