Physical attributes and organic material in pastures of Brachiaria brizantha at degradation levels

Paulo Roberto Da Rocha Junior,Felipe Vaz Andrade,Fabiano De Carvalho Balieiro,Guilherme Kangussú Donagemma,Renato Ribeiro Passos

doi:10.14393/bj-v38n0a2022-54529

Paulo Roberto Da Rocha Junior, Felipe Vaz Andrade + Show 3 more

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https://doi.org/10.14393/bj-v38n0a2022-54529

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Abstract

Pastures cover, in Brazil, around 165 million ha, most of them are at some degradation level. Recovering these pastures is essential. The objective of this study was to evaluate the sensibility of soil organic matter (SOM) and its physical attributes in pasture soil at different degradation levels (1 to 4), Capoeiras (1 and 2) and secondary Forest (Control). Samples were collected at four depths (0.00-0.05, 0.05-0.10, 0.10-0.20 and 0.20-0.40 m). We verified higher values for SOM and hydraulic conductivity (Ko) in Forest, especially in the most superficial layer (0.00-0.05). We noted low values for macroporosity in this area. In all areas under Pastures lower values for Ko were observed in the superficial layer (0.00-0.05 m) when compared to layers 0.05-0.10 and 0.10-0.20 m, which indicates that the pasture management and cattle trampling negatively affect the physical quality of the pastures. For field capacity and wilting point the average values were observed in Pasture 4 (more degraded), which caused higher values for water availability. According to the principal components analysis, except for SOM at 0.20-0.40 m, all variables studied presented correlation above 0.6. From grouping analysis, we separated 3 groups: Forest; Capoeiras 1 and Capoeira 2 and Pastures 1 to 4.

Highlights

IntroductionDegradation of soil under pastures is a global problem, and in Brazil due to the unsuitable environmental conditions and management, most of these pastures are highly degraded (Zúñiga et al 2015; Perreira et al 2018; Sattler et al 2018; Calegario et al 2019)
Degradation of soil under pastures is a global problem, and in Brazil due to the unsuitable environmental conditions and management, most of these pastures are highly degraded (Zúñiga et al 2015; Perreira et al 2018; Sattler et al 2018; Calegario et al 2019).Soil degradation in these areas leads to a decrease of soil organic matter (SOM), resulting in a decrease of soil quality, reducing the ability of these areas to provide environmental services, and reducing the support capacity of these areas (Rocha Junior et al 2020)
In all areas under Pastures lower values for Ko were observed in the superficial layer (0.00-0.05 m) when compared to layers 0.05-0.10 and 0.10-0.20 m, which indicates that the pasture management and cattle trampling negatively affect the physical quality of the pastures

Summary

Introduction

Degradation of soil under pastures is a global problem, and in Brazil due to the unsuitable environmental conditions and management, most of these pastures are highly degraded (Zúñiga et al 2015; Perreira et al 2018; Sattler et al 2018; Calegario et al 2019) Soil degradation in these areas leads to a decrease of soil organic matter (SOM), resulting in a decrease of soil quality, reducing the ability of these areas to provide environmental services, and reducing the support capacity of these areas (Rocha Junior et al 2020). Pasture degradation is related to several causes, such as low soil fertility and lack of or excessive rainfall, inadequate pasture management practices and failure to establish pasture (Dias Filho 2015). Physical attributes and organic material in pastures of Brachiaria brizantha at degradation levels

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