Soil nutrient testing: how to get meaningful results

Applying sufficient but not excessive amounts of fertiliser is an integral part of good turf management. Periodic testing of the soil has traditionally been used to determine the amounts of different nutrients (other than nitrogen) that should be applied in a fertiliser program, while regular plant tissue testing enables plant nutrient status to be monitored. However, as with any analytical service, the results can only ever be as representative of the area as the sample submitted, and only as accurate as the analytical techniques employed in the laboratory.

Soil testing is an important but sometimes misused tool for turf producers and turf managers. The link below provides access to a paper that explains the principles on which good soil testing is based, how the results should be interpreted and what can be reasonably expected of a soil test in a turf situation. The paper was extracted from the workshop ‘Healthy soils for great turf’, held at Cleveland on 20 February 2006 by the Department of Primary Industries and Fisheries, Queensland.

The subjects considered in the paper include:

• why soil is tested
• taking a representative soil or plant tissue sample
• analytical methods and objective standards for soil and plant tissue testing
• interpreting soil test results and the significance of calibration experiments
• problems with the concept of the Base Saturation Ratio approach
• the complementary use of plant tissue analysis.