EFFECTS OF SOIL NITRATE LEVEL ON NITROGEN DISTRIBUTION AND REMOBILIZATION IN FIELD-GROWN SOYBEANS (Glycine max (L.) Merr.)

1986 ◽  
Vol 66 (1) ◽  
pp. 67-77 ◽  
Author(s):  
B. R. BUTTERY

Soil tests, nodule weights, acetylene reduction rates and nitrate reductase measurements indicated that considerable differences in mode of N-nutrition of soybeans (Glycine max (L.) Merr.) were achieved by treating field plots with ground-up corn cobs or with high levels of NH4NO3. This had no effect on the final N content or dry weight of the seed or whole plant. Treatment differences at 78–85 days in N content, apparent mobilization (transfer) from non-seed parts of the plant, N content and mobilization of N in lower leaves suggest that the route to this common end product differed between the two soil treatments. Movement of N out of the leaves was estimated by weekly sampling of individual leaves at all nodes on the plant. Lower leaves began transferring N and dry matter to other parts of the plant before pods had begun to form. The leaves provided the same amounts of N (287–293 mg/plant) in both soil treatments, but pods, stems and roots in the +cobs treatment provided 234 mg N but only 166 mg N in the +NO3 treatment.Key words: Soybean, nitrate, N2-fixation, re-mobilization, nitrate reductase

2000 ◽  
Vol 77 (10) ◽  
pp. 1432-1438
Author(s):  
J Kevin Vessey ◽  
Bert Luit

Previously, we have shown that the Glycine max (L.) Merr. -Bradyrhizobium japonicum symbiosis is very sensitive to inhibition by NH4+. The current study addresses whether the supernodulating soybean mutant, nts382, which is known to be tolerant of NO3-, is also tolerant of NH4+. The nts382 mutant and its wild-type parent, Bragg, were grown in continuous-flow hydroponic culture in the presence of 0, 0.25, 0.5, or 1.0 mM 15N-enriched NH4+. Plants were harvested at 14, 21, and 28 days after inoculation. Both cultivars had the highest dry weight (DW) at each harvest date when grown on 0.25 mM NH4+. At 0.25 mM NH4+, whole plant DW increased by 5.3- and 3.2-fold in Bragg and nts382, respectively, compared with the 0.0 mM NH4+ control by the end of the experiment. As expected, whole-plant nodulation (nodules per plant), DW-specific nodulation (nodules per gram root dry weight), and nodule DW were severely inhibited in Bragg at all levels of NH4+. However, in nts382, whole-plant nodulation was not affected by NH4+ treatment, and nodule DW increased by as much as fivefold. Whereas DW-specific nodulation decreased by 94% in Bragg, this parameter decreased by only 52% in the nts382 mutant. Likewise, while the nitrogen derived from the atmosphere decreased by approximately 40% in NH4+-supplied Bragg, it increased 2.8-fold at 0.25 and 0.5 mM NH4+ in nts382. This study demonstrates that both nodulation and N2 fixation in nts382 are more tolerant of NH4+ than in the wild-type Bragg.


2001 ◽  
Vol 36 (2) ◽  
pp. 249-256 ◽  
Author(s):  
Altair Toledo Machado ◽  
Ladaslav Sodek ◽  
Mânlio Silvestre Fernandes

In order to identify useful parameters for maize genetic breeding programs aiming at a more efficient use of N, two maize varieties of contrasting N efficiency, Sol da Manhã NF (efficient) and Catetão (inefficient) were compared. Experiments were carried out under field and greenhouse conditions, at low and high N levels. The parameters analysed included total and relative plant and grain N content, biomass and the activities of nitrate reductase and glutamine synthetase in different parts of the plant. It was found that the translocation efficiency of N and photoassimilates to the developing seeds and the source-sink relations were significantly different for the two varieties. N content of the whole plant and grain, cob weight and the relative ear dry weight were useful parameters for characterizing the variety Sol da Manhã NF as to its efficient use of N. Enzymes activity of glutamine synthetase (transferase reaction) and nitrate reductase did not differ among the varieties.


2019 ◽  
Vol 70 (7) ◽  
pp. 585 ◽  
Author(s):  
Xiaoning Cao ◽  
Tingting Wu ◽  
Shi Sun ◽  
Cunxiang Wu ◽  
Caijie Wang ◽  
...  

Root traits are essential for optimising nutrient and water absorption and anchorage. However, changes in root traits and the contribution of root-to-shoot growth and development of soybean (Glycine max (L.) Merr.) across a century of breeding are poorly documented. In this study, we adopted a grafting technique, using 55 cultivars released in the three main soybean-production regions in China as rootstocks in a pot experiment and 24 cultivars from the Yellow-Huai-Hai Valley (YHH) region as rootstocks in a field experiment, with cv. Zigongdongdou as the common scion. Changes in soybean roots, including dry weight (DW) of roots, lateral root number (LRN) and taproot length (TRL), and their contribution to shoot development and biomass formation, including shoot DW, plant height and node number, were evaluated under optimal conditions in 2011. Aboveground traits declined with year of release in the YHH region and did not vary over time in the northern Heilongjiang province and mid-south Heilongjiang region except for shoot DW. The root traits root DW, LRN and TRL were similar over years of release in the pot and field experiments. The results suggest that the newer cultivars have lesser shoot growth and root capacity but the same amount of root growth as older cultivars. Root traits did not change during selection, suggesting that improvement in soybean root traits should be an aim in future breeding.


2009 ◽  
Vol 89 (2) ◽  
pp. 265-272
Author(s):  
L. R. Brown ◽  
D. E. Robinson ◽  
K. Chandler ◽  
C. J. Swanton ◽  
R. E. Nurse ◽  
...  

There have been anecdotal accounts of increased crop sensitivity due to herbicide drift followed by an in-crop herbicide. An experiment was conducted from 2005 to 2007 at Elora, Ridgetown, and Woodstock, Ontario, to determine the effects of simulated mesotrione drift followed by in-crop applications of glyphosate, imazethapyr, bentazon and glyphosate plus chlorimuron on glyphosate-resistant soybean [Glycine max (L.) Merr.] visual injury, plant height, plant density, shoot dry weight, and seed yield. As the rate of simulated mesotrione drift increased, there was an increase in soybean injury and a decrease in shoot dry weight, height, and yield. Simulated mesotrione drift followed by bentazon resulted in synergistic responses in injury shortly after application in some environments. This increase in injury was transient, with no synergistic responses in density, shoot dry weight, and yield. In contrast, antagonistic responses were observed when glyphosate, imazethapyr, or glyphosate plus chlorimuron were applied after simulated mesotrione drift in some environments. Further research is required to develop a better understanding of the interactions of drift followed by the application of an in-crop herbicide. Key words: Bentazon, chlorimuron, glyphosate, imazethapyr, mesotrione, synergism


1986 ◽  
Vol 66 (3) ◽  
pp. 505-510 ◽  
Author(s):  
J. A. STONE ◽  
B. R. BUTTERY

The objective of this study was to determine the effect of nitrate on some morphological aspects of soybean (Glycine max (L.) Merr.) root growth and to determine the role of drainage in the response. Two indeterminate soybean cultivars were grown on 0, 10 and 40% mixtures of perlite and Brookston clay loam, supplied with Bradyrhizobium japonicum strain USDA 110, and watered with nutrient solutions containing 0 or 6 mM nitrate. Plants were grown in acrylic tubes until 21 and 53 d after emergence in corresponding field and growth room experiments, respectively. Response variables measured were the rate of taproot extension, root counts at the acrylic-soil interface, and top, root, and nodule dry weight. Nitrate suppressed nodule development and increased top dry weight but had no effect on the rate of taproot extension. Nitrate increased root counts and root dry weights in the field test, but decreased root counts in the growth room test. Top:root ratio was increased in the growth room but not in the field test. Increasing the proportion of perlite generally increased rates of root extension, root counts, and top dry weights in the field and growth room experiments. However, the soil mixture had no effect on nodule dry weight at either location, or on root dry weight in the growth room.Key words: Root extension, Glycine max, indeterminate, drainage


Author(s):  
Ogbuehi HC ◽  
Ibe PK

A pot experiment was conducted under rainfed condition to study the effect of water hyacinth compost on the morpho-physiological parameters of soybean (Glycine max L.) at the Teaching and Research Farm of Faculty of Agriculture and Veterinary Medicine, Imo State University, Owerri. The treatments were control (T1) 100g (T2), 150g (T3) and 200g (T4) of water hyacinth compost and replicated four times. The treatments were arranged in Complete Randomized Design (CRD). The parameters measured were plant height, number of leaves, leaf area (cm2), leaf area index, relative growth rate (RGR), Net assimilation rate (NAR), shoot dry weight(g), yield and yield components (Number of pods, pods weight, 100 seed weight). The results obtained indicated that T3 significantly produced highest plant height (57.6cm) compare to control. While it was observed that T4 (200g) significantly produced the highest number of leaves (233.25), leaf area (631.80cm2), shoot dry weight (15.445g), number of pods (129.75), pod weights (25.38g) seed weight (7.23g) and yield (0.72kg/ha) relative to control and other treatment levels. Root parameters were also significantly improved by the rates of water hyacinth application compared to control. It will be worthy to note that there was no nodulation perhaps that was why the yield was poor. The results showed that soybean growth can effectively be improved with incorporation of water hyacinth into soil.


Author(s):  
E. Oral ◽  
R. Tunçtürk ◽  
M. Tunçtürk

Background: This study was carried out to determine the effects of rhizobacteria and blue green algae applications on some physiological properties of soybean (Glycina max L.) grown under water stress. Methods: The experiment was conducted in factorial order with 4 replications according to the randomized plot trial design. In the research, Arýsoy variety belonging to soybean (Glycine max L.) species was used. In the experiment, it was aimed to examine the effects of three different irrigation levels (100, 50 and 25%) on some physiological characteristics of soybean with a control (control (B0), two different bacteria used. In this study, strains R1 of Azospirillum lipoferum bacteria, strains numbered 98 belonging to Bacillus megaterium bacteriaein and one blue green algae (Chlorella saccharophilia) were used. Result: According to the average data obtained, root length is 24.75 cm- 30.85 cm, seedling length 28.10-36.57 cm, root fresh weight 1.10-1.43 g, seedling wet weight 1.55-2.41 g, root dry weight 0.15-0.18 g, seedling dry weight 0.38-0.46 g, azote balance index 70.64-82.90 (dualex value), flavonol 0.375-0.398 (dualex value) and anthocyanin 0.016-0.045 (dualex value), with water restriction showed a decrease in most of these values. It has been determined that the rhizobacteria and blue-green algae have a decreasing and regulating effect on the physiological properties examined.


Sign in / Sign up

Export Citation Format

Share Document