Asymbiotic nitrogen fixation in litter from Pacific Northwest forests

1988 ◽  
Vol 18 (1) ◽  
pp. 68-74 ◽  
Author(s):  
B. Heath ◽  
P. Sollins ◽  
D.A. Perry ◽  
K. Cromack Jr.
Keyword(s):  
Nitrogen Fixation ◽  
C:N Ratio ◽  
Dry Weight ◽  
Weight Percent ◽  
Douglas Fir ◽  
The Other ◽  
N Fixation ◽  
Litter Layer ◽  
Willamette Valley ◽  
Asymbiotic Nitrogen Fixation

Asymbiotic nitrogen fixation in litter was assayed by acetylene reduction across a range of 25 forested sites in the Willamette Valley and Oregon Cascade and Coast ranges and periodically over a year at two Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) plantations in the Willamette Valley. Laboratory experiments showed that optimal conditions for N fixation by Douglas-fir litter were 200% moisture content and 22 °C. Annual fixation was 1.08 ± 0.13 kg/ha at one Willamette Valley plantation, 0.39 ± 0.06 kg/ha at the other. Fixation rates at the other 23 sites, which were sampled less frequently, ranged from 0 to 5 g N ha−1 day−1 and exceeded trace levels at only six sites, indicating annual totals much less than those at the Willamette Valley plantations. At four coastal and valley sites sampled by litter layer, older L layer Douglas-fir litter fixed the most N per gram dry weight. Percent N, percent C, and the C:N ratio of that litter layer did not differ significantly among sites or correlate with N-fixation rates. Forest-floor litter in most Northwest forests fixes no more than trace amounts of N, at most ~1 kg N ha−1 year−1. These amounts are smaller than N input from precipitation.

Patterns of log decay in old-growth Douglas-fir forests

1987 ◽  
Vol 17 (12) ◽  
pp. 1585-1595 ◽  
Author(s):  
Phillip Sollins ◽  
Steven P. Cline ◽  
Thomas Verhoeven ◽  
Donald Sachs ◽  
Gody Spycher
Keyword(s):  
C:N Ratio ◽  
Dry Weight ◽  
Douglas Fir ◽  
Time Span ◽  
Western Hemlock ◽  
Tissue Type ◽  
Old Growth ◽  
Total N ◽  
Red Cedar ◽  
Western Red Cedar

Fallen boles (logs) of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), western hemlock (Tsugaheterophylla (Raf.) Sarg.), and western red cedar (Thujaplicata Donn) in old-growth stands of the Cascade Range of western Oregon and Washington were compared with regard to their physical structure, chemistry, and levels of microbial activity. Western hemlock and western red cedar logs disappeared faster than Douglas-fir logs, although decay rate constants based on density change alone were 0.010/year for Douglas-fir, 0.016/year for western hemlock, and 0.009/year for western red cedar. We were unable to locate hemlock or red cedar logs older than 100 years on the ground, but found Douglas-fir logs that had persisted up to nearly 200 years. Wood density decreased to about 0.15 g/cm3 after 60–80 years on the ground, depending on species, then remained nearly constant. Moisture content of logs increased during the first 80 years on the ground, then remained roughly constant at about 250% (dry-weight basis) in summer and at 350% in winter. After logs had lain on the ground for about 80 years, amounts of N, P, and Mg per unit volume exceeded the amount present initially. Amounts of Ca, K, and Na remained fairly constant throughout the 200-year time span that was studied (100-year time span for Na). N:P ratios converged toward 20, irrespective of tree species or wood tissue type. C:N ratios dropped to about 100 in the most decayed logs; net N was mineralized during anaerobic incubation of most samples with a C:N ratio below 250. The ratio of mineralized N to total N increased with advancing decay. Asymbiotic bacteria in fallen logs fixed about 1 kg N ha−1 year−1, a substantial amount relative to system N input from precipitation and dry deposition (2–3 kg ha−1 year−1).

The Effects of Irrigation, Inoculants and Fertilizer Nitrogen on Peanuts (Arachis hypogaea L.). I. Nitrogen Fixation

1980 ◽  
Vol 7 (2) ◽  
pp. 114-119 ◽  
Author(s):  
V. M. Reddy ◽  
J. W. Tanner
Keyword(s):  
Nitrogen Fixation ◽  
Arachis Hypogaea ◽  
Dry Weight ◽  
N Fixation ◽  
Nitrogen Application ◽  
Fertilizer Nitrogen ◽  
Nodule Number ◽  
Arachis Hypogaea L ◽  
Different Strains

Abstract Effects of irrigation, inoculants and fertilizer nitrogen (N) on N2(C2H2) fixation in peanuts were studied in 1976 and 1977 at Delhi, Ontario. Inoculant application increased nodulation and N-fixation in both years. Powdered peat and granular formulations containing the same strains of rhizobia resulted in almost the same amounts of nodulation and N-fixation (80 kg/ha on average). Differences in nodulation from inoculants containing different strains of rhizobia were not consistent over the two years. However, 60% difference in N-fixation resulted from the inoculants containing different strains of rhizobia in both years. Nitrogen application decreased the nodule number, nodule dry weight, and N-fixation of all the inoculated peanuts. Irrigation increased the N-fixation of the peanuts treated with granular inoculant in 1976 by an average of 45% and all the inoculated peanuts in 1977 by an average of 54% but had no effect on nodulation in either year.

Studies in the nodulation of Kenya white clover (Trifolium semipilosum) under field conditions in south-east Queensland

1975 ◽  
Vol 15 (75) ◽  
pp. 519
Author(s):  
RM Jones ◽  
RA Date
Keyword(s):  
Nitrogen Fixation ◽  
White Clover ◽  
Nitrogen Deficiency ◽  
Dry Weight ◽  
Field Conditions ◽  
N Fixation ◽  
Original Strain ◽  
Serological Identification ◽  
Seed Application ◽  
Inoculum Strain

The nodulation of Kenya white clover (Trifolium semipilosum) was examined under field conditions to evaluate reported establishment problems attributed to poor nodulation. Two isolates of Rhizobium identified as strain CB782 were obtained from nodules of T. semipilosum located in separate field sowings each of which was considered an establishment failure but which had recovered to healthy stands at the time of sampling. The two isolates were compared with a laboratory maintained culture of CB782 for nodulation and nitrogen fixation. Both isolates and the original strain were equally effective in N-fixation and all three increased plant dry weight, per cent plants with effective (pink) nodules and amount of nitrogen fixed compared with an uninoculated control. Increasing the level of seed application of inoculum up to the normal rate increased effective nodulation, but excess inoculum levels resulted only in greater numbers of smaller effective (pink) nodules without any increase in nodule dry weight. High inoculum levels decreased the number of white and green nodules compared with the control. Over 50 per cent effective nodulation was obtained with less than 50 Rhizobium seed-1 at sowing. Serological identification and effectiveness tests of strains in nodules confirmed that most white and green nodules on T. semipilosum resulted from infection by naturally occurring white clover rhizobia. These were ineffective in nitrogen fixation with T. semipilosum but fully effective on T. repens. Serological typing of nodules also indicated that normal levels of inoculation resulted in more than 80 per cent of nodules being formed by the specific inoculum strain. We conclude that field sowings of T. semipilosum can be effectively nodulated by the specific inoculum strain CB782 which is both effective and persistent under south-east Queensland conditions. We suggest that most reported nitrogen deficiency symptoms of establishing T. semipilosum are due to infection by Rugose Leaf Curl Virus.

Correction - Studies in the nodulation of Kenya white clover (Trifolium semipilosum) under field conditions in south-east Queensland

1975 ◽  
Vol 15 (75) ◽  
pp. 519
Author(s):  
RM Jones ◽  
RA Date
Keyword(s):  
Nitrogen Fixation ◽  
White Clover ◽  
Nitrogen Deficiency ◽  
Dry Weight ◽  
Field Conditions ◽  
N Fixation ◽  
Original Strain ◽  
Serological Identification ◽  
Seed Application ◽  
Inoculum Strain

The nodulation of Kenya white clover (Trifolium semipilosum) was examined under field conditions to evaluate reported establishment problems attributed to poor nodulation. Two isolates of Rhizobium identified as strain CB782 were obtained from nodules of T. semipilosum located in separate field sowings each of which was considered an establishment failure but which had recovered to healthy stands at the time of sampling. The two isolates were compared with a laboratory maintained culture of CB782 for nodulation and nitrogen fixation. Both isolates and the original strain were equally effective in N-fixation and all three increased plant dry weight, per cent plants with effective (pink) nodules and amount of nitrogen fixed compared with an uninoculated control. Increasing the level of seed application of inoculum up to the normal rate increased effective nodulation, but excess inoculum levels resulted only in greater numbers of smaller effective (pink) nodules without any increase in nodule dry weight. High inoculum levels decreased the number of white and green nodules compared with the control. Over 50 per cent effective nodulation was obtained with less than 50 Rhizobium seed-1 at sowing. Serological identification and effectiveness tests of strains in nodules confirmed that most white and green nodules on T. semipilosum resulted from infection by naturally occurring white clover rhizobia. These were ineffective in nitrogen fixation with T. semipilosum but fully effective on T. repens. Serological typing of nodules also indicated that normal levels of inoculation resulted in more than 80 per cent of nodules being formed by the specific inoculum strain. We conclude that field sowings of T. semipilosum can be effectively nodulated by the specific inoculum strain CB782 which is both effective and persistent under south-east Queensland conditions. We suggest that most reported nitrogen deficiency symptoms of establishing T. semipilosum are due to infection by Rugose Leaf Curl Virus.

Function of coprophagous beetles (Coleoptera: Scarabaeidae, Geotrupidae, Hydrophilidae) in cattle pastures inferred from pitfall trapping data

2010 ◽  
Vol 27 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Martin Šlachta ◽  
Jan Frelich ◽  
Tomáš Tonka
Keyword(s):  
Seasonal Variation ◽  
Spatial Variation ◽  
Dry Weight ◽  
Seasonal Distribution ◽  
The Other ◽  
Pitfall Trapping ◽  
Other Hand ◽  
Nested Anova ◽  
Species Groups ◽  
Dung Decomposition

Function of coprophagous beetles (Coleoptera: Scarabaeidae, Geotrupidae, Hydrophilidae) in cattle pastures inferred from pitfall trapping dataAn analysis of data on the dry weight biomass of coprophagous beetles in standardized dung (4.5 l) was conducted in order to characterize the spatial and the seasonal distribution of the beetles' biomass in cattle pastures and to elucidate their function in dung decomposition. Nested Anova with factors of farm, site (nested in farm), seasonal period and year was used to evaluate the effect of these factors on the biomass of four functional species groups: the dung dwellers ofScarabaeidae(subfamilyAphodiinae), the dung dwellers ofHydrophilidae, the small tunnellers ofScarabaeidae(subfamilyCoprinae) and the large tunnellers ofGeotrupidae. The spatial variation of biomass (between the sites and the farms) was insignificant (P>0.05) in the two dung-dweller groups and in the large-tunnellers group. On the other hand, a significant (P<0.05) seasonal variation of biomass was found in all but the large tunneller group. In dung dwellers, the spring biomass was formed mainly by two species,Aphodius prodromusandA. sphacelatus. In summer, most of the biomass was accounted for bySphaeridium lunatum, S. scarabaeoidesandA. rufipes. In the two tunneller groups,Onthophagus fracticornis, Geotrupes stercorariusandG. spinigerformed a majority of the biomass in dung.

Comparative Effect of Groundnut (Arachis hypogea l.) Genotypes on Yield and N Fixation in Sudan and Northern Guinea Savannahs of Nigeria

2019 ◽  
pp. 61-67
Keyword(s):  
Agricultural Research ◽  
Cropping Systems ◽  
Block Design ◽  
Dry Weight ◽  
Field Trials ◽  
Yield Potential ◽  
N Fixation ◽  
Maize Crop ◽  
Significant Interaction Effect ◽  
Pod Yield

Recognition of high yielding and nitrogen (N) fixing groundnut genotypes and desegregating them in the cereal-based cropping systems common in savannah regions will enhance food security and reduce the need for high N fertilizers hence, minimize the high cost and associated environmental consequences. Field trials were conducted during the 2015 growing season at the Research Farms of Bayero University Kano (BUK) and Institute for Agricultural Research (IAR), Ahmadu Bello University, Samaru-Zaria to assess the yield potential and Biolog- ical N fixation in 15 groundnut genotypes (ICG 4729, ICGV-IS 07823, ICGV-IS 07893, ICGV-IS 07908, ICGV- SM 07539, ICGV- SM 07599, ICGV-IS 09926, ICGV-IS 09932, ICGV-IS 09992, ICGV-IS 09994, SAMNUT-21, SAMNUT-22, SAMNUT-25, KAMPALA and KWANKWAS). The groundnut genotypes and reference Maize crop (SAMMAZ 29) were planted in a randomized complete block design in three replications. N difference method was used to estimate the amount of N fixed. The parameters determined were the number of nodules, nod- ule dry weight, shoot and root dry weights, pod, and haulm yield as well as N fixation. The nodule dry weight, BNF, haulm, and pod yield were statistically significant (P<0.01) concerning genotype and location. Similarly, their interac- tion effect was also highly significant. ICGV-IS 09926 recorded the highest nod- ule dry weight of 2.07mg /plant across the locations while ICGV-IS 09932 had the highest BNF value of 140.27Kg/ha. Additionally, KAMPALA had the high- est haulm yield, while ICGV-IS 07893 had the highest pod yield across the loca- tions with a significant interaction effect. The result shows that ICGV-IS 07893 and ICGV-IS 09932, as well as ICGV-IS 09994 and SAMNUT – 22, were the best genotypes concerning BNF, haulm and pod yield in the Northern Guinea and Sudan Savannahs of Nigeria respectively with the potential for a corresponding beneficial effect.

scholarly journals Innovative Ultrasound-Assisted Approaches towards Reduction of Heavy Metals and Iodine in Macroalgal Biomass

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 649
Author(s):  
Estefanía Noriega-Fernández ◽  
Izumi Sone ◽  
Leire Astráin-Redín ◽  
Leena Prabhu ◽  
Morten Sivertsvik ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Dry Weight ◽  
The Other ◽  
Laminaria Hyperborea ◽  
Other Hand ◽  
Macroalgal Biomass ◽  
Ultrasound Assisted ◽  
I 31

The aim of this work was to evaluate the potential of ultrasound (US), alone or in combination with mild heating and/or EDTA towards reduction of As, Cd, I, and Hg content of Laminaria hyperborea. Concentrations of As, Cd, I, and Hg of 56.29, 0.596, 7340, and <0.01 mg kg−1 of dry weight, respectively, were found in L. hyperborea blades. Treatment with US at 50 °C increased approx. 2-fold the amount of As released, although did not affect significantly the content of Cd or I, as compared to control (no US) samples. Reducing the temperature to 8 °C significantly decreased the effect of US, but heating at 80 °C did not cause a significant effect as compared to treatments at 50 °C. On the other hand, treatment with 0.1 N EDTA at 50 °C enhanced the percentage of Cd released by approximately 7-fold, regardless of sonication. In the present work, the combination of US and EDTA at 50 °C for 5 min led to a significant reduction of the As (32%), Cd (52%) and I (31%) content in L. hyperborea, thus improving the product’s safety for consumers.

scholarly journals Mutation in the ntrR Gene, a Member of the vap Gene Family, Increases the Symbiotic Efficiency of Sinorhizobium meliloti

2001 ◽  
Vol 14 (7) ◽  
pp. 887-894 ◽  
Author(s):  
Boglárka Oláh ◽  
Erno Kiss ◽  
Zoltán Györgypál ◽  
Judit Borzi ◽  
Gyöngyi Cinege ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Pathogenic Bacteria ◽  
Sinorhizobium Meliloti ◽  
Root Nodules ◽  
Nifh Gene ◽  
Dry Weight ◽  
Nodule Occupancy ◽  
Gene Encoding ◽  
Symbiotic Efficiency ◽  
Host Interactions

In specific plant organs, namely the root nodules of alfalfa, fixed nitrogen (ammonia) produced by the symbiotic partner Sinorhizobium meliloti supports the growth of the host plant in nitrogen-depleted environment. Here, we report that a derivative of S. meliloti carrying a mutation in the chromosomal ntrR gene induced nodules with enhanced nitrogen fixation capacity, resulting in an increased dry weight and nitrogen content of alfalfa. The efficient nitrogen fixation is a result of the higher expression level of the nifH gene, encoding one of the subunits of the nitrogenase enzyme, and nifA, the transcriptional regulator of the nif operon. The ntrR gene, controlled negatively by its own product and positively by the symbiotic regulator syrM, is expressed in the same zone of nodules as the nif genes. As a result of the nitrogen-tolerant phenotype of the strain, the beneficial effect of the mutation on efficiency is not abolished in the presence of the exogenous nitrogen source. The ntrR mutant is highly competitive in nodule occupancy compared with the wild-type strain. Sequence analysis of the mutant region revealed a new cluster of genes, termed the “ntrPR operon,” which is highly homologous to a group of vap-related genes of various pathogenic bacteria that are presumably implicated in bacterium-host interactions. On the basis of its favorable properties, the strain is a good candidate for future agricultural utilization.

Soybean (Glycine max) Cultivar Response to Metribuzin in Solution Culture

Weed Science ◽  
1979 ◽  
Vol 27 (3) ◽  
pp. 278-279 ◽  
Author(s):  
W. S. Hardcastle
Keyword(s):  
Glycine Max ◽  
Dry Weight ◽  
Solution Culture ◽  
Hydroponic Culture ◽  
The Other ◽  
Top Dry Weight

Twenty-eight commercial soybean [Glycine max(L.) Merr.] cultivars of maturity classes V through VIII were evaluated for differences in response to metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] 0.125 ppm w/w in hydroponic culture. Top dry weight (TDW) of treated ‘FFR 666’ soybeans equaled that of the cultivar check and five other cultivars were not significantly different (P = 5%). ‘Semmes' was most sensitive to the herbicide with TDW 40% of cultivar check. ‘Tracy’ and ‘Coker 156’ were not significantly different (P = 5%) from Semmes. The other cultivars tested were intermediate in response to metribuzin.

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