Source: Moolenaar and Lexmond (1998).

Source: Moolenaar and Lexmond (1998).

fertilizer (see Table 33.2), were calculated for the conventional farming system as a whole (CAFS-total). The values for the input rates, removal rates by harvest, and leaching rates were substituted in the dynamic balance equations. With these rates the development of soil content, leaching and uptake was projected. Soil Cd content would increase from 0.5mg/kg to exceed the Dutch reference value for this soil (0.6mg/kg) and to increase further towards a steady-state value of about 1.7mg/kg. The leaching rate would increase from about 0 to 0.9 grams per hectare per year (g/[ha.yr]) while the offtake rate would increase from about 0.8 to 4.9g/[ha.yr]. These numbers are illustrated in Figure 33.1. The high average Cd offtake rate would result in quality standards of some crops being exceeded, as is shown in the next section, on sustainability indicators.

Figure 33.2 shows that the copper soil content decreases from 60 to less than 14mg/kg at steady state, with associated reductions in leaching and crop offtake rates from 8 to 4

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