Magnesium deficiency symptoms associated with sugar maple dieback in a Lower Laurentians site in southeastern Quebec

1988 ◽  
Vol 18 (10) ◽  
pp. 1265-1269 ◽  
Author(s):  
B. Bernier ◽  
M. Brazeau

Observations made in 1987 on sugar maple (Acersaccharum Marsh.) dieback in the deciduous forest of the Lower Laurentians, northwest of Quebec City, revealed the occurrence of magnesium deficiency in various sites. Visual foliar symptoms observed on sugar maple in a severely declining stand growing on well-drained, stony, loamy-sand soil of granitic origin are briefly described and illustrated. Magnesium concentrations in the foliage of both trees and regeneration in early August averaged 0.06% (range 0.03–0.09%). Other tree or plant species present also exhibited conspicuous magnesium deficiency symptoms. The occurrence of magnesium deficiency in this and other sites of the deciduous forest in the Lower Laurentians contrasts with the general absence of this deficiency in a previously studied large section of forest in the Quebec Appalachians, where soils are derived from other rock formations.

2014 ◽  
Vol 3 (1) ◽  
pp. 150-158 ◽  
Author(s):  
Mohey A. Hassanain ◽  
Nawal A. Hassanain ◽  
Esam A. Hobballa ◽  
Fatma H. Abd- El Zaher ◽  
Mohamed Saber M. Saber

A surface sample representing a high contaminated loamy sand soil irrigated with sewage effluent since 30 years and was cultivated with artichoke was collected from Abu-Rawash sewage farm. The existence of HVC, enteric infectious bacteria and parasites in sewaged soil found to be negative for the forward and positive for the latter's. Out of the 30 samples separated from the sewaged soil sample, only 3 samples contained parasitic fauna of developed and undeveloped Ascaris (10%) and five samples contained Entamoeba coli. Results showed that the number of Ascaris eggs/gm soil was 0.017 and the number of E. coli/gm was 0.26. Decontamination of soil parasites was effective using either calcium hypochlorite or potassium permanganate. Salmonella, Vibrio and Campelobacter were detected in the high contaminated sewaged soil and survived for 120 days in the sewaged soil under all control and bioremediated treatments irrigated with either sewage effluent or water.


2018 ◽  
Vol 43 (2) ◽  
pp. 93-99
Author(s):  
Avi Friedman

A common practice in some of North Americans' residential development is to alter the site's natural conditions prior to and during construction. Rock formations are removed or changed, new terrain grading created, and landscape features uprooted. An approach whereby the design will be made to fit the site's characteristics is often avoided. Fitting a master plan of a new community to existing geo-environmental conditions was a principal objective in the planning of a 350-dwelling development on a 41-hectare site near Quebec City, in the province of Quebec, Canada. For the densely forested site, the author developed design guidelines that considered the roads' routes, parking areas, foundation, and footprint of each building. A pillar of this approach was to model the design after the terrain's condition by adopting flexible planning strategies. The project, now in advanced stages of construction, have earned many accolades from conservationists and demonstrated that once documentation of the site's natural conditions has taken place, the fitting of design to the site becomes easier to implement. This paper outlines the design challenges, show patterns that were developed specifically for the project and elaborate on the building process and its outcome.


Author(s):  
Allison Neil

Soil properties are strongly influenced by the composition of the surrounding vegetation. We investigated soil properties of three ecosystems; a coniferous forest, a deciduous forest and an agricultural grassland, to determine the impact of land use change on soil properties. Disturbances such as deforestation followed by cultivation can severely alter soil properties, including losses of soil carbon. We collected nine 40 cm cores from three ecosystem types on the Roebuck Farm, north of Perth Village, Ontario, Canada. Dominant species in each ecosystem included hemlock and white pine in the coniferous forest; sugar maple, birch and beech in the deciduous forest; grasses, legumes and herbs in the grassland. Soil pH varied little between the three ecosystems and over depth. Soils under grassland vegetation had the highest bulk density, especially near the surface. The forest sites showed higher cation exchange capacity and soil moisture than the grassland; these differences largely resulted from higher organic matter levels in the surface forest soils. Vertical distribution of organic matter varied greatly amongst the three ecosystems. In the forest, more of the organic matter was located near the surface, while in the grassland organic matter concentrations varied little with depth. The results suggest that changes in land cover and land use alters litter inputs and nutrient cycling rates, modifying soil physical and chemical properties. Our results further suggest that conversion of forest into agricultural land in this area can lead to a decline in soil carbon storage.


2004 ◽  
Vol 52 (2) ◽  
pp. 199-203 ◽  
Author(s):  
G. Singh ◽  
R. S. Jolly

Two field experiments were conducted during the kharif (rainy) season of 1999 and 2000 on a loamy sand soil to study the effect of various pre- and post-emergence herbicides on the weed infestation and grain yield of soybean. The presence of weeds in the weedy control plots resulted in 58.8 and 58.1% reduction in the grain yield in the two years compared to two hand weedings (HW) at 30 and 45 days after sowing (DAS), which gave grain yields of 1326 and 2029 kg ha-1. None of the herbicides was significantly superior to the two hand weedings treatment in influencing the grain yield. However, the pre-emergence application of 0.75 kg ha-1 S-metolachlor, and 0.5 kg ha-1 pendimethalin (pre-emergence) + HW 30 DAS were at par or numerically superior to this treatment. There was a good negative correlation between the weed dry matter at harvest and the grain yield of soybean, which showed that effective weed control is necessary for obtaining higher yields of soybean.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6027
Author(s):  
Julia J. Mlynarek ◽  
Amélie Grégoire Taillefer ◽  
Terry A. Wheeler

Saproxylic insects, those associated directly or indirectly with decaying wood for all or part of their life cycle, compose a large proportion of forest organisms. Flies (Diptera) are often the most abundant and species-rich group of insects in forest microhabitats, yet most work to date on saproxylic insect diversity and ecology has focused on beetles (Coleoptera). We compared saproxylic Diptera assemblages reared from two tree species (sugar maple and American beech) at two stages of decay (early/young and advanced/old) for a total of 20 logs in an eastern Canadian Nearctic old-growth forest. We found that communities are distinct within both species type and decay stage of wood. Early decay stage wood is more variable in community composition than later decay stage; however, as the age of the decaying wood increases, the abundance of Diptera increases significantly. Most indicator species are discernible in later decay stage and wood type. We venture to suggest that stochastic and deterministic processes may play a role in driving Diptera communities in temperate deciduous forests. To retain the highest saproxylic Diptera diversity in a forest, a variety of decaying wood types at different stages of decomposition is necessary.


2019 ◽  
Vol 11 (12) ◽  
pp. 3460 ◽  
Author(s):  
Abdulaziz G. Alghamdi ◽  
Hesham M. Ibrahim

Applications of large amounts of biosolid to agricultural lands have raised the concern over its potential impact on co-transport of metal contaminants. In this study, bulk biosolid was fractioned into six macro- and nano-biosolid fraction sizes. We investigated variations in the physicochemical properties of the different biosolid fraction sizes, and assessed sorption affinity and transport of Pb in a loamy sand soil. Decreasing biosolid fraction size from macro to nano resulted in consistent increases in surface area, surface charge, and a decrease in pore size. Biosolid particles >1000 µm showed similar surface properties that differ from biosolid particles < 1000 µm. Sorption affinity for Pb was larger on nano-biosolid as compared to all macro-biosolid fraction sizes. This is mainly attributed to the larger surface area and zeta potential of nano-biosolid, leading to increased surface reactivity and greater stability. Total amount eluted of Pb was increased in the presence of macro- and nano-biosolid by 21.3% and 45.6%, respectively. Our findings suggest that the application of the >1000 µm biosolid fractions can help to minimize adverse effects of biosolid applied in areas susceptible to potential environmental risk of contamination by heavy metals. Further assessment of potential mobility of nano-biosolid at the field scale is needed before the recommendation of including such approach during land application of biosolid.


Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 418 ◽  
Author(s):  
Jacob Lisuma ◽  
Ernest Mbega ◽  
Patrick Ndakidemi

Tobacco (Nicotiana tabacum L.) is associated with great uptake of soil macronutrients. Following the need to understand the macronutrients levels before and after tobacco cultivation, research was conducted in loamy sand soil of Sikonge, Urambo, and sand soil of Tabora, Tanzania. The initial macronutrients levels in the soil were compared with those measured after unfertilized and fertilized tobacco. Results showed that unfertilized tobacco plant influences the increase of nicotine to the rhizosphere, the macronutrients Ca (135%) > N (25%), decrease in the order of S (81%) > P (49%) > Mg (12%) > K (11%). The sole effect of nitrogen–phosphorus–potassium (NPK) and calcium–ammonium–nitrate (CAN) 27% fertilizers increased further nicotine, Ca (25%) > N (20%) > S (8%) > Mg (4%) > P (3%), and decreased K (3%) in the rhizosphere. Both tobacco plant and NPK + CAN fertilizers on the rhizosphere increased Ca (193%) > N (50%) and decreased S (80%) > P (48%) > K (14%) > Mg (8%). Leaf concentrations in fertilized tobacco increased Ca (197%) > K (28%) > P (27%) > S (26%) > N (18%) > Mg (12%). Therefore, tobacco plant increases soil N and Ca but decreases P, K, Mg, and S.


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