The stability of soil aggregates as affected by organic materials, microbial activity and physical disruption

On moist incubation the equivalent of 50 t ha-1 or more of ground, readily decomposable organic materials greatly increased the proportion of stable aggregates of Shepparton fine sandy loam within 1-4 weeks; the aggregates remained stable for up to 32 weeks if left undisturbed. Severe restriction of microbial activity in aggregates of Shepparton fine sandy loam by sterilization or dryness increased the effect of physical disruption associated with intermittent wetting and drying, and simulated cultivation. The results suggest that microorganisms in non-sterile moist soil can produce bonding substances which compensate partially for those bonds broken physically.

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The effect of crop rotation on aggregation in a red-brown earth

Soil Research ◽

10.1071/sr9800423 ◽

1980 ◽

Vol 18 (4) ◽

pp. 423 ◽

Cited By ~ 151

Author(s):

JM Tisdall ◽

JM Oades

Keyword(s):

Organic Matter ◽

Crop Rotation ◽

Sandy Loam ◽

Crop Rotations ◽

Total Organic Matter ◽

Fine Sandy Loam ◽

The Stability ◽

Practical Implications

Fifty years of crop rotations have decreased the stability of macroaggregates (> 250�m diameter) of Urrbrae fine sandy loam and simultaneously decreased the lengths of roots and hyphae and the percentage total organic matter in the soil. Regardless of the rotation, particles 50-250 �m diameter were very stable and were stabilized by organic matter. Practical implications of the results are discussed

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The role of Ca-organic interactions in soil aggregate stability .II. Field studies with 14C-labeled straw, CaCO3 and CaSO4.2.H2O

Soil Research ◽

10.1071/sr9890401 ◽

1989 ◽

Vol 27 (2) ◽

pp. 401 ◽

Cited By ~ 64

Author(s):

M Muneer ◽

JM Oades

Keyword(s):

Wheat Straw ◽

Sandy Loam ◽

Aggregate Stability ◽

Field Studies ◽

Soil Aggregate ◽

Soil Aggregate Stability ◽

Fine Sandy Loam ◽

The Stability ◽

Dispersible Clay

Uniformly 14C-labelled straw with or without CaCO3 or CaSO4.2H2O was incubated in a leached, fine sandy loam in the field. The addition of both Ca salts increased the residual 14C in the soil after several months decomposition, CaSO4.2H2O being more effective than CaCO3 in this respect. Addition of the Ca salts decreased the amount of dispersible clay and increased the proportion of particles 50-250 �m diameter. The addition of 14C-labelled wheat straw (with or without CaSO4.2H2O or CaCO3) increased the stability of aggregates >2000 pm diameter. Addition of Ca during decomposition of straw resulted in a synergistic stabilization of aggregates >1 mm. Moreover, the stabilization was prolonged in the presence of Ca.

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Carbon balance of sandy loam soils in arid landscapes of the Chechen Republic

BIO Web of Conferences ◽

10.1051/bioconf/20224202005 ◽

2022 ◽

Vol 42 ◽

pp. 02005

Author(s):

Rustam Gakaev

Keyword(s):

Soil Erosion ◽

Sandy Loam ◽

Soil Aggregates ◽

Soil Layer ◽

Organic Matter Content ◽

Aggregate Stability ◽

Arid Environment ◽

Matter Content ◽

The Stability ◽

Semi Arid

The spatial variability of the stability of soil aggregates and its relationship with runoff and soil erosion were studied in a semi-arid environment in the field in order to assess the validity of the stability of structures as an indicator of soil erosion in soils of sandy loam ridges. The influence of soil and relief properties on the variability of aggregate stability was also investigated. Significant relationships were found in the number of water droplets required to break down the aggregate, as well as the rate of runoff and erosion. The most significant correlation was found between the number of droplet impacts and the soil organic matter content. The stability of aggregates in the upper soil layer is apparently a valuable indicator of field runoff and inter-season soil erosion of sandy loamy ridges in semi-arid conditions.

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Moist-soil response to brief intense radiative heating

Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences ◽

10.1098/rspa.1992.0166 ◽

1992 ◽

Vol 439 (1907) ◽

pp. 531-552

Keyword(s):

Interstitial Water ◽

Early Response ◽

Radiative Heating ◽

Heated Layer ◽

Moist Soil ◽

Soil Response ◽

Average Temperature ◽

Convective Mixing ◽

The Stability ◽

Interstitial Air

We consider the early response of a layer of moist soil to a short intense radiative pulse, of duration on the order of one second, and of intensity on the order of 400 J cm -2 s -1 . In the initial stages of the phenomenon, evaporated interstitial water, interstitial air, and possibly soil are lofted into a layer that underlies a somewhat displaced slab of the atmosphere. Then, depending on the stability of that configuration, convective mixing may ensue and may produce, during the next few seconds, a thicker and cooler hot layer. We quantify reliably the thickness and temperature distribution during the radiative phase of the event, and we also estimate much more crudely the thickness and the average temperature at limited later times. With even less detail we quantify the importance of ice, snow or vegetation on the structure of the heated layer.

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THE EFFECT OF ANTECEDENT FREEZE-THAW FREQUENCY ON RUNOFF AND SOIL LOSS FROM FROZEN SOIL WITH AND WITHOUT SUBSOIL COMPACTION AND GROUND COVER

Canadian Journal of Soil Science ◽

10.4141/cjss89-080 ◽

1989 ◽

Vol 69 (4) ◽

pp. 799-811 ◽

Cited By ~ 14

Author(s):

LINNELL M. EDWARDS ◽

J. R. BURNEY

Keyword(s):

Prince Edward Island ◽

Sandy Loam ◽

Bare Soil ◽

Winter Rye ◽

Rainfall Simulator ◽

Fine Sandy Loam ◽

Freeze Thaw ◽

Sediment Loss ◽

Freezing Period ◽

Subsoil Compaction

Three soils from Prince Edward Island (a loam, a fine sandy loam, and a sandy loam) were tested under a laboratory rainfall simulator to examine the effects of frequency of freezing and thawing, winter rye cover, incorporated cereal residue, and subsoil compaction on runoff volume and sediment loss. Wooden soil boxes were subjected to simulated rain (i) at the end of a 10-d freezing period, and (ii) at the end of the 5th 24-h freezing period of a 10-d alternating freeze-thaw cycle (freeze/thaw). Where the soil was continuously frozen for 10 d, there was 178% greater sediment loss and 160% greater runoff than with daily freeze/thaw over the same period, but there was no difference in sediment concentration. Incorporated cereal residue decreased sediment loss to 50% and runoff to 77% of that from bare soil. Winter rye cover decreased sediment loss to 73% of that from bare soil. Simulated soil compaction caused a 45% increase in sediment loss. The loam soil showed 16.5% greater loss of fine sediment fractions <0.075 mm than the fine sandy loam which showed 23.4% greater loss than the sandy loam. Key words: Freeze-thaw, erosion, compaction, winter rye, cereal residue, rainfall simulator, Prince Edward Island soils

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CHEMICAL CHARACTERISTICS OF HIDALGO FINE SANDY LOAM

Soil Science ◽

10.1097/00010694-194612000-00004 ◽

1946 ◽

Vol 62 (6) ◽

pp. 457-468

Author(s):

F. L. WYND ◽

G. R. NOGGLE

Keyword(s):

Sandy Loam ◽

Chemical Characteristics ◽

Fine Sandy Loam

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Effect of Fertilizer Management on NPKS Leaching Loss from Sandy Loam Soil under Alternate Wetting and Drying Condition

Bangladesh Rice Journal ◽

10.3329/brj.v20i1.30630 ◽

2016 ◽

Vol 20 (1) ◽

pp. 59-64

Author(s):

MN Islam ◽

MM Rahman ◽

MJA Mian ◽

MH Ali

Keyword(s):

Sandy Loam ◽

Foliar Spray ◽

Sandy Loam Soil ◽

Fertilizer Management ◽

Wetting And Drying ◽

Leaching Loss ◽

Randomized Design ◽

Loam Soil ◽

Dry Soil

Leaching loss of nutrients hampers plant growth and contributes to environmental pollution. An experiment was conducted at the net house of Soil Science Department, Bangladesh Agricultural University, Mymensingh during January to May 2009 to find out the leaching loss of N, P, K and S from sandy loam soil. Each pot received 6.67 kg dry soil with an opening at the bottom for collecting leachates. Six treatments were used: T0 = control, T1 = NPKS (120, 25, 60 and 20 kg ha-1), T2 = NPKS (180, 37, 90 and 30 kg ha-1), T3 = NPKS (90, 5, 28 and 17 kg ha-1) + cowdung (2.5 t ha-1), T4 = NPKS (109, 25, 60 and 20 kg ha-1, N as USG) and T5 = as T1 but N applied as foliar spray. Treatments were arranged in a completely randomized design with three replications. Leachates were collected at 15 days interval for determination of NPKS. The total leaching loss of N, P, K and S due to different treatments ranged from 16.00 to 90.21, 0.07 to 0.29, 9.60 to 11.20 and 3.75 to 17.81 kg ha-1, respectively. Application of chemical fertilizer at higher rates resulted in greater loss of nutrients. Integrated fertilizer management with cowdung (T3) minimized such losses. Use of USG also reduced leaching loss of N, P, K and S. The application of cowdung and USG with recommended balanced fertilizer might be useful for minimizing N, P, K and S loss from wetland rice field.Bangladesh Rice j. 2016, 20(1): 59-64

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Bactericidal and virucidal efficacies of food additive grade calcium hydroxide under various concentrations, organic material conditions, exposure duration, and its stability

Veterinary World ◽

10.14202/vetworld.2019.1383-1389 ◽

2019 ◽

Vol 12 (9) ◽

pp. 1383-1389

Author(s):

Sakchai Ruenphet ◽

Kornkamon Paditporn ◽

Darsaniya Punyadarsaniya ◽

Tippawan Jantafong ◽

Kazuaki Takehara

Keyword(s):

Calcium Hydroxide ◽

Organic Material ◽

Exposure Duration ◽

Organic Materials ◽

Exposure Period ◽

Food Additive ◽

E Coli ◽

Dry Conditions ◽

Material Conditions ◽

The Stability

Aim: This study aimed to evaluate the bactericidal and virucidal activity of food additive grade calcium hydroxide (FdCa(OH)2) under various concentrations, organic material conditions, and exposure duration including its stability. Materials and Methods: The FdCa(OH)2 powder as well as the 0.17% and 3% solutions were evaluated for bacteria and virus inactivating efficacies against Salmonella infantis (SI), Escherichia coli, Newcastle disease virus (NDV), and avian influenza virus (AIV), in the absence or presence of organic materials. In addition, the stability of FdCa(OH)2, was also examined using wet-dry conditions and under sunlight. Results: The FdCa(OH)2 powder could inactivate both NDV and AIV in the absence and presence of organic materials within a 3 min exposure period. The bactericidal efficacy using solution form revealed that 0.17% and 3% of FdCa(OH)2 could inactivate SI in the absence and presence of organic materials within 3 min of exposure. However, 3% of FdCa(OH)2 inactivated E. coli both with and without organic materials within 3min, while 0.17% required 5 min to be efficacious. The virucidal efficacy also showed that 0.17% FdCa(OH)2 could inactivate NDV in the absence and presence of organic materials within 10 min and 30 min, respectively. However, AIV inactivation was achieved within 30 sec under all conditions. In addition, under wet and dry conditions, FdCa(OH)2 powder demonstrated high efficacy when re-suspended at least 16 times for NDV and 7 times for AIV. Simultaneously, the FdCa(OH)2 powder retained its efficacy under the sunlight during up to 4 months for NDV and at least 6 months for AIV. Conclusion: The present study indicates that FdCa(OH)2 powder and solutions could inactivate SI, E. coli, NDV, and AIV while retaining good stability under challenging environmental conditions. Finally, the FdCa(OH)2 is safe for consumers because it is of food additive grade and can be useful as an alternative disinfectant, especially for biosecurity enhancement on and around poultry farms.

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