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ARS Home » Southeast Area » Florence, South Carolina » Coastal Plain Soil, Water and Plant Conservation Research » Research » Publications at this Location » Publication #363556
Research Project: Improvement of Soil Management Practices and Manure Treatment/Handling Systems of the Southern Coastal Plain

Location: Coastal Plain Soil, Water and Plant Conservation Research

Title: Influence of pyrolyzed grape-seeds/sewage sludge blends on the availability of P, Fe, Cu, As and Cd to maize

Author
item ACENA-HERAS, SARA - University Of Madrid
item Novak, Jeffrey
item CAYUELA, MARIA - Universidad De Murcia
item PENALOSA, JESUS - University Of Madrid
item MORENO-JIMENEZ, EDUARDO - University Of Madrid

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/2019
Publication Date: 7/22/2019
Citation: Acena-Heras, S., Novak, J.M., Cayuela, M.L., Penalosa, J.M., Moreno-Jimenez, E. 2019. Influence of pyrolyzed grape-seeds/sewage sludge blends on the availability of P, Fe, Cu, As and Cd to maize. Agronomy [MDPI]. 9:406. https://doi.org/10.3390/agronomy9070406.
DOI: https://doi.org/10.3390/agronomy9070406

Interpretive Summary: Sewage sludge is the solid waste produced in urban wastewater treatment plants. It is one of the most abundant organic wastes from the service industry and its production is expected to increase due to expanding urbanization and industrialization. Sewage sludge composition varies with treatment technology, but in general, it contains valuable plant nutrients and therefore is recycled as a soil amendment in agriculture. However, the application of sewage sludge as fertilizer for food production is limited by its high concentrations of heavy metals. For this reason, extensive research has been developed during the last decades to guarantee the safe application of sewage sludge to agricultural soils. One technological treatment that has gained attention is the pyrolysis of sewage sludge to produce biochar. We conducted a study using different pyrolyzed materials based on mixtures of grape seeds and sewage sludge wastes to examine their agronomic potential and environmental impacts. We found that the recommended ratio of sludge:grape seeds treatment is 50% grape seeds -50% sewage sludge due to its intermediate behaviour of nutrient leaching, tolerable heavy metal concentrations, and its ability to promote highest corn biomass production relative to the control.

Technical Abstract: Current intensive agricultural practices, although highly successful from a productive point of view, have been found to be environmentally unsustainable. One of the crucial approaches to increase agricultural sustainability is the recycling of organic wastes, since these materials often retain many beneficial nutrients for soil and agriculture. Currently, pyrolytic conversion of biodegradable waste into charred material has gained global attention as an amendment to recycle nutrients while improving soil health. Increasing interest in the beneficial applications of pyrolyzed biomass has expanded multidisciplinary areas for science and engineering. The fertilizers used in this study were prepared by pyrolyzing mixtures of two abundant residues in Mediterranean areas: grape seeds and sewage sludge, in different proportions. In addition, fresh sludge was mixed with pyrolized grape seeds and included as an additional treatment. Results of the study indicated that the unpyrolyzed sludge mixture contained the largest amount of nutrients -iron, copper and phosphorus. In agreement, this treatment -mixed with a Chromic Luvisol soil increased elements uptake in corn (Zea mays L. – LG ambitious) resulting in a yield increase by 60%. However, this mixture also contained more contaminants (Arsenic and Cadmium). According to our results, the treatments where grape seeds and sewage sludge were mixed at 50% exhibited the optimal compromise between efficiency (nutrients uptake) and tolerable levels of toxic elements in leachates.