Core Ideas In situ remediation of brine spills is possible via surface extraction of salts. A crystallization inhibitor allowed for 29 to 57% of salts to be harvested from the soil surface. Methods for surface extraction of salts can aid in expediting brine spill remediation timelines. Well drilling for energy resources innately produces brine waters. These brines often contain sodium in the 10,000 to >100,000 mg L−1 range. In situ soil remediation of brine spills traditionally consists of diluting salts with organic materials and then infiltrating divalent cations. This leaching technique can require years to centuries, as a function of soil clay content, to remove salts from the root zone. We present a new in situ remediation method that extracts salts from the soil surface and expedites remediation. Surface application of a crystallization inhibitor (ferric hexacyanoferrate) to brine‐contaminated soils followed by an evaporative flux resulted in dendritic crystal growth above the soil surface. This process allowed easy harvest of 29 to 57% of salts within 7 d without mechanical disturbance to the soil. Future studies should include loading‐rate optimization, in‐field testing, evaluation of reaction product fate and transport, and identification of other amendments to rapidly extract salts.

Core Ideas Brine‐contaminated soils require remediation in many oil‐producing regions. A crystallization inhibitor induced harvestable salt efflorescence on contaminated soils. Crystallization inhibitors can be part of the remediation effort on brine‐contaminated soils. We hypothesize that a crystallization inhibitor will induce harvestable salt efflorescence on the surface of brine‐contaminated soils. If proven, the harvest of effloresced salts will provide a novel method for remediating brine spills. Our objectives were to evaluate salt efflorescence on brine‐contaminated soil columns as a function of (i) crystallization‐inhibitor concentration, (ii) application method, (iii) soil texture, (iv) subsequent harvesting, and (v) salt species. We conducted three laboratory incubations with 0.00001 to 0.01 M ferric hexacyanoferrate solutions applied to salt‐contaminated soil columns over 7 to 28 d. The 0.01 M solution successfully effloresced an average of 0.46, 0.57, and 0.29 g g−1 (i.e., grams of harvested salt at the soil surface per total grams of NaCl applied to the soil) on sandy loam, loam, and silty clay columns, respectively. However, negligible quantities of efflorescence occurred when applying the crystallization inhibitor (i) at concentrations <0.001 M, (ii) and subsequently mixing the soil, (iii) with NaCl solutions <0.6 M, (iv) and attempting to further induce salt efflorescence after a first harvesting, and (v) to soil with elevated levels of sulfate or calcium. This novel method for brine spill remediation shows great potential for remediating NaCl‐contaminated soils. Future research should include field evaluation on real brine spills to determine the efficacy of the new method in practice.

Crop species composition and richness exert a strong infl uence on soil C and N dynamics through the proportion of decomposable organic compounds returned to the soil. Under no-till, soil C and N pools were compared for fi ve crop rotations, (1) continuous corn (Zea mays L.; CC), (2) spring wheat (Triticum spp.)-soybean [Glycine max (L.) Merr.; SW-S], (3

Soil salinity caused by oil-production-water (brine) contamination is a major issue in regions of oil and gas development. However, rapid site assessment tools such as soil-to-water suspension electrical conductivity (EC) methods and conversion equations have not been previously calibrated and validated for brine-contaminated soils. Our objective was to compare three soil EC methods and derive conversion equations for EC values commonly observed at brine-spill sites. Brine-contaminated soils from western North Dakota were assessed for salinity. Electrical conductivity was determined using 1:1 and 1:5 soil-to-water suspensions (EC 1:1 , EC 1:5 ) and saturated paste extracts (EC e ). Soil EC equilibration times for soil-to-water suspensions were also assessed. Significant relationships (r 2 = 0.91 to 0.97, P < 0.0001) existed among all methods for EC values ranging between 0 and 126 dS m −1 . Conversion equations were developed based on these relationships and then validated with an independent data set. These new equations reduced EC e prediction errors by 2 to 4.5 times when compare with 14 predictive equations reported in the literature. The conversion equations developed here are recommended for use in remediation efforts when converting EC 1:1 and EC 1:5 data to EC e on brine-contaminated and noncontaminated soils where EC e is highly correlated to Na concentrations.Key words: soil salinity, electrical conductivity, oil production, saturated paste, soil-to-water suspension, brine.Résumé : La salinité du sol résultant de la contamination de ce dernier par l'eau des puits de pétrole (saumure) est un problème majeur dans les régions où l'on exploite des nappes de pétrole et de gaz. Cependant, les outils d'évaluation rapide des sites comme la conductivité électrique (CE) d'une suspension de sol dans l'eau et les équations de conversion n'ont jamais été étalonnés ni validés pour les sols contaminés de la sorte. Les auteurs voulaient comparer trois méthodes reposant sur la CE et dériver les équations de conversion pour les valeurs les plus couramment observées là où de la saumure a été accidentellement déversée. Pour cela, ils ont évalué la salinité de sols de l'ouest du Dakota Nord pollués par de la saumure. La conductivité électrique a été déterminée grâce à des suspensions 1: 1 et 1: 5 de sol dans l'eau (EC 1:1 , EC 1:5 ) et à des extraits de pâte de papier saturée (EC e ). Parallèlement, ils ont établi le temps nécessaire pour que les suspensions de sol dans l'eau parviennent à la CE d'équilibre. Il existe des relations significatives (r 2 = 0,91 à 0,97, P < 0,0001) entre les différentes méthodes testées pour les valeurs de la CE situées entre 0 et 126 dS par m. Des équations de conversion ont été élaborées d'après ces relations, puis validées avec un jeu de données indépendant. Les nouvelles équations réduisent les erreurs de prévision pour EC e par un facteur de 2 à 4,5 comparativement à 14 équations similaires trouvées dans la littérature. Les auteurs préconisent l'utilisation de leurs équations da...