Assessing nutrient use efficiency and environmental pressure of macronutrients in biobased mineral fertilizers : a review of recent advances and best practices at field scale

Anaerobic digestion is an established technology to convert bio-waste into renewable energy and nutrient-rich digestates. Nutrient recovery from these digestates as renewable fertilizers with high nutrient use efficiency or as P-poor alternative fertilizers has gained increased attention in order to meet both regulatory drivers and market demands, while producing an internal revenue source. However, until now this opportunity has been difficult to realise due to obstacles and inconsistencies in legislative systems, and lack of insights in the composition and properties of these products, as well as in their impact on crop yield and soil quality. The aim of this review is to prove the effectiveness of fertilization strategies using bio-digestion waste derivatives as compared to conventional practices using animal manure and chemical fertilizers. As adequate field-scale data are lacking in literature, a ground-breaking three-year field trial has been performed. The value and impact of these bio-based fertilizers is demonstrated by use of high level performance indicators measuring farming’s pressure on the environment and how that pressure is changing over time. Bottlenecks for marketing and legislative constraints are discussed. An economic and ecological evaluation is also assessed. The proof-of-concept provided in this chapter should help to better classify these bio-based products in fertilizer and environmental legislations and serve as a support to stimulate their use in the farming community. Moreover, this review should stimulate and provide guidance for further field research on bio-based fertilizers, which is highly essential in the development and implementation of more effective and environmentally friendly farming strategies.Anaerobic digestion is an established technology to convert bio-waste into renewable energy and nutrient-rich digestates. Nutrient recovery from these digestates as renewable fertilizers with high nutrient use efficiency or as P-poor alternative fertilizers has gained increased attention in order to meet both regulatory drivers and market demands, while producing an internal revenue source. However, until now this opportunity has been difficult to realise due to obstacles and inconsistencies in legislative systems, and lack of insights in the composition and properties of these products, as well as in their impact on crop yield and soil quality. The aim of this review is to prove the effectiveness of fertilization strategies using bio-digestion waste derivatives as compared to conventional practices using animal manure and chemical fertilizers. As adequate field-scale data are lacking in literature, a ground-breaking three-year field trial has been performed. The value and impact of these bio-based fertilizers is demonstrated by use of high level performance indicators measuring farming’s pressure on the environment and how that pressure is changing over time. Bottlenecks for marketing and legislative constraints are discussed. An economic and ecological evaluation is also assessed. The proof-of-concept provided in this chapter should help to better classify these bio-based products in fertilizer and environmental legislations and serve as a support to stimulate their use in the farming community. Moreover, this review should stimulate and provide guidance for further field research on bio-based fertilizers, which is highly essential in the development and implementation of more effective and environmentally friendly farming strategies.A