Use Of Soil Surveys Research Articles

Modelling and mapping erosion in smallholder agro‐ecosystems, Tanzania

AbstractThe West Usambara Highlands in north‐eastern Tanzania have many smallholder agro‐ecosystems with unknown composition, management, and vulnerability to erosion. Their specific locations and spatial extent are difficult to trace by satellite images or remote sensing imagery alone. To address these limitations, we combined ground soil surveys, geographic information system, and erosion modelling to (a) locate and map smallholder agro‐ecosystems, (b) determine their biophysical characteristics, and (c) model their soil losses. Land resource information was collected from 301 random 0.1‐ha plots sampled from a total area of 200 km2. Annual soil losses were estimated using the universal soil loss equation. The study located six dominant agro‐ecosystems with the following spatial extent: maize‐bean (24.9%), maize‐bean‐agroforestry (31.2%), maize‐bean‐agroforestry‐high value trees (18.9%), tree farms (7.0%), forests (15.6%), and grazing lands (2.3%). Agroforestry and other tree‐based agro‐ecosystems dominate the area due to historical land use change and later institutional interventions. This study finds combined use of soil surveys, geographic information system, and modelling to be reliable in locating, mapping, and assessing soil losses in smallholder agro‐ecosystems. The agro‐ecosystems differ significantly (p < 0.05) in slope, vegetation cover, soil conditions, and soil losses. Soil loss in the maize‐bean agro‐ecosystem (28.3 t ha−1 yr−1) was 18 times higher compared with natural forests (1.57 t ha−1 yr−1) due to lower soil cover and inefficient conservation and cultivation practices. Our results show that adoption of soil conservation measures and improved vegetation cover technologies across the agro‐ecosystems reduces soil losses by 37% and increases organic carbon levels by 16%.

The Use of Soil Surveys to Aid in Geologic Mapping with an Emphasis on the Eastern and Midwestern United States

The Use of Soil Surveys to Aid in Geologic Mapping with an Emphasis on the Eastern and Midwestern United States

Record Month for Web Soil Survey Use in March

Soil Survey HorizonsVolume 51, Issue 1 p. 2-2 Spring Soil News 2010 Record Month for Web Soil Survey Use in March First published: 04 August 2015 https://doi.org/10.2136/sh2010.1.0002Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume51, Issue1Spring 2010Pages 2-2 RelatedInformation

Soil Type and Herbicides Adsorption

Abstract Herbicides behaviour in soils greatly depends on adsorption through its influence on degradation and movement. The adsorption intensity depends on both the chemical structure of pesticides, the nature of soil constituents and soil physico-chemical factors such as the pH. In this paper, the role played by these factors is analysed and used to evaluate the possible use of soil surveys for assessing adsorption behaviour of pesticides in soils. The analysis is based on adsorption measurements of three herbicides (atrazine, terbutryn and 2,4-D) by several soils differing in their mineralogical composition, organic matter content and pH. Using statistical analysis, it is shown that some relations can be defined between soil types and adsorption behaviour. These relations are strongly dependent on the electrical state of the herbicide molecule (cationic, anionic and neutral).

Promoting the Use of Soil Survey through the Use of Improved Delivery Systems

Promoting the Use of Soil Survey through the Use of Improved Delivery Systems

Use of soil survey reports by secondary school educators in Indiana

Soil survey reports are readily available and an importnt source of soils information for each Indiana county. This information has great potential value to both rural and urban young men and women and could easily be taught in the secondary schools. Awareness, use, and attitude of Indiana secondary school agriculture and social science educators toward soil survey reports were determined using a mailed questionnaire. Results were analyzed based on teaching discipline and geographic location (urban and rural). In general, social science respondents were not aware of and did not use soil survey reports as a teaching aid, whereas agriculture respondents did. The majority of educators responded positively to statements regarding usefulness of soil surveys. No significant differences were found between urban and rural areas. Results indicated that teaching discipline was the critical factor determining educator use of soil surveys.

Soil properties and fast-growing tree species in Tanzania

This study examined growth rates and soil conditions of 11–14-year-old forest plantations and adjacent unmanaged natural forests at three climatically and geologically distinct sites in Tanzania. The sites differ markedly in growth rates, soil conditions and potential for management. At the Uluguru Forest Reserve on quartzo-feldspathic granulite and mica with average rainfall of 1058–1377 mm y −1, regenerating evergreen forest and a plantation of Acacia mearnsii have grown at 2.6–7.2 and 3.5 m 3 ha −1 y −1, respectively. At the East Chenene Forest Reserve on granite where rainfall averages 573–625 mm y −1, mature dry woodland and plantations of Cassia siamea and Eucalyptus citriodora have grown at 0.2-2.0 and 1.4-2.2 m 3 ha −1 y −1, respectively. Fertility of the acid soils at these sites depends on litterfall and organic matter decomposition, and it declines when leaching increases after forest clearing. At the Sambasha Forest Reserve on volcanic ash soils with average rainfall of 1200–1800 mm y −1, mature evergreen forest and a plantation of Cupressus lusitanica have grown at 2–9 and up to 15 m 3 ha −1 y −1, respectively. Soil fertility here is much less dependent on organic matter additions. In forest management where neither fertilizer nor irrigation is used, inherent soil fertility has a marked effect on growth. Growth rates in this study are related to rainfall and soil nutrient status at each site, with the fastest growth occurring on wet, recent volcanic soil (Sambasha). The slowest growth was measured at the dry site (East Chenene) where soils are developed from nutrient-poor acid rock. At their present slow rates of growth, plantations will not make a significant contribution in the near future to alleviating deforestation and related scarcity of forest products in semiarid regions of Tanzania. Four actions are urgently needed: (1) identification of the best sites for tree plantations; (2) identification of the most promising exotic and indigenous species; (3) identification of the constraints on growth of promising species; and (4) formulation of economically and physically feasible management techniques to overcome constraints to growth. These can be achieved through increased use of soil surveys; establishment of comparative field trials with varying site/species combinations; recognition of the limited potential of species that require intensive management by local people; and exploitation of the inherent advantages of indigenous species.

Land resources of the world; their use and reserves. Definition of land quality and agricultural potential by soil survey maps

The author discusses the use of soil survey maps to define the existing quality and agricultural potential of the world's land. He describes the pioneer work in this field by Russian scientists at the turn of the century and its subsequent continuation in the U.S.S.R., and the recent work by FAO-UNESCO in Russia, America and elsewhere. He also shows how soil types and their agricultural potential may be classified, and urges that existing soil maps should be brought up to date and amplified by including new data obtained through satellite survey techniques. He recommends that the maps produced at various times, by various agencies, should be analysed and collated by computer to assemble the most detailed information possible on the world's soils and their agricultural potential and to provide a universal system of classification. It is already clear that much land is under-cultivated; but the author points out that to bring such land to its full potential would demand immense work and investment.

The Use of Soil Survey and Classification in the Planning of Land Use and the Problem of It

The Use of Soil Survey and Classification in the Planning of Land Use and the Problem of It

Use of Soil Survey of England and Wales data bank (1950–1973) to summarize and establish relations between soil analyses, observed gley status and lithological contribution

SummaryA statistical analysis is presented of published laboratory data on 4407 soil horizon samples collected by the Soil Survey of England and Wales during 1950–73, to typify soil taxa. Seventy-five percent of the profiles have fine textured parent materials in both calcareous and non-calcareous categories. Moderate to large increases in clay content down the profile, which could indicate argillio horizons, are found in 56% of the profiles but the influence of lithological discontinuities has not been eliminated. Argillic horizons are commonest on calcareous or low grade metamorphic rocks and non-calcareous clayey or silty sediments. Less than half the average frequency of clay increase between middle and bottom horizons is shown in the igneous and high grade metamorphic lithological type.pH gradient down the profile is not clearly related to altitude. The pH change (0·7) between top and bottom horizons in profiles from calcareous and igneous parent materials is twice as great as in other non-calcareous profiles. There is usually less clay in the top horizons than in others; the top horizon contains more than 35% clay about half as frequently as the lower horizons. Clay content categories have closely similar frequency in middle and bottom horizons. Gleying in horizon 1 is observed somewhat less frequently with increasing CaCO3. No consistent trend is found in the other horizons. Soil pH in 0·01 M-CaCl2 (pH8) is between 5·1 and 7·0 in 51% of all samples. pH5, values less than 4 occur in only 8% and are twice as common in top horizons (more than 5 cm thick) as in deeper ones. pH8, values greater than 7 are nearly twice as frequent (31%) in the bottom horizon as in the upper ones. Correlation of pH in water (pHw) with pH8 always exceeds 0·93 irrespective of lithological type. The difference of pHw from pH8 (δpH) calculated from the regression equation is 0·7–0·8 at pH6 values less than 4; it varies inversely with pH8, up to a value of 0·4–0·5 at pH6 greater than 7. Neutrality (pHw, 7) corresponds to pH8 6·5–6·6. There is no indication that δpH is related to altitude or gleying intensity but it varies according to lithological type by about 0·1 unit. Organic-matter content, as indicated by loss on ignition (950 °C) minus 10% of the measured clay percentage (LOIadj%) is little affected by lithological type; decrease with depth is steeper at pH8 less than 4 than at higher pH. Gleyed top horizons contain more organic matter than ungleyed; gradient down the profile is positively related to gleying intensity.The overall multiple regression of cation exchange capacity (CEC) on clay percentage and organic matter (LOIadj%) is (CEC = 1·21 + 0·40 clay% + 1·32 LOIadj), accounting for 61·4% of the total variance. When lithological types are considered separately the partial regression coefficients for clay percentages are greater in the two calcareous lithological types than in the non-calcareous. With lithological type 5 the large constant term and small coefficient of clay percentage indicate considerable contribution to CEC from particles or aggregates larger than 2 μm. Partial regression coefficients (lithological types 1–4 taken together), although similar both within horizon and within gley category are nevertheless shown to be significantly different. Within pH8 category, both partial regression coefficients increase directly with pH. Calculation of mean values of CEC on a clay basis for horizon 3, where contribution from organic matter is minimal, does not show significant differences between pH8 categories or gley categories.Although quantification of relationships has been possible, correlations are rarely high, so that predictive power is limited. Availability of soil group or subgroup categorizations using constant definitions based on objective measurements is suggested as a useful way of increasing predictive power within resulting smaller groups. The calculation of geographic (areal) distribution is probably the most useful purpose of a data bank of routine measurements, but the selection of samples to typify soil taxa used in this study would preclude such a use.

Use of Soil Survey for Assessing Agricultural Land

Use of Soil Survey for Assessing Agricultural Land

Soil surveys — their value and use to communities in Massachusetts

For many decades, the study and mapping of soils in Massachusetts has primarily been related to farming with little or no attention given to other uses. About 1960 important changes in the use of soil surveys occurred in the state. Planners and communities drastically increased their demand for soil surveys and, particularly, for nonagricultural soil interpretations. Towns and cities have contributed $1/2 million since 1962 to accelerate soil surveys and have received special soil reports for operational planning. They have saved millions of dollars through the use of soil survey information. A number of examples are cited indicating the use and value of soil data to planners and communities.

The Use of Soil Survey Information in an Area of Rapid Urban Development

AbstractUrban, as well as rural planning, are necessarily influenced by certain soil properties such as drainage, permeability, type of parent material, soil texture, and depth to bed rock, water table, or an indurated horizon. These properties affect both sanitary measures and development costs. Information concerning soil characteristics of an area is contained in, or can be interpreted from, a soil survey map and report.The Fairfax County (Virginia) soil survey is being made largely because of requests from the Fairfax County Planning Commission, a commercial planning firm, and a real estate agent. Local funds are made available to the Virginia Agricultural Experiment Station to defray a part of the costs. The Planning Commission and the commercial planning firm consider soil survey information vital for preparing an overall or master plan for Fairfax County. They feel that it is especially useful in zoning, planning septic tank sewage disposal systems, and agricultural planning, and that the same information is also useful in planning highways, recreational areas, and in arriving at equitable tax adjustments. If this survey meets their expectations in helping them answer questions related to rural and urban planning, it may lead to increased future demands for soil surveys.It is desirable that persons trained in soil classification, management, and interpretation assist the various users of soil surveys. This assistance can be provided by personal consultation and carefully prepared descriptive legends and reports to accompany the map. The reports should include examples of how soils can be grouped for special purposes.The expanding use of soil surveys presents a challenge to the soil scientist. It emphasizes the need for adequate classification of soils, closer field observations, improved field techniques, basic research, and careful interpretation of data.