MONTHLY AND YEARLY CHANGES IN AGGREGATE SIZE OF SURFACE SOILS

1968 ◽  
Vol 48 (2) ◽  
pp. 159-164 ◽  
Author(s):  
Frederick Bisal ◽  
W. S. Ferguson

Repeated sampling at a single location on each of three soil types at irregular intervals during the 12-year period 1955–1967 indicated a highly monthly and yearly variation in the percentage of the total soil in aggregates < 0.84 mm in diameter (the erodible fraction) by dry-sieve analysis. The greatest degree of variation occurred in the clay soil. Increases and decreases in aggregation were correlated among soils.The amount of the erodible fraction determined by dry-sieve analysis is highly dependent on the date of sampling. Consequently, the value of dry sieving as a method of predicting the susceptibility of soils to wind erosion over an extended period of time is limited.

Solid Earth ◽  
2016 ◽  
Vol 7 (4) ◽  
pp. 1233-1242 ◽  
Author(s):  
Carlos Asensio ◽  
Francisco Javier Lozano ◽  
Pedro Gallardo ◽  
Antonio Giménez

Abstract. Wind erosion is a key component of the soil degradation processes. The purpose of this study is to find out the influence of material loss from wind on soil properties for different soil types and changes in soil properties in olive groves when they are tilled. The study area is located in the north of the Tabernas Desert, in the province of Almería, southeastern Spain. It is one of the driest areas in Europe, with a semiarid thermo-Mediterranean type of climate. We used a new wind tunnel model over three different soil types (olive-cropped Calcisol, Cambisol and Luvisol) and studied micro-plot losses and deposits detected by an integrated laser scanner. We also studied the image processing possibilities for examining the particles attached to collector plates located at the end of the tunnel to determine their characteristics and whether they were applicable to the setup. Samples collected in the traps at the end of the tunnel were analyzed. We paid special attention to the influence of organic carbon, carbonate and clay contents because of their special impact on soil crusting and the wind-erodible fraction. A principal components analysis (PCA) was carried out to find any relations on generated dust properties and the intensity and behavior of those relationships. Component 1 separated data with high N and OC contents from samples high in fine silt, CO3= and available K content. Component 2 separated data with high coarse silt and clay contents from data with high fine sand content. Component 3 was an indicator of available P2O5 content. Analysis of variance (ANOVA) was carried out to analyze the effect of soil type and sampling height on different properties of trapped dust. Calculations based on tunnel data showed overestimation of erosion in soil types and calculation of the fraction of soil erodible by wind done by other authors for Spanish soils. As the highest loss was found in Cambisols, mainly due to the effect on soil crusting and the wind-erodible fraction aggregation of CaCO3, a Stevia rebaudiana cover crop was planted between the rows in this soil type and this favored retention of particles in vegetation.


Agrikultura ◽  
2017 ◽  
Vol 28 (1) ◽  
Author(s):  
Fizrul Indra Lubis ◽  
Sudarjat Sudarjat ◽  
Danar Dono

ABSTRACTPopulation of soil palm weevil pollinator Elaeidobius kamerunicus FAUST and its impact on fruit setvalue at clay, sandy and peat soil types in central Kalimantan, di IndonesiaOil palm weevil pollinator Elaeidobius kamerunicus Faust plays an important role in the increasing oilpalm fruit set value. Along with the development of oil palm, fruit set problems occurred in recentdecades in some parts of Indonesia. An experiment was carried out on a seven years old oil palmplantation located at Selangkun Estate, Kotawaringin Barat, Central Kalimantan, Indonesia to find outthe influence of population E. kamerunicus on pollination efficiency at clay, sandy and peat soil types.Relative to other soil types, a high weevil population on male (50,811 weevils/ha ; 72 weevils/spikelet)and female (219 weevils) inflorescences had been recorded at clay soil. Fruit set value on clay soil 58.9%and significantly different with sandy soil of 49.8% and peat soil of 46.4%. Population E. kamerunicusper ha influenced fruit set value at clay, sandy and peat soil types. Number of E. kamerunicus visitedfemale inflorescences did not influenced fruit set value at clay, sandy and peat soil types.Keywords: Clay soil, Elaeidobius kamerunicus, fruit set, peat soil, population, sandy soil ABSTRAKSerangga penyerbuk kelapa sawit Elaeidobius kamerunicus FAUST berperan penting dalam peningkatannilai fruit set kelapa sawit. Seiring dengan perkembangan kelapa sawit, adanya permasalahan nilai fruitset telah terjadi dalam beberapa kurun waktu di beberapa wilayah Indonesia. Penelitian dilakukan diperkebunan kelapa sawit yang telah berumur tujuh tahun, berlokasi di Selangkung, Kotawaringin Barat,Kalimantan Tengah, Indonesia dan bertujuan untuk mengetahui pengaruh populasi E. Kamerunicusterhadap efisiensi penyerbukan pada tipe tanah liat, pasir dan gambut. Berdasarkan tipe tanahdilaporkan bahwa tingginya populasi kumbang pada bunga jantan yaitu (50.811 kumbang/ha; 72kumbang/spikelet) dan bunga betina yang sedang mekar (219 kumbang) pada tipe tanah berliat.Adapun, nilai fruit set pada tanah liat sebesar 58,9% dan berbeda nyata dibandingkan dengan tanahberpasir (49,8%) dan gambut (46,4%). Populasi E. kamerunicus per ha berpengaruh terhadap nilai fruitset pada tipe tanah liat, pasir dan gambut. Namun, jumlah E. kamerunicus yang mengunjungi bungabetina yang sedang mekar tidak berpengaruh terhadap nilai fruit set pada tipe tanah liat, pasir dangambut.Kata Kunci : Elaeidobius kamerunicus, Fruit set , Populasi, Tanah Gambut, Tanah liat, Tanah Pasir


2013 ◽  
Vol 33 (5) ◽  
pp. 965-975 ◽  
Author(s):  
Aloisio Bianchini ◽  
Pedro H. de M. Borges

The destruction of the cotton crop residues (cotton stalks) is a mandatory procedure in Brazil for prophylactic issues, but is a subject unexplored by the research and there are few studies that deal with this issue. However, this is not encouraged in recent decades, studies aimed at developing and evaluating equipment for this purpose. The present study had the objective to evaluate six methods for mechanical destruction of cotton crop residues. Each method was defined based on the principle of operation of the active parts of the equipment, which were tested in medium texture soil and in a clayey one. The variables used to evaluate the efficiency of the equipment were the regrowth rate, the theoretical field capacity and energy demand. The equipment with convergent concave disks (DCC) and flat cutters discs from manufacturer A (CPS-a) showed the best results in cotton stalks destruction in both soil types. The harrow disc (GPD) was efficient only in clay soil. It was concluded that the equipment with convergent concave disks, among those tested, was the most efficient to destroy cotton stalks, regardless of soil type, and that the harrow disc was not included among the best performers.


1985 ◽  
Vol 104 (1) ◽  
pp. 239-242
Author(s):  
R. B. Wedgwood

Soils derived from Gault Clay in the eastern region of England are notorious for giving very variable yields of wheat. Whereas in recent years yields on other soil types have increased remarkably, largely owing to the use of high-yielding varieties and increased use of nitrogen (e.g. Holbrook, Osborne & Ridgman, 1982), yields from Gault Clay soils have remained at much the same level as the best crops of 30 years ago.


Soil Research ◽  
1980 ◽  
Vol 18 (2) ◽  
pp. 233 ◽  
Author(s):  
AV Blackmore

A study was made of the diffusion of hydroxide ions, added as leachant, from the inter-aggregate pores of a red-brown earth subsoil into the microporous fabric of the aggregates themselves, and then out again when the columns were leached with water. Electrical conductivity and pH were monitored within the column, in the leachate, and in extracts of the soil. The effects of flow rate, aggregate size, neutral salt content, change of cation, and the state and concentration of the hydroxide were considered. In systems having calcium as the dominant cation, the hydroxyls were able to freely enter the fabric and to react with edges of clay particles. In systems with sodium dominant both of these processes were actively inhibited. Strong anion exclusion, arising in the double layers at clay surfaces, operates in sodium but not in calcium systems. Leaching with water, which by hydrolysis reverses the edge adsorption of hydroxyl, revealed a low reservoir of hydroxide ions in sodium systems but a large one, resulting in strong buffering at high pH, in calcium. It is contended that other anions, although less mobile and less reactive than hydroxyl, will also respond to double layers in their approach and their entry to clay soil fabric. Consequently, any ionic solutes, introduced in the leaching stream or produced by root processes, will sometimes be impeded in penetrating soil fabric, just as such solutes are impeded in leaving it.


1972 ◽  
Vol 79 (3) ◽  
pp. 543-545 ◽  
Author(s):  
P. C. Longden

SUMMARYSeven soil conditioners added to a sandy clay soil at Saxmundham did not benefit sugar-beet seedling emergence in four experiments in 3 years. In microplots at Broom's Barn free draining peat and sandy loam gave consistently more seedlings than limestone loam or flinty loam. In the laboratory, for each of three soil types, emergence was maximal only for a small soil moisture range and decreased rapidly when soils became drier or wetter. This suggests that conditioners which increase water-holding capacity should be tested on sandy loams rather than clay soils and that seed-bed preparation on heavier soils should seek to aerate the soil.


2021 ◽  
Vol 926 (1) ◽  
pp. 012102
Author(s):  
M Carlina ◽  
Y Apriyanti ◽  
F Fahriani

Abstract In the construction of road construction, soil bearing capacity, such as the CBR value, needs to be considered. In clay soil, the CBR value of the soil is low, so that stabilization material can be added to its repair. In this study, the stabilization materials used were waste materials in the form of bagasse ash and eggshell powder. Variations in the mixture of bagasse ash mixture used in this study were 7%, 10%, and 13% plus 3% eggshell powder. Testing in this study includes testing moisture content, sieve analysis, specific gravity, consistency limits, compaction testing, and CBR. The soil classification system used is the Unified classification (USCS), a test guideline based on SNI. From the CBR soaked test, it was found that the CBR value of clay soil increased along with the increase in the percentage of bagasse ash plus 3% eggshell powder and the increase in collisions on the soil. The percentage increase in the CBR value of clay soil with a mixture of stabilization to clay soil is 92.303%. at 65 blow. So that bagasse ash and eggshell powder greatly affect the increase in the CBR value of clay soil.


2021 ◽  
Vol 24 (1) ◽  
pp. 56-62
Author(s):  
Lenka Lackóová ◽  
Jana Kozlovsky Dufková

Abstract Soil erosion by wind is the primary land degradation process which affects natural environments and agricultural lands. In agricultural lands, soil erosion by wind mainly results from removing of the finest and most biologically active part of the soil richest in organic matter and nutrients. Repeated exposure to wind erosion can have permanent effects on agricultural soil degradation. Knowing spatial and temporal changes in soil conditions and soil erodibility is essential to understand wind erosion processes. There are many methodologies to predict the susceptibility of landscape to erosion. The more complex is the scheme combining multiple factors, the more accurate the estimate is. There are very few studies on mapping the changes in soil grain size and erodible fraction due to wind erosion. Existing studies only deal with eroded soil units (where particles are removed – deflation) and not the eroded units (areas) to which the eroded particles are wound – accumulated. Prevailing wind direction should also be taken into account when mapping changes in erodible fractions of wind-eroded soils and the nature of the soil (whether soil particles accumulate or deflate). In this study the “historical“ grain size distribution of the soil in three cadastral areas using data from complex soil survey (1968) and year 2018/2019 was analysed. Erodible fraction change was also calculated and compared for both time periods.


Author(s):  
Jens Erik Blomquist ◽  
Kerstin Berglund

Two dates (early, normal) for application and incorporation of structure lime to clay soil were examined at four field sites, to test whether early liming had more favourable effects on aggregate stability. Aggregate size distribution measurements revealed a finer tilth at the early liming date (20 August) than the normal date (14 September). Aggregate stability estimated one year later, using as a proxy turbidity in leachate from 2–5 mm aggregates subjected to two simulated rainfall events, was significantly improved (11% lower turbidity) with early compared with normal liming date. Three years after structure liming, soil structural stability measurements on lysimeters (15 cm high, inner diameter 18 cm) subjected to repeated simulated rainfall events showed no significant differences in turbidity in leachate between the early and normal liming dates. However, there was a strong interaction between liming date and site indicating different reactions at different sites. Our results suggest that early spreading and incorporation can improve the success of structure liming, but only if soil conditions are favourable.


1999 ◽  
Vol 79 (1) ◽  
pp. 127-135 ◽  
Author(s):  
Murray S. Bullock ◽  
Francis J. Larney ◽  
Sean M. McGinn ◽  
R. César Izaurralde

Freeze-drying has been implicated as a factor causing soil aggregate breakdown on the Canadian Prairies and northern Great Plains. Aggregates of a Dark Brown Chernozemic clay loam soil sampled in October 1993 and January and April 1994 were subjected to repeated cycles of wetting (to 0.1, 0.2 and 0.3 kg kg−1 water contents) freezing, and freeze-drying under laboratory conditions. The October 1993 samples showed less disruption when initially exposed to freeze-drying cycles compared to samples taken in January and April 1994. Using regression analysis, we predicted that 31 freeze-dry cycles were required for the 0.1 kg kg−1 water content aggregates to reach 60% erodible fraction (EF, % aggregates <0.86 mm), 9 cycles for the 0.2 kg kg−1 aggregates and 2 for 0.3 kg kg−1 aggregates. In a field study, conducted over the 1994–1995 winter on a similar clay loam soil, we estimated the number of freeze-drying cycles using large vapour pressure (VPL) and small vapour pressure (VPS) gradients between the soil surface (which had a mean winter water content of ~0.1 kg kg−1) and the atmosphere. With solar energy adjustments, we predicted that the number of freeze-dry cycles required for the soil to reach 60% EF was 60 for VPL and 37 for VPS conditions. The latter number was similar to the 31 cycles predicted in the laboratory study of aggregates at 0.1 water content. Our results demonstrate that freeze-drying is an important overwinter process in the breakdown of soil aggregates and hence wind erosion risk in the Canadian prairie region. Key words: Freeze-drying, wind erosion, erodible fraction


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