Keywords: Fertiliser blending, Fertiliser quality, Segregation, Size grade number, SGN.

Blending as a way of manufacturing compound fertilisers has been a part of the fertiliser business for many years. In some countries it represents nearly 100% of compound production. There are a number of 'problem areas' associated with blends and the blending process, some of which are genuine and some merely perceived. This paper attempts to separate the genuine problems from the perceived problems and offers techniques for solving some of them.

Starting with some clear definitions of the terminology, the paper examines what makes a good blend and critically examines systems which have been developed to improve the quality of blends. This is followed by a comparison of the advantages and disadvantages of blends versus complex fertilisers. The paper also considers aspects such as the sampling and analysis of blended fertilisers and the current and proposed legislation covering their production and marketing.

The paper concludes with an outline Code of Practice to assist blenders in improving the quality and image of their products.

Graham E N Lance, Consultant, UK.

40 pages, 9 Tables, 5 Figures.