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

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.

Macrophytes as Source of Nutrients on Initial Growth of Sunflower Plants

“…at 120 Kg N treatment showed a higher number of leaves and average of 6.8 leaves per plant, representing increase of 42 and 48% respectively when compared to sand and humus at 80 Kg N ha -1 treatments. The results were similar to those of Brito et al (2018), which proved that at 21 DAS, treatments supplemented with macrophytes residues reached an average of 7.5 leaves per plant, 36% higher than the others. According to the results found, the increase in the number of leaves, especially at 21 DAS, has proven the relevance of the macrophytes over the photosynthetic process, especially when associated to increase in leaf area (KARADOGAN and AKGÜN, 2009).…”

“…It presented an average of 3,30 mm and a growth superior to humus 80 Kg N ha -1 in 33%. Similarly, Brito et al (2018), Barbosa et al (2017) and Junior et al (2016) found, at 21 DAS, growth increments for the variable. Barbosa et al (2017) and Brito et al (2018), who studied the use of organic waste from Eichhornia crassipes and seaweed, respectively, as source of nutrients to analyze the initial growth of sunflower plants, observed increments in the diameters and heights of the plants.…”

“…Similarly, Brito et al (2018), Barbosa et al (2017) and Junior et al (2016) found, at 21 DAS, growth increments for the variable. Barbosa et al (2017) and Brito et al (2018), who studied the use of organic waste from Eichhornia crassipes and seaweed, respectively, as source of nutrients to analyze the initial growth of sunflower plants, observed increments in the diameters and heights of the plants. Souza et al (2019), using different macrophyte species, also observed increases in sunflower plant growth variables, especially with Salvinia auriculata at 150% nitrogen recommendation (NR).…”

Caracterização química, potencial antioxidante e atividade biológica de macroalgas arribadas do litoral brasileiro

“…The use of organic waste from beach-cast algae can be an alternative to fertilizing plant cultivation, besides to value a sustainable destination (Britto et al, 2018). The use of beach-cast macroalgae as alternative fertilizer has been also demonstrated to be better than commercial fertilizers in lettuce Lactuca sativa L. (Sacramento et al, 2013) and seedlings of Moringa oleifera Lam (Nova et al, 2014).…”

“…The literature of beach-cast algae in Brazil is still scarce; most studies have evaluated only the taxonomy and abundance of this biomass on different beaches for the country (Nascimento, 2010;Rios, 2010;. These studies show that Brazil has an incredible potential for this waste and underused biomass and many of them evaluate their potential use as fertilizer (Britto et al, 2018;Coelho et al, 2018). On the other hand, the potential of beach-cast macroalgae as a raw material for several applications, combined with the large quantity available on the beaches of certain regions along the Brazilian coast, should be better understanding and suitable application must be proposed.…”