Correlations of soybean yield with soil porosity and bulk density of an Oxisol

Rafael Montanari,Diego Dos Santos Pereira,Flávio Carlos Dalchiavon,Christtiane Fernandes Oliveira,Sérgio Ricardo Lima Negro

doi:10.1590/1983-40632018v4852654

Abstract

ABSTRACT The spatial variability of soil physical attributes is important to indicate management practices that best suit agricultural areas. This study aimed to analyze spatial correlations between soybean grain yield and soil mass-volume relationships, in order to select which attribute is correlated with yield, as well as to evaluate the spatial variability of soil attributes and yield components of this crop, in an Oxisol under no-tillage system. The soil attributes analyzed (0.0-0.10 m and 0.10-0.20 m) were the following ones: soil bulk density (paraffin-coated clod and volumetric ring methods), particle density (volumetric flask and modified volumetric flask methods) and total porosity. The soybean yield components were evaluated as it follows: grain yield, number of pods per plant, number of grains per pod, mass of 100 grains, grain mass per plant, plant population and plant height. The total soil porosity, calculated by the relations between the bulk density (volumetric ring method) and particle density (volumetric flask), in the 0.10-0.20 m layer, was the best indicator of soybean grain yield under no-tillage conditions.

Highlights

The biomass production in an agricultural ecosystem depends, in principle, on environmental factors such as solar radiation, CO2, climate, water and soil nutrients for the photosynthesis process
The values determined for number of pods per plant, number of grains per pod, grain mass per plant and plant population agreed with the magnitude of those obtained by Dalchiavon et al (2011), except for grain yield, which showed an average variability of the data (19.9 %) and the aforementioned high variability (21.8 %)
The total soil porosity (TP2) calculated by the soil bulk density determined by the volumetric ring method (BD2) and the particle density determined by the volumetric flask method (PD2) were the most promising indicators of grain yield; 2

Summary

Introduction

The biomass production in an agricultural ecosystem depends, in principle, on environmental factors such as solar radiation, CO2, climate, water and soil nutrients for the photosynthesis process. The physical characteristics of the ecosystem and the interaction between ecological factors (geology, relief, hydrography, climate, soils and vegetation) determine the potentialities, fragilities and limitations of each environment, and should be considered for a sustainable biomass production. This means that the farther the agricultural ecosystem is from its natural state, the more dependent a sustainable production will be on human management actions. Universidade Estadual Paulista, Departamento de Fitosssanidade, Engenharia Rural e Solos, Ilha Solteira, SP, Brasil

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Conclusion