Temporal Variation of Soil Physical Quality under Conventional and No-Till Systems

Esteban Melani,Rafael Villarreal,Carlos Germán Soracco,Luis Alberto Lozano,Guillermo Oliverio Sarli

doi:10.1590/18069657rbcs20170408

Abstract

ABSTRACT: Determination of soil physical quality (SPQ) is very important because it is related to many important soil processes. However, it is not clear which indicators should be considered in this evaluation, and information about temporal variation of SPQ under different soil tillage systems is scarce. The aim of this study was to determine the effects of no tillage (NT) and conventional tillage (CT) on temporal variation of capacity SPQ indicators [bulk density (BD), macroporosity (Pmac), air capacity (AC), plant [...]

Highlights

The aim of this study was to determine the effects of no tillage (NT) and conventional tillage (CT) on temporal variation of capacity soil physical quality (SPQ) indicators [bulk density (BD), macroporosity (Pmac), air capacity (AC), plant available water capacity (PAWC), relative field capacity (RFC), Dexter's (S), and structural stability index (SSI)], and dynamic SPQ indicators [field saturated hydraulic conductivity (K0), water-conducting macroporosity, and mesoporosity; and pore continuity indexes based on water flux of total porosity (CWTP), of macroporosity (CWmac), and of mesoporosity (Cwmes)]
Capacity SPQ indicators were derived from the soil water retention curve determined using sand box and pressure chambers, and dynamic SPQ indicators were derived from field infiltration data measured using a tension disc infiltrometer
Dynamic SPQ indicators varied differently during the growing season depending on the management system

Summary

Introduction

Assessing the soil physical quality (SPQ) of the A horizon of the soil is fundamental because soil quality determines many agronomical and environmental processes (Reynolds et al, 2002, 2009) related to crop yield.Soil physical quality has usually been evaluated through information on organic carbon (OC), bulk density (BD), and soil water retention curve (SWRC) parameters (Reynolds et al, 2002; Dexter, 2004a; Reynolds et al, 2007, 2009). A capacity parameter gives information about composition of a given soil volume; does not describe its functionality (Horn and Kutilek, 2009) In this regard, Lozano et al (2016) found that capacity indicators measured after crop harvest were not capable of distinguishing the effects of the decompaction of an Argiudoll from the Argentinean pampas region under no tillage in relation to soybean yield. Poor SPQ is related to lower crop performance (Reynolds et al, 2002, 2009) In this regard, Keller et al (2012) found that crop yield was correlated with hydraulic conductivity (K) in an agricultural field. Other authors found that NT increased plant available water capacity (PAWC) compared to conventional tillage (CT), which resulted in higher corn yield under NT in a soil from the Argentinean pampas region. Alvarez and Steinbach (2009), studying soils from the Argentinean pampas region, concluded that soybean yield was not affected by the tillage system, whereas wheat and corn yields were higher under CT than under reduced tillage and NT without nitrogen fertilization

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