SOIL MOISTURE SPACE-TIME ANALYSIS TO SUPPORT IMPROVED CROP MANAGEMENT

Bruno Montoani Silva,Geraldo César De Oliveira,José Maria De Lima,Nilton Curi,Walbert Junior Reis Dos Santos,João José Marques

doi:10.1590/s1413-70542015000100005

Bruno Montoani Silva, Geraldo César De Oliveira + Show 4 more

Open Access

https://doi.org/10.1590/s1413-70542015000100005

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Abstract

The knowledge of the water content in the soil profile is essential for an efficient management of crop growth and development. This work aimed to use geostatistical techniques in a spatio-temporal study of soil moisture in an Oxisol in order to provide that information for improved crop management. Data were collected in a coffee crop area at São Roque de Minas, in the upper São Francisco River basin, MG state, Brazil. The soil moisture was measured with a multi-sensor capacitance (MCP) probe at 10-, 20-, 30-, 40-, 60- and 100-cm depths between March and December, 2010. After adjusting the spherical semivariogram model using ordinary least squares, best model, the values were interpolated by kriging in order to have a continuous surface relating depth x time (CSDT) and the soil water availability to plant (SWAP). The results allowed additional insight on the dynamics of soil water and its availability to plant, and pointed to the effects of climate on the soil water content. These results also allowed identifying when and where there was greater water consumption by the plants, and the soil layers where water was available and potentially explored by the plant root system.

Highlights

Water holding capacity of soils is due to adsorption and capillary forces, that are an expression of soil structure and electrical charges, which can be changed according to soil management (Ferreira, Fernandes; Curi,1999; Oliveira, 2004; Tormena, Silva; Libardi,1999; Silva et al, 2012a; Veiga, Reinert; Reichert, 2010; Leão et al, 2006; Bamberg et al, 2011)
The continuous surface relating depth x time (CSDT) generated by kriging showed high accuracy with alow root mean squared error (RMSE) and a high R2
The CSDT allowed additional insight on the influence of rainfall, water extraction and redistribution of water in the space-temporal dynamics of soil water content stored in the soil profile

Summary

Introduction

Water holding capacity of soils is due to adsorption and capillary forces, that are an expression of soil structure and electrical charges, which can be changed according to soil management (Ferreira, Fernandes; Curi,1999; Oliveira, 2004; Tormena, Silva; Libardi,1999; Silva et al, 2012a; Veiga, Reinert; Reichert, 2010; Leão et al, 2006; Bamberg et al, 2011). The amount of stored water in a given soil is a result of rate of rainfall, irrigation, drainage, run-off and evapotranspiration (Silva et al, 2001; Mota et al, 2010); which all change seasonally within the soil profile. These changes can be characterized using geoestatistical techniques that allow one to know the spatial distribution of soil moisture (Western et al, 2004). This soil moisture distribution is time dependent (Grego et al, 2006; Herbst; Diekkrüger2003; Hu et al.,2010; Reichert et al, 2008; Reichardt et al, 2001; Vinnikov et al, 1996; Mello et al, 2011). Based on geostatistical theory, there is no restriction to work with space and time simultaneously

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