Composting as a method to recycle renewable plant resources back to the ornamental plant industry: Agronomic and economic assessment of composts

In this experiment, three piles were elaborated with rose waste (RW), sawdust (S), and different manures - broiler chicken manure (BCM), hen manure (HM), and quail manure (QM) - and were composted by windrow composting. Parameters associated with the degradation and humification of organic matter (OM) during composting and with the agronomic and economic value of the final composts were determined. All piles had temperatures >55 °C for more than two weeks, ensuring compost sanitization. OM degradation was greater and faster in the pile with QM. This pile had the lowest water-soluble polyphenol content. Principal component analysis indicated that the use of BCM augmented the OM humification during composting; this material also influenced the mineralization of the OM. In general, the composts obtained presented an adequate level of stability and maturity and an absence of phytotoxicity, and there were notable concentrations of OM and nutrients, especially nitrogen. In addition, all the composts had an economic value when their nutrient contents were assessed. Phosphorus was the fertilization unit with the greatest contribution to the total value of the composts. However, the use of BCM produced a compost with properties that made it more suitable as an organic amendment for rose growing.