Rob O'Connor, an experienced Irrigation Officer with DEDJTR works with Accelerating Change on all things irrigation, including scheduling. Rob shares with us, below, lessons learnt from the project about soil moisture monitoring and the use of moisture probes, and the value of using ET data to schedule irrigations.
Lessons learnt about soil moisture monitoring
Soil moisture probes have been used on the partner farms under different forages in 2015-16 and through the recent winter-spring period. The probes have provided useful information largely for irrigation scheduling, particularly when the moisture probe information was regularly revised and used in conjunction with other scheduling methods already used on farm.
Getting the most out of probes
It was evident from probe data that a shallower depth of moisture extraction was occurring under pasture compared to lucerne. Moisture uptake was typically occurring to a depth of 50-70cm under pasture and 100-120cm for lucerne. (Refer to figures...
Many of the learnings to come from the presentations were directly applicable to dairy farms in our region. Faced with uncertain and varied climatic conditions, water availability and market volatility, grain farmers are chasing efficiency and looking to lower costs of production where it is sustainable and profitable to do so. Coupled with best management practice to get the basics right, farmers were encouraged to use a range of information tools available to them to identify where those extra 1-2% gains could be made.
Technology to drive efficiency: Moisture probes, drones and satellites.
A focus on lifting water productivity came through in technical presentations on irrigation scheduling and soil moisture monit...
At their meeting the Stewart PIT also discussed initial data from the 5 Observant capacitance probes installed on the Stewart farm. Throughout the project the PIT farmers have had numerous discussions on the value of moisture probes and how to use them most effectively.
Soil moisture probe take home messages
Look for the decline in daily water use and ground truth what the cause is. Is it moisture stress or another factor?
Set your own refill and full point management lines. Probe software might give you indicative positions but you have to tailor it to your farm, your soil, your crop and your water infrastructure. If it takes a few days to order or apply water give yourself a bigger buffer between timing of irrigation and the point of water stress, in case things go wrong.
Check it regularly! Read the soil moisture probe graph every couple of days and more frequently if you are nearing irrigation or there is a big change in weather-either rain or heat wave.
Recently both PITs have had technical sessions on the value of moisture probes. Rob O’Connor and Dale Board, both from DEDJTR, have been talking to PIT farmers about the benefits and challenges of using soil moisture monitoring tools. A summary of Dale’s previous research into these tools in the region can be found here: http://irec.org.au/farmer_f/pdf_186/Soil-moisture-monitoring.pdf
Soil moisture monitoring provides a tool that enables irrigators to make more informed decisions regarding water requirements of various crops, which can result in on-farm water efficiency gains and increased productivity.
Some key lessons discussed for moisture probe sessions:
Moisture probes allows you to refine your irrigation schedule to increase water efficiency and productivity
You get the best value from moisture probes when you aim maximise production rather than to minimise absolute water use
Moisture probes allow you to maximise return on investment in farm layout and deli...