Classical fertilisers have a low efficiency becasue only a minor part of the fertiliser reaches plant roots. As a consequence a major part of classical fertilisers escapes rapidly toward groundwater, thus polluting drinking water with nitrates. Research has therefore invented controlled-released fertilizers to feed the plant slowly in the long run. Controlled-released fertilizers include polymeric material – a kind of plastic – to slow down fertiliser feeding. In other words controlled-released fertilizers are comparable to pasta that provide energy slowly in the long run, whereas classical fertilisers are similar to sweets that provide high energy fast. Agronomists Wang et al. have evidenced improved nitrogen uptake and reduced nitrogen loss using a polymer-coated urea fertiliser to grow flooded rice in southeast China.
