Colour me phosphorous (P)

Soil: Australian soils are often low in phosphorous (P). Native plants have adapted to this efficient take up of any available phosphorous, but exotic plants and food crops require supplementing with phosphorous. Phosphorous is most available to plants in a 6-7pH range.

Plants: This energy mineral is used in virtually every aspect of plant growth, including photosynthesis, and the formation of plant sugars and starches. Phosphorous promotes vigorous early root (excellent for root vegetables) as well as stem growth and flowering. The colour intensity of flowers, fruit and vegetables is determined by phosphorous.

People: Phosphorous is needed by every cell in the body and together with calcium, is essential for bone structure, pH balance and membrane structure in cells. This mineral  closely linked to reproductive health.

Animals: As with people, phosphorous is essential for bone structure and must be balanced with calcium and vitamin D for maximum benefit. It is essential in the production and mobilisation of energy and is required for reproductive efficiency.

Plant Deficiency Symptoms : Plants are usually stunted with a reduced capacity to produce fruit. Leaves can take on a dull green to purple hue, often affecting older leaves first. Purple lower leaves are a classic sign of phosphorous deficiency.

Old farm sites often have a good store of phosphorous locked away from years of super phosphate applications. Home gardeners can tap into this frozen reserve using inoculums of phosphate solubilising organisms.

Soil pH is a powerful guideline to nutrient uptake and it has been determined that a pH of 6.4 is ideal. At that level, the best balance of availabilities is found, so that your food plants will be providing the highest nutrient density for you and your family.

People often think pH as an indicator of calcium levels in soil, but magnesium is just as important, particularly in lighter soils. In these soils it is advised to use dolomite rather than limestone as you will require both calcium and magnesium.

An acid soil is equivalent to an empty pantry because it is dominated by the mineral, hydrogen, which is the acid element and it is not a plant food.