Plant Nutrition Effects, Partial Fractionation of Water-Soluble Nitrogen from Coastal Bermuda Grass Growing under Various Soil Nitrogen Levels

1957 ◽  
Vol 5 (7) ◽  
pp. 506-509
Author(s):  
E. R. Ibert ◽  
F. L. Fisher ◽  
J. F. Fudge
Botany ◽  
2011 ◽  
Vol 89 (4) ◽  
pp. 255-261 ◽  
Author(s):  
Corinthe Zekveld ◽  
John Markham

Plants can respond to herbivore damage by mounting a resistance response or by compensating for lost fitness. Both plant nutrition and interactions with soil microbes can affect these responses. It has been shown that resistance responses can occur before plants have been attacked by herbivores. Here we show that a tolerance type of response can occur when plants are exposed to, but not fed on by, herbivores. Alnus viridis (Chaix) DC. spp. crispa (Ait.) Turrill were grown in sealed containers under positive air pressure with either 0.5 mmol·L–1 or 2.0 mmol·L–1 nitrate and either inoculated or not inoculated with Frankia , their nitrogen-fixing symbiont. Plants were then exposed to the genus-specific aphid Prociphilus tessallatus Fitch, which failed to establish feeding colonies. Exposure to aphids, formation of nitrogen-fixing nodules, and elevated soil nitrogen levels all significantly increased plant yield with no interaction among these factors. A combination of high soil nitrogen, nodulation, and exposure to aphids resulted in the lowest plant root:shoot ratio. Plants that were grown with low nitrogen and were exposed to aphids showed increased nitrogen-fixing activity within a day of being exposed. These results provide further evidence to support the observation that plants can respond to cues from other organisms prior to receiving herbivore damage.


1971 ◽  
Vol 11 (50) ◽  
pp. 295 ◽  
Author(s):  
RR Storrier ◽  
AT Hanly ◽  
TB Spence ◽  
AN Smith

Linear regression analyses were used to evaluate the usefulness of a number of measures of the available soil nitrogen in accounting for the variability in wheat yields under field conditions in southern New South Wales. Single soil tests, such as total mineral nitrogen in the surface sample (0-10 cm depth), could account for only 38 and 18.5 per cent of the variation in yield at flowering and harvest respectively. However, the Use of bilinear regression involving boiling water soluble nitrogen in the surface horizon and nitrate-nitrogen in the sub-soil (10-30 cm depth) accounted for 64 and 36 per cent of the variation in yield at flowering and harvest respectively. The use of these tests to predict the nitrogen fertilizer requirement of wheat will necessitate the measure ment of climatic, cultural and edaphic factors as well as response to nitrogen fertilizer.


2007 ◽  
Vol 35 (2) ◽  
pp. 597-600
Author(s):  
Ida Kincses ◽  
Tibor Filep ◽  
Péter Nagy ◽  
Andrea Kovács

1988 ◽  
Vol 68 (1) ◽  
pp. 63-75 ◽  
Author(s):  
LEONARD J. EATON ◽  
DAVID G. PATRIQUIN

Soil ammonium and nitrate in the top 15 cm of soil were monitored after application of ammonium nitrate and ammonium sulfate to plots at 14 PF (previously fertilized) and 12 NF (never fertilized) lowbush blueberry (Vaccinium angustifolium Ait.) stands representing a range of soil types and management histories. Overall, nitrate values in unfertilized and ammonium sulfate plots were higher at PF than at NF sites, suggesting greater nitrification at PF sites. In laboratory incubation studies, nitrification proceeded immediately in soil from a PF site, but only after a 4-wk lag in that from an adjacent NF site. Nitrification rates were low compared to that in a garden soil (pH 6.6). N-Serve inhibited nitrification in both soils. In ammonium nitrate plots, "excess" N values (N values in fertilized plots minus values in unfertilized plots) were higher for PF than for NF sites, suggesting greater immobilization, plant uptake or loss of N at NF sites. There was no evidence, in laboratory studies, of immobilization of added N by soil from either type of site. Rhizome N concentration increased significantly in response to fertilization at an NF site, but not at a PF site. Key words: Blueberry (lowbush), fertilizer and soil nitrogen


Foods ◽  
2018 ◽  
Vol 7 (8) ◽  
pp. 125 ◽  
Author(s):  
Oya Berkay Karaca ◽  
Mehmet Güven

Effects of proteolytic (Neutrase, Bacillus subtilis-originate, 0.20 (P1) and 0.40 g 100 L−1 (P2)) and lipolytic (Piccantase A, Mucor miehei-originated, 0.05 (L1) and 0.10 g 100 L−1 (L2)) enzyme supplementations to cheese milk on lipolysis and proteolysis characteristics of 90-day ripened cheese samples were investigated in this study. While enzyme supplementation did not have significant effects on titratable acidity, fat and protease-peptone nitrogen ratios of cheese samples, dry matter, salt, protein, water soluble nitrogen, 12% trichloroacetic acid soluble nitrogen ratio (TCA-SN), 5% phosphotungstic acid soluble nitrogen (PTA-SN), casein nitrogen ratios, penetrometer value, total free fatty acids (TFFA) and total free amino acids (TFAA) were significantly influenced by enzyme supplementations. Individual free amino acids (15 of them) were also determined. Free amino acid contents of enzyme-supplemented cheeses were higher than the control cheese and the values increased in all cheese samples with the progress of ripening (p < 0.05). The highest amino acids in all periods of ripening were identified as glutamic acid, lysine, proline and aspartic acid. The major (Ca, P, Na, K, Mg) and minor (Zn, Fe, Cu, Mn) mineral levels of cheeses decreased with the progress of ripening and the effects of enzyme supplementations on these attributes (except for magnesium and manganese) were found to be significant (p < 0.01). As to conclude, enzyme supplementations increased proteolysis and lipolysis and accelerated ripening and thus reduced ripening durations. Especially the enzyme ratios in P1 and L1 cheeses were found to be suitable for reducing the ripening period in White cheese without any adverse effects.


2021 ◽  
Vol 3 (2) ◽  
pp. 156-162
Author(s):  
T. A. Adegbola ◽  
A. U. Mba ◽  
F. O. Olubajo

FOUR fistulated and four intact West African dwarf Sheep, maintained on hay and concentrate supplements were used for a study of metabolic faecal nitrogen (MEN) endogenous urinary nitrogen (EUN). The composition of the faecal losses was examined. The values obtained enabled calculation of nitrogen requirement of the sheep for maintenance, as well as the value of the experimental rations in the nutrition of the sheep. Values of MFN obtained by two methods were 3.31 and 3.10 g/kg Dry matter (DM) intake. Endogenous urinary nitrogen value was 0.024 g/day per metabolic weight (Wkg0.75.) Analysis of the faeces of the sheep showed that 21.1% of faecal nitrogen (N) were present as microbial and endogenous nitrogen (MEN) and 17.3% was present as water-soluble nitrogen. The biological values (BV) of the rations ranged from 85.7% to 100.0% and the digestibility for maintenance, were 1.20 and 0.41 g/day/Wkg 0.75 during the feeding trials. Values obtained for endogenous N losses and N requirement for low maintenance were low compared with reported values and this may indicate adaptation of the dwarf sheep for survival under inadequate dietary protein supply.


2019 ◽  
Vol 70 (3) ◽  
pp. 1669
Author(s):  
S. KAMINARIES ◽  
A. SCORDOBEKI ◽  
E. ZOIDOU ◽  
G. MOATSOU

Novel reduced-fat goat-cheese (R) was produced from high-pasteurized milk using Penicillium candidum as an adjunct. A full-fat goat-cheese (F) from pasteurized milk without mold addition was produced for comparison reasons. Physicochemical analyses of the two cheeses were performed through the 14-d period of ripening. The effect of P.candidum on proteolysis of goat-cheese caseins and the production of hydrophilic and hydrophobic peptides during cheese ripening were investigated. To our knowledge, similar results for reduced-fat, mold-ripened, goat-milk cheeses have not been previously reported before. R-cheese exhibited a higher organoleptic score and developed properties similar to Kopanisti, which is a Protected Designation of Origin Greek soft cheese with specific intense flavour manufactured from raw milk without the use of starters. Moreover, R-cheese had significantly higher moisture, protein in dry matter and water soluble nitrogen contents than F-cheese and was less adhesive. The high-pasteurization improved the texture and cheese yield, while the use of P. candidum as an adjunct improved the flavour, increased and accelerated proteolysis in R-cheese. According to the results, the technology for R-cheese employed in the present study can be easily adopted and could be used to produce a reduced-fat goat-cheese.


1995 ◽  
Vol 41 (6) ◽  
pp. 470-476 ◽  
Author(s):  
D. Trzesicka-Mlynarz ◽  
O. P. Ward

A mixed culture, isolated from soil contaminated with polycyclic aromatic hydrocarbons (PAHs), grew on and degraded fluoranthene in aqueous media supplemented with glucose, yeast extract, and peptone. Increased complex nitrogen levels in the medium promoted bacterial growth and a greater extent of fluoranthene degradation. Amendment of the media with high glucose levels also diminished specific fluoranthene degradation. The mixed culture was capable of degrading a range of other PAHs, including benzo[a]pyrene, anthracene, phenanthrene, acenaphthene, and fluorene. The mixed culture contained four predominant isolates, all of which were Gram-negative rods, three of which were identified as Pseudomonas putida, Flavobacterium sp., and Pseudomonas aeruginosa. Better degradation of a defined PAH mixture was observed with the mixed culture than with individual isolates. A reconstituted culture, prepared by combining the four individual isolates, manifested a similar PAH biodegradation performance to the original mixed culture. When compared with the mixed culture, individual isolates exhibited a relatively good capacity to remove more water-soluble PAHs (acenaphthene, fluorene, phenanthrene, fluoranthene). In contrast, removal of less water-soluble PAHs (anthracene and pyrene) was low or negligible with isolated cultures compared with the mixed culture.Key words: polycyclic aromatic hydrocarbons, mixed culture, fluoranthene, Pseudomonas, Flavobacterium.


2005 ◽  
Vol 72 (2) ◽  
pp. 234-242 ◽  
Author(s):  
Mutlag M Al-Otaibi ◽  
R Andrew Wilbey

This study demonstrated that both chymosin and salt-in-moisture (SM) were important factors for proteolysis in the manufacture of ultrafiltrated white-salted cheese, with significant effects on water-soluble nitrogen and nitrogen soluble in trichloroacetic acid. In contrast, the levels of free amino acids were not significantly affected by chymosin and salt treatments. The cheeses made using high levels of chymosin with low SM had lower levels of residual αs1- and β-casein at the end of ripening. On texture profile analysis, the hardness and fracturability of the cheeses significantly increased with SM and decreased during ripening. Increases in chymosin significantly contributed to the overall weakening of the structure throughout ripening. Bitter flavour was detected after 12 weeks in the cheese made with the higher chymosin level and lower SM, which could be the result of accumulation of γ-casein fractions. The sensory data indicated that the hedonic responses for low chymosin with low SM cheeses were good and acceptable in flavour, which may be due to the moderate levels of proteolysis products.


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