Soil moisture monitoring is an area of growing study for dry land farming and irrigators alike. Accurate monitoring of soil moisture penetration into the soil depth profile is key to efficient and effective irrigation techniques. Optimum timing of effective irrigation can lead to increased yields by preventing plant stress days and keeping nutrients in the fibrous root zone.
Coupling soil moisture readings with weather station parameters such as wind, temperature, RH, rainfall and solar irradiance can greatly aid modelling and prediction of plant soil moisture requirements ahead of time.
Benefit for Irrigators
- RAW – Readily Available Water in your soil provides a zone between over and underwatering where you crop can readily extract water from the soil. RAW is determined by soil type, crop, rooting depth (restricted by soil tension) and form of irrigation used. The chart indicates the RAW zone as “available water”.
- Ongoing monitoring of soil moisture levels can help to understand your soils relationship to irrigation and moisture holding capacity.
- Studying of daily soil moisture patterns can reveal a daily uptake of soil moisture by your crop as part of an evapotranspiration process. The transpiration process also acts as a cooling mechanism for crops to prevent heat stress. As such soil moisture will generally not deplete much overnight when the photosynthesis process is not taking place and the crop isn’t experiencing heat stress. Ideally this would result in a distinctive stepped soil moisture pattern from day to day. When these steps get smaller and smaller without a notable weather change this can be a sign of plant stress. It should be noted that plant water uptake will vary throughout its development process.
- For seasonal crops, root depth can be tracked by studying the depths of the soil profile that show a daily decrease in soil moisture.
- Combining soil moisture with salinity provides an alternative means of tracking fertiliser movement through the soil. If overwatering occurs during fertiliser application the fertiliser nutrients can be carried past the root zone and unable to be reached by your crop.
Benefits for Dry Land Production
- Key benefits of monitoring dry land soil moisture profile are the knowledge available deep soil moisture to carry a crop through to maturity after the root system reach a deep moisture zone.
- Monitoring of summer crops or cover crop effectiveness toward deep soil moisture retention over summer periods.
- Determine which crops are heaver on soil moisture and model soil moisture to crop yields.
- Tracking of plant root growth through the soil profile by monitoring depth of moisture extraction.