Comparison of pedotransfer functions to estimate the van Genuchten parameters from soil survey information

2013 ◽  
Vol 62 (1) ◽  
pp. 5-22 ◽  
Author(s):  
Brigitta Tóth ◽  
András Makó ◽  
Gergely Tóth ◽  
Csilla Farkas ◽  
Kálmán Rajkai
Keyword(s):  
Soil Survey ◽  
Pedotransfer Functions

Kutatásunk célja a víztartóképesség-függvény (VKF) paramétereit az átnézetes térképeink adattartalmával becslő módszerek megbízhatóságának összehasonlítása és továbbfejlesztésük vizsgálata a Magyarországi Részletes Talajfizikai és Hidrológiai Adatbázison (MARTHA).Az irodalomban fellehető módszerek közül VKF-becslő módszert hazai átnézetes talajtérképi információkra eddig egyedül a Kreybig térképekre alkalmazták (Bakacsi et al., 2012). Ők a talaj higroszkópossága (hy) alapján becsülték adott talaj FAO (1995) fizikai féleség kategóriába tartozását. Wösten és munkatársai (1999) és Nemes (2003) pedotranszfer-függvényei alapján rendelték továbbá a talajhoz a fizikai féleség kategóriára meghatározott víztartóképesség-függvény (VKF) van Genuchten paramétereit (HYPRES_hy és HUNSODA_hy módszerek).Bakacsi és munkatársai (2012) eljárását követve, a MARTHA adatbázison vizsgáltuk a hy és az ötkategóriás FAO fizikai féleség kapcsolatát. A fizikai féleség becslését az Arany-féle kötöttség (KA) alapján is kidolgoztuk.Wösten és munkatársai (1999) módszerével meghatároztuk a MARTHA adatbázis talajainak a FAO fizikai féleség kategóriákra jellemző víztartóképességfüggvényeinek van Genuchten paramétereit. A meghatározást a pF6,2 értéken felül a legalább három, majd a legalább öt mért víztartóképesség-értékű talajmintákon végeztük.Megállapítottuk, hogy a KA alapján hatékonyabb a talajminták FAO fizikai féleség kategóriába sorolása, mint a hy alapján.Abban az esetben, amikor nem áll rendelkezésre mechanikai összetétel és a fizikai féleség kategóriába történő besorolást a talaj higroszkópossága alapján végezzük, akkor a VKF-becslés megbízhatósága szignifikánsan rosszabb. Hazai talajmintákon vizsgálva a MARTHA adatbázison pontosított VKF-becslő módszerek szignifikánsan megbízhatóbbak a HYPRES és HUNSODA VKF-becslő módszereinél. A hy-ból kiinduló MARTHA VKF-becslések annak ellenére szignifikánsan megbízhatóbbak a WÖSTEN és munkatársai (1999) módszerénél (HYPRES), hogy utóbbit nem rontja a fizikai féleségbe sorolás hibája.A dolgozat az EU FP7/2007-2013 (Nr. 263188) MyWater és a TÁMOP-4.2.2.A-11/1/KONV-2012-0064 projekt keretében készült. A TÁMOP projekt az Európai Unió támogatásával, az Európai Szociális Alap társfinanszírozásával valósul meg.

Using genetic programming to transform from Australian to USDA/FAO soil particle-size classification system

Soil Research ◽  
2012 ◽  
Vol 50 (6) ◽  
pp. 443 ◽  
Author(s):  
José Padarian ◽  
Budiman Minasny ◽  
Alex McBratney
Keyword(s):  
Particle Size ◽  
Genetic Programming ◽  
Classification Systems ◽  
Soil Survey ◽  
Pedotransfer Functions ◽  
Programming Technique ◽  
Size Classification ◽  
The Difference ◽  
Prior Models ◽  
Australian Soil

The difference between the International (adopted by Australia) and the USDA/FAO particle-size classification systems is the limit between silt and sand fractions (20 μm for the International and 50 µm for the USDA/FAO). In order to work with pedotransfer functions generated under the USDA/FAO system with Australian soil survey data, a conversion should be attempted. The aim of this work is to improve prior models using larger datasets and a genetic programming technique, in the form of a symbolic regression. The 2–50 µm fraction was predicted using a USDA dataset which included both particle-size classification systems. The presented model reduced the root mean square error (%) by 14.96 and 23.62% (IGBP-DIS dataset and Australian dataset, respectively), compared with the previous model.

Prediction of three key hydraulic properties in a soil survey of a small forested catchment

Soil Research ◽  
2002 ◽  
Vol 40 (2) ◽  
pp. 191 ◽  
Author(s):  
D. A. O'Connell ◽  
P. J. Ryan
Keyword(s):  
Hydraulic Conductivity ◽  
Water Content ◽  
Bulk Density ◽  
Hydraulic Properties ◽  
Saturated Hydraulic Conductivity ◽  
Soil Survey ◽  
Coarse Grained ◽  
Pedotransfer Functions ◽  
Explanatory Variables ◽  
Tree Models

Direct measurement of ψ(θ) and K(θ) relationships at all observation sites in soil survey is not feasible. Three key hydraulic properties — water content at field capacity (θ–5 kPa), water content at wilting point (θ–1.5 MPa), and saturated hydraulic conductivity (Ks) — can be used to derive K(θ) and ψ(θ) when combined with bulk density. These properties were measured in 'calibration' horizons in a soil survey in Yambulla State Forest in south-east New South Wales. Pedotransfer functions (PTFs) for predicting θ-5 kPa, θ–1.5 MPa, and Ks from the physical and morphologic soil attributes are presented and evaluated here. Models for predicting θ–5 kPa and θ–1.5 MPa relied on per cent clay. An R2 of 0.64 (for θ–5 kPa) to 0.67 (for θ–1.5 MPa) was obtained for linear regressions using only morphologic explanatory variables. An R2 of 0.73 (for θ–5 kPa) to 0.90 (for θ–1.5 MPa) was obtained if laboratory-measured clay content was included as an explanatory variable. Ks was measured in situ using well permeameters, and used for developing PTFs. Large cores were taken from a small subsample of horizons and measurements of Ks, K–0.1 kPa, K–0.2 kPa, and K–0.5 kPa were made in the laboratory. Ks measurements from well permeameters were similar to K-0.5 kPa from laboratory measurements. Regression and tree models were used to predict Ks. The linear regression had an R2 of 0.55, while the tree models accounted for approximately 40% reduction in deviance. Bulk density was the most useful predictor in all Ks models. The inclusion of per cent rock fragments, bulk density, and estimated percentage clay as useful explanatory variables demonstrated the utility of functional descriptors not routinely measured in soil survey. The models are empirical and were locally calibrated for use in a soil survey. They may be applicable in target domains similar to the source domain (i.e. coarse-grained adamellite soils in similar climatic regimes). surrogates, saturated hydraulic conductivity, K(θ), ψ(θ), Ks, pedotransfer functions, soil survey, soil morphology, PTF.

scholarly journals Predicting Soil Cation Exchange Capacity in Entisols with Divergent Textural Classes: The Case of Northern Sudan Soils

2021 ◽  
Vol 14 ◽  
pp. 117862212110423
Author(s):  
Mutwakil Adam ◽  
Ibrahim Ibrahim ◽  
Magboul Sulieman ◽  
Mojtaba Zeraatpisheh ◽  
Gaurav Mishra ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Regression Models ◽  
Soil Depth ◽  
Exchange Capacity ◽  
Soil Survey ◽  
Pedotransfer Functions ◽  
Coefficient Of Determination ◽  
Silty Clay ◽  
Environmental Models

Cation exchange capacity (CEC) is an important soil property because it affects the assimilation of nutrients and buffers against soil acidification. Thus, knowledge of CEC is considered key to developing agricultural and environmental models for land management planning. However, in developing countries such as Sudan, there is a lack of soil CEC data due to the absence of research projects and funding to develop this information. Therefore, this research was conducted to predict CEC for large areas using specific soil physical characteristics, including soil texture and saturation percentage (SP), for which there is potentially available data. To achieve this goal, the properties of 430 soil samples (301 for training and 129 for validation) were obtained from the soil database of the Soil Survey Administration, Ministry of Agriculture, Sudan, which had different soil depth intervals (0–0.3 m, 0.3–0.6 m, 0.6–0.9 m, 0.9–1.5 m, and >1.5 m) from Entisols in the Northern State of Sudan. The data were stratified into homogeneous groups based on the textural classes of the main soil order. Then, regression models were performed and evaluated using the coefficient of determination ( R2), standard error of the estimate (SEE), and root mean square error (RMSE). The results indicated that in individual Entisols and textural classes, the combined soil covariates silt, clay, and SP were the best properties to predict CEC values ( R2 ranged from 0.86 to 0.99). The regression models did not provide statistically significant results for the silty clay loam textural class ( R2 ranged from 0.01 and 0.35). The findings of this modeling study could be applied to other Entisols worldwide with divergent textural classes, which could be used to verify the suggested CEC pedotransfer functions and/or improve them. This would help farmers correctly design soil management plans and prevent acidification issues if combined with other soil properties data.

scholarly journals PEDOTRANSFER FUNCTIONS FOR WATER RETENTION IN THE MAIN SOILS FROM THE BRAZILIAN COASTAL PLAINS

2015 ◽  
Vol 39 (4) ◽  
pp. 331-338 ◽  
Author(s):  
Elidiane da Silva ◽  
Nilton Curi ◽  
Mozart Martins Ferreira ◽  
Margarete Marin Lordelo Volpato ◽  
Walbert Júnior Reis dos Santos ◽  
...  
Keyword(s):  
Water Retention ◽  
Direct Determination ◽  
Field Capacity ◽  
Soil Survey ◽  
Pedotransfer Functions ◽  
Coastal Plains ◽  
Soil Class ◽  
R Language ◽  
Wilting Point ◽  
Selection Of

Pedotransfer functions (PTFs) are equations used to estimate soil characteristics difficult to determine from other easily obtained ones. Water retention in soil is used in several agronomic and environmental applications, but its direct determination is time consuming and onerous, therefore PTFs are alternatives to obtaining this information more quickly and economically. The aims of this study were to generate a database and develop PTFs for water retention at potentials of -33 kPa (field capacity) and -1500 kPa (permanent wilting point) for Yellow Argisol and Yellow Latosol from the Brazilian Coastal Plains region. The Coastal Plains soils are mostly developed from Barreiras formation (pre-weathered sediments) and their main uses are sugarcane, livestock, forestry and fruticulture. The database to generate the PTFs was composed from the selection of information derived from scientific works and soil survey reports of the region. Specific PTFs were generated for each soil class, in their respective A and B horizons and for solum, through multiple regression by stepwise package of R language programming. Due to the small pedological variability (small number of soil classes containing great geographical expression) and mineralogical uniformity, usually observed in this environment, non-stratification of soil classes to create general PTFs presented similar or superior results compared to equations for each soil class. The adjustment of data demonstrated that water retention values at -33 kPa and -1500 kPa potentials can be estimated with adequate accuracy for the main soils of the Brazilian Coastal Plains through PTFs mainly from particle size distribution and secondarily from organic matter data.

Pedotransfer functions for estimating soil bulk density from existing soil survey reports in Brazil

Geoderma ◽  
2007 ◽  
Vol 139 (1-2) ◽  
pp. 90-97 ◽  
Author(s):  
Vinícius M. Benites ◽  
Pedro L.O.A. Machado ◽  
Elaine C.C. Fidalgo ◽  
Maurício R. Coelho ◽  
Beáta E. Madari
Keyword(s):  
Bulk Density ◽  
Soil Bulk Density ◽  
Soil Survey ◽  
Pedotransfer Functions

The use of Soil survey

1907 ◽  
Vol 64 (1657supp) ◽  
pp. 221-222
Author(s):  
J. A. Bonsteel
Keyword(s):  
Soil Survey

THE CLASSIFICATION OF LAND ACCORDING TO THE DEGREE OF RABBIT INFESTATION IN CENTRAL OTAGO

1987 ◽  
pp. 65-70
Author(s):  
I.G.C. Kerr ◽  
J.M. Williams ◽  
W.D. Ross ◽  
J.M. Pollard
Keyword(s):  
Carrying Capacity ◽  
Mediterranean Climate ◽  
Natural Habitat ◽  
Public Funding ◽  
Soil Survey ◽  
European Rabbit ◽  
Cultural Modification ◽  
Classification Information ◽  
Semi Arid

The European rabbit (Oryctolagus cuniculus) introduced into New Zealand in the 183Os, has consistently flourished in Central Otago, the upper Waitaki, and inland Marlborough, all areas of mediterranean climate. It has proved difficult to manage in these habitats. The 'rabbit problem' is largely confined to 105,000 ha of low producing land mostly in semi arid areas of Central Otago. No field scale modifications of the natural habitat have been successful in limiting rabbit numbers. The costs of control exceed the revenue from the land and continued public funding for control operations appears necessary. A system for classifying land according to the degree of rabbit proneness is described. Soil survey and land classification information for Central Otago is related to the distribution and density of rabbits. This intormation can be used as a basis for defining rabbit carrying capacity and consequent land use constraints and management needs. It is concluded that the natural rabbit carrying capacity of land can be defined by reference to soil survey information and cultural modification to the natural vegetation. Classification of land according to rabbit proneness is proposed as a means of identifying the need for, and allocation of, public funding tor rabbit management. Keywords: Rabbit habitat, rabbit proneness, use of rabbit prone land.

Developing a useful interim soil survey report

1985 ◽  
Vol 14 (2) ◽  
pp. 69-72
Author(s):  
A. Goldin ◽  
E. Hoerauf
Keyword(s):  
Soil Survey ◽  
Survey Report
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