What you should know about fertilisers

Fertilisers conjure up a vision of nasty poisonous chemicals in some people's minds. This leaflet summarises the need for plant foods, and outlines the origins and uses of potassium - a "fertiliser" which is one of the most vital elements for plants, animals and mankind.

Plant Foods

All plants require food just like humans. In Nature plants live and die in the same place - nothing is removed and their constituents are recycled. Where crops are grown for human use, the products - grain, potatoes, fruit, vegetables etc. are harvested and removed from the field and the plant foods contained in these products are lost from the soil.

In today's society only a small fraction of this removal is returned in the form of organic sewage sludge. If this process of removal without replacement is continued for many years, soils would become impoverished and no longer be able to produce crops or support normal growth. Farmers, growers and gardeners therefore need to apply a balanced diet of fertilisers and manures in order to replace plant foods removed and maintain the fertility of the soil and the vigour and health of the crops.

Range of plant foods

All plants require a number of different elements to feed on, namely:- nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), sulphur (S), calcium (Ca), iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), boron (B), molybdenum (Mo), chlorine (Cl), nickel (Ni). Potassium is the nutrient required by most plants in the largest quantities. This element occurs abundantly throughout Nature in soils, sea-water, plants, animals and man. It is the seventh commonest element on earth.