Work

The use of recovered struvite and ammonium nitrate in fertigation in a horticultural rotation: agronomic and microbiological assessment

Year: 2022

Type: article

Abstract: Phosphorus and nitrogen recovery from wastewater as struvite and ammonium nitrate (AN) may be viable alternative fertilizers to boost circularity in horticulture. A 2-year fertigated crop rotation in soil under greenhouse conditions was evaluated to determine the efficiency of both recovered products as raw materials for a nutrient solution (NS) manufacture. The effects of these treatments versus synthetic fertilizers were compared in terms of crop performance, plant nutrient uptake, soil chemistry and microbiota. This is the first study to implement struvite through fertigation as the sole source of P in soil crops. Results showed that both recovered products can be used as fertilizers in NS, due to the similar response to the control for different parameters and crops (tomato, lettuce, and cauliflower). However, the AN treatment showed lower yield in the first tomato crop, which results may depend on the cultivar ammonium tolerance. Besides, the concentration of heavy metals in fruits/leaves was below the permissible limits. Total and Olsen phosphorus soil analysis revealed no differences among treatments, resulting in a similar performance of P-struvite to commercial phosphate. Bulk soil bacteria structure, richness and relative dominance were increased over time, while archaea only showed lower evenness, both despite the fertilization strategy. Shannon diversity was not significantly affected. A predominance of ammonia-oxidizing bacteria (AOB) versus archaea (AOA) was observed, while nitrite-oxidizing bacteria (NOB), dominated by Nitrospira, increased with fertigation. Our results demonstrate that fertilizer blends for NS containing recovered nutrients are a feasible alternative to synthetic fertilizers.

Source: Environmental Technology

DOI: 10.1080/09593330.2022.2154172

Authors: Mar Carreras-Sempere, Carmen Biel, Marc Viñas, Miriam Guivernau, Rafaela Caceres

Institution: Institute of Agrifood Research and Technology

Language: English

Topic: Phosphorus and nutrient management

Subfield: Waste Management and Disposal

Field: Environmental Science

Domain: Physical Sciences

SDGs: Responsible consumption and production, Zero hunger, Clean water and sanitation

Open Access status: green

Funders: Centres de Recerca de Catalunya, Generalitat de Catalunya, Universitat Autònoma de Barcelona