scholarly journals Soil compaction by the tractor in spring and its effect on soil porosity 

1983 ◽  
Vol 55 (2) ◽  
pp. 91-107
Author(s):  
Erkki Aura

The effect on soil porosity of tractor compaction of soil in the spring was studied by taking cylindrical core soil samples. The profile samples showed that the tractor most seriously compacts the soil below the harrowed layer at the depth of 10-25 cm. Soil was compacted most severely when till age and drilling were performed under wet conditions about one week be for enormal sowing time. The sub soil at the depth of 35-40 cm was compacted only under very wet conditions. The grain yield of wheat was significantly reduced when the volume of large pores was reduced to about 10 % or less. Porosity measurements showed that the severely compacted soil almost completely recovered from one spring to the next. Theoretical calculations suggested that compaction by normal traffic does not cause a shortage of oxygen at least in the inter-crumb pores of soil if the soil surface structure is not dispersed and encrusted. The decrease in crop growth by compaction is primarily due to mechanical impedance, which slows down development of the root system.


2008 ◽  
Vol 1 (1) ◽  
pp. 92-107 ◽  
Author(s):  
Mohammad Shafiul Azam ◽  
Md. Shafiquzzaman ◽  
Iori Mishima ◽  
Jun Nakajima

To measure easily soluble fraction of arsenic, a sequential extraction method by 0.1N HCl and 0.1N NaOH was used according to the soil phosphorus extraction procedure. The effects of reducing conditions on arsenic extraction were examined in incubation test. In high reducing conditions arsenic solubility was shown to be high and seemed to be controlled by dissolution of iron oxy-hydroxides. pH played a predominant role in determining the concentrations of soluble arsenic. Arsenic solubility could be possible at low or high pH conditions. Released arsenic in different pH and redox conditions showed that it is a part of acid extractable arsenic which is sorbed weakly on the soil surface and can be extracted during acid-alkali sequential extraction. Therefore, the method could be applicable to measure potential solubility of arsenic as a result of alteration in soil (e.g. redox, pH) and environmental factors. Sequential extraction results of the soil samples collected in dry and wet season suggested that acid-alkali extracted arsenic fractions of surface and core soil samples of paddy field were increased in wet season. They seemed to be moved with irrigation groundwater. Keywords: Acid-alkali extraction; Arsenic contamination; Soil arsenic mobility; Groundwater contamination; Paddy soil.  © 2009 JSR Publications. ISSN: 2070-0237(Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i1.1058  



1985 ◽  
Vol 9 (1) ◽  
pp. 44-48 ◽  
Author(s):  
J. A. Gent ◽  
R. Ballard

Abstract Trafficking during harvesting significantly increased soil bulk density to depths of 3 to 6 inches in areas outside of primary skid trails and 9 to 12 inches in primary skid trails. On the Coastal Plain site, bedding was effective in offsetting soil compaction in areas outside of primary skid trails, forming a new soil surface, 7 to 8 inches in height, over the surface trafficked during harvest. Bedding may not be so effective in the skid trails, because the original soil surface under the bed was so compacted that root growth may be inhibited. On the Piedmont site, disking was effective in restoring bulk density to preharvest levels in the upper 3 to 5 inches of soil, but soil compaction in the upper 3 to 9 inches of drum-chopped areas may result in reduced root growth, because of mechanical impedance.



2007 ◽  
Vol 64 (6) ◽  
pp. 608-615 ◽  
Author(s):  
Amauri Nelson Beutler ◽  
José Frederico Centurion ◽  
Maria Aparecida Pessoa da Cruz Centurion ◽  
Onã da Silva Freddi ◽  
Eurico Lucas de Sousa Neto ◽  
...  

Excessive traffic on the soil may affect soybean development. This research was carried out to evaluate soybean root development and grain yield under compacted soil, in an Oxisol. The following traffic treatments were used: T0 = no traffic; T1* = 1 passage of a 4 t tractor; and, T1, T2, T4 and T6, respectively for 1, 2, 4 and 6 passages of an 11 t tractor on the same location, each besides the other. After compaction, soybean [Glycine max cv. MG/BR 46 (Conquista)] was cultivated. The experiment was arranged in a completely randomized design, with six compaction levels and four replicates (plots of 9.0 m²). Undisturbed soil samples were collected in the layers 0.03-0.06, 0.08-0.11, 0.15-0.18 and 0.22-0.25 m, for physical analyses. Root analyses were performed at layers of 0.0-0.10, 0.10-0.15 and 0.20-0.25 m. Soil compaction decreased deep root development and did not affect root amount, but its distribution. Yield decreased at the penetration resistance of 2.33 MPa or higher, and soil bulk density of 1.51 Mg m-3 or higher.



Irriga ◽  
2003 ◽  
Vol 8 (3) ◽  
pp. 242-249 ◽  
Author(s):  
Amauri Nelson Beutler ◽  
José Frederico Centurion ◽  
Cassiano Garcia Roque ◽  
Zigomar Menezes de Souza

INFLUÊNCIA DA COMPACTAÇÃO E DO CULTIVO DE SOJA NOS ATRIBUTOS FÍSICOS E NA CONDUTIVIDADE HIDRÁULICA EM LATOSSOLO VERMELHO   Amauri Nelson BeutlerJosé Frederico CenturionCassiano Garcia RoqueZigomar Menezes de SouzaDepartamento de Solos e Adubos, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, Jaboticabal, SP. CEP 14870-000. E-mail: [email protected], [email protected]  1 RESUMO              Este estudo teve como objetivo determinar a influência da compactação e do cultivo de soja nos atributos físicos e na condutividade hidráulica de um Latossolo Vermelho de textura média. O experimento foi conduzido na Universidade Estadual Paulista – Faculdade de Ciências Agrárias e Veterinárias, Jaboticabal (SP). Os tratamentos foram: 0, 1, 2, 4 e 6 passadas de um trator, uma ao lado da outra perfazendo toda a superfície do solo, com quatro repetições. O delineamento experimental foi inteiramente casualizado para a condutividade hidráulica e, em esquema fatorial 5 x 2 para os atributos físicos. Foram coletadas amostras de solo nas faixas de profundidades de 0,02-0,05; 0,07-0,10 e 0,15-0,18 m, por ocasião da semeadura e após a colheita para determinação da densidade do solo, porosidade total, macro e microporosidade do solo. A condutividade hidráulica do solo foi determinada após a colheita. O tempo entre a semeadura e a colheita de soja foi suficiente para aumentar a compactação do solo apenas na condição de solo solto. A compactação do solo reduziu a condutividade hidráulica em relação a condição natural (mata) e a condição de solo solto, sendo que esta não foi reduzida, após a primeira passagem, com o aumento no número de passagens.  UNITERMOS: Densidade do solo, porosidade do solo, infiltração de água, soja.  BEUTLER, A. N.; CENTURION, J. F.; ROQUE, C. G.; SOUZA, Z. M. COMPACTION AND SOYBEAN GROW INFLUENCE ON PHYSICAL ATTRIBUTES AND  HYDRAULIC CONDUCTIVITY IN RED LATOSSOL SOIL   2 ABSTRACT  The purpose of this study was to determine the influence of compaction and soybean grow on physical attributes and hydraulic conductivity of a Red Latossol, medium texture soil. The experiment was carried out in the experimental farm at the Paulista State University  – Agricultural Science College, Jaboticabal – São Paulo state. The treatments were 0, 1, 2, 4 and 6 side-by-side tractor strides on the soil surface with four replications. The experimental design was completely randomized for hydraulic conductivity and a 5 x 2 factorial design for soil physical attributes. Soil samples have been collected at 0.02-0.05, 0.07-0.10 and 0.15-0.18 m depth at sowing season and after harvest in order to determine soil bulk density, total porosity, macro and micro porosity. Soil hydraulic conductivity was determined after harvest. The time period between the soybean sowing and harvesting was enough to increase soil compaction only in loose soil condition. Soil compaction reduced hydraulic conductivity compared to the natural (forest) and loose soil condition  KEYWORDS: Bulk density, soil porosity, water infiltration, soybean.



Jurnal Solum ◽  
2007 ◽  
Vol 4 (1) ◽  
pp. 5
Author(s):  
Syafrimen Yasin ◽  
Gusnidar Gusnidar ◽  
Dedy Iskandar

A research conducted in Sungai Rumbai, Dharmasraya Regency and in Soil Laboratory Andalas university was aimed to evaluate soil fertility status on the depth below 0-20 cm from several land use types , especially under Mixed Garden and annual cultivated dryland soil.  Soil samples were taken on Ultisol at 0-8% slope (late-waving soil surface).  Land use types evaluated were forest, annual cultivated dryland, bush land, rangeland covered by Imperata cylindrica and mixed garden.  Composite soil samples for soil chemical analysis were taken on the 0-20 cm soil depth with four replications, and 5 drillings for each replication.  Undisturbed soil samples by using sample ring were used to analyze sol bulk volume.  The data resulted were compared to the criteria and were statistically tested using Analysis of Variance and then were continued by LSD at 5% level.  From the results of analyses could be concluded that land use  for mixed garden had the higher Organic Carbon (OC) content and the lower bulk volume (BV) than those for annual cultivated dryland soil.Key Words: Degradasi Lahan, Kebun Campuran, Tegalan



2011 ◽  
Vol 356-360 ◽  
pp. 1786-1789 ◽  
Author(s):  
Yi Hua Liu ◽  
Fu Bin Tang ◽  
Guo Nian Zhu

Anilofos is the organophosphorus herbicide widely used in China. However, little is known on the processes governing the environmental fate of anilofos in soils and its environmental risk for groundwater. Several environmental fate studies were performed concerning the degradation, sorption, photolysis and mobility of anilofos in soils. The degradation of anilofos in three Chinese soil samples followed first-order kinetics, with half-lives between 64.2 d-161.2 d. The adsorption coefficient (KF) values for the three soils were 10.67 (loam), 31.29 (clay) and 11.63 (sand). No notable photolysis of anilofos occurred on soil surface. Leaching tests, performed in manually packed soil glass-plate, indicated that anilofos moved very slowly on the three types of soil thin layer. Thus, the leaching behavior of anilofos coincided well with the results of the batch sorption and degradation experiments. The data generated from this study could be helpful for risk assessment studies of the pesticide in the environment.



2019 ◽  
Vol 37 (1) ◽  
pp. 28-38
Author(s):  
Clara Esperanza León-Moreno ◽  
Jairo Rojas-Molina ◽  
Carlos E. Castilla-Campos

In Colombia, cacao farms are located mainly in areas with edaphoclimatic limitations. The predominant soil fertility characteristics from small cacao farms in 13 provinces were evaluated. A total of 635 soil samples (0-20 cm) were taken between 2011 and 2013 from the main cacao producer regions in Colombia. The number of samples was assigned based on the regional cacao production. The resulting data were analyzed with a linear regression model using pH as the dependent variable and soil chemical and physical parameters as the independent variables. Soil texture ranged between 14 and 40% clay, and 31 and 65% sand. Bulk density ranged between 1.07 and 1.28 Mg m-3 with a calculated porosity between 48.8 and 55.0%. There was no evidence of soil compaction. The national pH ranged between 3.9 and 7.9 and was negatively correlated with Al+3 content (R2 = 0.68) and Al saturation (R2 = 0.80) and redicts Al saturation in the range of available Al up to pH >5.2- 5.5. In this range, available P (as P2O5) was lower than 12 mg kg-1 and was accepted as a minimum value for a sustainable production. With 4.0 cmolc kg-1 of Ca and 60% saturation of the effective cation exchange capacity (ECEC). A minimum ECEC is proposed at 6.0 cmolc kg-1. A reference table for soils in Colombia is proposed as a guide for the establishment and management of productive and sustainable plantations.



2016 ◽  
Vol 17 (3) ◽  
pp. 175-176 ◽  
Author(s):  
D. Sharma-Poudyal ◽  
C. Fraley ◽  
N. K. Osterbauer

The goal of this study was to determine the risk of finding virus-vectoring nematodes in containerized blueberry plants placed on gravel. To detect dagger nematode, soil, and potting media samples were collected from blueberry nurseries growing plants in containers using soilless potting media, with the containers placed on a gravel bed or, for one nursery, on a plastic sheet placed on the soil surface. Potting media samples were collected from containers holding plants and soil samples were collected from beneath the gravel or plastic barrier. Nematodes were extracted from all of the samples using sucrose centrifugation. No dagger or other plant parasitic nematodes were detected in any of the samples tested. These results suggest no treatment of soilless potting media is necessary before planting blueberries into containers. Similarly, the gravel layer seems to be an effective barrier for suppressing dagger and other plant parasitic nematodes. Accepted for publication 25 July 2016. Published 8 August 2016.



1993 ◽  
Vol 44 (6) ◽  
pp. 1311 ◽  
Author(s):  
GM Lodge ◽  
AJ Schipp

Two experiments examined the effects of sowing time and depth (surface and 10, 25, 50 mm) on emergence of Danthonia richardsonii Cashmore and Danthonia linkii Kunth. Experiment 1 was conducted from January to December 1990 on a loam/sand mixture in boxes. Emergence was highest in both species for seeds sown onto the soil surface in summer and autumn (P < 0.05). Sowing at any depth at any time of the year, or surface sowing in winter and spring, markedly reduced emergence. Experiment 2 was conducted in the field at Tamworth, northern New South Wales from September 1991 to August 1992, on a red brown earth and a black earth. This study confirmed that emergence in both species was highest from surface sown seed. Field emergence was lowest in winter, but in contrast to experiment 1, it was higher in spring, particularly on the black earth. Seedling emergence appeared to be related to mean maximum temperature, decreasing in winter as it declined below 20�C, and increasing in spring when it was greater than 23�C. Differences in seed weight were reflected in emergence of D. richardsonii and D. linkii in experiment 1. Similar emergence was recorded for the loamlsand mixture and sand, indicating that there was little effect of texture. Phalaris aquatica L. cv. Sirosa surface sown in December had lower emergence ( P < 0.05) than both Danthonia spp., but emergence of this larger seeded cultivar was higher at depths of 10 and 25 mm. Laboratory studies to determine reasons for the low emergence of D. richardsonii and D. linkii from depth, indicated that neither had an obligate light requirement for germination. Depth, however, reduced germination (P < 0.05) compared with surface sowing of seed. Seedlings at depth also were observed to have slower rates of shoot and root elongation. In the field, the most successful establishments of D. richardsonii and D. linkii seedlings are likely to occur from surface sowings in April and May. Sowing in spring may also be possible if mean maximum soil temperatures exceed 23�C, and seedlings can establish before the onset of hot, dry conditions in summer.



Soil Research ◽  
1979 ◽  
Vol 17 (3) ◽  
pp. 483 ◽  
Author(s):  
J Mott ◽  
BJ Bridge ◽  
W Arndt

Stable bare degraded areas exist in the lightly grazed perennial grass understorey existing in the eucalypt woodlands of northern Australia. Examination of these areas showed large differences in infiltration which led to increased runoff from the bare sites. However, there was little difference in soil composition between grass-covered and degraded sites apart from a higher organic carbon content in surface soil under grass. Micromorphological examination showed that soil without grass cover had lost its original open structure in the surface layers, developing a surface seal. The surface soil of the bare sealed area was shown to slake readily under quick wetting in contrast to soil surface under grass cover which did not slake. Heavy grazing of the grass understorey destroyed grass clumps within two wet seasons. Once the clumps were killed the soil surface quickly collapsed to form sealed areas, with the same properties as those occurring in ungrazed sites. The persistence of the bare sealed areas is attributed to seed removal during runoff, high temperatures and low moisture content in the sealed layer, as well as mechanical impedance preventing seedling emergence. As re-establishment of native grasses is difficult in this region, care must be taken in pastoral management to prevent the formation of degraded sites, which may take many years to re-vegetate.



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