scholarly journals Use of 33P to trace in situ the fate of canola below-ground phosphorus, including wheat uptake in two contrasting soils

2016 ◽  
Vol 67 (7) ◽  
pp. 726 ◽  
Author(s):  
Foyjunnessa ◽  
Ann McNeill ◽  
Ashlea Doolette ◽  
Sean Mason ◽  
Mike J. McLaughlin
Keyword(s):  
Brassica Napus ◽  
Phosphoric Acid ◽  
P Uptake ◽  
Bulk Soil ◽  
P Pools ◽  
P Cycling ◽  
Below Ground ◽  
Crop Root

Our understanding of the contribution of crop root residues to phosphorus (P) cycling is mainly derived from studies using excavated roots re-introduced to soil. This study aims to quantify total below-ground P (BGP) of mature canola in situ and to estimate directly the proportion accessed by subsequent wheat. 33P-Labelled phosphoric acid was fed by stem wick to canola (Brassica napus) grown in sand or loam in pots. Shoots were removed from all plants at maturity. Half of the pots were destructively sampled. After a 3-week fallow, wheat was grown for 5 weeks in the remaining undisturbed pots. At canola maturity, 23–36% of the 33P was partitioned in recovered roots and 34–40% in the soil. More 33P was recovered in the loam than the sand. Within the soil, 6–10% of the fed 33P was present in resin P and 3–5% was in hexanol-released P pools. Ratios of shoot P : BGP (8 : 1 in sand and 15 : 1 in loam) were much narrower than those of shoot P : recovered root P (17 : 1 in sand and 39 : 1 in loam). A greater proportion and amount of the mature canola BG33P was recovered by wheat grown in the loam (26%, 2.6 mg/plant) than in the sand (21%, 1.5 mg/plant). The majority of canola BG33P remained in the bulk soil. Input of P below-ground by mature canola and subsequent P benefit to wheat was greater in loam than sand. The P from canola below-ground residues contributed up to 20% of P uptake in wheat during the first 5 weeks of growth. Longer term benefits of P from below-ground residues require investigation.

Use of in situ 15N-labelling to estimate the total below-ground nitrogen of pasture legumes in intact soil - plant systems

1997 ◽  
Vol 48 (3) ◽  
pp. 295 ◽  
Author(s):  
Ann M. McNeill ◽  
Chunya Zhu ◽  
Ian R. P. Fillery
Keyword(s):  
Subterranean Clover ◽  
Bulk Soil ◽  
Vegetative Stage ◽  
Residual Fraction ◽  
N Fixation ◽  
15N Labelling ◽  
Below Ground ◽  
Sampling Procedures ◽  
Intact Soil

A leaf-feeding technique for in situ 15N-labelling of intact soil–pasture plant systems was assessed, using subterranean clover (Trifolium subterraneum L.) and serradella (Ornithopus compressus L.) grown under glasshouse conditions. Total recoveries of fed 15N were 87–100% following leaf-feeding of plants at flowering but were lower (74–84%) following the feed at the vegetative stage. Below-ground recovery of fed 15N ranged from 7 to 26%, with serradella partitioning a greater proportion of labelled N below ground than subterranean clover. Additionally, plants of both species fed at the vegetative stage accumulated a greater proportion of the 15N label below ground than did those fed at flowering. Dry sampling procedures, which utilised freeze-drying, enabled fractionation of the below-ground portion of the system into ‘clean’ nodulated macro-roots with no adhering soil, residual uncleaned root, rhizosphere, and bulk soil. Calculated specific enrichment for the ‘clean’ roots at different depths demonstrated a relatively uniform distribution of 15N label in the subterranean clover roots, whereas the presence of large indeterminate nodules in the crown region of serradella roots contributed to apparent uneven distribution of label. Approximately half of the N in the residual fraction of both species consisted of labelled material, postulated to be mostly fine root. Additionally, 5–20% of the rhizosphere N and 0·5–3% of the N in bulk soil was legume root-derived, with some 15N detected in the extractable total soluble N and microbial N pools. Rhizodeposition of N represented approximately 10% of total plant N and 17–24% of total below-ground N for subterranean clover, whereas values for serradella were 20 and 34–37%, respectively. Estimated total below-ground N of subterranean clover reached a maximum value of 177 mg N/plant at 98 days after sowing, which corresponded with a peak shoot N of 243 mg N. Maximum below-ground N for serradella attained 196 mg N/plant 84 days after sowing with a corresponding shoot biomass of 225 mg N. There was a decline in the total below-ground N of serradella at maturity. Overall, recovered clean root N represented 30–62% of estimated total below-ground N, so it was concluded that standard root recovery procedures might be likely to underestimate severely the total below-ground N accretion and N turnover by legumes. The implications of these results for field estimation of total legume N yield, biological N fixation, and the N benefit from legumes in rotations are discussed.

The impact of biomass harvesting on phosphorus uptake by wetland plants

2001 ◽  
Vol 44 (11-12) ◽  
pp. 61-67 ◽  
Author(s):  
S-Y. Kim ◽  
P.M. Geary
Keyword(s):  
Plant Biomass ◽  
Phosphorus Uptake ◽  
P Uptake ◽  
Plant Parts ◽  
Biomass Harvesting ◽  
Below Ground ◽  
The Impact ◽  
Total P ◽  
Better Than ◽  
P Removal

Two species of macrophytes, Baumea articulata and Schoenoplectus mucronatus, were examined for their capacity to remove phosphorus under nutrient-rich conditions. Forty large bucket systems with the two different species growing in two types of substrate received artificial wastewaters for nine months, simulating a constructed wetland (CW) under high loading conditions. Half of the plants growing in the topsoil and gravel substrates were periodically harvested whereas the other half remained intact. Plant tissue and substrate samples were regularly analysed to determine their phosphorus concentrations. With respect to phosphorus uptake and removal, the Schoenoplectus in the topsoil medium performed better than the Baumea. Biomass harvesting enhanced P uptake in the Schoenoplectus, however the effect was not significant enough to make an improvement on the overall P removal, due to the slow recovery of plants and regrowth of biomass after harvesting. From P partitioning, it was found that the topsoil medium was the major P pool, storing most of total P present in the system. Plant parts contributed only minor storage with approximately half of that P stored below ground in the plant roots. The overall net effect of harvesting plant biomass was to only remove less than 5% of total phosphorus present in the system.

scholarly journals Study of Oak Ridge soils using BONCAT-FACS-Seq reveals that a large fraction of the soil microbiome is active

2018 ◽  
Author(s):  
Estelle Couradeau ◽  
Joelle Sasse ◽  
Danielle Goudeau ◽  
Nandita Nath ◽  
Terry C. Hazen ◽  
...  
Keyword(s):  
Soil Microbes ◽  
Sequence Similarity ◽  
Large Fraction ◽  
Amplicon Sequencing ◽  
Bulk Soil ◽  
Soil Microbiome ◽  
Active Fraction ◽  
Soil Microbial Diversity ◽  
Oak Ridge

AbstractThe ability to link soil microbial diversity to soil processes requires technologies that differentiate active subpopulations of microbes from so-called relic DNA and dormant cells. Measures of microbial activity based on various techniques including DNA labelling have suggested that most cells in soils are inactive, a fact that has been difficult to reconcile with observed high levels of bulk soil activities. We hypothesized that measures of in situ DNA synthesis may be missing the soil microbes that are metabolically active but not replicating, and we therefore applied BONCAT (Bioorthogonal Non Canonical Amino Acid Tagging) i.e. a proxy for activity that does not rely on cell division, to measure translationally active cells in soils. We compared the active population of two soil depths from Oak Ridge (TN) incubated under the same conditions for up to seven days. Depending on the soil, a maximum of 25 – 70% of the cells were active, accounting for 3-4 million cells per gram of soil type, which is an order of magnitude higher than previous estimates. The BONCAT positive cell fraction was recovered by fluorescence activated cell sorting (FACS) and identified by 16S rDNA amplicon sequencing. The diversity of the active fraction was a selected subset of the bulk soil community. Excitingly, some of the same members of the community were recruited at both depths independently from their abundance rank. On average, 86% of sequence reads recovered from the active community shared >97% sequence similarity with cultured isolates from the field site. Our observations are in line with a recent report that, of the few taxa that are both abundant and ubiquitous in soil, 45% are also cultured – and indeed some of these ubiquitous microorganisms were found to be translationally active. The use of BONCAT on soil microbiomes provides evidence that a large portion of the soil microbes can be active simultaneously. We conclude that BONCAT coupled to FACS and sequencing is effective for interrogating the active fraction of soil microbiomes in situ and provides new perspectives to link metabolic capacity to overall soil ecological traits and processes.

In situ phytomanagement with Brassica napus and bio-stabilised municipal solid wastes is a suitable strategy for redevelopment of vacant urban land

2020 ◽  
Vol 47 ◽  
pp. 126550 ◽  
Author(s):  
Fátima Míguez ◽  
María T. Gómez-Sagasti ◽  
Antonio Hernández ◽  
Unai Artetxe ◽  
Fernando Blanco ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Urban Land ◽  
Solid Wastes ◽  
Municipal Solid Wastes

scholarly journals Doubled haploids of interspecific hybrids between Brassica napus and Brassica rapa for canola production with valuable breeding traits

OCL ◽  
2020 ◽  
Vol 27 ◽  
pp. 45
Author(s):  
Ainash Daurova ◽  
Dias Daurov ◽  
Dmitriy Volkov ◽  
Kuanysh Zhapar ◽  
Daniyar Raimbek ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Seed Germination ◽  
Brassica Rapa ◽  
Doubled Haploid ◽  
Interspecific Hybrids ◽  
Nutritional Value ◽  
Doubled Haploids ◽  
Doubled Haploid Plants ◽  
Haploid Plants

Doubled haploids (DH) were obtained from two interspecific hybrids between Brassica napus and Brassica rapa. Seeds of doubled haploid plants differed in colour and size. The hybridity of the obtained doubled haploid is shown using genomic in situ hybridization (GISH) analysis. Evaluation of drought tolerance during seed germination on PEG-6000 showed the advantage of doubled haploid plants of interspecific hybrids over the parent cultivars. The oil from seeds of doubled haploid plants showed good nutritional value.

A chiral Brønsted acid-catalyzed highly enantioselective Mannich-type reaction of α-diazo esters with in situ generated N-acyl ketimines

2018 ◽  
Vol 54 (28) ◽  
pp. 3516-3519 ◽  
Author(s):  
Rajshekhar A. Unhale ◽  
Milon M. Sadhu ◽  
Sumit K. Ray ◽  
Rayhan G. Biswas ◽  
Vinod K. Singh
Keyword(s):  
Phosphoric Acid ◽  
Reaction Conditions ◽  
Type Reaction ◽  
Chiral Phosphoric Acid ◽  
Brönsted Acid ◽  
Diazo Esters ◽  
Reaction Proceeds ◽  
Acid Catalyzed ◽  
Chiral Bronsted Acid

A chiral phosphoric acid-catalyzed asymmetric Mannich-type reaction of α-diazo esters with in situ generated N-acyl ketimines, derived from 3-aryl-3-hydroxyisoindolinones has been demonstrated. The reaction proceeds smoothly under mild reaction conditions.

Chiral phosphoric acid catalyzed enantioselective N-alkylation of indoles with in situ generated cyclic N-acyl ketimines

2018 ◽  
Vol 54 (66) ◽  
pp. 9230-9233 ◽  
Author(s):  
Lvye Zhang ◽  
Binqiang Wu ◽  
Zhangtao Chen ◽  
Jinjin Hu ◽  
Xiaofei Zeng ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Alkylation Reaction ◽  
Chiral Phosphoric Acid ◽  
Acid Catalyzed

A chiral SPINOL derived phosphoric acid-catalyzed asymmetric N-alkylation reaction of indoles with cyclic α-diaryl-substituted N-acyl imines, which are generated in situ from 3-aryl 3-hydroxyisoindo-linones, has been demonstrated.

Estimates of lupin below-ground biomass nitrogen, dry matter, and nitrogen turnover to wheat

1996 ◽  
Vol 47 (7) ◽  
pp. 1047 ◽  
Author(s):  
CA Russell ◽  
IRP Fillery
Keyword(s):  
Dry Matter ◽  
Soil Columns ◽  
Soil System ◽  
Wheat Growth ◽  
Ground Biomass ◽  
Plant Soil ◽  
Below Ground ◽  
3.0 T ◽  
Net Mineralisation

The amount of lupin below-ground biomass (BGB), BGB nitrogen (N) content, and utilization of BGB-N by subsequent wheat was estimated from lupins grown in soil columns. Lupin plants were enriched in situ with 15N-labelled urea through a cotton wick inserted through the stem. Of the applied 15N. 92% was recovered in the lupin plant-soil system at maturity: 87% of this 15N was in lupin aboveground biomass and 13% in the soil columns. Total mature lupin dry matter (DM) approximated 11 t/ha, with 3.0 t/ha (27%) of this DM below ground. Total mature lupin N approximated 321 kg/ha, of which 91 kg/ha (28%) resided below ground. In terms of N and DM, BGB was the largest lupin residue component even though only 35% of this was recoverable as root material. About 13% of the BGB-N was in inorganic form at maturity. The net mineralisation of lupin BGB-N after 2 consecutive years of wheat growth was 27%. and wheat assimilated about 74% of this N (i.e. 20% of BGB-N), with equal quantities assimilated in each year. The contribution of lupin BGB-N to the N in wheat tops ranged from 40% for soil columns receiving no fertiliser N to 15-20% for soil columns fertilised with 30 kg N/ha. The net mineralisation of BGB-N and the assimilation of BGB-N by wheat were unaffected by the application of fertiliser N.

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