Feeding the world’s growing population
New Zealand’s reputation as a quality food producer is growing.
The Fertiliser Association of New Zealand promotes and encourages responsible and scientifically-based nutrient management.
As well as keeping fertiliser to the target area, application needs to be even across this area at the desired fertiliser application rate. The potential evenness of application for any given fertiliser is affected by:
The evenness of distribution is described using the coefficient of variation (CV%). This can be measured by catching fertiliser in collectors across the distribution area and weighing the fertiliser in each container.
A high CV indicates poor (uneven) spreading while a CV of zero indicates perfectly even spreading.
The target application rate should be chosen to meet the true plant nutrient requirements. Inappropriate application may increase the risk of adverse environmental effects and reduce production potential.
In New Zealand, the standards set under the Spreadmark Code of Practice for the Placement of Fertiliser allows for a single pass transverse spreading CV of no greater than 15% for nitrogen fertilisers and 25% for all other fertilisers. When making recommendations for the amount of fertiliser to be applied, fertiliser providers and consultants assume a CV of zero percent.
Modern technology, such as GPS and GIS systems, has enabled commercial fertiliser spreaders (ground and aerial) to achieve a high degree of fertiliser spreading accuracy. This technology enables spreaders to cover precise areas with minimal overlap or gaps between spreading runs and to achieve accurate buffers between target and non-target areas.