NUTRIENTS

Major Elements  Plants take up nutrients from the soil with the water they take into their roots.  The three main elements they need are:  Nitrogen(N)  Potassium(K)  Phosphorous (P)

Trace Elements The elements that plants need in smaller amounts are:  magnesium(Mg)  sulfur(S)  calcium(Ca)  manganese(Mn)  Molybdenum(Mo)  Copper(Cu)  Zinc(Zn)  Boron(B)  The elements in bold are the trace elements that plants require the most

Fertilisers  If elements are lacking in the soil, they can be supplied in the form of fertilisers.  Organic fertilisers have been made directly from plant and animal material  Inorganic fertilisers have been made by chemical reactions  Liming is the application of calcium carbonate to the soil. Liming adds calcium and makes the soil less acidic.  Compost adds organic matter to the soil which breaks down to make chemical nutrients which the plants can take up

Nutrient Deficiency Indicators  If a plant is lacking a certain nutrient, it will generally show certain signs. NutrientPlant UseIndicator that nutrient is deficient Nitrogen used for leaf growth and the formation of proteins. Yellow leaves and stunted growth Phosphorous Used for root growth and helps seeds reach maturity Purplish leaves, poor root growth and stunted growth Potassium Used by leaf for photosynthesis, flowering and fruit ripening Leaves are brown at the edges and growth is slow Sulfur Needed in the formation of proteins Light-green leaves Calcium Essential for plants to reach maturity Terminal bud is brown and growth stops MagnesiumNeeded for plant to carry out photosynthesis Yellow leaves

NPK ratio  The ratio is a series of three or more numbers found on the packaging of fertiliser. This shows the proportion of the major nutrients in the fertiliser.  The numbers found in the ratio are the percentages of nitrogen (N) phosphorus (P), potassium (K), and sometimes sulfur (S) and magnesium (Mg).  The numbers are always in the same order, N, P, K.

 This information is useful as it tells you what the fertiliser will supply.  The grower can then match the soil and crop needs to a suitable fertiliser that can supply the nutrients.  A simple fertiliser contains only one nutrient. Urea is an example of a simple fertiliser that provides nitrogen.  When the fertiliser contains more than one nutrient it is called a compound fertiliser.

How to apply nutrients  Fertilisers can be applied in different ways:  base fertiliser is put in the soil or growing media before planting the seeds or plants. Sometimes it is also called a base dressing  side dressing/fertiliser is put around plants once they are established and growing.  Soil should be wet when the grower apples fertiliser to help the fertiliser dissolve and be taken up by the plant.  The fertiliser needs to be applied evenly  Fertiliser should not be applied to the plant itself ie. Leaves and flowers