Comparative efficiency of organic and mineral fertilization on cotton growth and metabolism

• Autor(a) principal: da Silva Tavares, Miriam
• Data de Publicação: 2020
• Outros Autores: Esberard de Macêdo Beltrão (In memorian), Napoleão
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Revista de Ciências Agrárias (Belém. Online)
• Texto Completo: https://ajaes.ufra.edu.br/index.php/ajaes/article/view/3219
• topic: Gossypium hirsutum L.; nitrogen; organics residues; Soil; Gossypium hirsutum L.; nitrogênio; resíduos orgânicos; Solos

The combination of mineral and organic fertilizers has been recommended as an alternative management, especially when the applied organic material has a high carbon: nitrogen ratio (C/N). The objective of this study was to evaluate the growth and physiological aspects of cotton under doses of castor bean cake and peel associated with soluble nitrogen sources.  Adopted a randomized closed block design with 24 treatments and 3 repetitions. The treatments consisted of four doses of castor cake (0 – 0,8 – 1,6 e 2,4 t ha-1) and four doses of castor fruit peel (0 – 0,8 – 1,6 e 2,4 t ha-1), supplemented with three levels of soluble N at a dose of 120 kg h-1 (ausent, urea and ammonium sulfate). At 90 days were quantified: plant height, stem diameter, leaf area, dry mass (air, root and mulch), chlorophyll content, flavanoids, anthocyanin, nitrogen balance index and membrane disruption. It was observed that ammonium sulfate was a viable alternative when combined with castor cake in relation to urea. The best results for height and chlorophyll contente  were obtained with the application of 1,6 t ha-1 of castor bean hulls associated with ammonium sulfate. The use of castor bean cake and peel associated with urea and ammonium sulfate did not influence the stem diameter, flavanoid, anthocyanin content and nitrogen balance index. The use of 0.8 t ha-1 of urea castor bean cake promoted the largest electrolyte leakage and lower plasma membrane instability.