Growth, relative chlorophyll content and concentration of inorganic solutes in sunflowers plants supplemented with marine macroalgae organic residue

Paulo Ovídio Batista De Brito,Kaio Martins,Rifandreo Monteiro Barbosa,Franklin Aragão Gondim,Julyanne Fonteles De Arruda,Pedro Bastos De Macedo Carneiro

doi:10.1590/0034-737x201865050003

Paulo Ovídio Batista De Brito, Kaio Martins + Show 4 more

Open Access

https://doi.org/10.1590/0034-737x201865050003

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Abstract

ABSTRACT One effect of the tidal dynamics is the accumulation during the low tide of large volumes of macroalgae, named “arribadas algae”. The objective of this work was to analyze the effects of using arribada alga e organic residues (AAOR) on the initial growth of sunflower plants, where the following were evaluated: plant growth, relative chlorophyll content and inorganic solids content (Na, K, Cl and NO3). The algae were collected on Praia do Pacheco in Caucaia, state of Ceará, Brazil, washed in running water and placed to dry in the sun for seven days, then dried in a forced circulation oven at 80 ºC and crushed. The sunflower seeds were sown in 5L plastic buckets, containing: 1) 100% (in volume) of sand; 2) sand + 100% of nitrogen recommendation - NR in commercial fertilizer (80kg of N.ha-1); 3) sand + 50% of the NR in macroalgae; 4) sand + 100% of NR in macroalgae; and 5) sand + 150% of the NR in macroalgae. The use of AAORimproved the growth of the analyzed variables in relation to the plants grown in substrate with sand or sand + fertilizer. The best results were observed at 50% of the NR in AAOR. The addition of increasing concentrations of AAOR allowed a greater accumulation of beneficial ions such as K and NO3 while no significant differences were observed for toxic ions such as Na and Cl in relation to plants supplemented with fertilizer or sand. The use of AAOR in substrates can be an alternative to fertilizers in plant cultivation since it reduces production costs besides being a sustainable destination.

Highlights

The production of seedlings is an important stage of the productive system; it is highly dependent on inputs
At 15 and 22 days after sowing (DAS), chlorophyll relative contents (Figure 1A) presented the greatest values for the plants in the treatment supplemented with organic algae residue (AAOR) at 150% of the nitrogen recommendation (NR)
At 15 DAS, the 150% NR in arribadasalgae organic residues (AAOR) was 18% greater than the groups at 50 and 100% of the NR in AAOR, and 80% greater than the commercial fertilizer and sand

Summary

Introduction

The production of seedlings is an important stage of the productive system; it is highly dependent on inputs. The use of renewable materials as a source of nutrients, besides being an interesting solution for waste disposal, is an alternative for reducing the high input costs required for agricultural production (Trazzi et al, 2013). The use of waste is an environmental management practice foreseen in the Brazilian National Solid Waste Policy (PNRS), Law no. The environmental aspect is added, since the use of organic residues allows the reduction in the production costs. Brazil is a country rich in marine macroalgae diversity. It has approximately 800 taxa of identified marine macroalgae. The use of this resource represents a great potential for farming (Machado et al, 2011)

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