Abstract
We investigated the effect of planting density on soybean (Glycine max (L.) Merr.) yield in glasshouse and field experiments. Because net canopy photosynthesis increases with increasing plant density, we hypothesized that increasing planting density would result in increasing rates of dinitrogen fixation in soybeans and higher yields per unit land area.
In glasshouse studies, Wayne variety soybeans were planted in 10-cm diameter pots, 1 plant pot-1 in matrices of 10-, 15-, 20-, 25-, or 30-cm equidistant intervals. Bradyrhizobium japonicum inoculum was added to half of the plants in each treatment. Replicate measurements of total stem height, internode lengths, leaf mass, stem mass, root mass, nodule number, nodule mass, and nitrogenase activity were obtained at 3, 6, and 9 weeks post-emergence. Fruits were harvested and counted at week 14. As planting density increased there were (1) altered morphology and growth rates, (2) increased apparent specific nodule activity (SNA), (3) decreased nodule number and mass, and (4) nearly constant fruit and seed production/plant. Expressed on a unit area basis, nitrogen influx and yield increased geometrically as planting density increased, with maximum values observed for 10-cm plantings.
Field studies of Wayne, Stein, Williams, and Gold Harvest soybean varieties were made in 1985. Plots were established containing 100 plants spaced at 10-, 20-, and 30-cm distances. Measurements made during the growing season and at harvest established the same relative trends identified from the glasshouse studies. Increasing plant densities resulted in higher yields per unit land. Varietal differences were almost significant.
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References
Atkins C A, Pate J S, Griffiths G J and White T 1980 Economy of carbon and nitrogen in nodulated and non-nodulated (NO3-grown) cowpea [Vigna unguiculata (L.) Walp.]. Plant Physiol. 66, 978–983.
Basnet B, Mader E L and Nickell C D 1974 Influence of between and within-row spacing on agronomic characteristics of irrigated soybeans. Agron. J. 66, 657–659.
Bergersen F J 1970 The quantitative relationship between nitrogen fixation and the acetylene-reduction assay. Aust. J. Biol. Sci. 23, 1015–1025.
Bergersen F J 1980 Methods for Evaluating Biological Nitrogen Fixation. Wiley, New York.
Christy A L and Porter C A 1982 Canopy photosynthesis and yield in soybean. In Photosynthesis—Applications to Food and Agriculture. Ed. Govindjee. pp 499–511. Academic Press.
Cordonnier M J and Johnston T J 1983 Effects of wastewater irrigation and plant and row spacing on soybean yield and development. Agron. J. 75, 908–912.
Crafts-Brandner S J, Below F E, Harper J E and Hageman R H 1983 Metabolism of carbon and nitrogen by soybean seedlings in response to vegetative apex removal. Plant Physiol. 73, 6–10.
Doss B D and Thurber D L 1974 Irrigation, row width, and plant population in relation to growth characteristics of two soybean varieties. Agron. J. 66, 620–623.
Finn G A and Brun W A 1982 Effect of atmospheric CO2 enrichment on growth, nonstrutural carbohydrate content, and root nodule activity in soybean. Plant Physiol. 69, 327–331.
Imsande J and Ralston E J 1982 Dinitrogen fixation in male-sterile soybeans. Plant Physiol. 69, 745–746.
Lehman W F and Lambert J W 1960 Effects of spacing of soybean plants between and within rows on yield and its components. Agron. J. 84–86.
Minchin D M and Pate J S 1973 The carbon balance of a legume and the functional economy of its root nodules. J. Exp. Bot. 24, 259–271.
Munoz A E, Holt E C and Weaver R W 1983 Yield and quality of soybean hay as influenced by stage of growth and plant density. Agron. J. 75, 147–14.
Noel K D, Carneol M and Brill W J 1982 Nodule protein synthesis and nitrogenase activity of soybeans exposed to fixed nitrogen. Plant Physiol. 70, 1236–1241.
Patterson T G and LaRue T A 1983 Root respiration associated with nitrogenase activity (C2H2) of soybean, and a comparison of estimates. Plant Physiol. 72, 701–705.
Paul E A and Kucey R 1981 Carbon flow in microbial associations. Science 213, 473–478.
Probst A H 1945 Influence of spacing on yield and other characters in soybeans. Am. Soc. of Agron. J. 37, 549–554.
Rainbird R M, Atkins C A and Pate J S 1983 Diurnal variation in the functioning of cowpea nodules. Plant Physiol. 72, 308–312.
Reibach P H and Streeter J G 1983 Metabolism of 14-C-labeled photosynthate and distribution of enzymes of glucose metabolism in soybean nodules. Plant Physiol. 72, 634–680.
Rinehart C A, Tingey S V and Anderson W R 1983 Variability of reaction kinetics for Ribulose-1,5-Bisphosphate carboxylase in a barley population. Plant Physiol. 72, 76–79.
Roberts G P and Brill W J 1981 Genetics and regulation of nitrogen fixation. Annu. Rev. Microbiol. 30, 207–235.
Rufty T W and Huber S C 1983 Changes in starch formation and activities of sucrose phosphate synthetase and cytoplasmic 6-bisphosphatase in response to source-sink alterations. Plant Physiol. 72, 474–480.
Smuker A J M, McBurney S L and Srivastava A K 1982 Quantitative separation of roots from compacted soil profiles by the hydropneumatic elutriation system. Agron. J. 74, 500–503.
Streeter J G, H J Mederski and Ahmad R A 1979 Coupling between photosynthesis and nitrogen fixation. In World Soybean Research Conference II: Proceedings. Ed. F T Corbin. pp 129–137. Westview Press, Boulder, CO.
Vance C P, Stade S and Maxwell A 1983 Alfalfa root nodule carbon dioxide fixation. Plant Physiol. 72, 469–473.
Wiggans R G 1939 The influence of space and arrangement on the production of soybean plants. Am. Soc. Agron. J. 31, 314–321.
Williams L E, DeJong T M and Phillips D A 1981 Carbon and nitrogen limitations on soybean seedlings. Plant Physiol. 68, 1206–1209.
Williams L E, DeJong T M and Phillips D A 1982 Effect of changes in shoot carbon-exchange rate on soybean root nodule activity. Plant Physiol. 69, 432–436.
Williams L E and Phillips D A 1980 Effect of irradiance on development of apparent nitrogen fixation and photosynthesis in soybean. Plant Physiol. 66, 968–972.
Zar J H 1974 Biostatistical Analysis. Prentice Hali, Englewood Cliffs, NJ. 620 p.
Zelitch I 1982 The close relationship between net photosynthesis and crop yield. BioScience 32, 796–802.
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Kapustka, L.A., Wilson, K.G. The influence of soybean planting density on dinitrogen fixation and yield. Plant Soil 129, 145–156 (1990). https://doi.org/10.1007/BF00032407
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DOI: https://doi.org/10.1007/BF00032407