Composted sewage sludge as an alternative substrate for forest seedlings production

Abstract

The production of forest seedlings with adequate morphological and physiological characteristics is essential for the success of plantations. Substrates and irrigation are the major factors determining seedlings' growth. Substrates made of urban and agricultural residues are a sustainable alternative to peatbased substrates. In this study, we evaluated how composted sewage sludge substrates affect the growth and gas exchange in seedlings of Cedrela fissilis Vell. Seedlings were produced under daily irrigation depths of 6, 9, and 12 mm, and on different substrates. The substrates were based on sewage sludge composted with Eucalyptus bark or sugarcane bagasse, and a commercial substrate based on peat, involving a double factorial design with 12 treatments (3 irrigation depths × 3 substrates). Both physical and chemical characteristics of substrates were analyzed, and morphological traits and gas exchanges of seedlings were measured. Sewage sludge-based substrates presented different characteristics according to the material it was mixed. Eucalyptus bark provided higher bulk density (0.19 g cm -3 ) and lower total porosity (75%) to the substrate, while sugarcane bagasse increased macroporosity up to 60%. Seedlings produced in sewage sludge-based substrates presented a height up to 17.8 cm and stem diameters of between 8.39-10.29 mm. Higher shoot and root dry mass was obtained in sewage sludge-based substrates with irrigation depth of 9 mm, which were 3.71 and 2.01 g, respectively. Photosynthetic carbon assimilation varied between 2.26 and 3.23 µmol CO2 m -2 s -1 , and water use efficiency varied from 2.058 to 3.395 µmol CO2 (mol H2O) -1 , with the highest values being obtained in seedlings produced in sewage sludge-based substrates with irrigation depth of 6 mm. Our results demonstrate that sewage sludgebased substrates are an efficient alternative to commercial peat-based substrates for seedling production.

Substrates based on composted sewage sludge for land recultivation

“…Organic compounds such as sewage sludge have a high density and consequently low overall porosity (Raviv, 2013) but we observed that the addition of structuring materials (wood chips) in the composting process made these materials suitable for creating a growth substrate. Research (Gabira et al, 2021) was conducted to create a sediment-based substrate for growing forest seedlings. They note the successful use of sediment as a component of the substrate.…”

Identificación de hongos filamentosos asociados al suelo del bosque protegido de Prosperina

“…Según lo que se observa las tres estaciones varían muy poco en la clasificación de géneros encontrados, gracias a su cosmopolita distribución y siendo que están en una posición geográfica muy cercana, la poca variación observada en su micro diversidad puede sugerirse que es debido a características del suelo, factores ambientales, la presencia de agua o factores humanos 24 , lo que hace que muchos de ellos presenten características dominantes a estos factores Figura 1. Diversidad de hongos de la Estación 1, Aspergillus flavipes (1), Aspergillus neoflavipes( 2), Penicillium guttulosum(3), Curvularia lunata(4), Aspergillus keveii (5), Trichoderma spirale (6), Gongronella butleri (7), Aspergillus brasiliensis (8), Aspergillus neoflavipes (9), Penicillium limosum (10), Talaromyces liani (11), Cladosporium crousii (12), Aspergillus pseudonomiae( 13), Absidia sp. ( 14), Trichoderma amazonicum (15), Penicillium limosum (16), Talaromyces flavus (17), Penicillium limosum (18), Penicillium limosum (19), Humicola fuscogrisea (20).…”

“…El potencial microbiano del BPP puede ser aprovechado para el desarrollo de productos a bases de micotoxinas que pueden actuar como biocontroladores de fitopatógenos en alimentos, también contribuyen en la regeneración de suelos maltratados en la que necesitan incorporarse microorganismos presentes en la materia orgánica de bosques a través de la elaboración de compost 6,7 . Adicionalmente, los hongos filamentosos pueden ser empleados en la biotecnología fúngica porque permiten fomentar la economía circular, mitigar el cambio climático y generar la producción sostenible de alimentos, combustibles, textiles, fármacos, entre otros 8 .…”

“…Diversidad de hongos de la Estación 3. Penicillium rubidurum (1), Cladosporium cladosporioides(2), Aspergillus keveii(3), Aspergillus aculeatus(4), Cunninghamella echinulata(5), Purpureocillium sp(6), Fusarium falciforme(7), Penicillium vinaceum(8), Penicillium shearii(9), Fusarium solani(10), Trichoderma erinaceum(11), Penicillium steckii(12) Aspergillus aculeatus(13), Penicillium vinaceum(14), Penicillium vinaceum(15), Penicillium citrinum(15), Absidia caatinguensis(16).…”

Manejo De Irrigação Em Viveiros Florestais: Uso Racional Da Água E Análise Da Qualidade Das Mudas

“…De autoria própria.De acordo comMathers et al (2005),Sammons e Struve (2008) ePride (2014), é possível aumentar a eficiência da irrigação aplicada por microaspersão a partir de ajustes nas estruturas dos viveiros e nos manejos praticados, a saber: 1) instalar sistemas de irrigação com maior uniformidade na distribuição de água; 2) implantar quebra-ventos no perímetro do viveiro (Figura 8); 3) agrupar as mudas de espécies com características semelhantes; 4) controlar os volumes lixiviados; 5) utilizar substratos com maior capacidade de retenção, como a turfa, a fibra de coco e o lodo de esgoto compostado ou biossólido (Figura 8) (TRIGUEIRO;GUERRINI, 2014;KRATZ et al, 2017;GABIRA et al, 2021);Gabira et al (2020b) afirmam que para proporcionar condições adequadas de aeração e disponibilidade de água às mudas, dois ou mais materiais devem ser utilizados na composição de um substrato. Nesse sentido,Simões et al (2012),Kratz e Wendling (2013);Kratz et al (2013a) eGabira et al (2020a) alertam para necessidade de se ajustar os manejos praticados no viveiro em função das características físicas e químicas dos substratos; 6) dispor as mudas nos canteiros de forma a reduzir as áreas vazias; 7) não irrigar em dias chuvosos; e 8) adotar a irrigação cíclica, isto é, dividir uniformemente o volume de irrigação diário aplicado em intervalos (ciclos).…”