Pedotransfer functions to estimate retention and availability of water in soils of the state of Santa Catarina, Brazil

André Da Costa,Rodrigo Vieira Luciano,Jackson Adriano Albuquerque,Adriano Da Costa,Jaime Antônio De Almeida

doi:10.1590/s0100-06832013000400007

André Da Costa, Rodrigo Vieira Luciano + Show 3 more

Open Access

https://doi.org/10.1590/s0100-06832013000400007

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Abstract

Studies on water retention and availability are scarce for subtropical or humid temperate climate regions of the southern hemisphere. The aims of this study were to evaluate the relations of the soil physical, chemical, and mineralogical properties with water retention and availability for the generation and validation of continuous point pedotransfer functions (PTFs) for soils of the State of Santa Catarina (SC) in the South of Brazil. Horizons of 44 profiles were sampled in areas under different cover crops and regions of SC, to determine: field capacity (FC, 10 kPa), permanent wilting point (PWP, 1,500 kPa), available water content (AW, by difference), saturated hydraulic conductivity, bulk density, aggregate stability, particle size distribution (seven classes), organic matter content, and particle density. Chemical and mineralogical properties were obtained from the literature. Spearman's rank correlation analysis and path analysis were used in the statistical analyses. The point PTFs for estimation of FC, PWP and AW were generated for the soil surface and subsurface through multiple regression analysis, followed by robust regression analysis, using two sets of predictive variables. Soils with finer texture and/or greater organic matter content retain more moisture, and organic matter is the property that mainly controls the water availability to plants in soil surface horizons. Path analysis was useful in understanding the relationships between soil properties for FC, PWP and AW. The predictive power of the generated PTFs to estimate FC and PWP was good for all horizons, while AW was best estimated by more complex models with better prediction for the surface horizons of soils in Santa Catarina.

Highlights

Water retention and availability in the soil affect plant growth and crop yield. This property depends on particle size distribution, structure, mineralogy and organic matter content, among other factors, which are quite variable in space and time (Nielsen et al, 1973; Souza et al, 2004)
Discussion of results from path analysis The Field capacity (FC) and permanent wilting point (PWP) were highly dependent on particle size distribution and on organic matter (OM) contents of the soil; soils with finer texture or with greater OM content retain greater water content
Path analysis allowed a visualization of the importance of the direct effect of OM content on water retention in the surface horizons of the soils of Santa Catarina (SC), which had a greater effect on increasing FC in comparison to PWP

Summary

Introduction

Water retention and availability in the soil affect plant growth and crop yield This property depends on particle size distribution, structure, mineralogy and organic matter content, among other factors, which are quite variable in space and time (Nielsen et al, 1973; Souza et al, 2004). In regions with a great diversity of soil types, water retention and availability vary widely among different soil areas. This relationship has been extensively studied in developed countries, especially in those with a temperate climate (Rawls et al, 1982; Wösten et al, 1999; Saxton & Rawls, 2006). In developing countries, especially with a tropical climate, studies of this kind are still fairly few (Hartemink, 2002)

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