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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Publications at this Location » Publication #302365
Title: A hydrophysical database to develop pedotransfer functions for Brazilian soils: challenges and perspectives

Author
item OTTONI, MARTA VASCONCEL - CPRM - SERVIÇO GEOLÓGICO DO BRASIL
item LOPES-ASSAD, M.L.R.C. - UNIVERSIDADE FEDERAL DE SAO CARLOS
item Pachepsky, Yakov
item ROTUNNO FILHO, OTTO CORREA - FEDERAL UNIVERSITY - BRAZIL

Submitted to: Application of Soil Physics in Environmental analyses: measuring, modelling and data integration
Publication Type: Book / Chapter
Publication Acceptance Date: 7/5/2014
Publication Date: 8/27/2014
Citation: Ottoni, M.O., Lopes-Assad, M., Pachepsky, Y.A., Rotunno Filho, O. 2014. A hydrophysical database to develop pedotransfer functions for Brazilian soils: challenges and perspectives. In Application of Soil Physics in Environmental analyses: measuring modelling and data integration. (pp. 467-494). Springer International Publishing.

Interpretive Summary: Knowing the ability of soil to retain and conduct water is critical in a multitude of agronomical and environmental projects. Measuring soil water retention and conductivity is extremely time- and resource-consuming. Consequently, it is a common practice to estimate soil water retention and soil hydraulic conductivity using more easily obtainable soil properties, such as particle size distribution or organic matter content; mathematical equations for such estimation are called pedotransfer functions, or PTFs. Useful PTFs have been developed from databases at the continental scale for the USA, Europe, and China. The purpose of this work was to assess the availability of data to establish PTFs for Brazil. We found more data, and of a higher quality, for Brazil than exists for Europe or China. The prospects for developing Brazilian PTFs are good; these PTFs may also be applicable in other tropical regions currently lacking PTFs. This work will be useful in environmental modeling at different scales in that it catalogs availability, geographic distribution, sources, and measurement methods of the soil data source of planetary importance.

Technical Abstract: Access to soil hydrological data is vital for hydrology projects and for supporting decision-making in issues related to the availability of food and water and the forecasting of phenomena related to soil surface stability. Brazil is a country of continental dimensions and has accumulated a significant body of soil information, holding a prominent position in tropical soil science. Nevertheless, a database with hydrophysical information on Brazilian soils has not been compiled so far, whereas much information is registered and analyzed. In this study we discuss the potential for the development of a Brazilian hydrophysical database and pedotransfer functions (PTFs). We elaborated a metadata describing the measuring methods of soil hydrophysical attributes and presenting the characteristics of the sites where these soil properties were determined. Statistical analyses were performed to characterize the dataset according to the metadata-based data structure. A total of 8,725 data (not considering replicates) contained soil water retention information associated with physical or chemical properties. Besides these, 1,253 data on saturated hydraulic conductivity together with water retention information were also available. Only 30 data were found containing information of unsaturated hydraulic conductivity. The results of this study suggest that it is possible to develop a representative hydrophysical database for Brazilian soils that covers most of Brazil’s federative states, with a substantial volume of data and homogeneous with respect to the methods of measuring soil properties. This creates excellent perspectives for PTFs development, especially for estimating water retention, on a national scale. Some limitations, however, were observed in relation to the data inventoried in this study, including the absence of data quality information. The challenge in the development of the Brazilian soil hydrophysical database seems to be to refine a data model that can encompass the wide range of available information and can provide answers to queries of interest to different types of users of soil information. Considering the size of the Brazilian territory, it would be of interest that the database development become a joint effort of government agencies, universities and commercial enterprises.