Bridging Gaps in the Agricultural Phosphorus Cycle from an Animal Husbandry Perspective—The Case of Pigs and Poultry

Abstract

Since phosphorus (P) is an essential element for life, its usage and application across agricultural production systems requires great attention. Monogastric species such as pigs and poultry can significantly contribute to global food security but these animals remain highly dependent on the supply of mineral inorganic P in their feeds. Pig and poultry, which represent 70% of the global meat production, are also major P excretors and thus represent important sources of environmental P inputs. Balancing the P cycle within farming systems is crucial to achieve P sustainable and resilient livestock production. Therefore, the interconnection of animal feed, livestock farming, manure, and soil/aquatic ecosystems requires multidisciplinary approaches to improve P management. With regard to a sustainable agricultural P cycle, this study addresses aspects of feeding strategies and animal physiology (e.g., phase feeding, P conditioning, liquid feeding, phytase supplementation, genetics), soil agroecosystems (e.g., P cycling, P losses, P gains), reuse and recycling (e.g., manure, slaughter waste), measures of farmers' economic performance (e.g., bio-economic models), and P governance/policy instruments (e.g., P quota, P tax). To reconcile the economic and ecological sustainability of animal husbandry, the strategic objective of future research will be to provide solutions for a sufficient supply of high-quality animal products from resource-efficient and economically competitive agro-systems which are valued by society and preserve soil and aquatic ecosystems.

Anthropogenic global shifts in biospheric N and P concentrations and ratios and their impacts on biodiversity, ecosystem productivity, food security, and human health

“…The differences in immobilization, leaching, and volatilization between the two elements lead to higher soil retention of P than N (Penuelas et al, , ). This trend in P retention tends to be more pronounced where the density of livestock, particularly pigs, and/or poultry is high (Arbuckle & Downing, ; Gomez‐Garrido, Martinez‐Martinez, Cano, Buyukkilic‐Yanardag, & Arocena, ; Hentz et al, ; Penuelas, Fernández‐Martínez, et al, ; Wironen et al, ), because the manure waste generated is characterized by very low N:P ratios (Humer, Schwarz, & Schedle, ; Oster et al, ). In conclusion, whereas in cropland soils and surrounding habitats such as lakes and ponds directly receiving non‐treated or diffuse wastes and leachates, N:P ratio has decreased in last decades, in the majority of other continental and coastal areas N:P tends to rise as a result of a greater spread capacity of N than P.…”

“…The threefold global increase in “livestock production for human consumption” over the last five decades has been a key driver of scarcity, environmental distribution, and decrease in the efficiency of P use (Liu et al, ). Globally, 70% of livestock comprises monogastric animals, such as poultry and pigs, which cannot absorb P from phytates and produce manure with very high P concentrations and low N:P ratios that lead to very low P‐use efficiency (Oster et al, ; Prasad et al, ; Wang, Ma, Strokal, Chu, & Kroeze, ). Land used for the intensive production of monogastric animals and that is fertilized with their manure exacerbates environmental imbalances in N:P ratios (MacDonald et al, ; Penuelas, Fernández‐Martínez, et al, ; Sileshi et al, ).…”

“…Letter size is proportional to concentration . This trend in P retention tends to be more pronounced where the density of livestock, particularly pigs, and/or poultry is high (Arbuckle & Downing, 2001;Gomez-Garrido, Martinez-Martinez, Cano, Buyukkilic-Yanardag, & Arocena, 2014;Hentz et al, 2016;Penuelas, Fernández-Martínez, et al, 2019;Wironen et al, 2018), because the manure waste generated is characterized by very low N:P ratios (Humer, Schwarz, & Schedle, 2015;Oster et al, 2018).…”

“…Stimuli for recycling P tend to be controlled by "legislative regulations and instruments" at the national or regional administrative level, sometimes supported by subsidies (Hukari et al, 2016;Withers et al, 2015). Legislation is usually not harmonized or coordinated among national agencies, so the likelihood of the large-scale production of secondary P fertilizer from processes of P recovery is low and requires multinational adoption of cutting-edge technologies (Hukari et al, 2016;Oster et al, 2018;Withers et al, 2015). Increases in the costs of P extraction and transport, however, may increase the economic feasibility of secondary P fertilizers (Mew, 2016).…”

Sustainable Mineral Resource Management—Insights into the Case of Phosphorus

“…. Circular principles for moving toward a circular phosphorus economy based on [22] categorizing [27][28][29][30][31][32][33][34][35][36][37][38][39].…”