Guideline Index

Chapter 3: Plant Nutrient Requirements

3.6 Summary

  • Nutrients are necessary for plant growth.
  • There are two categories of plant nutrients: macronutrients and micronutrients.
  • The major nutrients, or macronutrients, supplied by the soil are nitrogen, phosphorus, potassium, sulphur, magnesium and calcium.
  • The minor nutrients; also referred to as micronutrients or trace elements, supplied by the soil are molybdenum, copper, zinc, manganese, iron, boron, nickel and chlorine.
  • Fertilisers are required to overcome nutrient deficiencies and to replace the nutrients that are lost or removed from the soil and pasture.
  • Nutrient cycling (soil-plant-animal) involves nutrients:
      • Being brought onto the farm in various forms.
      • Undergoing ongoing reactions in the soil.
      • Being consumed by animals via the plants.
      • Being lost to the farm system by various means.
  • Nutrients are required for a number of tasks associated with plant growth.
  • A deficiency in any one of the 17 essential nutrients will reduce pasture growth and animal production.
  • Various trace elements are deficient in some dairying areas.
  • Although grazing animals receive most of their essential nutrients from pasture; plants and animals have different essential nutrient needs. In regard to trace elements, it is sometimes better to treat animal nutrient deficiencies directly rather than supply the nutrient indirectly through the pasture.