Portable penetrometer for agricultural soil: sensitivity test to identify critical compaction depth

João Carlos Medeiros,Getulio Coutinho Figueiredo,Álvaro Luiz Mafra

doi:10.1590/s0100-06832010000600006

João Carlos Medeiros, Getulio Coutinho Figueiredo + Show 1 more

Open Access

https://doi.org/10.1590/s0100-06832010000600006

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Abstract

To express the negative effects of soil compaction, some researchers use critical values for soil mechanical strength that severely impair plant growth. The aim of this study was to identify this critical compaction depth, to test the functionality of a new, portable penetrometer developed from a spring dynamometer, and compare it to an electronic penetrometer traditionally used in compaction studies of agricultural soils. Three soils with distinct texture were conventionally tilled using a disk plow, and cultivated with different plant species. The critical soil resistance defined to establish critical compaction depth was equal to 1.5 MPa. The results of the new equipment were similar to the electronic penetrometer, indicating its viability as a tool for assessing the soil physical conditions for plant growth.

Highlights

Soil penetration resistance (PR) is one of the most commonly used indicators of soil physical quality in agronomic evaluations (Beutler et al, 2001; Pedrotti et al, 2001)
The following penetrometers were tested: (a) electronic, Falker brand, cone standardized according to ASAE (S.313.3), base diameter 12.83 mm and an angle of 30° and (b) the proposed new, portable penetrometer, Hatô brand, consisting of a spring dynamometer with two calibrated reading scales for pressure units (MPa) and for soil strength (Figure 1)
Despite the horizon with a naturally higher clay content in Hapludult soils (Embrapa, 2006), raising the density and resistance values measured by the penetrometer, no layer with pronounced texture gradient was observed in this Hapludult

Summary

Introduction

Soil penetration resistance (PR) is one of the most commonly used indicators of soil physical quality in agronomic evaluations (Beutler et al, 2001; Pedrotti et al, 2001). PR is used as an indicator of the effect of soil management systems (Tormena & Roloff, 1996; Dexter et al, 2007; Ralisch et al, 2008; Veiga et al, 2009). It is determined by the use of penetrometers, which measure the resistance of the soil to penetration related to a standardized cone (ASAE, 1999), located at the end of a metal rod, which is inserted into the soil. The drawback of these systems is the damaging effects of vehicle traffic on the experimental areas

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