The most important nutrients a plant needs are the ones that are most limiting. Called the ‘law of the minimum’, a plant’s growth is dictated not by the total quantity of nutrients available, but rather by the scarcest one.

Crop plants need 16 essential nutrients to complete their life cycle. Divided into macro and micronutrients, plants require macronutrients in greater amounts compared to micronutrients, though from the plant’s point of view, all the nutrients are equally important for growth.

Three macronutrients – carbon, hydrogen and oxygen – are supplied to plants by the air so their delivery is not a problem.

Ideally, the remaining 13 nutrients should be present in the soil in adequate amounts and proportion for optimum plant growth.

A nutrient deficiency in crops and pasture can occur for several reasons:

» Insufficient nutrients are present in the soil.

» pH is either significantly high or low.

» A notable nutrient imbalance exists.

» Nutrients cannot be absorbed and utilised by plants as the result of unfavourable environmental conditions such as being too dry, wet or cold.

The impact of a nutrient deficiency, if not remedied, results in a loss of yield. To correct a poorly performing crop or pasture, consider complementary alternatives such as foliar nutrition.

The purpose of foliar nutrition is not to replace soil fertilisation, as granular fertiliser is the most effective and economical means of supplying a plant’s macronutrient needs. Rather, foliar nutrition supplies micronutrients, such as zinc and molybdenum, while supplementing the plant’s macronutrients such as nitrogen, phosphorus and potassium, that are needed for short-term growth. Foliar nutrition can also be utilised as a quick and effective management tool to favourably influence the growth of plants that have been compromised by environmentally induced stresses, from adverse growing conditions and/or poor nutrient availability.

Contact your local PGG Wrightson Technical Field Representative for advice on forming a foliar nutrition plan.

THE BENEFITS OF FOLIAR NUTRITION:

» Allows for the rapid correction of a nutrient deficiency, with the immediate uptake of applied nutrients.

» Provides accurate and even application of small amounts of key elements.

» Supplies plants with certain micronutrients that may not be readily available in the soil.

» Can be combined with other foliar chemicals, minimising application expenses.