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991.
Aimé J. Messiga Yuxin Ba Noura Ziadi Gilles Bélanger Jean Lafond 《Archives of Agronomy and Soil Science》2013,59(10):1445-1458
We analyzed in soils with contrasting cultivation histories the depletion of P following sequential extractions with soil testing solutions. Soil samples were collected in three experiments in eastern Canada (L’Acadie, Lévis, and Normandin) and P was sequentially extracted 16 times, once daily, using Mehlich-3 (M3) or Olsen (Ol) solution. The cumulative amount of P extracted was 252 mg PM3 kg?1 and 77 mg kg?1 POl for L’Acadie, 212 mg PM3 kg?1 and 66 mg POl kg?1 for Lévis, and 424 mg PM3 kg?1 and 83 mg POl kg?1 for Normandin. The depletion of P was described by a logarithmic function (Y = a ln (N) + b) for PM3, and a power function (Y = αNβ) for POl. The inorganic P pool decreased in the three soils. The organic P pool did not decrease possibly because soil testing solutions did not directly extract P from this pool. This study demonstrated that laboratory soil testing analysis using M3 or Ol solution principally target P from the inorganic pool, suggesting that P fertilizer recommendations to mineral soils relying on these methods do not account for the potential of the organic P pool to contribute to soil P availability. 相似文献
992.
Suvendu Das Jiin-Shuh Jean Sandeep Kar Sukalyan Chakraborty 《Biology and Fertility of Soils》2013,49(6):757-765
The importance of assessing the impacts of soil arsenic (As) contamination on microbial properties lay on the fact that microbes are instrumental in nutrient cycling and are therefore indicators of soil quality. In this study, soil chemical extraction methods were used to extract labile and freely exchangeable As (water-soluble As and sodium bicarbonate-extractable As), amorphous/crystalline Fe and Mn oxide-bound As (acid ammonium oxalate-extractable As and hydroxylamine hydrochloride-extractable As), and their impacts on microbial biomass (microbial biomass C, total bacterial and fungal biomass, active bacterial and fungal biomass), enzyme activities representing four major soil biogeochemical cycles, i.e., C (β-glucosidase activity), N (urease activity), P (acid phosphomonoesterase activity), S (acryl-sulfatase activity), and microbial activity (fluorescein diacetate hydrolysis and dehydrogenase activity) were investigated in As-contaminated soils of Ambagarh Chauki block, Chhattisgarh, Central India. The results revealed that the majority of the As in soils resided in the Fe/Mn oxide-bound fraction. The microbial biomass C, total and active fungal biomass, and enzyme activities were significantly inhibited by all the forms of As. However, water-soluble As, even though occupying only a small portion of the total As (0.9–2.9 %), exerted the greatest impact. Interestingly, total and active bacterial biomass was not significantly affected by As toxicity, suggesting their resistance to As. Urease activity was not affected by As pollution. 相似文献
993.
Melih Ertan inar Jean‐Pierre Fral Christos Arvanitidis Romain David Ergün Takin Maria Sini Thanos Dailianis Alper Doan Vasilis Gerovasileiou Alper Evcen Anne Chenuil Ertan Dali Veysel Aysel Yannis Issaris Kerem Bakir Melina Nalmpant Stephane Sartoretto Maria Salomidi Anastasia Sapouna Sermin Aik Charalampos Dimitriadis Drosos Koutsoubas Tuncer Kataan Bilal
ztürk Ferah Koak Deniz Erdogan‐Dereli Senem
nen
zge
zgen Neslihan Türkü Fevzi Kirkim Mesut
nen 《水产资源保护:海洋与淡水生态系统》2020,30(8):1578-1594
- 1. The coralligenous habitat was studied at the large Mediterranean scale, by applying a standardized, non‐destructive photo‐sampling protocol, developed in the framework of the CIGESMED project.
- 2. The results provided evidence to support the following statements: (a) the assemblage pattern is not homogeneously distributed across the four Mediterranean ecoregions studied (biotic gradients hypothesis); and (b) the assemblage pattern does not change significantly when the information is aggregated to higher taxonomic levels (taxonomic sufficiency hypothesis).
- 3. Surrogate taxonomic categories higher than species, such as genus and family, can be used to reveal the multivariate pattern of the coralligenous assemblages.
- 4. Although preliminary at the pan‐Mediterranean scale, these outcomes set the scene for future comparisons as more data sets become available but also for comparisons between taxonomic and functional patterns.
994.
Nils Teichert Jean‐Philippe Benitez Arnaud Dierckx Stphane Ttard Eric de Oliveira Thomas Trancart Eric Feunteun Michaël Ovidio 《水产资源保护:海洋与淡水生态系统》2020,30(8):1552-1565
- Changes in migration timing, resulting from the alteration in river continuity or the effect of climate change, can have major consequences on the population dynamics of diadromous fish. Forecasting the phenology of fish migration is thus critically important to implement management actions aimed at protecting fish during their migration.
- In this study, an 11‐year monitoring survey of Atlantic salmon smolts (Salmo salar) from the Ourthe River, Belgium, was analysed within a European Special Area of Conservation to improve the understanding of environment‐induced spring migration. A logistic model was fitted to forecast smolt migration and to calculate phenological indicators for management, i.e. the onset, end, and duration of migration, while accounting for the influence of photoperiod, water temperature, and hydrological conditions.
- The results indicated that the photo‐thermal units accumulated by smolts above a 7°C temperature threshold was a relevant proxy to reflect the synergistic effect between temperature and photoperiod on smolt migration. After integrating the effect of river flow pulses, the model accurately explained the inter‐annual changes in migration timing (R2 = 0.95). The model predictions provide decisive management information to identify sensitive periods during which mitigation measures (e.g. hydropower turbine shutdown, river discharge management) should be conducted to promote smolt survival.
- The model was used to predict phenological characteristics under future scenarios of climate change. The results suggest a joint effect of hydrological alterations and water warming. Temperature increases of 1–4°C were associated with earlier initiation of migration, 6–51 days earlier, and spring flood events greatly influenced the duration of the migration period. Accordingly, the combined effects of human‐induced modifications of the hydrological regimes and increasing temperatures could result in a mismatch between the smolt and favourable survival conditions in the marine environment.
995.
S. C. Pearce Jean M. S. Thom 《The Journal of Horticultural Science and Biotechnology》2013,88(4):261-267
Crop records axe examined from Nigerian native small holdings of cacao to find out how best such trees can be used as experimental material. 相似文献
996.
997.
998.
Renata Zocatelli Marlène Lavrieux Jean-Robert Disnar Claude Le Milbeau Jérémy Jacob Jean Gabriel Bréheret 《Journal of Soils and Sediments》2012,12(5):734-748
Purpose
Eighteen soils were sampled in the Lake Aydat catchment in order to analyse free fatty acid (FA) content; FAs are considered to be among the most amenable biomarkers to mobilisation by runoff waters. The majority of the study area has soil cover consisting of grasslands or forest since the 2nd World War, although some covers having changed more recently. 相似文献999.
Sacks GL Gates MJ Ferry FX Lavin EH Kurtz AJ Acree TE 《Journal of agricultural and food chemistry》2012,60(12):2998-3004
1,1,6-Trimethyl-1,2-dihydronaphthalene (TDN) is well-known to contribute "petrol" aromas to aged Riesling wines, but its prevalence and contribution to young Riesling or non-Riesling wines is not well understood. TDN concentrations were measured in 1-3-year-old varietal wines produced from Cabernet franc (n = 14 wines), Chardonnay (17), Cabernet Sauvignon (4), Gewurztraminer (4), Merlot (9), Pinot gris (6), Pinot noir (9), Riesling (28), or Sauvignon blanc (6). TDN concentrations in the Riesling wines, 6.4 ± 3.8 μg/L, were significantly higher than in all other varietals, 1.3 ± 0.8 μg/L. The odor detection thresholds for TDN were then determined in both model wine and a neutral white wine. Group sensory thresholds were found to be the same in both matrices, 2 μg/L, indicating little masking of TDN due to the odorants in the neutral white. The TDN sensory threshold was a factor of 10 below the previously reported odor threshold. On the basis of this revised threshold, 27 of 28 Riesling wines had suprathreshold TDN, whereas only 7 of 69 non-Riesling wines had suprathreshold TDN. The monoterpenes linalool and geraniol were also measured in the Riesling wines, and odor activity values (OAVs) were calculated for the monoterpenes and TDN. The OAV for TDN was higher than for the monoterpenes in 25 of 28 Riesling wines. 相似文献
1000.
Organic complexed superphosphates (CSP): physicochemical characterization and agronomical properties
Erro J Urrutia O Baigorri R Aparicio-Tejo P Irigoyen I Torino F Mandado M Yvin JC Garcia-Mina JM 《Journal of agricultural and food chemistry》2012,60(8):2008-2017
A new type of superphosphate (organic complexed superphosphate (CSP)) has been developed by the introduction of organic chelating agents, preferably a humic acid (HA), into the chemical reaction of single superphosphate (SSP) production. This modification yielded a product containing monocalcium phosphate complexed by the chelating organic agent through Ca bridges. Theoretically, the presence of these monocalcium-phosphate-humic complexes (MPHC) inhibits phosphate fixation in soil, thus increasing P fertilizer efficiency. This study investigateed the structural and functional features of CSP fertilizers produced employing diverse HA with different structural features. To this end were used complementary analytical techniques: solid-phase 31P NMR, 13C NMR, laser-confocal microscopy, X-ray diffraction, and molecular modeling. Finally, the agronomical efficiency of four CSP have been compared with that of SSP as P sources for wheat plants grown in both alkaline and acidic soils in greenhouse pot trials under controlled conditions. The results obtained from the diverse analytical studies showed the formation of MPHC in CSP. Plant-soil studies showed that CSP products were more efficient than SSP in providing available phosphate for wheat plants cultivated in various soils with different physicochemical features. This fact is probably associated with the ability of CSP complexes to inhibit phosphate fixation in soil. 相似文献