scholarly journals Dryland irrigation increases accumulation rates of pedogenic carbonate and releases soil abiotic CO2

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Anna C. Ortiz ◽  
Lixin Jin ◽  
Nives Ogrinc ◽  
Jason Kaye ◽  
Bor Krajnc ◽  
...  
Keyword(s):  
Agricultural Fields ◽  
Accumulation Rates ◽  
Flood Irrigation ◽  
Pedogenic Carbonate ◽  
Salt Loading ◽  
Pedogenic Carbonates ◽  
Irrigation Intensity ◽  
Alfalfa Field ◽  
Multiple Variables ◽  
Irrigated Soils

AbstractAgricultural fields in drylands are challenged globally by limited freshwater resources for irrigation and also by elevated soil salinity and sodicity. It is well known that pedogenic carbonate is less soluble than evaporate salts and commonly forms in natural drylands. However, few studies have evaluated how irrigation loads dissolved calcium and bicarbonate to agricultural fields, accelerating formation rates of secondary calcite and simultaneously releasing abiotic CO2 to the atmosphere. This study reports one of the first geochemical and isotopic studies of such “anthropogenic” pedogenic carbonates and CO2 from irrigated drylands of southwestern United States. A pecan orchard and an alfalfa field, where flood-irrigation using the Rio Grande river is a common practice, were compared to a nearby natural dryland site. Strontium and carbon isotope ratios show that bulk pedogenic carbonates in irrigated soils at the pecan orchard primarily formed due to flood-irrigation, and that approximately 20–50% of soil CO2 in these irrigated soils is calcite-derived abiotic CO2 instead of soil-respired or atmospheric origins. Multiple variables that control the salt buildup in this region are identified and impact the crop production and soil sustainability regionally and globally. Irrigation intensity and water chemistry (irrigation water quantity and quality) dictate salt loading, and soil texture governs water infiltration and salt leaching. In the study area, agricultural soils have accumulated up to 10 wt% of calcite after just about 100 years of cultivation. These rates will likely increase in the future due to the combined effects of climate variability (reduced rainfall and more intense evaporation), use of more brackish groundwater for irrigation, and reduced porosity in soils. The enhanced accumulation rates of pedogenic carbonate are accompanied by release of large amounts of abiotic CO2 from irrigated drylands to atmosphere. Extensive field studies and modelling approaches are needed to further quantify these effluxes at local, regional and global scales.

scholarly journals Using Carbon Isotope Equilibrium to Screen Pedogenic Carbonate Oxygen Isotopes: Implications for Paleoaltimetry and Paleotectonic Studies

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Nathan D. Sheldon
Keyword(s):  
Carbon Isotope ◽  
Fickian Diffusion ◽  
Pedogenic Carbonate ◽  
Southwestern Montana ◽  
Pedogenic Carbonates ◽  
Moisture Regimes ◽  
Theoretical Predictions ◽  
Elevation Changes ◽  
Geologic Record ◽  
Isotope Equilibrium

Stable isotope compositions of pedogenic carbonates (δ13Ccarb, δ18Ocarb) are widely used in paleoenvironmental and paleoaltimetry studies. At the same time, both in vertical stratigraphic sections and in horizontal transects of single paleosols, significant variability in δ18Ocarb values is observed well in excess of what could reasonably be attributed to elevation changes. Herein, a new screening tool is proposed to establish which pedogenic carbonate δ18Ocarb compositions reflect formation in isotopic equilibrium with environmental conditions through the use of the co-occurring δ13Corg composition of carbonate-occluded or in profile organic matter, where Δ13C = δ13Ccarb – δ13Corg. Based upon 51 modern soils from monsoonal, continental, and Mediterranean moisture regimes, Δ13C = +15.6 ± 1.1‰ (1σ), which closely matches theoretical predictions for carbonates formed at carbon isotope equilibrium through Fickian diffusion. Examples from both disequilibrium and equilibrium cases in the geologic record are examined, and it is shown that previous δ18Ocarb records used to infer Cenozoic uplift in southwestern Montana do not provide any constraint on paleoelevation because >90% of the pedogenic carbonate isotopic compositions are out of equilibrium. Guidelines for future paleoaltimetry studies include collection of both vertical stratigraphic sections and lateral transects, of at least three nodules per horizon, petrographic screening of nodules for diagenesis, collection of at least one independent proxy for paleoclimate or paleovegetation, and screening δ18Ocarb values using Δ13C measured for each paleosol.

Effect of irrigation method on the recovery of 15N fertilizer in a slowly permeable clay soil cropped with maize

Soil Research ◽  
1986 ◽  
Vol 24 (1) ◽  
pp. 1 ◽  
Author(s):  
AR Mosier ◽  
WS Meyer ◽  
FM Melhuish
Keyword(s):  
Plant Stress ◽  
N Recovery ◽  
Fertilizer N ◽  
Flood Irrigation ◽  
Mineral N ◽  
N Content ◽  
Total N ◽  
Maize Plants ◽  
And Control ◽  
Irrigated Soils

A study using 15N~labelled fertilizer was initiated in a lysimeter facility to quantify the amount of N assimilated by maize plants and that which remained in the soil at the end of a cropping season. Maize was planted in 0.43 m2 by 1.35 m deep intact Marah clay loam soil cores removed from an improved pasture in mid-October 1983. Two irrigation treatments, flood-impounding water on the soil for up to 72 h, and control-applying enough water to prevent plant stress without ponding, were employed. The crop was harvested in early April 1984 and the amount of fertilizer- and soil-derived N in the plant and remaining in the soil was determined. Grain yields were reduced about 33% by flood irrigation. Although about 30 kg N ha-1 more fertilizer N was lost from the flood-irrigated system, the difference in N recovery between the flood- and control-irrigated soils was not sufficient to account for the reduced grain yield. Flood-irrigated plants were less efficient in transporting fertilizer N to the seed than were control irrigation plants. The data suggest that the reduced seed yield and total N content of maize plants grown under flood irrigation was metabolically controlled rather than being derived from a difference in soil mineral N content compared with control-irrigated soils.

Aridity-driven decoupling of δ13C between pedogenic carbonate and soil organic matter

Geology ◽  
2020 ◽  
Vol 48 (10) ◽  
pp. 981-985 ◽  
Author(s):  
Jiawei Da ◽  
Yi Ge Zhang ◽  
Gen Li ◽  
Junfeng Ji
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Pore Space ◽  
C4 Plants ◽  
Atmospheric Co2 ◽  
Chinese Loess Plateau ◽  
Pedogenic Carbonate ◽  
Chinese Loess ◽  
Pedogenic Carbonates ◽  
Soil Pore Space

Abstract Pedogenic carbonate is an invaluable archive for reconstructing continental paleoclimate and paleoecology. The δ13C of pedogenic carbonate (δ13Cc) has been widely used to document the rise and expansion of C4 plants over the Cenozoic. This application requires a fundamental presumption that in soil pores, soil-respired CO2 dominates over atmospheric CO2 during the formation of pedogenic carbonates. However, the decoupling between δ13Cc and δ13C of soil organic matter (δ13CSOM) have been observed, particularly in arid regions, suggesting that this presumption is not always valid. To evaluate the influence of atmospheric CO2 on soil δ13Cc, here we performed systematic δ13C analyses of paleosols across the Chinese Loess Plateau, with the sample ages spanning three intervals: the Holocene, the Late Pleistocene, and the mid-Pliocene warm period. Our paired δ13Cc and δ13CSOM data reveal broadly divergent trending patterns. Using a two-component CO2-mixing model, we show substantial incorporations of atmospheric CO2 (up to 60%) into soil pore space during carbonate precipitation. This result readily explains the enrichment of δ13Cc and its divergence from δ13CSOM. As a consequence, δ13C of pedogenic carbonates formed under semiarid and/or arid conditions are largely driven by regional aridity through its control on soil CO2 composition, and thus cannot be used to evaluate the relative abundance of C3 versus C4 plants. Nonetheless, these carbonates can be applied for atmospheric CO2 reconstructions, even for periods with low CO2 levels.

Soil quality changes due to flood irrigation in agricultural fields along the Rio Grande in western Texas

2018 ◽  
Vol 90 ◽  
pp. 87-100 ◽  
Author(s):  
Christine Cox ◽  
Lixin Jin ◽  
Girisha Ganjegunte ◽  
David Borrok ◽  
Vanessa Lougheed ◽  
...  
Keyword(s):  
Soil Quality ◽  
Rio Grande ◽  
Agricultural Fields ◽  
Quality Changes ◽  
Flood Irrigation

A STUDY OF MACROCRYSTALLINE PEDOGENIC CARBONATES USING SUBMICROSCOPIC TECHNIQUES

1981 ◽  
Vol 61 (2) ◽  
pp. 261-272 ◽  
Author(s):  
A. R. MERMUT ◽  
R. J. ST. ARNAUD
Keyword(s):  
Electron Probe ◽  
Size Range ◽  
X Ray Diffraction ◽  
Pedogenic Carbonate ◽  
X Ray ◽  
Pedogenic Carbonates ◽  
Layered Crystals ◽  
Magnesium Calcite ◽  
Sem Analyses

Calcitic plasmic fabric, grain calcans, neocalcitans and carbonatic glaebules with diffuse boundary were studied in situ, in soils by electron probe and SEM analyses. The occurrence of pedogenic magnesium-bearing calcite, previously detected by a shift of X-ray diffraction spacing on bulk samples, was verified by electron probes analyses on purely pedogenic carbonatic sites. This made it possible to understand further the nature of carbonates and to differentiate pure calcite from magnesium-bearing calcite. Common types of microcrystalline pedogenic carbonates included elongated, equidimensional, rod-shaped, and layered crystals. Equidimensional crystals were common in calcite, whereas elongated and rod types occurring sometimes as bundles of coalescing fibres were found to be magnesium calcite. Most visible pedogenic carbonate crystals in the soils studies had a diameter of 0.3–1.0 μm. This size range may be important in establishing relative levels of secondary carbonates in soils. Phosphorus values for studied features were higher than in the entire soil and arc evidence of precipitation of this element with pedogenic carbonates.

Volatilization of S-ethyl N,N-dipropylthiocarbamate from water and wet soil during and after flood irrigation of an alfalfa field

1980 ◽  
Vol 28 (3) ◽  
pp. 610-613 ◽  
Author(s):  
Mark M. Cliath ◽  
William F. Spencer ◽  
Walter J. Farmer ◽  
Thomas D. Shoup ◽  
Raj Grover
Keyword(s):  
Flood Irrigation ◽  
Alfalfa Field

scholarly journals Changes in Soil Organic Carbon Concentration and Stock after Forest Regeneration of Agricultural Fields in Taiwan

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1222
Author(s):  
Yi-Han Lin ◽  
Pei-Chen Lee ◽  
Oleg V. Menyailo ◽  
Chih-Hsin Cheng
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Forest Regeneration ◽  
Soil Depth ◽  
Accumulation Rate ◽  
Soil Samples ◽  
Agricultural Fields ◽  
Subtropical Climate ◽  
Accumulation Rates ◽  
Organic Carbon Concentration

Afforestation or abandonment of agricultural fields to forest regeneration is a method of sequestering carbon to offset the increasing atmospheric concentration of CO2. We selected 11 sites with altitudes ranging from 14 to 2056 m and with paired forest regenerated and adjacent agricultural fields. Our objectives were to (1) examine the changes in soil organic carbon (SOC) concentration and stock after forest regeneration of agricultural fields and (2) identify the factors related to elevation and adjacent agricultural practices that affect the SOC accumulation rate. Our results demonstrated overall increases in both SOC concentrations and stocks after forest regeneration of the abandoned agricultural fields. The average increase rates of SOC concentrations in the forest regenerated soil samples were 1.65 and 0.95 g C kg−1 at 0–10 and 10–20 cm depths, respectively, representing 101% and 65% increases relative to those in the soil samples from agricultural fields. The average accumulation rates of SOC stocks in the regenerated forests were 13.0 and 6.7 ton C ha−1 at the 0–10 and 10–20 cm depths, respectively, representing 96% and 62% increases relative to those in the agricultural soil samples. The average annual sequestration rate was 1.03 Mg C ha−1 year−1 for the top 0–20 cm soils, which is greater than that observed by previous reviews and meta-analyses. The tropical/subtropical climate, sampling soil depth, forest regeneration period, and tree species in this study are likely to have contributed to the high average SOC accumulation levels. In addition, the SOC stock accumulation rates were higher at low-elevation sites than at middle-elevation sites, which could also be attributed to the favorable climatic conditions at the low-elevation sites. Along with the build-up of carbon sequestration in the forest floor and tree biomass, the afforestation/abandonment of agricultural fields to forest regeneration appears to be a promising carbon offset mechanism.

Pedogenic carbonates and flood sediment accretion rates: a quantitative model for alluvial arid-zone lithofacies

1975 ◽  
Vol 112 (3) ◽  
pp. 257-270 ◽  
Author(s):  
M. R. Leeder
Keyword(s):  
General Model ◽  
Drainage Basin ◽  
Arid Zone ◽  
Quantitative Model ◽  
Critical Values ◽  
Sediment Accretion ◽  
Pedogenic Carbonate ◽  
Alluvial Sediments ◽  
Pedogenic Carbonates ◽  
Accretion Rates

SummaryA general model for pedogenic carbonate development in alluvial sediments is based upon of rates flood sediment accretion versus time taken for particular carbonate profiles to develop. Conclusions regarding rates of Holocene carbonate pedogenesis and the changing morphology and thicknesses of carbonate profiles with time are used to predict critical values of floodbasin accretion rates which would have enabled particular ancient profiles to develop. Local (intra-drainage basin) and regional profiles are separated and a number of models for calcrete genesis are outlined. The presence or absence of particular genetic stages of calcrete may be used as a rough guide to estimate ancient floodbasin accretion rates.

Abusive Men's Use of Children to Control Their Partners and Ex-Partners

2007 ◽  
Vol 12 (1) ◽  
pp. 54-61 ◽  
Author(s):  
Marisa L. Beeble ◽  
Deborah Bybee ◽  
Cris M. Sullivan
Keyword(s):  
United States ◽  
Intimate Partner Violence ◽  
Partner Violence ◽  
Emotional Abuse ◽  
The United States ◽  
Intimate Partner ◽  
Anecdotal Evidence ◽  
Multiple Variables ◽  
The Relationship

While research has found that millions of children in the United States are exposed to their mothers being battered, and that many are themselves abused as well, little is known about the ways in which children are used by abusers to manipulate or harm their mothers. Anecdotal evidence suggests that perpetrators use children in a variety of ways to control and harm women; however, no studies to date have empirically examined the extent of this occurring. Therefore, the current study examined the extent to which survivors of abuse experienced this, as well as the conditions under which it occurred. Interviews were conducted with 156 women who had experienced recent intimate partner violence. Each of these women had at least one child between the ages of 5 and 12. Most women (88%) reported that their assailants had used their children against them in varying ways. Multiple variables were found to be related to this occurring, including the relationship between the assailant and the children, the extent of physical and emotional abuse used by the abuser against the woman, and the assailant's court-ordered visitation status. Findings point toward the complex situational conditions by which assailants use the children of their partners or ex-partners to continue the abuse, and the need for a great deal more research in this area.

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