Changes in a Rhodic Hapludox under no-tillage and urban waste compost in the northwest of Rio Grande do Sul, Brazil

Moacir Tuzzin De Moraes,Maurício Roberto Cherubin,Reimar Carlesso,Henrique Debiasi,Renato Levien,Vanderlei Rodrigues Da Silva

doi:10.1590/s0100-06832014000400028

Abstract

The use of urban waste compost as nutrient source in agriculture has been a subject of investigation in Brazil and elsewhere, although the effects on soil physical and chemical properties and processes are still poorly known. The aim of this study was to evaluate the effect of application of urban waste compost and mineral fertilizer on soil aggregate stability and organic carbon and total nitrogen content of a Rhodic Hapludox under no-tillage in the northwestern region of Rio Grande do Sul, Brazil, in the 2009/2010 and 2010/2011 growing seasons. The experiment was arranged in a 2 × 6 (seasons and fertilization) factorial in a randomized complete block design with four replications. The factor time consisted of two growing seasons (sunflower in 2009/10 and maize in 2010/11) and the factor fertilization of five rates of urban waste compost (0, 25, 50, 75 and 100 m³ ha-1), and mineral fertilizer. Soil samples were collected from the 0.0-0.10 m layer to determine aggregate stability (mean weight and geometric diameter), soil organic carbon (SOC) and total nitrogen (TN). Rates of up to 75 m³ ha-1 of urban waste compost, after two years of application to no-tillage maize and sunflower, improved aggregation compared to mineral fertilization in a Rhodic Hapludox. After the second crop, the SOC and TN contents increased linearly with the levels of urban waste compost.

Highlights

The growth of large urban centers has led to uncontrolled increases in the generation and disposal of organic wastes, accelerating the degradation rate of natural resources
In the first year of cultivation (2009/10), the rate of 100 m3 ha-1 of urban waste compost (UWC) led to significant increases in the values of GMD and MWD compared to mineral fertilization (Table 5)
High GMD and MWD values were observed in the control treatment, which is associated with the characteristic large amount of Fe and Al oxide and Al in Oxisols (Azevedo & Bonumá, 2004)

Summary

Introduction

The growth of large urban centers has led to uncontrolled increases in the generation and disposal of organic wastes, accelerating the degradation rate of natural resources. The use of urban waste compost in agriculture allows the cycling of organic matter and nutrients (Melo et al, 2011), and helps to maintain or restore soil chemical, physical and biological properties (Kray et al, 2011; Krob et al, 2011) In this sense, several studies have addressed the changes in soil chemical properties and plant nutrition induced by the application of urban waste compost (Sampaio et al, 2010; Krob et al, 2011; Lima et al, 2011). Studies on the effects of this compost as soil conditioner are scarce in Brazil (Costa et al, 2008; Sampaio et al, 2012)

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