Inland Sand Dune Mycorrhizae: Effects of Soil Depth, Moisture, and pH on Colonization of Oryzopsis hymenoides

Mycologia ◽  
1995 ◽  
Vol 87 (1) ◽  
pp. 54 ◽  
Author(s):  
A. K. Al-Agely ◽  
F. B. Reeves
Weed Science ◽  
1987 ◽  
Vol 35 (4) ◽  
pp. 513-518 ◽  
Author(s):  
M. L. H. Kaul ◽  
P. D. Mangal

Crownbeard [Verbesina encelioides(Cav.) Benth. & Hook. f. ex. A. Gray # VEEEN (Compositae)] exhibited rapid seedling, vegetative, and reproductive growth. Seed germination under ideal conditions was high and occurred in varying soils except in gravel. It was significantly suppressed under drought and waterlogged conditions and was maximum at 21% moisture regimes. Larger and heavier seeds which exhibited higher germination were produced by the plants growing in open and sand dune habitats. Seedling emergence was highest from surface-sown seeds and least in those sown at 2.5-cm soil depth, beyond which no emergence occurred. High phenotypic plasticity, ecological variability, phenological diversity, seed germination in varied soils and under diverse moisture regimes, quick seedling growth and subsequent establishment, coupled with versatile breeding system, contribute to the successful growth, propagation, and spread of this species in nature in India.


Author(s):  
J.N. Abedalrahman ◽  
R.J. Mansor ◽  
D.R. Abass

A field experiment was carried out in the field of the College of Agriculture / University of Wasit, located on longitude  45o   50o   33.5o   East and latitude 32o 29o 49.8o North, in Spring season of the agricultural season 2019, in order to estimate the water consumption of potato crop using SWRT technology and under the drip irrigation system. The experiment was designed according to Randomized Complete Block Design (RCBD) with three replications and four treatments that include of the SWRT treatment (the use of plastic films under the plant root area in an engineering style), and the treatment of vegetal fertilizer (using Petmos), organic fertilizer (sheep manure), and the control treatment . Potato tubers (Solanum tuberosum L.)  var. Burin was planted for spring season on 10/2/2019 at the soil depth of 5-10 cm. The highest reference water consumption for the potato crop during the season was calculated by Najeeb Kharufa, which was 663.03 mm. The highest actual water consumption for the potato crop during the season for the control treatment was 410.1 mm. The results showed increase in the values of the crop coefficient (Kc) in the stages of tubers formation and tubers filling stage as compared to the vegetative and ripening stages, ranged from 1.37-1.92 for the two stages of tubers formation and tubers filling. The SWRT treatment gave the highest water use efficiency during the season, was 3.46 kg m-3 .


2018 ◽  
Vol 28 (3) ◽  
pp. 336-345
Author(s):  
Nguyễn Xuân Tặng

Groundwater in coastal sand dune area in the south of Quang Binh province and posibility for exploitation


2015 ◽  
Vol 68 ◽  
pp. 446-446
Author(s):  
D.J. Wilson ◽  
P.J. Gerard

Spiny snout mite (Neomolgus capillatus) is a potential biocontrol agent for clover flea (Sminthurus viridis) a white clover pest on dairy farms in warmer and wetter parts of New Zealand In the 1990s this mite was introduced from Brittany France into Tasmania for clover flea control Results during the release programme were highly promising and subsequent anecdotal farmer reports indicate widespread decreases in damage As N capillatus is a predatory mite and already known to attack nontarget organisms habitat specificity will determine whether it could be introduced into New Zealand without risk to native insects To assess this pastures on nine of the original Tasmanian release farms and adjacent nontarget habitats ranging from bush wetlands eucalypt stands to sand dune country were sampled in April 2014 Litter samples were collected heat extracted and mite species identified Neomolgus capillatus was found at effective densities in pastures that had good clover cover Where present it displaced Bdellodes spp mites that are ineffective against clover flea No N capillatus were found in the nontarget habitats all of which lacked clover and contained other predatory mites including Bdellodes spp Therefore the preference by N capillatus for lush pastures makes it an excellent prospect for introduction as a biocontrol agent into clover flea prone regions of New Zealand


Author(s):  
Matt Bristow

A new analytical method is presented to determine the effects of cyclic loading on laterally loaded piles. The method uses a new numerical procedure to quantify the effects of the cyclic loading at each soil depth and convert that to a set of cyclic p-y modifiers. The reduced foundation stiffness associated with the cyclic loading can be determined, including the residual static capacity and an estimate of the accumulated displacement. The new method introduces the concept of cyclic degradation damage, which is defined as sum of the cyclic degradation that is occurring at each soil depth. Cyclic degradation calculations are based on the shear stresses in the soil. Consequently, anything that causes the shear stresses to change (e.g. pile length, pile diameter, applied loading, etc.) will automatically be included in the calculation of cyclic p-y modifiers. The method has been validated by comparing the cyclic p-y curves produced using the new method with established cyclic p-y curves derived from fielding testing. The new method has also been used to investigate what happens to the cyclic p-y modifiers as one moves away from the reference conditions used to determine the established cyclic p-y curves in API RP2A (2000). The new method shows that every application (e.g. combination of cyclic loading, pile properties, and soil characteristics) has its own unique set of cyclic p-y curves, though most p-y curves fit within an upper and lower bound range. Examples are provided for large diameter monopiles.


2020 ◽  
Vol 3 (2) ◽  
pp. 49-59 ◽  
Author(s):  
Yogesh Badhe ◽  
Ravindra Medhe ◽  
Tushar Shelar

The site suitability for construction of water conservation structures is an important step towards groundwater conservation in arid and semi-arid regions. Water is the most crucial for maintaining an environment and ecosystem which is helpful to sustaining all forms of the life. The increasing water scarcity day to day has been one of the common problems over a period of time. On top of it, when the area is a part of rain shadow zone like Ahmednagar district, water conservation activities are become more important. The present study aims to identify the suitable zones for water conservation activity. Multi- criteria evaluation is carried out using Geographic Information System (GIS) techniques to help the choice makers in defining suitable site for construction of water conservation structures. Different layers which were considered for multi-criteria evaluation: slope, land use land cover, soil texture, lithology, soil depth, soil erosion, wells, lineaments and drainage network. Analytical Hierarchy Processes (AHP) is used for weighted sum to find suitable sites for implementation of water conservation activity using selected criterions. The site suitability map was classified into four classes: highly suitable, moderately suitable, less suitable and not suitable with area of 19.19%, 26%, 49.03% and 5.78, respectively. This map will help for selection of suitable sites for construction of Mati Nala Bund (MNB), Check Dam, Cement Nala Bund (CNB) and Continuous Contour Trenches (CCT) for conservation of groundwater resource in the region.


1971 ◽  
Vol 2 (2) ◽  
pp. 79-92 ◽  
Author(s):  
K. J. KRISTENSEN ◽  
H. C. ASLYNG

The lysimeter installation described comprises 36 concrete tanks each with a soil surface of 4 m2. The installation is useful for plant growth experiments under natural conditions involving different treatment combined with various controlled water supplies. The ground installation is at least 20 cm below the soil surface and tillage can be done with field implements. The lysimeter tanks are provided with a drainage system which can drain the soil at the bottom (100 cm depth) to a tension of up to 100 cm. A constant ground-water table at less than 100 cm soil depth can also be maintained. The soil moisture content at different depths is determined from an underground tunnel by use of gamma radiation equipment in metal tubes horizontally installed in the soil. Rainfall is prevented by a movable glass roof automatically operated and controlled by a special rain sensor. Water is applied to the soil surface with a special trickle irrigation system consisting of a set of plastic tubes for each lysimeter tank and controlled from the tunnel. Fertilizers in controlled amount can be applied with the irrigation water.


2001 ◽  
Vol 66 ◽  
Author(s):  
M. Aslanidou ◽  
P. Smiris

This  study deals with the soil moisture distribution and its effect on the  potential growth and    adaptation of the over-story species in north-east Chalkidiki. These  species are: Quercus    dalechampii Ten, Quercus  conferta Kit, Quercus  pubescens Willd, Castanea  sativa Mill, Fagus    moesiaca Maly-Domin and also Taxus baccata L. in mixed stands  with Fagus moesiaca.    Samples of soil, 1-2 kg per 20cm depth, were taken and the moisture content  of each sample    was measured in order to determine soil moisture distribution and its  contribution to the growth    of the forest species. The most important results are: i) available water  is influenced by the soil    depth. During the summer, at a soil depth of 10 cm a significant  restriction was observed. ii) the    large duration of the dry period in the deep soil layers has less adverse  effect on stands growth than in the case of the soil surface layers, due to the fact that the root system mainly spreads out    at a soil depth of 40 cm iii) in the beginning of the growing season, the  soil moisture content is    greater than 30 % at a soil depth of 60 cm, in beech and mixed beech-yew  stands, is 10-15 % in    the Q. pubescens  stands and it's more than 30 % at a soil depth of 60 cm in Q. dalechampii    stands.


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