Life Sciences Commons^™

Soil Test And Phosphorus Rate For High Rainfall Clover Pastures, Robert Summers, David Weaver

Bulletins 4000 -

When new land was first developed, phosphatic fertilisers had to be applied at high rates to overcome Phosphorus (P) deficiency, and to increase P fertility. Once good P fertility has been established after a number of years of applying P, the requirement for applying high rates of P falls. After that you only need to apply enough fertiliser P to replace that removed in products, fixed by the soil, eroded and leached, that is a maintenance rate of P.

In relation to P fertiliser decisions for pastures you need to ask:

• Do I need P?

• How do I …

Potassium For High Rainfall Pastures, Mike Bolland, Bill Russell

Bulletins 4000 -

Potassium plays a major role in plant growth. It maintains the solutions in plant cells at ionic strengths suitable for maintaining strong plant walls and for the proper functioning of leaf pores (stomata) and plant processes such as photosynthesis, transport of sugars and enzyme activation.

Potassium does not become a direct part of the plant structure but acts to regulate water balances, nutrient and sugar movement in plant tissue. Plants deficient in potassium cannot use other nutrients and water efficiently. They are less tolerant of stresses such as drought and waterlogging and are more susceptible to pests and diseases.