RESPONSE FUNCTION FOR THE SRELATIVE INDEX IN CAMBISOL TREATED WITH AND WITHOUT BOVINE LIQUID BIOFERTILIZER

Thiago Leite De Alencar,Arilene Franklin Chaves,Jaedson Cláudio Anunciato Mota,Luis Felipe Rodrigues De Aquino Sousa

doi:10.1590/1983-21252018v31n223rc

Thiago Leite De Alencar, Arilene Franklin Chaves + Show 2 more

Open Access

https://doi.org/10.1590/1983-21252018v31n223rc

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Journal: Revista Caatinga	Publication Date: Jun 1, 2018
License type: cc-by

Affiliation: Universidade Federal do Ceará

Abstract

ABSTRACT The present study aimed at assessing the influence of physical properties associated with soil structure on the Srelative index. Two soil conditions under Ficus carica L. cultivation were studied (with or without liquid bovine biofertilizer in the irrigation water), in the 0-0.1 m and 0-0.3 m layers. Disturbed and undisturbed soil samples were collected from the above-mentioned layers and physical analyzes, pertinent to the study objective, were performed. The response function model was applied to verify how the soil independent physical variables influence on the Srelative index in the 0-0.1 m and 0-0.3 m layers, with 0 and 60% biofertilizer, being combined two to two. Once the response functions were known, the slopes of both functions were compared, being represented by the coefficients β11-β12 and β21-β22. This comparison enabled verifying whether there was an effect of the treatments on the response variable. In addition, the standard error of the difference between coefficients was calculated, and the Student's t-test applied. The method of multiple regression was also used to confirm the effect of the variables on the Srelative index for the 0-0.3 m layer in both treatments. Then, the variables with greater weight were selected by a backward elimination method to estimate the Srelative. The results showed that the Srelative index is strongly influenced by properties of the porous fraction, with total porosity and continuity of pores being of significant influence. Management with liquid bovine biofertilizer results in improvement in the soil structure, with effects measured by the Srelative index.

Highlights

Soil physical quality is designated as its ability to meet the demands of plants and ecosystems for water flows, gas and heat, as well as its capacity to resist and recover from a process by which such ability could be reduced (MCKENZIE; TISDALL; VANCE, 2014).In degraded soils, the addition of organic material such as liquid bovine biofertilizer has been an anthropic action to improve the functional performance of agricultural systems
Assis Júnior et al (2016) presented an assessment index for soil structure (Srelative), which derived from the S index proposed by Dexter (2004)
A hose was adapted to the lid and its other end was immersed in a container with water at a height of 0.20 m for gas output

Summary

Introduction

The addition of organic material such as liquid bovine biofertilizer (organic waste from biodigestion) has been an anthropic action to improve the functional performance of agricultural systems. Such use has improved the soil quality in addition to providing nutrients, acting as a cementing agent between soil particles and improving some soil properties related to the its structure, especially density and resistance to penetration (ALENCAR et al, 2015; KITAMURA et al, 2008; RAUBER et al, 2012). Assis Júnior et al (2016) presented an assessment index for soil structure (Srelative), which derived from the S index proposed by Dexter (2004)

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Results