Response of Douglas-fir seedlings to nitrate and ammonium nitrogen sources under various environmental conditions

1975 ◽  
Vol 42 (3) ◽  
pp. 685-702 ◽  
Author(s):  
R. Van Den Driessche ◽  
J. Dangerfield
1971 ◽  
Vol 51 (1) ◽  
pp. 29-33 ◽  
Author(s):  
R. G. ROSS ◽  
FRANCES D. J. BREMNER

Perithecia of Venturia inaequalis did not form in a basal medium to which was added ammonium sulfate, chloride, phosphate or tartrate as the sole sources of nitrogen, when the pH of the medium was allowed to fall to inhibitory levels. Perithecia formed with these ammonium salts as nitrogen sources when calcium carbonate was added to control the pH. With ammonium carbonate and oxalate there was no appreciable change in pH, and perithecia formed with these salts as nitrogen sources. Perithecia did not form in media with leucine as a nitrogen source. Formation of perithecia with other amino acids depended on the concentration of amino-nitrogen in the media. A substance toxic to perithecial formation may form in cultures containing leucine; if so, it is produced in different amounts by the two isomers and the racemic mixture of this amino acid.


Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 221
Author(s):  
Paraskevi Psachoulia ◽  
Sofia-Natalia Schortsianiti ◽  
Urania Lortou ◽  
Spyros Gkelis ◽  
Christos Chatzidoukas ◽  
...  

Four microalgae species were evaluated for their bioremediation capacity of anaerobic digestion effluent (ADE) rich in ammonium nitrogen, derived from a biogas plant. Chlorella vulgaris, Chlorella sorokiniana, Desmodesmus communis and Stichococcus sp. were examined for their nutrient assimilation efficiency, biomass production and composition through their cultivation in 3.7% v/v ADE; their performance was compared with standard cultivation media which consisted in different nitrogen sources, i.e., BG-11NO3 and BG-11ΝΗ4 where N-NO3 was replaced by N-NH4. The results justified ammonium as the most preferable source of nitrogen for microalgae growth. Although Stichococcus sp. outperformed the other 3 species in N-NH4 removal efficiency both in BG-11NH4 and in 3.7% ADE (reaching up to 90.79% and 69.69% respectively), it exhibited a moderate biomass production when it was cultivated in diluted ADE corresponding to 0.59 g/L, compared to 0.89 g/L recorded by C. vulgaris and 0.7 g/L by C. sorokiniana and D. communis. Phosphorus contained in the effluent and in the control media was successfully consumed by all of the species, although its removal rate was found to be affected by the type of nitrogen source used and the particular microalgae species. The use of ADE as cultivation medium resulted in a significant increase in carbohydrates content in all investigated species.


HortScience ◽  
1990 ◽  
Vol 25 (2) ◽  
pp. 194-196 ◽  
Author(s):  
Charles F. Mancino ◽  
Joseph Troll

Combining frequent N applications and irrigations for turfgrasses grown in sandy soils is a common occurrence on golf course putting greens. A greenhouse study was conducted to determine leaching losses of nitrate and ammonium nitrogen from `Penncross' creeping bentgrass (Agrostis palustris L.) growing on an 80 sand:20 peat soil mixture following frequent, moderately heavy irrigations and light or moderate N fertilizer applications. Nitrogen sources included calcium nitrate, ammonium nitrate, ammonium sulfate, urea, urea formaldehyde and isobutylediene diurea. Application levels were 9.76 kg N/ha per 7 days and 19.52 kg N/ha per 14 days for 10 weeks. Irrigation equivalent to 38 mm·week-1 was applied in three equal applications. Overall, 46% of the applied water leached. Total leaching losses were <0.5% of the applied N. Nitrate represented the major portion of the leached N, with ammonium losses being negligible. There were no differences between sources when applied at these levels. In a second study, a single 48.8 kg N/ha application resulted in higher leaching losses of N, but only calcium nitrate and ammonium nitrate had total losses > 2% (2.80% and 4.13%, respectively, over an n-day period). Nitrate concentrations were found to exceed 45 mg·liter-1 for ammonium nitrate.


2020 ◽  
Author(s):  
Jing-Zhong Lu ◽  
Stefan Scheu

AbstractTree - soil interactions depend on environmental context. Plantations of trees may impact soil microorganisms more strongly under unfavorable environmental conditions, compromising long-term ecosystem services. To contextually understand the effects of tree species composition on soil microorganisms, we quantified structural and functional responses of soil microorganisms to forest types across environmental gradients using substrate-induced respiration and phospholipid fatty acid analyses. Five forest types were studied including pure stands of native European beech (Fagus sylvatica), range expanding Norway spruce (Picea abies), and non-native Douglas-fir (Pseudotsuga menziesii), as well as the two conifer - beech mixtures. We found that microbial functioning strongly depends on environmental conditions, in particular on soil nutrients. At nutrient-poor sites, both pure and mixed coniferous forests, but especially Douglas-fir forests, stressed soil microorganisms compared to beech forests. By contrast, microbial structure and functional indicators in beech forests varied little with site conditions, likely because beech provided high amounts of root-derived resources for microbial growth. The results indicate that, at nutrient-poor sites, long-term effects of planting exotic Douglas-fir on ecosystem functioning need further attention, but planting Douglas-fir at nutrient-rich sites may be of little concern from the perspective of microbial communities. Overall, the results point to the importance of root-derived resources in determining the structure and functioning of soil microbial communities, and document the sensitivity of soil microorganisms to planting tree species that may differ in the provisioning of these resources.


1985 ◽  
Vol 63 (12) ◽  
pp. 2283-2287
Author(s):  
Olubukanla T. Okusanya ◽  
Olusola O. Lakanmi

The growth responses of Luffa aegyptiaca to various nitrogen sources and concentrations were investigated. In sand culture at high concentrations of nitrogen, the species showed equally favourable responses to nitrate nitrogen (KNO3 or Ca(NO3)2), ammonium nitrogen ((NH4)2SO4), and the combination of nitrate and ammonium nitrogen (NH4NO3). There was poor growth in response to NaNO3, CO(NH2)2, and a solution lacking nitrogen. In lateritic soil, the species responded better to ammonium nitrogen and the combination of nitrate and ammonium nitrogen than to nitrate nitrogen. Growth was generally poorer in lateritic soil than in sand. Neither the nitrogen sources nor their concentrations had any significant effect on root weight or the leaf weight ratio. There was a significant decrease in growth as nitrogen concentration decreased in KNO3 and Ca(NO3)2 treatments but it was only at the low concentrations of (NH4)2SO4 and NH4NO3 that growth was significantly reduced. The shoot: root mass ratio decreased as nitrogen concentration decreased. The nature of the growth media and the ecological habit of the species are used to partly explain its responses to different nitrogen sources and concentrations. The possible application of these results to increasing the production of L. aegyptiaca is also discussed.


1968 ◽  
Vol 14 (10) ◽  
pp. 1035-1037 ◽  
Author(s):  
C. B. Willis

A wide range in growth responses was obtained by two isolates each of Sclerotinia trifoliorum Erikss. and S. sclerotiorum (Lib.) d By. in stationary culture in a synthetic liquid medium containing a number of nitrogen sources representing both organic and inorganic forms. Good sources of nitrogen were casein hydrolysate, L-proline, DL-asparagine, L-arginine, L-glutamic acid, L-aspartic acid, L-histidine, L-alanine, ammonium chloride, ammonium nitrate, L-tryptophan, ammonium sulfate, and DL-phenylalanine. Poor nitrogen sources included potassium nitrite, sodium nitrite, DL-lysine, L-valine, L-cysteine, DL-threonine, and DL-methionine. An additional eight sources were intermediate in the amount of growth supported. Growth by the S. trifoliorum isolates on the ammonium nitrogen sources was significantly greater than on the nitrate sources. No such difference was observed for the S. sclerotiorum isolates. DL-Phenylalanine ranked much lower and L-glutamic acid and calcium nitrate much higher as nitrogen sources for the S. sclerotiorum isolates than for S. trifoliorum isolates. Significant differences between the isolates of each species were observed on a number of nitrogen sources.


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