Water Erosion on an Oxisol under Integrated Crop-Forest Systems in a Transitional Area between the Amazon and Cerrado Biomes

Fernando Alexandre Rieger,Austeclínio Lopes De Farias Neto,Janaina Paulino,Eduardo Da Silva Matos,Ciro Augusto De Souza Magalhães,Adilson Pacheco De Souza,Cornélio Alberto Zolin

doi:10.1590/18069657rbcs20150111

Abstract

Water erosion is one of the main factors driving soil degradation, which has large economic and environmental impacts. Agricultural production systems that are able to provide soil and water conservation are of crucial importance in achieving more sustainable use of natural resources, such as soil and water. The aim of this study was to evaluate soil and water losses in different integrated production systems under natural rainfall. Experimental plots under six different land use and cover systems were established in an experimental field of Embrapa Agrossilvipastoril in Sinop, state of Mato Grosso, Brazil, in a Latossolo Vermelho-Amarelo Distrofico (Udox) with clayey texture. The treatments consisted of perennial pasture (PAS), crop-forest integration (CFI), eucalyptus plantation (EUC), soybean and corn crop succession (CRP), no ground cover (NGC), and forest (FRS). Soil losses in the treatments studied were below the soil loss limits (11.1 Mg ha-1 yr-1), with the exception of the plot under bare soil (NGC), which exhibited soil losses 30 % over the tolerance limit. Water losses on NGC, EUC, CRP, PAS, CFI and FRS were 33.8, 2.9, 2.4, 1.7, 2.4, and 0.5 % of the total rainfall during the period of study, respectively.

Highlights

Water erosion has had extensive negative impacts on soil quality throughout Brazil
To set up the experiment, soil decompaction operations were conducted to make the soil structure more uniform. After these operations, which were performed in November and December 2011, the following activities were performed, constituting the treatments used in each plot: PAS – pasture (Brachiaria brizantha cultivar Marandu); CFI – crop-forest integration, containing triple rows of the eucalyptus (Eucalyptus urograndis) clone h13 as the tree component, with a 3.5 × 3 m spacing and 30 m between rows, intercropped with soybean and corn; EUC – eucalyptus plantation (Eucalyptus urograndis, clone h13); CRP – soybean and corn crop succession; NGC – no ground cover; and FRS – forest
The values obtained for water loss ranged from 10.3 to 675.3 mm, which represented 0.5 % and 33.8 % of the rainfall accumulated in the period studied in the FRS and NGC treatments, respectively (Table 1)

Summary

Introduction

Water erosion has had extensive negative impacts on soil quality throughout Brazil. Soil tolerance to losses determines factors like magnitude of the erosion and impacts over time (Nunes et al, 2012). Determining soil losses does not restrict land use and management; it only controls the choice of the techniques to be adopted, without considering economic factors (Lombardi Neto and Bertoni (Lombardi Neto and Bertoni, 1975). Methods to estimate tolerance to soil loss by erosion are empirical as regards the definition of the weighting factors used to express the effect of each variable, which leads to different estimates of tolerance for the same soil (Bertol and Almeida, 2000)

Objectives

Methods

Results

Conclusion