Terrace Soil Research Articles

Pedogenesis of Cotiga Mound, a 2100‐Year‐Old Woodland Mound in Southwest West Virginia

AbstractCotiga Mound, an Early Woodland mortuary mound constructed 2100 YBP, was sampled to evaluate diagnostic horizon development during a well‐defined, relatively short period of time. Five columns (profiles), three of which extended into the submound terrace soil, and one Giddings core of the terrace soil were sampled for particle‐size, pH, organic C, and micromorphology analysis. Six additional cores were collected to characterize the terrace soil. The mound was constructed of acid, silty material, in a manner that resulted in basketloading macrofabric consisting of long, sinuous, thin layers contrasting in color and texture. Pedogenesis destroyed the macrofabric and formed a solum in the upper 0.75 to 1.0 m of the mound. The solum consisted of a thin, dark A horizon; and intermittent, thin E horizon; and a variable B horizon. The B horizon was thickest at the mound crest, contained clay films on ped surfaces, and was designated Bt. On side slopes, the B horizon was thinner, lacked clay films, and was designated Bw. No B horizon was formed at the mound periphery. Clay distribution indices indicated that the Bt horizon was borderline cambic‐argillic, consistent with those typical of 2000‐yr‐old mid‐Atlantic alluvial soils. Clay films were sparsely distributed throughout the mound, indicating that clay accumulation mechanisms were largely inefficient in the 2100 yr. Mound soils were classified as Typic Dystrochrepts grading to Typic Hapludults at the mound crest. These soils are similar to floodplain soils mapped nearby. Submound terrace soils and adjacent terrace soils were classified as Humic Hapludults.

Effects of Recent Land‐Use Practices on Soil Nutrients and Succession under Tropical Wet Forest in Costa Rica

The effects of a variety of agricultural land uses were studied using soil nutrients, forest structure, and species assemblages as indicators. We compared soil properties and successional forests between abandoned cacao (Theobroma cacao) and abandoned palm (Bactris gasipaes) orchards, abandoned pasture, and mature forest. These sites co‐occupy an alluvial terrace soil (Andic Dystropept) at La Selva Biological Station, Costa Rica. The agricultural sites were originally cleared of most or all forest vegetation approximately 30 years ago and went into succession approximately 7 years ago. Forest structure, species composition, soil nitrogen and phosphorus pools, and nitrogen‐mineralization and nitrification rates were measured for each site. The abandoned palm orchard had lower basal area and stem density than other secondary forests of the same age. It also had significantly smaller nitrate (NaOH‐extractable) and organic phosphorus pools and significantly lower net rates of nitrogen‐mineralization and nitrification. It is evident that preserving tree cover does not necessarily maintain soil fertility. We found species richness and diversity in the secondary forests to be positively correlated with basal area at the time of abandonment.

Intraspecific variation of conifer phenolic concentration on a marine terrace soil acidity gradient; a new interpretation

Interaction between soil acidity and vegetation phenolic concentration was investigated to identify mechanisms by which forests sustain productivity on extremely acidic, infertile soils. Contrasting soils on well-preserved marine terraces of the “Ecological Staircase’ near Mendocino, CA comprise an extreme edaphic gradient. Pygmy forests of dwarf (< 5m) Mendocino cypress (Cupressus pygmaea), Bolander pine (Pinus contorta var. bolanderi), and Bishop pine (Pinus muricata) are found on the oldest, most acidic soils, and along a gradient that includes three distinct levels of soil acidity, with pH(CaCl2) ranging from 5.0 to 3.0 in the upper mineral soil and from 4.0 to 2.0 in the litter layer where fine roots are concentrated. Mature foliage was collected from five sites on this edaphic gradient. Aqueous methanol extracts of the samples were analyzed for concentrations of total phenols and condensed tannin by the Prussian blue and acidified vanillin assays, respectively. There were significant differences (p<0.05) in foliar condensed tannin and phenolic concentrations within each species and concentrations were inversely related to soil pH, approximately doubling along the gradient. Natural selection for soil-regulated variation in polyphenol concentration is interpreted in the context of plant-litter-soil interactions as an adaptation that permits these conifers to survive in extremely acidic soils. H Lambers Section editor

Long-term Application of Organic Residues to Improve Soil Properties and to Increase Crop Yield in Terrace Soil of Bangladesh

Long-term Application of Organic Residues to Improve Soil Properties and to Increase Crop Yield in Terrace Soil of Bangladesh

INFILTRATION RATE, HYDRAULIC CONDUCTIVITY AND MOISTURE RETENTION CHARACTERISTICS OF SOME SOILS OF LOWER BHAVANI PROJECT COMMAND AREA, TAMIL NADU

Five typical soil profiles under Lower Bhavani Project Command area, representing various physiographic situations were the materials for this study. Soil texture, pH, Electrical conductivity and organic carbon content etc. were influenced by physiographic units. The infiltration rate and hydraulic conductivity were high in Lithic Haplustalf and low in Typic Haplustalf and Typic Chromustert (Black clay loam soil). The study of moisture retension at variation tension indicated that upper terraced to middle terraced soils (Lithic Haplustalf, Typic Ustochrept, Typic stifluvent, Typic Haplustalf) are having low available water content compared to lower physiography Typic Chromustert.

Soil development indices of soils developed on fluvial terraces (Pen˜aranda de Bracamonte, Salamanca, Spain)

We have determined both morphological and analytical soil profile and horizon development indices for seven fluvial terrace soils of Holocene to Middle Pleistocene age in relation to the sandy gravel parent material. The relationship between age of fluvial terrace soils and morphological and chemical indices of horizons and their depth indicates two main trends: (i) as soil age increases, index values tend to increase throughout the chronosequence; (ii) the degree of differentiation between the horizons of each soil becomes progressively more evident. In the Holocene soils the rate of soil formation is rapid, decreasing in soils of Late Pleistocene age. At some 100,000 years, soils reach a state of maturity. Finally, in Middle Pleistocene soils (300,000 to 600,000 years old), evolution of these Palexeralfs is even slower. Morphological and analytical indices in all these soils undergo continuous changes throughout the chronosequence without seeming to reach a steady state.

Effect of Annual Amendments of Compost on Nitrate Leaching in Nursery Stock

Municipal solid waste (MSW) compost was applied at rates of 56 and 112 t/ha (incorporated) and 224 t/ha (mulch) to mitigate topsoil loss in nursery stock production. In two years, nitrate concentrations in ground water beneath all plots remained below 10 ppm with no significant differences between treatments.In another experiment, nitrate in ground water was measured beneath a high coductive sandy terrace soil amended with a variety of composts. In one experiment, spent mushroom compost (SMC) and chicken manure compost (CMC) were applied yearly at rates of 56 and 112 t/ha to provide all the fertilizer requirements for intensive vegetable production. Nitrate concentrations in ground water beneath all compost-amended plots remained below 10 ppm during the three-year study, while concentrations beneath the fertilized control reached 14.7 ppm in an unusually wet spring. After heavy rains, control plots were more susceptible to nitrate leaching than compost-amended plots in the first two years of the study. Th...

Late quaternary alluvial history of Nowlands Creek, Hunter Valley, NSW

SUMMARY The valley‐fill sequence of Nowlands Creek, a 5.5 km2 basin in the Central Lowlands of the Hunter Valley, is characterised by three inset river terraces whose sediments contain either Aboriginal or European artefacts. The highest and oldest terrace is characterised by a well‐developed yellow duplex soil with Aboriginal artefacts in the A horizon. Deposition of the bulk of the terrace sediments occurred before 11 400 yrs BP when Nowlands Creek was a low‐sinuosity, high‐energy, gravel‐bed stream. Texture contrast of the terrace soil is due partly to the superpositioning of Holocene sandy colluvium over Pleistocene fluviatile clay. The middle terrace is characterised by a deep minimal prairie soil containing Aboriginal artefacts. Deposition of the middle‐terrace sediments occurred mainly after 11 400 yrs BP when Nowlands Creek was a small‐capacity, mud‐bed channel with chains of ponds and well‐vegetated banks. The lowest terrace occupies a discontinuous trench incised into the middle terrace and was ...

Sustained Vegetable Production for Three Years Using Composted Animal Manures

Intensive vegetable production trials were conducted for three years at Windsor (sandy terrace soil) and Mt. Carmel Connecticut (loamy upland soil) following yearly applications of spent mushroom compost (SMC) and chicken manure compost (CMC) applied at two rates (56 or 112 t/ha) as the sole source of nutrients. Yields of seven crops from these amended plots were compared to yields from control plots fertilized with NPK fertilizer. Yields of all vegetables increased as the rate of compost increased. Average yields of tomatoes (Lycopersicon esculentum Mill.), peppers (Capsicum annuum L.), and spring and fall broccoli (Brassica oleracea L.) on all CMC-amended plots at both rates and sites in all years equaled or were greater than fertilized controls. Yields of eggplant (Solanum melongena L.) from all compost-amended plots at both sites in all years equaled or were greater than fertilized controls. Cauliflower (spring and fall) (Brassica oleracea L.) yields from CMC-amended plots (both rates) equaled or exce...

Phosphorus removal from secondary-treated wastewater using overland flow

The removal of total phosphorus from secondary effluent by overland flow was studied using five terraces constructed 91 m in length and 140 or 70 m in width. Three methods of wastewater application were tested on the terraces including sprinkler, fan nozzle, and gated pipe. In addition, three different application rates were used. Samples of applied wastewater, runoff collected at points along the terraces, effluent from each terrace, and soils were analyzed for total phosphorus over a ten-month period. Hydraulic application rate had a significant effect on the removal of total phosphorus; the removal efficiency was inversely proportional to the hydraulic application rate. However, the method of application did not have an effect on phosphorus removal. An increase in phosphorus was observed in terrace soil samples; the increase was attributed to adsorption and precipitation.

Nitrate Leaching from Compost-Amended Soils

Nitrate in ground water was measured for three years beneath a sandy terrace soil with high conductivity which had been amended yearly with spent mushroom compost (SMC) and chicken manure compost (CMC) at rates of 25 and 50 T/A. The compost provided all the fertilizer requirements for intensive vegetable production. Nitrate concentrations in ground water from beneath all compost-amended plots remained below 10 ppm during the course of the study while concentrations beneath the fertilized control climbed to 14.7 ppm in an unusually wet spring. After heavy rains, control plots were more susceptible to nitrate leaching than compost-amended plots in the first two years of the study. The overall mean of the control (4.2 ppm) was significantly higher than all the other compost-amended plots except SMC amended at 25 T/A (3.4 ppm). Nitrate concentrations in ground water from CMC plots amended at 50 T/A peaked at 9.2 ppm after three consecutive years of compost application indicating a cumulative effect in the soi...

Study on clay mineralogical characteristics of hill and terrace soils of Bangladesh.

Brown Hill Soil and five terrace soil types (Shallow Red Brown Terrace Soil, Deep Red Brown Terrace Soil, Brown Mottled Terrace Soil, Shallow Grey Terrace Soil and Deep Grey Terrace Soil) were investigated to characterize their clay mineralogical compositions as a part of the systematic studies of General Soil Types of Bangladesh. The clay of Brown Hill Soil was rich in mica and hydroxy-Al interlayered vermiculite with relatively low contents of smectite, vermiculite, kaolinite and chlorite (less than 10%). In contrast to hill soil, all five terrace soil clays examined were differentiated by the trace or very low presence of smectite and vermiculite, which were also different from the clays of previously studied calcareous and noncalcareous soils

Distribution of micronutrients in arid zone soils of Punjab and their relation with soil properties

Abstract Profile distribution was investigated for total and DTPA‐extractable Zn, Cu, Mn, and Fe in soils developed on three physiographic zones (alluvial terraces, interdunal areas, and sand dunes) in the arid zone of Punjab in northwest India. Total and DTPA‐extractable micronutrient cations were highest in soils of alluvial terraces followed by soils of interdunal areas and sand dunes. Irrespective of physiographic zone the soils did not show any pattern of depth distribution of DTPA‐extractable micronutrients. Total Zn and Mn showed accumulation in the B horizons, whereas Cu and Fe did not exhibit any specific pattern. Differences in organic carbon content and size fractions that were associated with changes in physiography had a strong influence on the micronutrient status of the soil. Based on linear coefficients of correlation, DTPA‐extractable micronutrients increased with an increase in organic carbon, cation exchange capacity, silt, and clay, and decreased with an increase in sand content, where...

Stream-terrace genesis: implications for soil development

Genesis of three distinct types of stream terraces can be understood through application of the concepts of tectonically induced downcutting, base level of erosion, complex response, threshold of critical power, diachronous and synchronous response times, and static and dynamic equilibrium. Climatic and tectonic stream terraces are major terraces below which flights of minor complex-response degradation terraces can form. These three types of terraces can be summarized by describing a downcutting-aggradation-renewed downcutting sequence for streams with gravell bedload. By tectonically induced downcutting, streams degrade to achieve and maintain a dynamic equilibrium longitudinal profile at the base level of erosion. Lateral erosion bevels bedrock beneath active channels to create major straths that are the fundamental tectonic stream-terrace landform. Aggradation events record brief reversals of long-term tectonically induced downcutting because they raise active channels. They may be considered as major (the result of climatic perturbations) or minor (the result of complex-response model types of perturbations). Climatically controlled aggradation followed by degradation leaves an aggradation surface; this type of fill-terrace tread is the fundamental climatic stream-terrace landform. Aggradation surfaces may be buried by subsequent episodes of deposition unless intervening tectonically induced downcutting is sufficient for younger aggradation surfaces to form below older surfaces. Raising of the active channel by either tectonic uplift or by climatically induced aggradation provides the vertical space for degradation terraces to form; first in alluvial fill and then in underlying bedrock along tectonically active streams. These are complex-response terraces because they result from interactions of dependent variables within a given fluvial system. Pauses in degradation to a new base level of erosion, and/or minor episodes of backfilling, lead to formation of complex-response fill-cut and strath, or of fill terraces. Fill-cut terraces are formed in alluvium; they are complex-response terraces because they are higher than the base level of erosion. Good exposures and dating are needed to distinguish static equilibrium complex-response minor strath terraces from dynamic equilibrium tectonic (major) straths. Strath terraces may be regarded as complex-response terraces where degradation rates between times terrace-tread formation exceed the long-term uplift rate for the reach based on ages and positions of tectonic terraces. Late Quaternary global climatic changes control aggradation events and even the times of cutting of major (tectonic) straths, because the base level of erosion can not be attained during times of climatically driven aggradation-degradation events. Most terrace soils form on treads of climatic and complex-response terraces. Aggradation surfaces may provide an ideal flight of terraces on which to study a soils chronosequence. Each aggradation event is recorded by a single relict soil where tectonically induced downcutting is sufficient to provide clear altitudinal separation of the terrace treads. Multiple paleosols are typical of tectonically stable regions where younger aggradation events spread alluvium over treads of older climatic terraces. Pedons on a climatic terrace in a small fluvial system commonly are roughly synchronous - variations of soil properties that can be attributed to temporal differences will be minor compared to altitudinally controlled climatic factors. Climatic terraces of adjacent watersheds also should be roughly synchronous (correlatable) - variations of soil properties that can be attributed to temporal differences will be minor compared to lithologic and climatic factors between different watersheds. Such generalizations may not apply to basins with sufficient relief that geomorphic responses to climatic changes occur at different and overlapping times, and to large rivers whose widely separated reaches are characterized by different response times to climatic perturbations. Soils on climatic terraces of distant watershedswill not be synchronous if their respective aggradation events occur during full-glacial times and interglacial times. Soils on some complex-response terraces may be diachronous within a given fluvial system, and typically are diachronous between watersheds.

Close-Interval Spatial Variability of Udertic Paleustalfs in East Central Texas

Close-interval spatial variability analysis of the Tabor soil mapping unit in Brazos County, Texas, depict a stream terrace soil with well-developed gilgai-like subsurface microhighs and microlows. Computer-generated topographic surface nets of the contact between the surface (A+E) and subsurface (Bt) show enclosed basins and ridges. Approximately 31% of the 10-m2 area studied was classified as subsurface microknolls, whereas 25% was subsurface microdepressions and the remaining 44% represented transitional zones between the subsurface highs and lows. Soil characterization of three paired pedons (six profiles), with differing epipedon thicknesses, from within the sampled grid system indicates that, despite strong morphological evidence of vertic features, only two of the three subsurface microhighs and none of the microlow profiles met coefficient of linear extensibility (COLE) and potential linear extensibility (PLE) vertic classification criteria. Extrapolation of these data to the surrounding grid, based on subsurface Bt expression, suggests that approximately half of the total area can be considered vertic by present definitions. Soils with such intermittent and discontinuous vertic conditions would more appropriately be classified as Ruptic Vertic Paleustalfs. Alternatively, it is proposed that the vertic criteria be revised to include vertic features such as slickensides, either independently or in conjunction with COLE and PLE indices, to reveal the presence of potential hazards resulting from soil-strength failure.

Steady State Flow to Drains in Terraced Multilayered Anisotropic Soils

ABSTRACT Results for steady-state water flow in layered soils with subsurface drains are presented. The soil was assumed to consist of one or more layers bounded below by an impervious barrier at an infinite depth and above by a bench terraced soil surface. Each soil layer was considered water-saturated and uniformly isotropic or anisotropic within the layer. Anisotropy was defined such that I 9^ x: where | and K are the horizontal and vertical hydraulic conductivities, respectively. The finite element method was used in the numerical solution for steady and saturated flow. Although the numerical techniques presented can handle any number of layers, results are only presented for one- and two-layered profiles. The effect of the degree of anisotropy (R) and equivalent hydraulic conductivity (K) for individual layers (where R = [|/x:]^^2 and K = [| xY^^) on drain outflow, water seepage at the soil surface and the flow within each layer was investigated. The presence of subsurface drains increased the total flow into the terraced soil surface and decreased (often eliminated) water seepage outflow from the bottom of the terraced slope. In a two-layered system, the simple effects of drain depth, degree of anisotropy, and equivalent hydraulic conductivity of the individual layers were masked by interactions of their effects. At the shallow drain depth, when the equivalent conductivities of the two layers were the same, flow increased as degree of anisotropy increased if the lower layer was anisotropic. Flow decreased as the degree of anisotropy increased if the upper layer was anisotropic. At deeper drain depths, flow tended to increase as degree of anisotropy decreased. When the lower layer was more conductive than the upper layer, flow increased significantly as the degree of anisotropy in the upper layer decreased and as drain depth increased. When the lower layer was anisotropic, flow increased as degree of anisotropy increased at shallow depths but gradually changed to decreased flow with increasing degree of anisotropy for deep drains.

A soil chronosequence in northwestern Italy: Morphological, physical and chemical characteristics

A chronosequence of soils developed on fluvial terraces dating from lower Middle Pleistocene to upper Upper Pleistocene was studied to identify the morphological, physical and chemical soil properties most sensitive to soil development and to further test the usefulness of iron oxides as indicators of relative age. A relative horizon distinctness (RHD) index and the Buntley-Westin and Hurst colour indices clearly reflected differences in soil development with age. Among physical characteristics, clay content and aggregation, obtained by comparison of clay dispersion before and after removal of cementing agents, were most efficient in indicating differences in duration of pedogenesis. Cation exchange capacity, as related to clay content, was the chemical property most useful to distinguish soils of different terraces. Iron-oxide ratios were again useful as indices of soil development.

A multivariate analysis of alluvial terrace soils of the clarendon and cranebrook formations, Nepean River, NSW

The techniques of cluster analysis and principal component analysis (PCA) were applied to soils data from two Pleistocene alluvial terraces on the Nepean River, N.S.W., the Clarendon and Cranebrook Formations, to address issues raised in the literature regarding their stratigraphic relationships. A total of 160 profiles were sampled at four fixed depths to 1 8 m. Profiles were located in four 1000 by 400 m sample areas, two on each terrace. Soil samples were analysed for colour, pH, and 2.8 M HCl extractable Fe2+, Mn2+, Na2+, K+, Ca2+ and Mg2+. Data were analysed by using whole profiles as the soil entities. One branch of the dendrogram resulting from the cluster analysis contained soil profiles exclusively from sample areas on the Cranebrook Formation, whilst the other branch contained profiles exclusively from sample areas on the Clarendon Formation. Soils typical of the Lowlands Formation, Londonderry Clay and minor subdivisions within the terraces could be distinguished on the dendrogram. Similar subdivisions could also be observed on a PCA scattergram. The Clarendon and Cranebrook Formations are complex units which contain minor terrace features. Each has a distinctly different suite of soils which is consistent with their continued designation as separate stratigraphic units. The Lowlands Formation can be separated from the Cranebrook Formation upstream of Castlereagh and the Clarendon Formation should have its southern boundary to the Londonderry Clay moved north towards Richmond and its stratigraphy redefined.

Genesis of marine terrace soils, Barbados, West Indies: Evidence from mineralogy and geochemistry

AbstractWell‐developed, clay‐rich soils dominated by interstratified kaolinite‐smectite are found on the uplifted coral reef terraces on the island of Barbados. The reef limestone is unlikely to have been the soil parent material however, because it is 98 per cent CaCO3 and geomorphic evidence argues against the 20 m of reef solution required to produce the soils by this process. The mineralogy of the sand, silt, and clay fractions of the soils, and trace element geochemistry, suggest that aeolian materials carried on the trade winds from Africa, volcanic ash from the island of St. Vincent, and quartz from Tertiary bedrock on the island itself are the parent materials for the soils.

THE AGE OF SOME HOLOCENE SOILS ON THE EAR LAKE TERRACES IN SASKATCHEWAN

Soil profiles on the lake bottom and on four successive postglacial lacustrine terraces situated on the edge of Ear Lake in west-central Saskatchewan were studied to contribute to the knowledge of processes associated with environments of soil formation since deglaciation. Detailed morphological studies and radiocarbon dates of selected horizons indicated incipient and well-developed paleosols have formed in response to progressive formation of the terraces. The ages of the paleosols revealed a possible relationship between postglacial climatic fluctuation and the formation of these terraces. Buried soils on the lower terraces meet the criteria for Solonetzic soils while surface soils of the upper terraces have Solonetzic characteristics. The study showed the presence of soils which have characteristics reflecting more than one interval of horizon differentiation and led to the suggestion that it may be erroneous to relate their properties solely to prevailing environmental conditions. Key words: 14C dates, terrace formation, soil age, Holocene soils, paleosol, Solonetzic soil