A substance flow analysis of phosphorus in the food production, processing and consumption system of the Netherlands

Abstract

Phosphorus (P) is an essential nutrient in agriculture. In recent years 15-18 Mt of P was used as mineral fertilizer in the global food production chain. The major source of this fertilizer is phosphate rock which is unfortunately a finite resource. In the long term this necessitates efficient use of fertilizer and optimized recycling of P rich waste streams (including manure). In order to determine the potential for sustainable use of P we performed a 3-year substance flow analysis (SFA) for the Netherlands, a country characterized by its intensive agriculture and a high livestock density. Such conditions occur in various regions of the world and can easily result either in environmental problems or an unsustainable use of P. Annual quantification of P flows were performed in 2005, 2008 and 2011. These were not restricted to agriculture. Industrial, household/retail and the environmental P-flows were also included. Due to relatively high quantities of feed imports, the national P-surplus amounted to almost 60 Mkg P in 2005, decreasing to 42 Mkg in the year 2011. A large proportion of this reduction was considered to be due to reductions in P fertilizer use. The SFA provided an insight into the fate of the national P surplus and the potential for recycling. In 2011 the major part of the 42 Mkg of P surplus was observed in waste streams from society (23 Mkg, e.g. sewage sludge incineration ashes, household refuse). During this study these waste streams were not reused within the national food production system or elsewhere. The remainder of the surplus accumulated in agricultural soils (around 12 Mkg) or were emitted through surface water (almost 7 Mkg).

Chemical phosphorus recovery from animal manure and digestate : Laboratory and pilot experiments

“…After WW II, the livestock numbers have increased substantially in the Netherlands up to 10 million cows, 14 million pigs and 95 million poultry in 1990. Although livestock numbers (cows, pigs) have somewhat declined (about 10-20%) during the last decade due to restrictions on production of milk and number of animals (production rights), the agricultural P balance of the Netherlands over the last decade is still positive (Table 1.1; Smit et al (2015)). In 2005, about 70%…”

Does balanced phosphorus fertilisation sustain high herbage yields and phosphorus contents in alternately grazed and mown pastures?

“…Soil processes like mobilisation, immobilisation or losses are not taken into account in these limits. The dairy sector in the Netherlands uses a significant part ([60 %) of agricultural land to produce roughages, such as grass, grass silage and maize silage and contributes to the net P accumulation in soil (Smit et al 2015). Moving towards balanced P fertilisation might affect grassland yield and quality, because soil processes might influence the P availability for plant uptake (Frossard et al 1995;Morgan 1997;Syers et al 2008).…”

“…This insufficiency may be addressed by supplementing P via manufactured feed or by accepting a decrease in the production of milk and meat per unit surface area. Supplementing P via feed will increase the P import and thereby may increase the necessity to export manure P (Smit et al 2015), whereas decreasing milk and meat production per ha may lower farm income.…”

The Latitudes, Attitudes, and Platitudes of Watershed Phosphorus Management in North America

“…Compared with other regions (e.g., Europe) and nations (e.g., New Zealand), P management in North America is spread across a patchwork of legislation and regulation. For instance, some European countries are forming P-related regulations around a circular economy, to codify P recovery and recycling (Schoumans et al, 2015;Smit et al, 2015;van Dijk et al, 2016). Canadian and US legislation and regulations related to P largely focus on the relationship between land use and water quality (Ross and Omelon, 2018).…”