scholarly journals Ecology and distribution of desert Truffles in Algeria.

2021 ◽  
Author(s):  
Zohra Fortas ◽  
Soulef Dib-Bellahouel ◽  
Gérard Chevalier
Keyword(s):  
Molecular Phylogeny ◽  
Calcareous Soil ◽  
Host Plants ◽  
Sandy Loam ◽  
Field Surveys ◽  
Growing Seasons ◽  
Ecological Requirements ◽  
Loam Soil ◽  
Desert Truffles

Abstract This first study focuses on geographical distribution of desert truffles in Algeria, their diversity and their ecological requirements during growing seasons according to field surveys carried out during thirty years (1986–2016). Investigations in 61 productive sites of desert truffles spread over several bioclimatic areas revealed the presence of nine species to genera Terfezia, Tirmania and Picoa and their host plants Helianthemum spp. This study complements our earlier work on characterization of Terfezia and Picoa samples harvested throughout Algeria by macro-and micromorphological studies and by molecular phylogeny. Pedoclimatic factors were evaluated, host plants species were identified and mycorrhizal relationships of these fungi species under field conditions were examined. Results revealed that good natural yield desert truffles species is closely linked to intensity and distribution of rainfall, the temperature, frequency of storms during ascomata growing seasons. Nine desert truffles species grow on sandy loam soil and form with annual or perennial Helianthemum spp. endomycorrhizae on calcareous soil and also ectomycorrhizae without mantle on acidic soil in Helianthemum guttatum..

Survival and Growth of Red Pine Planted on a Hardwood Site – A Second Look

1980 ◽  
Vol 56 (3) ◽  
pp. 112-114 ◽  
Author(s):  
Douglas M. Stone
Keyword(s):  
Sandy Loam ◽  
Site Index ◽  
Poor Quality ◽  
Red Pine ◽  
Northern Hardwood ◽  
Growing Seasons ◽  
Second Growth ◽  
Loam Soil ◽  
Survival And Growth ◽  
A Site

A 55-year-old stand of second-growth northern hardwood growing on a well-drained sandy loam soil was converted to red pine to compare with an adjacent 1929 plantation. Part of the plantation was cleaned during the second and third growing seasons and second-year survival was 72%. In the non-cleaned portion, which is reverting to maple sprouts, aspen suckers, brush, and weeds, pine survival was 38%. Annual height growth averaged 15.0 and 8.1 cm (6.0 and 3.2. in.), respectively. Differences in early success of the two plantings are attributed to: 1) greater competition after clearing pole-size hardwoods; 2) larger tops and better developed root systems of 2-1-2 transplants used in 1929; 3) planting in prepared spots in 1929; and 4) above normal growing season precipitation during 1929, and below normal in 1976. Converting pole-size northern hardwoods to red pine will be difficult and expensive. Competing vegetation will be the most serious problem, particularly on good hardwood sites. Investments in converting hardwoods to red pine should be concentrated in poor quality stands on well drained soils with a site index for maple of 50 or less.

scholarly journals Caracterización Eco-geográfica de melloco (Ullucus tuberosus C.) En la Región Alto Andina del Ecuador

2018 ◽  
pp. 31
Author(s):  
Edwin Jesús Naranjo Quinaluisa ◽  
César Guillermo Tapia Bastidas ◽  
Roberto Javier Velázquez Feria ◽  
Yudemir Cruz Pérez ◽  
Angélica Hipatia Delgado Pilla ◽  
...  
Keyword(s):  
Sandy Loam ◽  
Andean Region ◽  
Geographic Ranges ◽  
Palabras Clave ◽  
Ullucus Tuberosus ◽  
Temperature Ranges ◽  
Loam Soil ◽  
Resources Conservation ◽  
Edaphic Variables

Ecogeographic characterization of Melloco (Ullucus tuberosus C.) in the high Andean region of Ecuador Resumen El estudio se llevó a cabo en la región alto Andina del Ecuador, utilizando la colección nacional de Melloco (Ullucus tuberosus C.), perteneciente al Banco Nacional de Germoplasma del INIAP. El objetivo fue evaluar las características de los sitios de colecta, identificar rangos climáticos y ecosistemas favorables o marginales para el cultivo. Para la caracterización se utilizó información geo-referencial de puntos de colecta y 13 variables climáticas, geofísicas y edáficas. Se generó un Mapa de Caracterización Eco-geográfica del Terreno Específico (mapa ELC) aplicando la herramienta CAPFITOGEN y estadística descriptiva. Como resultados se identificaron categorías que establecen los rangos adaptativos en el cultivo, con 22 categorías definidas por el mapa ELC y el 39% (73) de las accesiones fueron colectadas en las categorías con rangos de temperatura de 11 ºC a 13 ºC, bajo contenido de materia orgánica, pendiente ligeramente inclinada, suelo franco arenoso, poco profundos y un pH moderadamente ácido. Las variables ambientales para las categorías más frecuentes presentaron valores promedios de temperatura entre 5 - 20 °C, una precipitación que oscila entre 379 - 3764 mm, con un rango de altitud entre los 1800 - 3800 msnm, pendiente de 8 - 9° y un pH de 5,7. Los mapas de caracterización eco-geográfica resultaron de utilidad para identificar zonas adecuadas para el melloco y otros tubérculos andinos en Ecuador, y conocer los rangos eco-geográficos para dicho cultivo. Palabras clave: Adaptación de las plantas; Biodiversidad; Conservación de recursos; Mapa; pH. Abstract The study was carried out in the high Andean region of Ecuador using the National collection of Melloco (Ullucus tuberosus C.), which belongs to the National Germplasm Bank of INIAP. The objective was to evaluate the characteristics of the collection sites, identify climatic ranges and favorable or marginal ecosystems for cultivation. For the characterization, georeferential information of collection points and other climatic, geophysical and edaphic variables were used. An Eco-geographic Characterization Map of the specific Land (ELC map) was generated applying the tool CAPFITOGEN and descriptive statistics. As results, categories that establish the adaptive ranges in the crop were identified, with 22 categories defined by the ELC map. 39% (73) of the accessions were collected in the categories with temperature ranges from 11ºC to 13ºC, low content of organic matter, slope slightly inclined, sandy loam soil, shallow and a pH moderately acidic. The environmental variables for the most frequent categories presented average values of temperature between 5 – 20ºC, a precipitation that oscillates between 379 – 3764 mm, with an altitude range between 1800 – 3800 masl, slope of 8 – 9º and pH of 5.7. The eco – graphical characterization maps were useful to identify suitable areas for melloco and other Andean tubers in Ecuador, and to know the eco – geographic ranges for the studied crop. Keywords: Plant adaptation; Biodiversity; Resources conservation; Maps; pH.

Soil-particle selection by the mound-building termite Macrotermes bellicosus on a sandy loam soil catena in a Nigerian tropical savanna

2009 ◽  
Vol 25 (4) ◽  
pp. 449-452 ◽  
Author(s):  
Susumu S. Abe ◽  
Sadahiro Yamamoto ◽  
Toshiyuki Wakatsuki
Keyword(s):  
Sandy Loam ◽  
Soil Particle ◽  
Clay Particles ◽  
Particle Selection ◽  
Ecological Requirements ◽  
Mound Construction ◽  
Soil Catena ◽  
Macrotermes Bellicosus ◽  
Loam Soil ◽  
The Tropics

Many species of termite (Isoptera) build their nests inside mounds because a mound has direct and positive feedback effects on the termite colonies through the maintenance of humidity and protection of the population from enemies, e.g. ants (Jouquet et al. 2006, Korb 2003, Noirot & Darlington 2000). Soil manipulation by termites (Isoptera) for mound construction is of particular interest for many researchers in terms of pedogenesis of the tropics (Lavelle et al. 1992, Lobry de Bruyn & Conacher 1990). The termites select soil particles according to ecological requirements such as water availability (Jouquet et al. 2002, 2007) and improve soil structural stability by means of application of clay particles and saliva/excreta (Fall et al. 2001, Jouquet et al. 2004). The nest-building activity of the termites inevitably causes regional translocation of soils (Bagine 1984, Holt & Lepage 2000) and distinctive patches in local ecosystems, which contributes to ecological diversity (Lavelle et al. 1992). This is the reason why termites are regarded as an ecological engineer (Jouquet et al. 2006). Soil-particle selection by the termites, however, has not been fully explored in relation to diverse ecologies and landscapes in Africa.

scholarly journals Comparing Beerkan infiltration tests with rainfall simulation experiments for hydraulic characterization of a sandy-loam soil

2017 ◽  
Vol 31 (20) ◽  
pp. 3520-3532 ◽  
Author(s):  
Simone Di Prima ◽  
Vincenzo Bagarello ◽  
Laurent Lassabatere ◽  
Rafael Angulo-Jaramillo ◽  
Inmaculada Bautista ◽  
...  
Keyword(s):  
Sandy Loam ◽  
Sandy Loam Soil ◽  
Rainfall Simulation ◽  
Simulation Experiments ◽  
Loam Soil ◽  
Infiltration Tests

Nitrous oxide emissions as affected by liquid and solid pig manures applied to annual and perennial forage crops on a sandy loam soil

2016 ◽  
Vol 96 (4) ◽  
pp. 361-371 ◽  
Author(s):  
Paligwendé Nikièma ◽  
O.O. Akinremi ◽  
M. Tenuta
Keyword(s):  
Nitrous Oxide ◽  
Sandy Loam ◽  
Sandy Loam Soil ◽  
Nitrous Oxide Emissions ◽  
Pig Manure ◽  
Soil Conditions ◽  
Forage Crops ◽  
Manure Application ◽  
Growing Seasons ◽  
Loam Soil

Emissions of nitrous oxide (N2O-N) from manure applied to annual crop (AC) and perennial forage (PF) are poorly quantified for the Canadian Prairie Region. This study used static chambers over two growing seasons to assess soil N2O-N emissions from solid pig manure (SPM) and liquid pig manure (LPM) in AC and PF systems on a sandy loam soil. In 2011, when manure application coincided with hot and wet soil conditions, both manure treatments in AC induced N2O-N emission episodes a week later. In the PF, however, only LPM resulted in an N2O-N emission peak after 8 d. In 2012, manure application did not coincide with hot and wet soil conditions, and emission rates were smaller. Overall, the effect of manure type was inconsistent. In 2011, cumulative emissions in AC from LPM and SPM were 5.8 and 7.8 kg N2O-N ha−1, respectively, and in PF were 10.7 and 0.6 kg N2O-N ha−1, respectively. In 2012, cumulative emissions were <1 kg N2O-N ha−1, except LPM in PF.  In 2011, LPM had significantly higher emission factor (EF ≍ 7%) than SPM (≤0.2%) in both AC and PF, whereas in 2012 manure type had no effect on EF (≍ 0). Over the two growing seasons and across manure types, EF did not differ between AC and PF. These results suggest that SPM would reduce N2O-N emission relative to LPM when conditions favor intense denitrification.

scholarly journals Comparison of June-budded and Grafted Two-year-old `Chandler' Walnut (Juglans regia) on Paradox Hybrid Root

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 531E-531
Author(s):  
Kathy Kelley ◽  
Dave Ramos
Keyword(s):  
Sandy Loam ◽  
Juglans Regia ◽  
Dry Weight ◽  
Root Diameter ◽  
Root Number ◽  
Graft Union ◽  
Trunk Diameter ◽  
Growing Seasons ◽  
Loam Soil ◽  
Total Dry Weight

Fifty trees each of 1-year-old Paradox rootstock June-budded to `Chandler' walnut and 2-year-old Paradox whipgrafted to `Chandler' were planted in a 28 × 28-ft spacing on a Hanford sandy loam soil. Ten trees of each type were selected at time of planting and the number of roots, individual root diameter, trunk diameter, root dry weight, scion dry weight, and total dry weight were compared. All parameters, with the exception of root number, were significantly greater for the grafted 2-year-old rootstocks. Growth of the trees measured as trunk circumference 20 cm above the graft union was significantly greater for the grafted 2-year-old rootstocks following the first season. There was no significant different in trunk circumference between the 1- and 2-year-old rootstocks following the second or third growing seasons.

scholarly journals Root Pruning and Soil Type Affect Pecan Root Regeneration

1998 ◽  
Vol 8 (4) ◽  
pp. 573-575 ◽  
Author(s):  
B.D. McCraw ◽  
M.W. Smith
Keyword(s):  
Soil Type ◽  
Sandy Loam ◽  
Root Pruning ◽  
Root Weight ◽  
Silt Loam ◽  
Carya Illinoensis ◽  
Growing Seasons ◽  
Root Regeneration ◽  
Loam Soil ◽  
Two Sides

Taproots of 2-year-old `Apache' seedling pecan [Carya illinoensis (Wang)] trees were pruned to 1 ft (30 cm), 2 ft (60 cm), or 3 ft (90 cm) in combination with wounding treatments consisting of no wounding, scraping through pericycle tissue on one or two sides of the taproot, or longitudinally splitting the taproot for about half its length. The trees were planted in a Port silt loam soil and a Teller sandy loam soil and grown without irrigation. At the end of the first and second growing seasons, top growth was measured, trees were dug and root system regrowth was evaluated. Tree root weight and number of roots per tree decreased with increasing taproot length.

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