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.
Weather conditions can significantly affect both the containment of fertiliser on the application site and the evenness of application within this site. The importance of weather conditions depends on the form of fertiliser, the application method and equipment used.
Recommendations and nutrient management plans from fertiliser and agricultural consultants assume the fertiliser material will be spread evenly and accurately over the target area at the target application rate. Poor spreading can negate the best management plans and result in significant production losses and pollution of waterways.
Ground based application includes a wide range of application methods to apply a vast array of fertiliser products, requiring careful matching of equipment and technique to the fertiliser and production system.
Spreading operators must understand the spreading characteristics of all products they spread, and how their equipment and equipment settings affect spreading performance. For example, products may be solid (free flowing particles or mass material) or fluid (solutions, suspensions, slurries). Particle sizes in free flowing solid fertilisers typically range from less than 1mm to over 5mm in diameter. When ejected laterally from spreading equipment, particles of different sizes have different ballistic trajectories and therefore variable spreading patterns. Particle shape also varies but is usually near spherical in manufactured products. Particle shape, density and surface roughness all affect the flowability of the product.
There are two broad types of ground based spreading equipment:
Factors that may affect ground based fertiliser spreading performance:
The application of fertiliser from ground based machinery should comply with the Code of Practice for the Placement of Fertiliser in New Zealand (Spreadmark).
In many situations, aerial application is the only practical means of applying fertiliser. Where fertiliser is applied by air, the minimum acceptable standards for evenness of spreading should be the same as for other application methods used on similar classes of land. Where the risk of environmental contamination is low, higher CV values for evenness of distribution may be acceptable.
Keys to quality aerial topdressing include:
The aerial application of fertiliser should comply with the Code of Practice for the Placement of Fertiliser in New Zealand (Spreadmark), Part The Aerial Spreadmark Code.