• Increasing the efficiency and recovery of N inputs;
• Utilising phased release P to minimise P losses, and
• Raising soil calcium levels and maintaining soil fertility.

'New Choice' works by aiming to meet the above criteria and by putting the research into practice.

NITROGEN (N)
Typically only 60% of N inputs are recovered from arable farming and only 10% from livestock farming. Recovery and efficiency of N can be increased by:

• Having a higher proportion of ammonium N to nitrate N, as ammonium N is less susceptible to leaching;
• Maintaining soil P, K and pH at optimum levels;
• Calcium plays a vital role in the uptake and utilisation of N so it is important to maintain optimum soil calcium levels.

There are differences between the various sources of nitrogen fertilisers in terms of their efficiency, susceptibility to nutrient loss and acidification of the soil.

The nitrogen in New Choice is from only two sources:

a) CAN (calcium ammonium nitrate) which contains calcium and magnesium the effect of which is to slow down the dissolution of the N giving the plant a better chance to take it up and utilise it. The calcium also reduces the acidification of the soil, which in turn reduces leaching losses of nitrate N.

b) ammonium phosphate providing slower acting, ammonium N which is less susceptible to leaching than nitrate N;

Table 1: Soil acidification of different types of N fertiliser

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