Effect of soil moisture condition on the conversion rate of oxamyl.

The decomposition of oxamyl in four soils under moist conditions was measured in incubation experiments at 15 deg C. Half-lives of oxamyl in soils with moisture tensions of approx. -9.8 X 103 Pa were 13 days in a clay loam, 14 days in a loamy sand, 34 days in a peaty sand and 39 days in a humic loamy sand. The rate of oxamyl decomposition in the clay loam decreased with decreasing soil moisture content down to values for below wilting point. Oxamyl decomposition in the humic loamy sand decreased with decreasing soil moisture content, but increased sharply in the very dry range. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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Regime and dynamics of soil moisture in forest ecosystems of Záhorská lowland

Journal of Forest Science ◽

10.17221/4492-jfs ◽

2012 ◽

Vol 52 (No. 3) ◽

pp. 108-117

Author(s):

L. Tužinský

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Forest Ecosystems ◽

Soil Moisture Content ◽

Atmospheric Precipitation ◽

Sandy Soils ◽

Growing Seasons ◽

The Town ◽

Water Holding ◽

Wilting Point

The paper describes the regime and dynamics of the soil moisture content of sandy soils in Záhorská lowland during different growing seasons. Research plots are situated near Kamenný mlyn, approximately 3 km from Plavecký &Scaron;tvrtok and 8 km southward from the town of Malacky. Changes in the soil moisture content are described by soil moisture constants (MCC, PDA, WP) and its relation to atmospheric precipitation and to the character of undergrowth is shown. The low water-holding capacity of sandy soils and their high drainage together with dense root system do not allow the sufficient saturation of soil during the growing season. The low wilting point value (2%) leads to the consumption of all available water in the soil. The most frequent is the semiarid interval of soil moisture (PDA –WP) with reduced availability of water to plants (> pF 3.1). The arid interval (< WP) occurrence on hot summer days results in a decrease in transpiration and assimilation intensity of plants, their physiological weakening and premature fall of assimilation organs. 

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Effect of Biochar on TDR-Based Volumetric Soil Moisture Measurements in a Loamy Sand Podzolic Soil

Soil Systems ◽

10.3390/soilsystems3030049 ◽

2019 ◽

Vol 3 (3) ◽

pp. 49 ◽

Cited By ~ 1

Author(s):

Wanniarachchi ◽

Cheema ◽

Thomas ◽

Galagedara

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Soil Moisture Content ◽

Podzolic Soil ◽

Dielectric Constants ◽

Loamy Sand ◽

Typical Application ◽

Podzolic Soils ◽

Volumetric Soil Moisture ◽

Time Domain Reflectometer

Considering the increased interests in biochar (BC) as a soil amendment and a growing media substrate in agriculture, we evaluated the effect of BC incorporation on TDR (time-domain reflectometer)-based volumetric soil moisture content (VSMC) estimations in a loamy sand podzolic soil. Two commercial BC types (powdered—BCP, and granular—BCG) were mixed in different rates (w/w) with a podzolic soil. The dielectric constants measured using a TDR cable tester (MOHR CT 100) were converted to VSMC. Three commonly used models: (i) Topp’s equation, M-1; (ii) mixing model, M-2; and (iii) the forest soil model, M-3, were used. The accuracy of the estimated VSMC using these three models was statistically compared with measured VSMC. BCP at lower rates produced very similar results to the actual VSMC with M-1 and M-2 but deviated with increasing rates. The M-3 showed a non-linear relationship with measured VSMC. In BCG treatments, all models overestimated the VSMC. BCG rates higher than 15% (w/w) resulted in highly attenuated TDR waveforms and the signal was completely dissipated when rates higher than 50% (w/w) were used (typical application for field soils is less than 5% w/w). These results showed that predictions of the soil moisture content based on the soil dielectric constant might not be feasible for tested podzolic soils amended at high BC rates.

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HUBUNGAN KETERSEDIAAN AIR TANAH DAN SIFAT-SIFAT DASAR FISIKA TANAH

Jurnal Ilmu Tanah dan Lingkungan ◽

10.29244/jitl.6.2.46-50 ◽

2004 ◽

Vol 6 (2) ◽

pp. 46-50

Author(s):

Kukuh Murtilaksono ◽

Enny Dwi Wahyuni

Keyword(s):

Organic Matter ◽

Soil Moisture ◽

Moisture Content ◽

Soil Moisture Content ◽

Organic Matter Content ◽

Clay Content ◽

Total Porosity ◽

Field Capacity ◽

Sand Content ◽

Wilting Point

This research was conducted to study relationship between soil moisture content and soil physical characteristics that affected the moisture.The soil samples were collected from 22 scattered sites of West Java and Central Java. Analysis of soil physical properties (texture, bulk density, particle density, total porosity and soil moisture retention) and soil chemical property (organic matter) was conducted at the laboratory of Department of Soil Sciences, Faculty of Agriculture, Bogor Agricultural University. Analysis of simple linier regression was applied to know the correlation between soil moisture content and other basic soil physical properties.Availability of soil moisture (pF 4.20 – pF 2.54) significantly correlated with organic matter, total porosity, and micro pores. The higher organic matter content as well as total porosity and micro pores the higher available soil moisture. Soil moisture of field capacity significantly correlated with clay content, sand content, micro and macro pores. The higher clay content and micro pores the higher soil moisture of field capacity. In the contrary, the higher macro pores and sand content the lower the field capacity. Soil moisture of wilting point significantly correlated with clay content and macro pores. The higher clay content the higher the wilting point, while the higher macro pores the lower soil moisture of wilting point. Keywords : Available soil water, field capacity, organic matter, soil pores, wilting point

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The influence of the initial soil moisture content on the degree of water stable aggregation as determined by wet sieving

Agricultural and Food Science ◽

10.23986/afsci.71490 ◽

1959 ◽

Vol 31 (1) ◽

pp. 233-239

Author(s):

Mikko Sillanpää

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Soil Moisture Content ◽

Soil Samples ◽

Moisture Condition ◽

Initial Soil Moisture ◽

Initial Soil ◽

Pre Treatment ◽

A Minor ◽

Wet Sieving

The effect of the soil moisture content (varying from the field-moist to air-dry before re-wetting the muddy clay soil samples for aggregate analysis) on aggregation was studied. Two wetting procedures were used and compared: They were spraying samples with a fine mist and wetting them by immersion; aggregate analyses were made by wet sieving method. The results of the aggregate analyses proved to be practically independent of the initial moisture condition of the soil samples when the samples were wetted slowly with a spray. When wetting the samples by direct immersion the mean weight diameters of aggregates decrease with decreasing initial soil moisture content to values of less than half of those obtained from samples in their original field-moist condition (34.6—36.7 % dry wt.) or of those wetted with a spray. Air-drying seems to be a minor factor affecting the destruction of aggregates but the destruction effect of the sample pre-treatment may be very harmful if immersion wetting is used. This, however, can be eliminated almost completely if wetting with a fine mist is used.

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Effect of imazamox, fomesafen, and acifluorfen soil residue on rotational crops

Weed Science ◽

10.1017/s0043174500090500 ◽

1998 ◽

Vol 46 (2) ◽

pp. 258-263 ◽

Cited By ~ 40

Author(s):

Tarcísio Cobucci ◽

Hélio T. Prates ◽

Christian L. M. Falcão ◽

Marcio M. V. Rezende

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Soil Moisture Content ◽

Field Studies ◽

Loamy Sand ◽

Herbicide Application ◽

Carryover Effect ◽

Rotational Crop ◽

Soil Residue ◽

Crop Planting

Field studies were conducted at Goiânia, GO, Brazil, on an Oxisol (clayey, kaolinitic, isothermic, Typic Haplustox) and at Jussara, GO, Brazil, on an Oxisol (loamy sand, kaolinitic, isothermic, Typic Haplustox) during 1995 and 1996 to determine the carryover effect of fomesafen, imazamox, and acifluorfen, applied to edible bean, on rotational crops (maize, sorghum, rice, and millet) and to estimate the level of soil residues under Brazilian Savanna conditions. Averaged across locale, year, and rate, fomesafen dissipation time (DT50) (37.5 d) was longer than acifluorfen (27.5 d) and imazamox (25.9 d). For both locations, soil herbicide persistence (average of herbicides) was longer in 1995 than in 1996. This was due to higher soil moisture content in 1996. The sensitivity of rotational crops to fomesafen and imazamox residues was, in decreasing order: sorghum, corn, millet, and rice, and for acifluorfen: sorghum, corn, rice, and millet. The period between herbicide application and rotational crop planting (PAP) varied in agreement with the sensitivity of rotational crops to herbicide residues in soil and the persistence of the herbicide. Considering both location and year, the PAP for fomesafen (250 g ai ha−1) ranged from 69 to 132 d for corn, 114 to 179 d for sorghum, 29 to 95 d for rice, and 52 to 111 d for millet; the PAP for imazamox (40 g ai ha−1) ranged from 68 to 111 d for corn, 78 to 139 d for sorghum, 25 to 75 d for rice, and 40 to 102 d for millet; and the PAP for acifluorfen (170 g ai ha−1) ranged from 56 to 89 d for corn, 96 to 139 d for sorghum, 61 to 95 d for rice, and 43 to 82 d for millet.

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The critical relationship between soil moisture content in the region of wilting point and the mineralization of natural soil nitrogen

The Journal of Agricultural Science ◽

10.1017/s0021859600034377 ◽

1957 ◽

Vol 49 (1) ◽

pp. 100-105 ◽

Cited By ~ 41

Author(s):

J. B. D. Robinson

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Incubation Period ◽

Soil Nitrogen ◽

Soil Moisture Content ◽

Ammonia Nitrogen ◽

Moisture Level ◽

Natural Soil ◽

Soil Moisture Level ◽

Wilting Point

1. Laboratory incubation studies with topsoil samples of the Kikuyu red loam coffee soil have shown that active nitrification of the natural soil nitrogen stops at a soil moisture level just below the permanent wilting percentage. Ammonification of natural nitrogen in this soil does not cease at this moisture level and ammonia nitrogen accumulates substantially, although the values found at the end of the 32-day incubation period, and the rate of ammonification are significantly lower as the moisture level is decreased from ⅚ to of the permanent wilting percentage.

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Development and Evaluation of Pedotransfer Functions to Estimate Soil Moisture Content at Field Capacity and Permanent Wilting Point for South African Soils

Water ◽

10.3390/w13192639 ◽

2021 ◽

Vol 13 (19) ◽

pp. 2639

Author(s):

Lindumusa Myeni ◽

Thandile Mdlambuzi ◽

David Garry Paterson ◽

Gert De Nysschen ◽

Mokhele Edmond Moeletsi

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

South African ◽

Soil Moisture Content ◽

Field Capacity ◽

Pedotransfer Functions ◽

Coefficient Of Determination ◽

Soil Horizons ◽

Permanent Wilting Point ◽

Wilting Point

This study was undertaken to develop new pedotransfer functions (PTFs) for the estimation of soil moisture content at field capacity (FC, at −33 kPa) and permanent wilting point (PWP, at −1500 kPa) for South African soils based on easily measurable soil physico-chemical properties. The new PTFs were developed using stepwise multiple linear regressions with the dependent variable (either FC or PWP) against clay, silt, sand and soil organic carbon (SOC) content from a total of 3171 soil horizons as the explanatory variables. These new PTFs were evaluated and compared with five well-established PTFs using a total of 3136 soil horizons as an independent dataset. The coefficient of determination (r2) values for the existing PTFs ranged from 0.65–0.72 for FC and 0.72–0.81 for PWP, whilst those developed in this study were 0.77 and 0.82 for FC and PWP, respectively. The root mean square error (RMSE) values for the well-established PTFs ranged from 0.052–0.058 kg kg−1 for FC and 0.030–0.036 kg kg−1 for PWP, whilst those developed in this study were 0.047 and 0.029 kg kg−1 for FC and PWP, respectively. These findings suggest that PTFs derived locally using a large number of soil horizons acquired from different agro-climatic locations improved the estimation of soil moisture at FC and PWP. Due to the range of conditions and large soil datasets used in this study, it is concluded that these new PTFs can be applied with caution in other regions facing data scarcity but with similar soil types and climatic conditions.

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Effect of different types of soil tillage for sunflower on some soil physical characteristics. Part I: soil moisture

Helia ◽

10.1515/helia-2020-0012 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Peter Yankov ◽

Miglena Drumeva

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Soil Moisture Content ◽

Soil Layer ◽

Soil Tillage ◽

No Tillage ◽

Plant Available Water ◽

Moisture Storage ◽

Direct Sowing ◽

Wilting Point

Abstract The investigation was carried out during 2014–2016 in the land of General Toshevo town in the South Dobrudzha region on slightly leached chernozem soil type. The effect of the types of soil tillage for sunflower given bellow was followed: ploughing at 24–26 cm, chisel-plough at 24–26 cm, disking with disk harrow at 10–12 cm and direct sowing (no-tillage) on the soil moisture content. Based on bulk density, wilting point and the determined soil moisture content the plant-available water was calculated. The additional soil tilths of the areas subjected to ploughing, chisel-ploughing and disking with disc harrow included double spring pre-sowing cultivation with harrowing. To destroy the emerging weeds in the variant with direct sowing, a total herbicide was applied. The soil moisture content was evaluated during three main stages of sunflower development: emergence, flowering and technical maturity. The investigated parameter was determined for each of the studied layers – 0–10, 10–20, 20–30, 30–40 and 40–60 cm. In years with normal amounts of rainfalls, no significant differences in the soil moisture under the different ways of soil tillage were observed. Conventional ploughing and tillage without turning of the soil layer contributed to accumulation of more moisture and to higher moisture storage down the soil profile under heavy and intensive rainfalls. Tillage without turning of the soil layer, minimal and no tillage maintained more and better soil moisture in years with limited precipitation and in periods of drought.

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