Spectrometric evaluation of biotransformed agro-industrial residues and their humic substances by UV–visible and infrared spectroscopy and their effect on winter wheat productivity

MOISÉS, J.; MARTINEZ, JM.; IOCOLI, GA.; DUVAL, ME.; GALANTINI, JA.

International Journal of Recycling of Organic Waste in Agriculture

Islamic Azad University

Año: 2022 vol. 12

2195-3228

Purpose: Agroindustrial residues could be biotransformed to improve crop production and reduce environmental risk. Application of humic substances (HS) extracted from residues could be an alternative fertilization strategy. The objectives were i) to characterize different biotransformed agroindustrial residues (BR) and their HS by combining UV-vis and FT-IR techniques, and ii) to assess the effects of their application on wheat crop development and production.Method: Two experiments were performed with winter wheat. The residues biotransformed used were sunflower shells by Pleurotus ostreatus fungus, alperujo naturally by microorganisms from the environment and municipal solid waste by Californian worms and composting. The HS were extracted from these residues. A pot experiment with a solid residue was incorporated into the soil (Petrocalcic Haplustoll) using four nitrogen (N) levels calculated as the equivalent amount of N considering its organic N (0, 50, 100 and 150 kg N ha-1). A Petri dish experiment was performed to evaluate the application of HS extracted from each BR on early wheat development.Results: In general, application of BR produced a negative crop response regardless of the residue and rate. The IR spectra of three BR showed similar absorption zones but with different intensities.Conclusion: The application of BR in terms of the type of residue and rate had variable effects on wheat crop but mostly negative. However, extraction of the HS from BR and subsequent application favored crop development. Spectrometric techniques, such as UV-Visible and FT-IR, are useful to verify their potential effect as biostimulants of plant growth.