Efficiency of the salt flotation technique in the recovery of Ascaris lumbricoides eggs from the soil

1995 ◽  
Vol 69 (1) ◽  
pp. 1-5 ◽  
Author(s):  
M.O. Ajala ◽  
S.O. Asaolu

AbstractThe efficacy of the salt flotation technique using saturated solutions of sodium nitrate (specific gravity 1.30) and zinc sulphate (specific gravity 1.16) for separating Ascaris lumbricoides eggs from clay, loamy and sandy soils has been investigated. Ten samples of each of the egg concentrations of 100, 500, 2500, 5000 and 10,000 eggs/25 g of soil were used for each soil type. Using T-test and ANOVA, the number of eggs recovered from sand was significantly higher than from loam and the number from loam significantly higher than from clay. With sodium nitrate, the maximum egg recovery rate was 25.04% from sandy soil at a concentration of 500 eggs/25 g soil while with zinc sulphate it was 13.88% also from sandy soil and concentration of 500 eggs/25 g soil. While the number of eggs recovered increased with soil egg concentration, the percentage of eggs recovered is inversely proportional to egg concentration. The number of eggs recovered with sodium nitrate was significantly higher than with zinc sulphate solution in the three soil types.

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1391
Author(s):  
Xizi Wang ◽  
Svend Christensen ◽  
Jesper Svensgaard ◽  
Signe M. Jensen ◽  
Fulai Liu

There is an urgent need among plant breeders for a deeper understanding of the links between wheat genotypes and their ability to utilize light for biomass production and their efficiency at converting the biomass into grain yield. This field trail was conducted to investigate the variations in radiation use efficiency (RUE) and harvest index (HI) of four spring wheat cultivars grown on two soil types with two nitrogen (N) fertilization levels. Grain yield (GY) was significantly higher with 200 kg N ha−1 than 100 kg N ha−1 and on clay soil than on sandy soil, and a similar trend was observed for shoot dry matter (DM) at maturity. RUE and HI was neither affected by cultivar nor N-fertilization, but was affected by soil type, with a significantly higher RUE and HI on clay than on sandy soil. The differences of water holding capacity between the two soil types was suggested to be a major factor influencing RUE and HI as exemplified by the principal component analysis. Thus, to achieve a high RUE and/or HI, sustaining a good soil water status during the critical growth stages of wheat crops is essential, especially on sandy soils with a low water holding capacity.


2009 ◽  
Vol 57 (8) ◽  
pp. 629 ◽  
Author(s):  
Timothy J. Curran ◽  
Peter J. Clarke ◽  
Nigel W. M. Warwick

The occurrence of dry rainforest in climates considered drier than the recognised limit for rainforest has been explained by the edaphic compensation hypothesis, which proposed that finer-textured soils facilitate the occurrence of rainforest at climatic extremes. We tested this by examining the effect of soil type on the water relations and plant traits of four dry rainforest species, during a severe drought and subsequent non-drought periods. We predicted plants growing in sandy soils would exhibit higher levels of water stress (lower predawn water potential and stomatal conductance) and possess morphological and physiological traits that more typically reflect drought resistance (late leaf fall in deciduous species, low specific leaf area, vertical leaf angles and stomata that close at low water potential) than those growing in loam soils. During drought, levels of water stress were similar across soil types, while post-drought plants on sandy soils were less stressed. Soil type did not cause shifts in drought tolerance traits, suggesting there has been no ecotypic differentiation of dry rainforest species across soil types for these traits. Hence, we found no support for the edaphic compensation hypothesis in adult plants; future studies should consider other life-cycle stages, such as seedlings.


1998 ◽  
Vol 72 (4) ◽  
pp. 359-361 ◽  
Author(s):  
T. Harnnoi ◽  
A. Wijit ◽  
N. Morakote ◽  
V. Pipitgool ◽  
W. Maleewong

AbstractThe specific gravity of the eggs of the liver fluke Opisthorchis viverrini was determined using a sucrose gradient centrifugation and found to range from 1.2713 to 1.3043. The peak egg count was located at the sucrose fraction with a specific gravity of 1.2814. An attempt to float eggs in saturated sodium nitrate solution, sp.gr. 1.4, failed. Examination of human stool specimens for O. viverrini eggs by simple flotation in saturated sodium nitrate solution and the formol-ether sedimentation technique revealed that the flotation technique was not as efficient as the sedimentation technique. It was suggested that the flotation techniques were inappropriate for the detection of O. viverrini eggs in faeces or contaminated soil.


2019 ◽  
Vol 11 (16) ◽  
pp. 206
Author(s):  
José F. Schlosser ◽  
Paula M. dos Santos ◽  
Daniela Herzog ◽  
Lucas S. da Rosa ◽  
Jaqueline Ottonelli

With the aim of studying the drawbar performance and power required by a commercial chisel plow with five shanks, an experiment was carried out involving two soil types (sandy and clayey) and three working depths (0.25, 0.35 and 0.45 m). A farm wheeled tractor, properly sized by the raw power of the engine, pulled the equipment. An electronic instrumentation was used for data acquisition to measure the drawbar pull. Furthermore, in addition, four other parameters were determined, as real travel speed and slippage of the tractor. Chiseling operations showed no statistically significant effect of soil type on drawbar pull in the different working depths. However, clayey soil presented higher values of slippage (34.44%), power performance (47.25 kW) and drawbar pull (40.26 kN) than sandy soil.


2000 ◽  
Vol 24 (4) ◽  
pp. 213-218
Author(s):  
Jonathan W. Pote ◽  
Charles L. Wax ◽  
Bob L. Karr

Abstract A computer model predicted soil moisture in three climate zones with three soil textures. A 30 yr daily simulation provided probable work days for the nine combinations. Criteria for work days were soil moisture capacities less than 95% of maximum for sandy soils, 80% for loamy soils, and 65% for clay soils. Results indicate that sandy soils in the inland zone allow 233 work days/yr at the 50% probability level, whereas clay soils there allow only 140 days at that level. In the coastal zone sandy soils allow 252 work days/yr at the 50% level and clay soils allow 122 days at that level. These results were produced at ten probability levels for all soil types and all zones, as well as for each month. Applied examples of uses of the results are included. South. J. Appl. For. 24(4):213-218.


2006 ◽  
Vol 84 (6) ◽  
pp. 832-838 ◽  
Author(s):  
D.T. Booth

This study examined the effect of soil type on burrowing behaviour and cocoon formation during aestivation in the green-striped burrowing frog, Cyclorana alboguttata (Günther, 1867). Given a choice, frogs always chose to burrow in wet sand in preference to wet clay. Frogs buried themselves faster and dug deeper burrows in sandy soil. However, under my laboratory conditions, there was little difference in the pattern of soil drying between the two soil types. Frogs in both sand and clay soil experienced hydrating conditions for the first 3 months and dehydrating conditions for the last 3 months of the 6-month aestivation period, and cocoons were not formed until after 3 months of aestivation. After 6 months, there were more layers in the cocoons of frogs aestivating in sand than those aestivating in clay. Frogs were able to absorb water from sandy soil with water potentials greater than –400 kPa, but lost water when placed on sand with a water potential of –1000 kPa.


2000 ◽  
Vol 53 ◽  
pp. 253-257
Author(s):  
T.K. James ◽  
A. Rahman

The viability of ragwort (Senecio jacobaea L) seed buried for several years at 0 2 4 6 and 19 21 cm depths was evaluated in four different soil types Seed samples in nylon mesh bags were removed after 1 2 3 5 11 and 16 years burial and their viability determined by germination After 16 years no viable seed was found in the clay soil In the silt loam and peat soils 1 3 viable seed remained while in the sandy soil up to 13 remained viable In the surface 0 2 cm layer of soil it took from 109 to 146 years for the percentage of viable seed to fall to 1 of the original viable seed depending on soil type At the 4 6 and 19 21 cm depths the corresponding times were 128 165 years and 130 180 years


2020 ◽  
Vol 55 (4) ◽  
pp. 499-506
Author(s):  
Michael Karounos ◽  
Ron Cherry ◽  
Mabry McCray ◽  
Shangning Ji

Abstract Wireworms (Coleoptera: Elateridae) are major economic pests of Florida sugarcane (Saccharum spp. hybrid). The corn wireworm, Melanotus communis (Gyllenhal), is the most important wireworm pest of Florida sugarcane occurring in both sandy and muck soils. The objective of this study was to determine survivability, preference, and dispersal of wireworms in sandy and muck soils. There was no significant difference in starved wireworm survival between the soils after 2 mo. However, the starved wireworms gained more weight in muck soil than in sand. Wireworms dispersed at similar rates toward oat baits in both soil types. Interestingly, in free choice tests wireworms showed a high preference to reside in muck versus sandy soil, which corresponds to the greater wireworm weight change found in muck versus sandy soil. The high preference for muck and greater weight gain in muck found in this study partially explains why M. communis is more abundant in muck soils than in sandy soils in Florida sugarcane.


HortScience ◽  
2006 ◽  
Vol 41 (1) ◽  
pp. 113-118
Author(s):  
Bodo Gutezeit

The effect of water supply on total mass and yield of broccoli (Brassica oleracea L. var. italica, `Emperor') was examined in an experiment carried out in a microplot field installation on three soil types: Gleyic Cambisol (sand) and Eutric Fluvisol (flood-plain loam) in spring and fall and on a Haplic Phaeosem (loessal loam) in fall. Soil moisture levels were established by irrigation under the following replacement protocols: 14 mm whenever the limit of 75% vol of the available soil water (ASW), 14 and 28 mm whenever the limit of 55% vol of ASW, and 14, 28, and 42 mm whenever the limit of 35% vol of ASW were reached. The highest total plant mass was achieved by irrigation at 75% vol of ASW on the sandy soil in spring cultivation, and at 55% vol of ASW (in doses of 28 mm) on the flood-plain loam in fall cultivation. The highest marketable yield (head mass) was obtained on the sandy soil at 55% vol of ASW (in doses of 14 mm) for both spring and fall production. The total plant mass and head mass was only significantly affected by reduced soil moisture at 35% vol of ASW in spring. At 75% vol of ASW, irrigation with 14 mm always resulted in reduced headmass. In fall, yield was not affected by soil moisture depletion or soil type. For the production of broccoli, it is recommended that irrigation be started when soil moisture falls below 55% vol of ASW, followed by a water application rates of either 14 or 28 mm.


2015 ◽  
Vol 8 (3) ◽  
pp. 269-275 ◽  
Author(s):  
Jason W. Adams ◽  
Rodney G. Lym

AbstractThe Sheyenne National Grassland (SNG) is a native tall grass and mixed grass prairie located in southeastern North Dakota. Approximately half of the SNG has been invaded by leafy spurge (Euphorbia esulaL.) and control methods have been limited. Many herbicides cannot be utilized at the SNG due to sandy soils (> 80%) and shallow groundwater, nor can they be applied near the western prairie fringed orchid (Platanthera praeclaraSheviak and Bowles), a federally listed threatened plant found on the SNG. Quinclorac and aminocyclopyrachlor were considered for use on the SNG but potential to enter the groundwater was unclear. Movement of quinclorac and aminocyclopyrachlor was evaluated in 70 cm soil columns that simulated field conditions from five ecological sites. Quinclorac leached further following the heavy rainfall event of 15 cm in 48 h compared to the annual precipitation of 51 cm applied over 9 wk. Quinclorac leached approximately 45 cm into the soil profile averaged over all soil types and both precipitation events but never exceeded 65 cm regardless of soil type. Aminocyclopyrachlor leaching was greater than quinclorac and moved through all soil types into the leachate following both watering regimes. Desorption of both herbicides was incomplete. Approximately 10 and 32% of applied aminocyclopyrachlor and quinclorac, respectively, remained in the top 5 cm of soil regardless of soil type or watering regime. Quinclorac but not aminocyclopyrachlor was considered suitable for use at the SNG to control leafy spurge and has the added benefit of not harming the western prairie fringed orchid.


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