Certain Soil Surfactants Could Become a Source of Soil Water Repellency after Repeated Application

Repeated application of soil surfactants, or wetting agents, is a common practice for alleviating soil water repellency associated with soil organic coatings. However, wetting agents are organic compounds that may also coat soil particle surfaces and reduce wettability. For this experiment, hydrophobic sands from the field and fresh, wettable sands were collected and treated with either a polyoxyalkylene polymer (PoAP) or alkyl block polymer (ABP) wetting agent, or water only treatments served as a control. Following repeated treatment application and sequential washings, dissolved and particulate organic carbon (OC) were detected in the leachates of both sand systems. The total amount of OC recovered in leachates was 88% or less than the OC introduced by the wetting agents, indicating sorption of wetting agent monomers to soil particle surfaces regardless of soil hydrophobicity status. While ABP treatment did not alter solid phase organic carbon (SOC) in the sands studied, PoAP application increased SOC by 16% and 45% which was visible in scanning electronic microscopy images, for hydrophobic and wettable sands, respectively. PoAP application also increased the hydrophobicity of both sands that were studied. In contrast, ABP treatment increased the wettability of hydrophobic sand. Our results provide strong evidence that certain wetting agents may increase soil hydrophobicity and exacerbate wettability challenges if used repeatedly over time.

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Influence of Repeated Application of Wetting Agents on Soil Water Repellency and Microbial Community

Sustainability ◽

10.3390/su11164505 ◽

2019 ◽

Vol 11 (16) ◽

pp. 4505 ◽

Cited By ~ 2

Author(s):

Enzhan Song ◽

Xiaowei Pan ◽

Robert J. Kremer ◽

Keith W. Goyne ◽

Stephen H. Anderson ◽

...

Keyword(s):

Soil Water ◽

Soil Microorganisms ◽

Water Repellency ◽

Organic Coatings ◽

Wetting Agent ◽

Microbial Populations ◽

Repeated Application ◽

Soil Water Repellency ◽

Soil Microbial ◽

Wetting Agents

Wetting agents are the primary tool used to control soil water repellency (SWR) and localized dry spot (LDS), especially on sand-based soils. However, the effect of repeated applications of wetting agents on soil microbial populations is unknown. This two-year field experiment investigated six wetting agents representing different chemistry effects on a creeping bentgrass (Agrostis stolonifera L.) putting green with existing SWR. Four out of the six wetting agents improved soil volumetric water content in the second growing season, while others showed no effect. This result was negatively correlated to the development of LDS, and positively correlated to occurrence of an air-borne turf disease. Soil microbial populations, determined by soil phospholipid fatty acid (PLFA) analysis, found that none of the treatments applied caused a shift in microbial populations between fungi and bacteria, or gram-positive and gram-negative bacteria. The stress indicators such as saturated to mono-unsaturated fatty acids were not affected by the wetting agents applied as well. However, the wetting agent that contains alkyl block polymers (ABP; Matador) with proven capability for removal of soil organic coatings showed inhibition of microbial populations at one evaluation timing. This result suggested a temporary restriction in soil carbon availability for soil microorganisms following repeated ABP application, which likely contributed to the elevated LDS development observed. Another wetting agent, a combined product of a nonionic surfactant plus acidifiers (NIS; pHAcid), which is designed to reduce inorganic carbonates while enhancing wetting, elevated all soil microbial populations tested at the end of the experiment, indicating a desirable improvement in soil health. However, repeated application of NIS did not reduce SWR at the conclusion of this experiment, which, in combination with a previous report, suggested a minimal disturbance of soil organic coatings of the hydrophobic sand. Overall, this experiment suggested that soil microbial populations can be affected by wetting agents which may further influence SWR, yet the actual effect on soil microorganisms varies depending on the chemistry of the wetting agents.

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Long-term cropping and fertilization influences soil organic carbon, soil water repellency, and soil hydrophobicity

Canadian Journal of Soil Science ◽

10.1139/cjss-2019-0129 ◽

2020 ◽

Vol 100 (3) ◽

pp. 234-244

Author(s):

J.J. Miller ◽

M.L. Owen ◽

X.M. Yang ◽

C.F. Drury ◽

W.D. Reynolds ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Water ◽

Perennial Grass ◽

Water Repellency ◽

Kentucky Bluegrass ◽

Soil Water Repellency ◽

Loam Soil ◽

Soil Hydrophobicity

Long-term (58 yr) cropping and fertilization effects on soil water repellency were determined for a clay loam soil in southwestern Ontario, Canada by measuring soil organic carbon (SOC), soil water repellency index (RI), and soil hydrophobicity (SH). The 12 treatments (non-replicated) included fertilized and non-fertilized legume-based crop rotation (ROT) with four phases (corn–oat–alfalfa–alfalfa), continuous corn (CC), and continuous Kentucky bluegrass (KBG). We hypothesized that SOC, RI, and SH would be greater for each phase of the ROT versus CC, KBG versus CC and ROT, and fertilized versus non-fertilized treatments. Surface (0–10 cm) soil samples were collected in the spring of 2017. Laboratory measurements were conducted to determine SOC, RI (ratio of soil sorptivity to ethanol and water), and SH (ratio of hydrophobic CH– to hydrophilic CO– functional groups). Mean SOC and SH were greater (P ≤ 0.05) for each phase of the ROT versus CC (33% to 2.4 times), KBG versus CC (3.2–6 times) and each phase of ROT (2.2–2.8 times), and fertilized versus non-fertilized rotation oats and KBG (15%–30%). Mean RI was greater for KBG versus CC (4.8 times) and KBG versus each phase of the ROT (3.0–5.5 times) under fertilization only, greater for fertilized versus non-fertilized KBG (6.8 times), but similar for each phase of ROT versus CC. In general, legume-based rotations, perennial grass, and fertilizer enhanced SOC and SH, and to a lesser extent soil RI.

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Influence of continuous application of feedlot manure and legacy treatments on soil organic carbon, soil hydrophobicity, and soil water repellency

Canadian Journal of Soil Science ◽

10.1139/cjss-2020-0074 ◽

2021 ◽

pp. 1-13

Author(s):

J.J. Miller ◽

M.L. Owen ◽

X. Hao ◽

X.M. Yang ◽

C.F. Drury ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Water ◽

Agricultural Soils ◽

Water Repellency ◽

Exponential Model ◽

Application Rate ◽

Soil Water Repellency ◽

Continuous Application ◽

Soil Hydrophobicity

Continuous or discontinued manure applications to agricultural soils may impact soil organic carbon (SOC) and water balances because of manure carbon inputs and the potential for manure-induced soil hydrophobicity (SH) and soil water repellency (SWR). A laboratory study was conducted using a long-term (44 yr) field experiment on a clay loam soil to determine the effect of application rate of feedlot manure under dryland (0, 30, 60, and 120 Mg·ha−1 wet weight) and irrigation (0, 60, 120, and 180 Mg·ha−1) on SOC, SH, and SWR. In addition, we compared the effect of 44 yr of continuous annual manure applications (C44) to legacy treatments which had discontinued applications for 14 (D14) or 30 yr (D30). Laboratory measurements were conducted on air-dried and sieved (<2 mm) soil to determine SOC, SH using Fourier transform infrared spectroscopy, and SWR using the repellency index (RI) method. Mean RI values for all treatments ranged from 2.20 to 13.0, indicating subcritical (RI > 1.95) SWR. Manure application rate had a significant (P ≤ 0.05) and positive effect on SOC and SH, and both followed an exponential model. In contrast, RI had a negative response to the application rate under dryland and had no response under irrigation. Overall, positive responses of SOC and SH to application rate supported our hypothesis, but it was not supported for RI. The hypothesis of greater SOC, SH, and RI for continuous versus discontinued treatments was also supported for SOC and SH but not for RI.

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829 PB 311 WETTING AGENT EFFECTS ON TURF SOIL-WATER REPELLENCY

HortScience ◽

10.21273/hortsci.29.5.552b ◽

1994 ◽

Vol 29 (5) ◽

pp. 552b-552

Author(s):

John L. Cisar ◽

Karen E. Williams

Keyword(s):

Soil Water ◽

Soil Depth ◽

Water Drop ◽

Water Repellency ◽

Fine Sand ◽

Wetting Agent ◽

Water Repellent ◽

Soil Water Repellency ◽

Wetting Agents ◽

Over Time

Soil-water repellency is often a problem for turfgrass grown on sand soils. Wetting agents used to alleviate repellency often provide mixed results. We evaluated AquagroL and an experimental material (ACA 864) at 0, 7, 14, and 21ml/m2 applied monthly to tifgreen bermuda grown on a soil-water repellent Margate fine sand over 6 months. Alleviation of repellency was based upon water drop penetration time (WDPT). Wetting agents did not effect turf quality, cover, or discoloration. Wetting agents did not reduce repellency 1 month after initial application. At 2 months, ACA 864 at 21ml/m2 significantly reduced WDPT. With repeat applications, lower rates of ACA 864 provided reductions in WDPT similar to the highest rate of ACA 864, suggesting an additive effect over time. There was a decline in WDPT for all wetting agent treatments, except the control, over time. Repellency decreased with soil depth, and repeat wetting agent application reduced WDPT at lesser depth.

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Soil wetting agents influences on soil hydrophobicity : the effects and mechanisms

10.32469/10355/63876 ◽

2017 ◽

Author(s):

◽

Enzhan Song

Keyword(s):

Microbial Community ◽

Soil Water ◽

Soil Microbial Community ◽

Soil Microbiology ◽

Wetting Agent ◽

Water Infiltration ◽

Water Repellent ◽

Soil Microbial ◽

Soil Hydrophobicity ◽

Wetting Agents

Soil water repellency (SWR), which causes uneven water distribution in top soil, is a common problem for sandy soils, especially on sand-based growing media such as USGA (United States Golf Association) greens. The SWR is caused by wax-like organic substances coating on the surface of sand particles which repel water. Wetting agent, which are surface active agents or surfactants, have bi-affinity structure with water-loving (hydrophilic) and water-repellent (hydrophobic) groups on each end of the structure, is the primary tool for treatment of SWR. The hydrophobic end will attach wetting agent compounds with SWR coatings at the sand surface, thus facing the water-loving side towards outside and interact with surrounding water molecules. Wetting agents are developed with mainly two purposes: enhancement of water infiltration and improving water retention. More recently designed products also aim at potentially remove SWR causing organic coatings from the soil profile thus provide longer and more efficient wetting. However, previous studies conducted in turf area on wetting agents related topics often only looked at the treatment effects on turfgrass responses and overall turf performance. The objective of this dissertation study is to comprehensively investigate the direct wetting agents influences on soil hydrology (soil water movement), soil chemistry (hydrophobic organic coating removal), and soil microbiology (soil microbial community), with goal of explaining the working mechanisms of different wetting agents. Except pHAcid, most tested wetting agents mitigated SWR with either enhanced infiltration rate or reduced soil hydrophobicity. While the compounds of OARS strongly sorped into the SWR sand system and increased SWR, Matador successfully removed significant amount of non-dissolved organic materials from the SWR sand and transformed the sand to spontaneous wetting status. The soil microbial community was significantly influenced by the weather conditions, while wetting agents that enhanced infiltration (e.g. Hydro-Wet) potentially reduced soil water holding capacity and led to decreased soil microbial abundancy.

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Effects of a Canary pine forest wildfire (Tenerife, Canary Islands, summer 2007) on selected soil properties and their relationship with short- to medium-term soil water repellency .

Spanish Journal of Soil Science ◽

10.3232/sjss.2013.v3.n1.04 ◽

2014 ◽

Vol 2 ◽

Author(s):

Alexis Hernández ◽

Natalia Rodríguez ◽

Marcelino del Arco ◽

Carmen Dolores Arbelo ◽

Jesús Notario del Pino ◽

...

Keyword(s):

Soil Properties ◽

Soil Water ◽

Forest Fires ◽

Sampling Site ◽

Aggregate Stability ◽

Water Repellency ◽

Pine Forest ◽

Soil Water Repellency ◽

Soil Hydrophobicity ◽

The Impact

Forest fires modify the soil environment, often triggering severe soil degradation. In this paper, we studied the impact of a large northern Tenerife Canariy pine forest wildfire on a set of relevant soil properties, focusing on their evolution in time and relationship with soil water repellency. To do this, soils were sampled at four sites (burned and non-burned) and several soil physical and chemical parameters were measured. The results show significant variations for soil pH, electric conductivity (CE1:5), and NH4+-N between burned and non-burned samples, whereas non-significant increases were found in burned soils for oxidizable carbon (Cox), total nitrogen (Ntot) , Ca2+, Mg2+, Na+ and K+, and soil hydrophobicity. The differences caused by the fire were no longer evident one year later. Furthermore, in one sampling site (Vitric Leptosols under low pine forest with a mixed heath/beech tree understory) a wide variation in the content of Cox and Ntot and high water repellency was observed relative to the other sites. These differences can be attributed to the composition of the understory vegetation. Significant correlations between soil hydrophobicity with CE1:5, aggregate stability and the contents of Cox, Ntot, NH4+-N, Ca2+, Mg2+, Na+ and K+ were found.

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Influence of crop residues and nitrogen fertilizer on soil water repellency and soil hydrophobicity under long-term no-till

Canadian Journal of Soil Science ◽

10.1139/cjss-2019-0003 ◽

2019 ◽

Vol 99 (3) ◽

pp. 334-344 ◽

Cited By ~ 1

Author(s):

J.J. Miller ◽

M.L. Owen ◽

B.H. Ellert ◽

X.M. Yang ◽

C.F. Drury ◽

...

Keyword(s):

Soil Water ◽

Crop Residues ◽

Water Repellency ◽

N Fertilizer ◽

Soil Water Repellency ◽

Index Method ◽

Organic C ◽

No Till ◽

Soil Hydrophobicity

Crop residues and N fertilizer under no-till may increase soil water repellency (SWR) and soil hydrophobicity, but few studies have examined these two treatment factors and their interaction. A laboratory study was conducted using a long-term (since 1999) field experiment on a clay loam soil to determine the effect of three crop residues and two N fertilizer levels on SWR and soil hydrophobicity under no-till within the Dark Brown soil zone of the semi-arid Canadian prairies. The three residue treatments were residues removed from soil (Rx0), residues returned to soil (Rx1), and residues supplemented to soil (Rx2). The two fertilizer N treatments were 0 (N0) and 45 kg N ha−1 (N1). Surface (0–10 cm) soil samples were taken in the spring of 2017 after 17 yr. Laboratory measurements were conducted on air-dried and sieved (<2 mm) soil to determine SWR using the repellency index method (RI), soil organic C, hydrophobic CH and hydrophilic CO functional groups, and soil hydrophobicity (CH/CO ratio). Mean RI values ranged from 2.19 to 2.75, indicating subcritical (RI > 1.95) SWR. Similar (P > 0.05) RI values were found for the three residue and two N fertilizer treatments, but the trend was for greater RI with increased residue addition (by 12%–26%) and N fertilizer (by 8%). Soil hydrophobicity was significantly greater by 47%–82% for straw returned or supplemented than straw removed treatments, and by 33% for fertilized than unfertilized treatments. Overall, greater residues and N fertilizer had no effect on SWR, but significantly increased soil hydrophobicity.

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Contributions of soil organic carbon to soil water repellency persistence: Characterization and modelling

Geoderma ◽

10.1016/j.geoderma.2021.115312 ◽

2021 ◽

Vol 401 ◽

pp. 115312

Author(s):

Zihuan Fu ◽

Wei Hu ◽

Michael H. Beare ◽

Karin Müller ◽

Dirk Wallace ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Water ◽

Water Repellency ◽

Soil Water Repellency

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Petroleum residues as water-repellent substances in weathered nonwettable oil-contaminated soils

Canadian Journal of Soil Science ◽

10.4141/s97-040 ◽

1999 ◽

Vol 79 (2) ◽

pp. 367-380 ◽

Cited By ~ 38

Author(s):

Julie L. Roy ◽

William B. McGill ◽

Marvin D. Rawluk

Keyword(s):

Soil Water ◽

Contaminated Soils ◽

Impact Ionization ◽

Water Repellency ◽

Solvent Mixture ◽

Water Repellent ◽

Soil Water Repellency ◽

Petroleum Origin ◽

Soil Hydrophobicity ◽

Gas Chromatography Mass Spectroscopy

Some soils develop severe water repellency several years or decades following oil contamination. We previously reported on the characteristics of three such soils. Here we report on the characteristics of putative water-repellent substances in them. We examined the effectiveness of various polar, nonpolar and amphiphilic solvents for removal of water-repellent substances in three nonwettable soils. Only the amphiphilic solvent mixture isopropanol/14.8 M ammonia (7:3, vol/vol) (IPA/NH4OH) completely eliminated soil water repellency in all three soils. We thus define putative water-repellent substances as those substances whose removal from soil by IPA/NH4OH removes water repellency. High-resolution CPMAS 13C-NMR spectroscopy and thermal desorption followed by conventional gas chromatography/mass spectroscopy with electron impact ionization (GC/EI/MS) and GC/MS with chemical ionization (GC/CI/MS) were used to characterize extracted putative water-repellent substances. We conclude that: (i) the identified representatives of these substances consist mostly of homologous series of long-chain and polycyclic aliphatic organic compounds; namely, n-fatty acids, n-alkanes, and cycloalkanes, and that (ii) they are of petroleum origin rather than plant or microbial origin. Key words: Soil hydrophobicity, petroleum hydrocarbons, soil water repellency, amphiphilic solvents, crude oil, nonwettable soil

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