Soil Tests

1. Soil Tests - Basis for Soil Testing - Result Interpretation

2. Why Carry Out a Soil Test? • Aid in providing the optimum availability of nutrients for turf growth • Identifies nutrient deficiencies and problems which can be addressed before a maintenance program is initiated • Opportunity to create and/or maintain optimal soil chemistry for turf growth

3. Benefits of Soil Testing • Optimise plant health • Reduce unnecessary maintenance practices and fertiliser applications • Opportunity to save both time and money • Removes guesswork from formulating fertiliser programs

4. Sampling Procedure • Reliable results depends on correct sampling • Aim to provide a representative sample • Sampling depth important due to profile horizon variation

5. Sampling Instructions • Approximately 200g of soil necessary for nutrient analysis • Depth of cores should measure 10cm • Small cores more suitable than hole changer- sized cores

6. Sampling Instructions cont. • Take samples from areas of average growth • Take cores from poorer spots only if they are numerous • Cores should not be taken from recently fertilised areas • Time of year is important for historical analysis

7. Soil Properties Analysed • Soil pH (water, and CaCl2) • Cation Exchange Capacity (CEC) or Sum of Cations • Total Soluble Salts (TSS)/Electrical Conductivity (EC) • Phosphorus (Olsen)

8. Soil Properties Analysed cont. • Potassium (Skene) • Ca/Mg Ratio • % Base Saturation Ca, Mg, Na, K

9. Interpretation of Results • Results interpreted specifically in relation to turf growth • Turf has specific nutrient requirements and tolerance to toxicities of various elements • Turf Use is used to assist in determining recommendations

10. pH

11. Total Soluble Salts (TSS)/ Electrical Conductivity(EC) • Reports the TSS in parts per million and the EC in dS/m. • TSS(ppm) = EC (dS/m) x 2970 • Ideal TSS level is <1000ppm or EC<0.34

12. Salinity

13. Cation Exchange Capacity (CEC) • Is equal to the sum of the of the 4 major cations (Ca, Mg, Na, K) measured in milli-equivalents/100g • Is largely dependent on soil type • low CEC: < 4 meq/100g (sands) • moderate CEC: 4-10 meq/100g (loams) • high CEC: >10 meq/100g (clays)

14. To Raise CEC • Incorporate organic matter • Increase % of loam and clay-sized particles in soil

15. Phosphorus (P)

16. Potassium (K)

17. Base Saturation • Used to assess the levels of Ca, Mg, Na and K as percentages of the total CEC. • Optimum Extractable level of an ion such as Ca is dependent on the CEC of the soil • Presenting levels as Base Saturation (or % of CEC) eliminates the need to consider CEC. • Recommendations based on ideal ranges of % base saturations

18. Base Saturations

19. Ca/Mg Ratio • Low: <2 Apply Gypsum • Optimal: 2-5 • High: >5 Apply Dolomite

20. Remedial Action • Products used in remedial treatments can have complimenting or conflicting effects on other soil properties. • Must take into account this range of effects when recommending remedial action. • Eg. Treatment of pH can effect the Ca/Mg Ratio

21. E.g. Remedial Treatments knowing the pH and Ca/Mg ratio

22. Nutrition Targets

23. Soil testing is an important tool for turf management. Results are most useful prior to renovation, but can be conducted year round Conclusion