Soil biological attributes in pastures of different ages in a crop-livestock integrated system

Luciano Cavalcante Muniz,Tarcísio Cobucci,Ilka South De Lima Cantanhêde,Beata Emöke Madari,Pedro Luiz Oliveira De Almeida Machado,José Benedito De Freitas Trovo,Aldi Fernandes De Souza França

doi:10.1590/s0100-204x2011001000021

Luciano Cavalcante Muniz, Tarcísio Cobucci + Show 5 more

Open Access

https://doi.org/10.1590/s0100-204x2011001000021

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Abstract

The objective of this work was to evaluate the effect of the pasture (Urochloa brizantha) component age on soil biological properties, in a crop-livestock integrated system. The experiment was carried out in a Brazilian savannah (Cerrado) area with 92 ha, divided into six pens of approximately 15 ha. Each pen represented a different stage of the pasture component: formation, P0; one year, P1; two years, P2; three years, P3; and final with 3.5 years, Pf. Samples were taken in the 0-10 cm soil depth. The soil biological parameters - microbial biomass carbon (MBC), microbial biomass respiration (C-CO2), metabolic quotient (qCO2), microbial quotient (q mic), and total organic carbon (TOC) - were evaluated and compared among different stages of the pasture, and between an adjacent area under native Cerrado and another area under degraded pasture (PCD). The MBC, q mic and TOC increased and qCO2 reduced under the different pasture stages. Compared to PCD, the pasture stages had higher MBC, q mic and TOC, and lower qCO2. The crop-livestock integrated system improved soil microbiological parameters and immobilized carbon in the soil in comparison to the degraded pasture.

Highlights

The conservation or improvement of soil quality is essential for a sustainable production
Microbial biomass increased according to the pasture ageing, up to P3 stage (Table 3), which had the highest values among all treatments, including the area under native vegetation (Cerrado)
According to Bayer & Mielniczuk (2008), the organic matter content of a soil under natural vegetation is in equilibrium; under agricultural use, it tends to diminish drastically, specially when intensive soil tillage is practiced combined with low levels of plant residue addition

Summary

Introduction

The conservation or improvement of soil quality is essential for a sustainable production. Among the human‐induced negative impacts on the environment, soil degradation is of main concern. Inappropriate land use can rapidly lead to organic matter depletion and, to alterations in soil physical, chemical and biological properties (Jakelaitis et al, 2008). There is a balance between soil cover and the soil physical, chemical and biological properties due to essential processes of nutrient cycling, Pesq. Conventional agricultural activities such as monoculture of grains using conventional tillage, or even improved soil management systems like no‐tillage with crop rotation, may lead to soil degradation (Denardin et al, 2008). Inappropriate pasture management frequently promotes extensive changes in soil attributes that cause, in most cases, negative environmental impact (Silva et al, 2007)

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