Surface sealing and water erosion of soils with mulching in the semi-arid region of Brazil

Fábio F Da Silva,Edivan R De Souza,Mário M Rolim,Marcelo M Correa,Thais E M Dos S Souza

doi:10.1590/1807-1929/agriambi.v23n4p277-284

Abstract

ABSTRACT Evaluating soil sealing process of the semi-arid region of Brazil is important to describe this process and mitigate its effects. The objective of this work was to evaluate surface sealing and physical properties of the main soils of the Upper Ipanema watershed, in Pesqueira, Pernambuco state, Brazil, with the use of mulch. The experiment was conducted in a completely randomized design with three replications, using a 3 × 3 × 2 factorial arrangement consisted of three soil classes (abruptic Eutrophic Yellow Argissolo - AEYA, typical Eutrophic Fluvic Neossolo - TEFN, and typical Eutrophic Yellow Argissolo - TEYA), three application times of simulated rainfalls (at 0, 24, and 48 h), and two mulching conditions (with and without mulch), totaling 54 tests. Soil erosion rates, surface sealing, and resistance to penetration were evaluated. The use of mulch decreased significantly the soil water losses by 71.9% (AEYA), 62.9% (TEFN), and 41.1% (TEYA) after the first rainfall application (0 h) when compared to treatments without mulch, and promoted a higher water infiltration rate. The lowest soil resistance to penetration were found in soils with mulch. The AEYA and TEFN presented changes in porosity and migration of fine particles in the treatment without mulch. The TENF was the only soil that presented an incipient soil surface sealing layer in the treatment without mulch.

Highlights

Inadequate soil management practices favor the formation of surface crusts, which reduce water infiltration and favor surface runoff, making it difficult for seedlings to emerge and growth of root systems (Lima et al, 2015).Soil water erosion caused by surface runoff is more intense in areas without vegetation because the energy of the impact of raindrops disaggregates and carries soil particles more in these areas (Silva et al, 2010)
The experiment was conducted in a completely randomized design with three replications, using a 3 × 3 × 2 factorial arrangement consisted of three soil classes, three application times of simulated rainfalls, and two mulching conditions, totaling 54 tests
The formation process of soil surface sealing occurs in the first few centimeters of the soil and affects several processes related to soil structuring; this process can be observed directly due to changes in the soil morphology, or indirectly due to the decreased water infiltration capacity and increased soil surface resistance to penetration (Rosa et al, 2013)

Summary

Introduction

Soil water erosion caused by surface runoff is more intense in areas without vegetation because the energy of the impact of raindrops disaggregates and carries soil particles more in these areas (Silva et al, 2010). Soil micromorphological analyses can be used to assess changes in soil structure and porous spaces in areas under degradation process (Lima et al, 2005). These analyses can show micromorphological changes in the soil surface structure and their effects on hydraulic conductivity and on water infiltration, which are important for regions that present water shortages (Castro et al, 2006)

Objectives

Methods

Results