Soil Temperature - An Under-Used Turf Management Tool
The use of soil temperature data is certainly useful for predicting the germination of annual weeds like Poa annua (21oC), Eleusine indica (16-18oC) and Digitaria sp. (12-15oC). This will then help with correct timing of pre-emergent herbicide treatments. But soil temperature can also be a useful tool for predicting disease activity, turfgrass growth patterns and to a lesser extent insect activity. The table shows critical soil temperature ranges which may be useful for turf managers. Most of this information is from the USA and should be appropriately used and adapted for Australian conditions.
Soil temperature information data can be obtained from the Bureau of Meteorology web-site, but measurement of temperature on site will be most valuable as significant variation can occur even across small distances depending on soil type, turf cover, aspect, shade etc. It is important to note that turf cover will have an insulating effect on soil temperature and so on site results may vary from those measured by the Bureau.
Click here to view Bayer's "Soil Temperature Chart"