Chemical attributes of soil and dry mass accumulation of maize fertilized with cassava wastewater

Adriana G Magalhães,Enio F De F E Silva,Anamaria S Duarte,Elvira M R Pedrosa,Mario M Rolim

doi:10.1590/1809-4430-eng.agric.v35n3p458-469/2015

Abstract

The aim of this study was to evaluate chemical attributes alterations of a clay-loam textured soil and dry mass accumulation of maize submitted to application of cassava wastewater doses in three assessment periods. The experiment was conducted under greenhouse using a completely randomized experimental design in a factorial 5 × 3, with four replicates. The analyzed factors of research were doses of cassava wastewater (0; 12.6; 25.2; 50.4; 75.6 m3 ha-1) andassessment periods (20, 40 and 52 days after germination). The following parameters were determined: electric conductivity of soil saturation extract, pH in water, content of available P, content of exchangeable K+, Ca2+, Mg2+ and Na+ of soil, dry mass of leaves and stem. The application of cassava wastewater on soil enables increase of pH, electric conductivity of saturation extract, contents of available P, contents of exchangeable K+ and Na+ and dry mass of leaves and stem. However, only pH and content of exchangeable K+ of soil, the electric conductivity of saturation extract and dry mass of leaves and stem are influenced by assessment period.

Highlights

Following maize and rice, cassava is the third biggest source of nutrition used in tropical and subtropical regions, consumed by approximately 600 million people, specially, those who live in Recebido pelo Conselho Editorial em: 21-11-2013Aprovado pelo Conselho Editorial em: 17-10-2014Eng
The results obtained by variance analysis of data related to chemical attributes of soil showed that studied variables were significantly influenced by application of increasing doses of cassava wastewater in soil, except the exchangeable calcium content (Table 3)
Regarding exchangeable potassium of soil (Figure 1), it is verified that application of increasing doses of cassava wastewater caused significant increase (P

Summary

Introduction

Cassava is the third biggest source of nutrition used in tropical and subtropical regions, consumed by approximately 600 million people, specially, those who live in Recebido pelo Conselho Editorial em: 21-11-2013Aprovado pelo Conselho Editorial em: 17-10-2014Eng. Cassava is the third biggest source of nutrition used in tropical and subtropical regions, consumed by approximately 600 million people, specially, those who live in Recebido pelo Conselho Editorial em: 21-11-2013. The cassava processing for production of flower and starch, according to CARDOSO et al (2009), generates solid (soil, peel and fibrous matter) and liquid (washing water and water resulting from root pressing) residues, that are rich in nutrients and, of great importance from the agricultural viewpoint, once they can be alternatives for mineral fertilizers use, reducing input costs. The cassava wastewater is a milky liquid of light- yellow coloration. It contains sugar, starch, proteins, linamarin, salts and other substances (INOUE et al, 2010; SANTOS et al, 2010). It is considered a potentially pollutant residue and toxic to the environment due to its organic load and linamarin, which is a glycoside cyanogenic, from which comes the hydrocyanic acid (HCN), that can bring serious environmental problems, such as: reduction of dissolved oxygen, eutrophication of water bodies and death of aquatic fauna (DUARTE et al, 2013)

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Results