Search Results (17)

In citriculture, inputs like water and fertilizer are applied through traditional basin methods, thereby incurring reduced use-efficiency. The response of conventional crop coefficient-based fertigation scheduling continues to be inconsistent and complex in its field implementation, thereby necessitating the intervention of sensor-based (Internet of Things; IoT) technology for fertigation scheduling on a real-time basis. The study aimed to investigate fertigation scheduling involving four levels of irrigation, viz., I₁ (100% evapotranspiration (ET) as the conventional practice), I₂ (15% volumetric moisture content (VMC)), I₃ (20% VMC), and I₄ (25% VMC), as the main treatments and three levels of recommended doses of fertigation, achieved by reappropriating different nutrients across phenologically defined critical growth stages, viz., F₁, F₂, and F₃ (conventional fertilization practice), as sub-treatments, which were evaluated through a split-plot design over two harvesting seasons in 2021–2023. Nagpur mandarin (Citrus reticulata Blanco) was used as the test crop, which was raised on Indian Vertisol facing multiple nutrient constraints. Maximum values for physiological growth parameters (plant height, canopy area, canopy volume, and relative leaf water content (RLWC)) and fruit yield (characterized by 9% and 5%, respectively, higher A-grade-sized fruits with the I₄ and F₁ treatments over corresponding conventional practices, viz., I₁ and F₃) were observed with the I₄ irrigation treatment in combination with the F₁ fertilizer treatment (I₄F₁). Likewise, fruit quality parameters, viz., juice content, TSS, TSS: acid ratio, and fruit diameter, registered significantly higher with the I₄F₁ treatment, featuring the application of B at the new-leaf initiation stage (NLI) and Zn across the crop development (CD), color break (CB), and crop harvesting (CH) growth stages, which resulted in a higher leaf nutrient composition. Treatment I₄F₁ conserved 20–30% more water and 65–87% more nutrients than the I₁F₃ treatment (conventional practice) by reducing the rate of evaporation loss of water, thereby elevating the plant’s available nutrient supply within the root zone. Our study suggests that I₄F₁ is the best combination of sensor-based (IoT) irrigation and fertilization for optimizing the quality production of Nagpur mandarin, ensuring higher water productivity (WP) and nutrient-use-efficiency (NUE) coupled with the improved nutritional quality of the fruit. Full article

Water quality affects soils by promoting their degradation by the accumulation of salts that will lead to salinization and sodification. However, the magnitude of these processes varies with soil attributes. Saturated hydraulic conductivity (K_sat) is the rate at which water passes through saturated soil, which is fundamental to determining water movement through the soil profile. The K_sat may differ from soil to soil according to the sodium adsorption ratio (SAR), water electrical conductivity (EC_w), soil texture, and clay mineralogical assemblage. In this study, an experiment with vertical columns and constant-load permeameters was conducted to evaluate changes in soil K_sat with waters comprising five EC_w values (128, 718, 1709, 2865, and 4671 µS cm⁻¹) and five SAR values [0, 5, 12, 20, and 30 (mmol_c L⁻¹)^0.5] in combination. Horizons from nine northeastern Brazilian soils (ranging from tropical to semiarid) were selected according to their texture and clay mineralogical composition. The data obtained were fit with multiple regression equations for K_sat as a function of EC_w and SAR. This study also determined the null SAR at each EC_w level, using K_sat = 0 on each equation, to predict the SAR needed to achieve zero drainage on each soil for each EC_w level and the threshold electrolyte concentration (C_TH) that would lead to a 20% reduction of maximum K_sat. Neither the EC_w nor SAR of the applied waters affected the K_sat of soils with a mineralogical assemblage of oxides and kaolinite such as Ferralsol, Nitisol, and Lixisol, with an average K_sat of 2.75, 6.06, and 3.33 cm h⁻¹, respectively. In smectite- and illite-rich soils, the K_sat increased with higher EC_w levels and decreased with higher SAR levels, especially comparing the soil’s estimated K_sat for water with low EC_w and high SAR in combination (EC_w of 128 µS cm⁻¹ and SAR 30) and water with high EC_w and low SAR in combination (EC_w of 4671 µS cm⁻¹ and SAR 0) such as Regosol (4.95 to 10.94 cm h⁻¹); Vertisol (0.28 to 2.04 cm h⁻¹); Planosol (0 to 0.29 cm h⁻¹); Luvisol (0.46 to 2.12 cm h⁻¹); Cambisol (0 to 0.23 cm h⁻¹); and Fluvisol (1.87 to 3.34 cm h⁻¹). The C_TH was easily reached in soils with high concentrations of highly active clays such as smectites. In sandy soils, the target C_TH was only reached under extremely high SAR values, indicating a greater resistance of these soils to salinization/sodification. Due to their mineralogical assemblage, soils from tropical sub-humid/hot and semiarid climates were more affected by treatments than soils from tropical humid/hot climates, indicating serious risks of physical and chemical degradation. The results showed the importance of monitoring water quality for irrigation, mainly in less weathered, more clayey soils, with high clay activity to minimize the rate of salt accumulation in soils of the Brazilian semiarid region. Our study also proved that clay mineralogy had more influence on the K_sat than clay concentration, mainly in soils irrigated with saline and sodic waters, and that soils with highly active smectite are more prone to degradation than soils with high concentrations of kaolinite. Full article

Greenhouse gas emissions from agricultural production systems are a major area of concern in mitigating climate change. Therefore, a study was conducted to investigate the effects of crop residue, nutrient management, and soil moisture on methane (CH₄) emissions from maize, rice, soybean, and wheat production systems. In this study, incubation experiments were conducted with four residue types (maize, rice, soybean, wheat), seven nutrient management treatments {N0P0K0 (no nutrients), N0PK, N100PK, N150PK, N100PK + manure@ 5 Mg ha⁻¹, N100PK + biochar@ 5 Mg ha⁻¹, N150PK+ biochar@ 5 Mg ha⁻¹}, and two soil moisture levels (80% FC, and 60% FC). The results of this study indicated that interactive effects of residue type, nutrient management, and soil moisture significantly affected methane (CH₄) fluxes. After 87 days of incubation, the treatment receiving rice residue with N100PK at 60% FC had the highest cumulative CH₄ mitigation of −19.4 µg C kg⁻¹ soil, and the highest emission of CH₄ was observed in wheat residue application with N0PK at 80% FC (+12.93 µg C kg⁻¹ soil). Nutrient management had mixed effects on CH₄ emissions across residue and soil moisture levels in the following order: N150PK > N0PK > N150PK + biochar > N0P0K0 > N100PK + manure > N100PK + biochar > N100PK. Decreasing soil moisture from 80% FC to 60% FC reduced methane emissions across all residue types and nutrient treatments. Wheat and maize residues exhibited the highest carbon mineralization rates, followed by rice and soybean residues. Nutrient inputs generally decreased residue carbon mineralization. The regression analysis indicated that soil moisture and residue C mineralization were the two dominant predictor variables that estimated 31% of soil methane fluxes in Vertisols. The results of this study show the complexity of methane dynamics and emphasize the importance of integrated crop, nutrient, and soil moisture (irrigation) management strategies that need to be developed to minimize methane emissions from agricultural production systems to mitigate climate change. Full article

Shrew communities play a crucial role in a diverse range of natural, urban, and agricultural ecosystems. We used Barn owl diet analysis as the ideal proxy to assess small-mammal distribution patterns on large spatial scales. More than 10,000 pellets were analyzed from Thessaly, the largest agricultural prefecture located in central Greece. A total of more than 29,000 prey items were identified, one of the largest datasets used in similar analyses in Europe. Three discrete shrew species were present in Thessaly agricultural plains, central Greece (Güldenstädt’s shrew Crocidura gueldenstaedtii, Bi-coloured shrew Crocidura leucodon, and Pygmy white-toothed shrew Suncus etruscus), which comprised a total of 7452 shrews, representing 25.64% of the total small-mammals’ dataset. C. gueldenstaedtii and S. etruscus demonstrated strong associations with heavy argillaceous-clay soils and Vertisol soil types, whereas S. etruscus was also associated with non-irrigated land and non-intensive cultivated plots. C. leucodon demonstrated no significant associations to any environmental gradient and demonstrated habitat plasticity, most possibly shaped by existing resources and competition. Our study highlights the important insights gained from Barn owl diet analysis in respect of small-mammal assemblages on broad geographical scales, and the inclusion of soil parameters as drivers of habitat suitability and distribution patterns for small-mammal responses. Full article

Low nitrogen (N) fertilizer use efficiency for irrigated cotton has been attributed to the limited ability of tap roots to access N from concentrated subsurface bands, or the preferential root uptake of microbially-mineralized dissolved organic N. This work investigated how applying high-rate banded urea affects the availability of N in soil and the capacity of cotton roots to take up N. Soil was analyzed for water-extractable total dissolved N and inorganic N species after urea or urea coated with 3,4-dimethylpyrazole phosphate (DMPP) was applied at concentrations of 261, 455, 461, and 597 mg N kg⁻¹ of (air-dry) soil (mean bulk density: 1.01 g cm⁻³). A mass balance was used to compare N applied as fertilizer and in unfertilized soil (supplied N) with the N recovered from soil within the cylinders (recovered N) at five plant growth phases. Root uptake was estimated by comparing ammonium-N (NH₄-N) and nitrate-N (NO₃-N) in soil sampled from within cylinders with soil sampled from immediately outside. Recovered N was up to 100% above supplied N within 30 days of applying urea above 261 mg N kg⁻¹ of soil. Significantly lower NO₃-N in soil sampled from immediately outside the cylinders suggests urea application stimulates cotton root uptake. The use of DMPP-coated urea prolonged high NH₄-N in soil and inhibited the mineralization of released organic N. These results imply the release of previously sequestered soil organic N within 30 days of applying concentrated urea enhances the availability of NO₃-N in the rhizosphere, reducing N fertilizer use efficiency. Full article

The increase in soil salinity due to human-induced processes poses a severe threat to agriculture on a regional and global scale. Soil salinization caused by natural and anthropogenic factors is a vital environmental hazard, specifically in semi-arid and arid regions of the world. The detection and monitoring of salinity are critical to the sustainability of soil management. The current study compared the performance of machine learning models to produce spatial maps of electrical conductivity (EC) (as a proxy for salinity) in an alluvial irrigation plain. The current study area is located in the Isparta province (100 km²), land cover is mainly irrigated, and the dominant soils are Inceptisols, Mollisols, and Vertisols. Digital soil mapping (DSM) methodology was used, referring to the increase in the digital representation of soil formation factors with today’s technological advances. Plant and soil-based indices produced from the Sentinel 2A satellite image, topographic indices derived from the digital elevation model (DEM), and CORINE land cover classes were used as predictors. The support vector regression (SVR) algorithm revealed the best relationships in the study area. Considering the estimates of different algorithms, according to the FAO salinity classification, a minimum of 12.36% and a maximum of 20.19% of the study area can be classified as slightly saline. The low spatial dependence between model residuals limited the success of hybrid methods. The land irrigated cover played a significant role in predicting the current level of EC. Full article

Increasing prevalence of cyanotoxins in surface water bodies worldwide threatens groundwater quality when contaminated water recharges an aquifer through natural or artificial means. The subsurface fate of anatoxin-a (ATX) is not well studied. Laboratory batch experiments were performed to expand the current knowledge of ATX sorption affinities to geologic media, with a focus on natural soil (Vertisol, Ultisol, Alfisol, and Inceptisol) and physical, chemical, and mineralogical characteristics. For a range of aqueous ATX concentrations (0.3–14 μg/L), linear, Freundlich, and Langmuir isotherms fit observed data well (r² = 0.92–1.00, RMSE = 0.4–6.3 μg/kg). Distribution coefficient (K_d) and retardation factor (R_f) values were computed for the linear isotherm, giving K_d of 22.3–77.1 L/kg and R_f of 62–256. Average percent removals were 85.0–92.2%. The strongest predictors of K_d were kaolinite and smectite group mineral abundances and for R_f were smectite group and silt and clay abundances. Results indicate that loamy, silty, or clayey soils—particularly Vertisols—tend to substantially slow migration of ATX through natural soil systems. Where implemented as a functionalized amendment in an engineered pollution control media, such soils may enhance natural ATX attenuation processes, thereby supporting the protection of in situ and extracted groundwater during irrigation, natural and managed aquifer recharge, or riverbank filtration. Full article

Soil salinity due to irrigation is a major constraint to agriculture, particularly in arid and semi-arid zones, due to water scarcity and high evaporation rates. Reducing salinity is a fundamental objective for protecting the soil and supporting agricultural production. The present study aimed to empirically measure and simulate with a model, the reduction in soil salinity in a Vertisol by the cultivation and irrigation of Echinochloa stagnina. Laboratory soil column experiments were conducted to test three treatments: (i) ponded bare soil without crops, (ii) ponded soil cultivated with E. stagnina in two successive cropping seasons and (iii) ponded soil permanently cultivated with E. stagnina with a staggered harvest. After 11 months of E. stagnina growth, the electrical conductivity of soil saturated paste (ECe) decreased by 79–88% in the topsoil layer (0–8 cm) in both soils cultivated with E. stagnina and in bare soil. In contrast, in the deepest soil layer (18–25 cm), the ECe decreased more in soil cultivated with E. stagnina (41–83%) than in bare soil (32–58%). Salt stocks, which were initially similar in the columns, decreased more in soil cultivated with E. stagnina (65–87%) than in bare soil (34–45%). The simulation model Hydrus-1D was used to predict the general trends in soil salinity and compare them to measurements. Both the measurements and model predictions highlighted the contrast between the two cropping seasons: soil salinity decreased slowly during the first cropping season and rapidly during the second cropping season following the intercropping season. Our results also suggested that planting E. stagnina was a promising option for controlling the salinity of saline-sodic Vertisols. Full article

Agriculture in a water-limited environment is critically important for today and for the future. This research evaluates the impact of deficit irrigation in different planting methods on the physio-morphological traits, grain yield and WUE of maize (Zea mays L.). The experiment was carried out in 2015 and 2016, consisting of three planting methods (i.e., BBF, SNF, and DWF) and four irrigation levels (i.e., I_10D: irrigation once in ten days, I₄₀: irrigation at 40% DASM, I₅₀: irrigation at 50% DASM, and I₆₀: irrigation at 60% DASM). The results reveal that varying degrees of water stress due to planting methods and irrigation levels greatly influenced the maize physio-morphological traits and yield attributes. The combined effect of DWF + I₅₀ benefited the maize in terms of higher leaf area, RWC, SPAD values, CGR, and LAD, followed by the SNF method at 60 DAS. As a result, DWF + I₅₀ and SNF + I₅₀ had higher 100 grain weight (30.5 to 31.8 g), cob weight (181.4 to 189.6 g cob⁻¹) and grain yield (35.3% to 36.4%) compared to other treatments. However, the reduction in the number of irrigations (24.0%) under SNF + I₅₀ resulted in a 34% water saving. Thus, under a water-limited situation in semi-arid tropics, the practice of the SNF method + I₅₀ could be an alternative way to explore the physio-morphological benefits in maize. Full article

The aim of this study was to explore the effect of sowing methods and deficit irrigation on weed dynamics, yield and water-use efficiency (WUE) of the maize–cowpea system during the summer and monsoon seasons, respectively. The field experiment was carried out for two years (2015 and 2016) using a split design with three replicates under irrigated (maize) and rainfed (cowpea) conditions on vertisols of a semi-arid region. Treatments included three sowing methods [i.e., broad bed and furrow (BBF), corrugated furrow (CF) and ridges and furrow (RF)] and four irrigation levels [i.e., irrigation once in 10 days (I_10D), irrigation at 40% (I₄₀), at 50% (I₅₀) and at 60% (I₆₀) depletion]. The results indicated that, regardless of weed flora (monocots, dicots and sedges), the RF method produced higher weed density (2.09–2.98 No. m⁻²) compared to CF (2.00–2.80 No. m⁻²) and BBF (1.85–2.64 No. m⁻²) in maize at 30 and 60 days after sowing (DAS). The RF method with irrigation at I₄₀ and I₅₀ recorded significantly higher weed density, followed by the CF and BBF method. A similar trend was also observed with dry weight of weeds (monocot; 24.19%, dicot; 25.52%, and sedges; 29.80%) in maize at 30 and 60 DAS. Higher weed density and dry weight of weeds in the RF method with I₄₀ was due to higher soil moisture availability and higher nutrient uptake due to larger lateral wetting of the soil and greater water use (29.27%). However, the BBF method favoured the growth of weeds (9.33–16.60%) in cowpea at 55 DAS and coped under rain-fed situation over CF and RF. The CF with moderate depletion (I₅₀) method produced significantly higher maize equivalent yield (MEY) of cowpea (10,000 kg ha⁻¹) with considerable reduction in the total water usage (19.33%). Therefore, under a water scarcity situation, growers can practice CF and I₅₀ for higher yield and WUE of maize–cowpea sequence cropping. Full article

The present work studied the effect of two consecutive years of regulated deficit irrigation (RDI) compared to rain fed management on the vegetative growth, yield, and quality of ‘Nero d’Avola’ grapes. The trial was conducted separately in two soils (vertisol and entisol) located at the top and bottom hillside of the same vineyard. Vertisol was characterized by greater depth, organic matter, exchangeable K₂O, and total N than entisol. RDI was based on an irrigation volume at 25% of estimated crop evapotranspiration (ET_c) up to end of veraison and 10% of estimated ET_c up to 15 days before harvest. Predawn water potential (PDWP) was used as indicator of plant water status and irrigation timing. No difference in irrigation management was evident between vertisol and entisol. Under Mediterranean climate conditions, RDI was able to enhance grape yield and vegetative growth, especially in vertisol, but it reduced berry titratable acidity and total anthocyanins. ‘Nero d’Avola’ showed to adapt to drought conditions in the open field. Both soil type and irrigation regimes may provide opportunities to obtain different ‘Nero d’Avola’ wine quality and boost typicality. Full article

Salinization and sodification are important processes of soil degradation affecting irrigated lands. A large proportion of the global irrigated area is affected by some degree of soil salinity or sodicity caused by the intensification of irrigation. The increase of the frequency of adverse climatic conditions, like high temperatures and variations in precipitation patterns caused by climate change, will potentially amplify these processes in arid, semi-arid, and Mediterranean areas. The use of integrated approaches for the spatial and temporal prediction of the risk of salinization and sodification in irrigated areas is of great value, helping in the decision-making regarding land uses and choice of more suitable agricultural practices. In this study, based on key criteria for the assessment of irrigation-related salinization processes (e.g., climate, topography, soil drainage, water quality for irrigation, and crop irrigation method), we developed a methodology for the prediction of soil salinity and sodicity risk in irrigated lands, using two composite indices, the Salinization Risk (RSA) index and the Sodification Risk (RSO) index. The application of these indices to a real scenario (a Mediterranean area in Southern Portugal) showed that 67% of the potentially irrigated area presented a low risk of salinity development, 68% had a moderate risk of sodification, and 16% was of high risk of sodicity development. Areas under moderate risk of salinization (26%) were mostly characterized by low slopes and fine-textured soils, like Luvisols and Vertisols, with limited drainage conditions. Areas with high risk of soil sodification presented a large incidence of low slope terrain, moderate-to-restricted soil drainage, in high clay content Luvisols, Vertisols and Cambisols, and land use dominated by annual crops irrigated with surface or sprinkler systems. These risk prediction tools have the potential to be used for resource use planning by policymakers and on-farm management decision by farmers, contributing to the sustainability of irrigated agriculture in Mediterranean regions. Full article

Modern rice varieties adapted to aerobic (dryland) conditions have expanded to new rice growing systems thanks to their plasticity in adapting to rainfed and irrigated conditions. This is important because, as water becomes scarce in paddy rice regions (as it is already in Australia), there will be a move towards tropical to subtropical dryland rainfed rice with attendant problems of drought and low temperature. To assess rice adaptability in the wet season of the semi-arid subtropical conditions of coastal central Queensland, field experiments were established for a late season (in January) planting in 2014 and early season planting in November 2015 with 13 varieties developed by Australian Agriculture Technologies (AAT) Ltd were seeded in a vertisol soil. This was to assess their adaptation to rainfed conditions and their response to strategic irrigation. Water scarcity and low temperature prior to and at flowering were important factors constraining yield. Early flowering varieties in the late season planting escaped the otherwise cold and drought stress during the reproductive stage and had higher yields. In the second year, earlier planting made possible with strategic irrigation avoided the low temperature constraint on yield, but without follow-up strategic irrigation, yields were still low. The average yield of varieties increased from 1.5 times (AAT 4) to 16.3 times (AAT 15) with strategic irrigation compared with rainfed yields averaged across years. The increase in yield with strategic irrigation was associated with a greater leaf area index, spikelet fertility, and instantaneous water use efficiency during flowering. Strategic irrigation concentrated roots in the top 15 cm, but differences in yield between varieties under rainfed conditions were not related to root properties. It is important to consider variations in flowering time, yield potential, and drought patterns when developing rice varieties for rainfed semi-arid tropical conditions, as well as when quantifying the benefits of strategic irrigation. Full article

The efficiency of mineral fertilizer use in most soils in Sub-saharan Africa is low. Prominent among the reasons for this is low soil carbon stock. In this study, we hypothesized that in the short term, combined use of biochar and inorganic fertilizer in irrigated rice (Oryza sativa var KRC Baika) cropping systems will increase soil organic carbon storage, N recovery and agronomic efficiency of N use (above world average of 55% and 20 kg grain·kg⁻¹·N respectively) and improved economic returns compared to the sole use of inorganic fertilizer. A two-year (4‒cropping cycles) field trial was, thus, conducted on a Vertisol. The experiments were designed as split–plot with two (0 and 10 t·ha⁻¹) biochar and four (0, 45, 90, 120 kg·ha⁻¹·N) nitrogen application rates. Additionally, the effect of biochar on the chemical properties of the soil was investigated using standard protocols. Biochar application improved the soil organic carbon storage in the topsoil. There were significant interactions between the application of biochar and nitrogen fertilizer on yield parameters. Introducing biochar significantly increased root volume and nutrient (N, P and K) uptake, resulting in increased grain and straw yield. Grain yields under biochar amended plots were higher than sole fertilizer amended plots in 14 out of 16 instances (cropping cycles × N rates). The increase in grain yield was between 12 to 29% across N rates. Biochar amendment also enhanced agronomic N use and apparent N recovery efficiencies in 3 out of the 4 cropping cycles. Gross margin indicated that biochar application under irrigated rice cropping systems is economically feasible in all cropping cycles and N rates. However, the value cost ratio of biochar application was higher than for sole inorganic fertilizer in three out of the four cropping cycles (each cropping cycle has three N rates). The soil organic carbon storage of biochar amended soil increased by 17% under unfertilized condition and by 32% under fertilized condition. To enable the promotion and efficient use of the biochar technology in enhancing productivity and profitability in irrigated rice, extension officers and farmers will need to be trained on how to char the rice husk to reduce emissions prior to upscaling the technology to farmers. Full article

Many soil regulating ecosystem services (ES) are linked to Earth’s atmosphere, but associated monetary values often are unknown or difficult to quantify. Atmospheric deposition of calcium (Ca²⁺) and magnesium (Mg²⁺) are abiotic flows (wet, dry, and total) from the atmosphere to land surfaces, which potentially can become available to sequester carbon (C) as soil inorganic carbon (SIC). However, these processes typically have not been included in economic valuations of ecosystem services. The primary objective of this study was to demonstrate an approach for valuing non-constrained potential SIC sequestration from atmospheric Ca²⁺ and Mg²⁺ deposition based on the concept of the avoided social cost of carbon dioxide emissions (SC-CO₂). Maximum monetary values associated with the non-constrained potential SIC sequestration were compiled for the contiguous United States (U.S.) by soil order, land resource region (LRR), state, and region using available deposition data from the National Atmospheric Deposition Program (NRSP-3). For the entire contiguous U.S., an average annual monetary value for the non-constrained potential SIC sequestration due to atmospheric Ca²⁺ and Mg²⁺ deposition was $135M (i.e., $135 million U.S. dollars, where M = million = 10⁶). Mollisols, Alfisols, and Entisols were soil orders with the highest average annual monetary values for non-constrained potential SIC sequestration. When normalized by land area, however, Vertisols had the highest average annual monetary values followed by Alfisols and Mollisols for non-constrained potential SIC sequestration. From a more agricultural perspective, the LRRs with the highest average annual monetary values for non-constrained potential SIC sequestration were the Western Range and Irrigated Region (D), the Central Feed Grains and Livestock Region (M), and the Central Great Plains Winter Wheat and Range Region (H). When normalized by area, the LRRS with the highest average annual monetary values were the Southwest Plateaus and Plains Range and Cotton Region (I) and the Florida Subtropical Fruit, Truck Crop and Range Region (U). Among the U.S. states, the highest average annual monetary values for non-constrained potential SIC sequestration were Texas, Kansas, and New Mexico, but when normalized by area the highest values by state were Kansas, Iowa, and Texas. Geographical regions in the contiguous U.S. with the highest average annual monetary values for non-constrained potential SIC sequestration were the South Central, Midwest, and West; when normalized by area, the highest values by region were South Central, Midwest, and Northern Plains. Constraints on maximum monetary values, based on physical, chemical, biological, economic, social, and political limitations, need to be considered and quantified to obtain more precise and accurate accounting of the ES associated with SIC sequestration due to atmospheric Ca²⁺ and Mg²⁺ deposition. Full article