The reason for this ongoing decline can be partly explained by the strong development of intensive livestock farming during the second half of the last century (e.g. CBS, 1999). The large surplus of P on the national balance forced the government to implement measures to reach a balance between input and output of P from manures and fertilisers. As a surplus leads to a penalty, farmers were forced to lower their P use. This was at the expense of P from fertilisers (Henkens and Van Keulen, 2001; Schroder et al, 2007). 37 5.3 Future trends Future phosphate consumption trends will be largely driven by changes in agricultural practice, which represents the bulk of phosphate consumption in the Netherlands. In 2006, existing regulations for nutrient application were replaced by a new legislative framework, the Fertilisers Act 2006 (Meststoffenwet 2006), which requires Dutch farmers to further reduce nutrient application, which will result in a further decrease in phosphate consumption. These regulations are mainly driven by European requirements with regard to nitrogen discharge from agricultural land to surface water and groundwater (Directive 91/676/EEC; see VROM, 2004, i.e. Nitrates Directive). The final goal of this directive is to reduce eutrophication and improve the ecology of surface water and groundwater. Eutrophication of surface and groundwater is still prevalent in large parts of Europe where agricultural activities are intensive (see e.g. EEA, 2009). In this context it is however interesting to note that phosphate concentrations in many agricultural soils in western Europe are so high that even without any additional phosphate fertilisation a high crop yield can be achieved for several years (Van der Werff et al., 1995). It is also estimated that phosphate fertilisation is currently not necessary at all on 35% of the agricultural soils in the Netherlands as a result of a high degree of phosphate saturation in these soils (see MNP, 2007). Although the situation in the Netherlands has significantly improved over the past few decades, nitrate concentrations in shallow groundwater in the sandy soils in the Netherlands generally do not meet the required EU level of 50 mg/L (Hooijboer et al., 2007; MNP, 2007). Furthermore, only 34% of the surface water monitoring locations met the maximum tolerable risk levels for nitrogen (2.2 mg/L), whereas 57% of the locations met the maximum tolerable risk levels for phosphate in 2005 (0.15 mg/L; MNP, 2007). The Fertilisers Act defines quota for the maximum amount of fertiliser that can be applied to the soil (phosphate application standards). This quota applies to the sum of all forms of fertilisers and animal manures. Other than for nitrate, however, soil conditions and crop requirements are not taken into account for phosphorus other than the phosphate Pagina 46

Pagina 48

Scoor meer met een webwinkel in uw maandbladen. Velen gingen u voor en publiceerden publicaties online.

458 Lees publicatie 159Home