balance in the Netherlands. The P balance of feedstock can be effectively lowered by reducing the net import of animal feed or, alternatively, by increasing the export of animal manure. 45 Agricultural phosphate balances Figure 6.1 shows the agricultural phosphate balances. Both a sector balance and a soil balance are given. The sector balance is based on the input of phosphate with feed concentrates, dietary phosphate, net import of roughage and the stock of fodder crops for 2005. The output consists of animal products, pet food, net export of compound feed, crop products and manure. An internal cycle redistributes input and output. The sector balance has a surplus of 85 Gg P2O5. Inputs in the soil balance are phosphate from manure, fertilisers, other soil amendments and crop residues. The output is based on P removed with harvested crops (off take). Although the sector balance and soil balance are calculated differently, both result in a similar estimate of the phosphate surplus (CBS, 2010). Figure 6.1: Phosphate in Dutch Agriculture in 2005 in Gg P2O5 (source CBS StatLine, 2010). The import of feed concentrates accounts for 61% of the Dutch phosphate input, and mineral fertilisers account for 22%. Dietary phosphates add another 7% to the input. Together they represent 90% of the total phosphate used by Dutch agriculture. The export of animal products accounts for 48% of the output, compound feeding stock accounts for 20%, and crop products for 17%. Manure export accounts for 12% of the output. Together these four outputs represent 96% of the total output. The agricultural phosphate balances show a 37% and 39% surplus for the sector balance and soil balance respectively. The accumulation of phosphate in soil increases the risk of leaching (section 5.4). It is estimated that 6.9 Gg P2O5 leaches annually from Dutch agricultural soils, equal to 9% of all phosphate accumulated in soil (Figure 6.1.). Manure spills to ditches and phosphate losses from Pagina 54

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