Soil Moisture Monitoring is used in agricultural water management applications such as irrigated fields, and in the turf industry for large grassed areas such as sports playing fields and market gardens to optimise the use of reticulation / irrigation system water usage. There is also a very large installed base in the viticulture industry. These systems may employ a range of different soil moisture sensors. The simple approach is to measure soil moisture directly and then decide on the best settings for a reticulation/ irrigation
A more complex and more detailed approach is to measure Evapotranspiration (ET). ET is the most significant indicator to measure water movement for agriculture. ET refers to two processes: water loss from surfaces such as soil (evaporation) and water loss from the leaves of crops (transpiration).
The weather affects ET, solar radiation, air temperature, air humidity, and wind speed. But ET also depends on the nature of the crop, how it changes with time, and soil moisture levels. Evaporation and transpiration occur simultaneously and dependently, so are treated as one process. When a crop is first planted, the soil is exposed to the sun and most of the water loss initially is through evaporation. But as the crop grows and starts to shade the soil, evaporation decreases and transpiration increases.
For the simple approach single soil moisture sensors can be an older style of gypsum block, measuring resistance across that block or a modern sensor using Time Domain Reflectometery (TDR) techniques to send out a pulse and measure the return echo to determine the water / moisture content of the soil.
The soil moisture sensor is connected to a data logger or Neon Remote Module and a scheme / program is set up to measure, store, and optionally display soil measurement data locally, or routinely send that data via the internet to a Neon Server, so it can be viewed on a standard web browser. The data logger or Neon Remote Module can also be programmed to react to certain events. For example, if it has rained and the soil is very moist, the data logger could be programmed to signal an irrigation system that it did not need to run at that time.
The turf industry, especially those that operate on sandy soil areas has been slow to take up soil moisture monitoring. With recent advances in technology and communications, however, soil moisture monitoring is now a real option.
Modern soil moisture probes are reliable and affordable. Telemetry options mobile phone / cell phone and satellite network modems are also affordable, so moving data from the field to websites, and easy access to data on mobile Web Browsers and specialized apps on iPads and iPhones make it easy for Turf managers and Irrigators to check soil moisture reading in the field.
The Unidata partner, Future Turf produces a complete system. This turf irrigation tracker system is easy to of install and there is minimal disruption to the sports oval playing surface. The user gets instant collection and transfer of data through its “plug and play” nature and soil moisture data is well presented on easy to understand graphs either on an iPad or Laptop. It is also easy to relocate the probe if needed.
The Irrigation Tracker generates important information for irrigation managers, such as confirmation of the amount of irrigation applied, monitoring irrigation depth, monitoring the soil moisture status of the root zone, monitoring root zone salinity and monitoring root zone soil temperature. The Irrigation Tracker components are securely housed in a standard valve box, or buried below the turf surface. A 40cm sub-surface probe with four sensors measures soil moisture, salinity and temperature at 10, 20, 30 & 40cm, The Neon Remote Module / logger stores data collected from the probe and sends that data back to a Neon Server daily. With a daily reporting period a battery pack can power the entire system for 2 years. For the more complex and detailed approach to measure ET we can estimate ET from meteorological data, but a far more direct, accurate and defensible measurement uses the ‘Eddy Covariance’ (EC) method. Instruments on the EC tower continuously and rapidly sample the turbulent airflow that transports water vapor, heat and carbon dioxide used, or given off, by plants during photosynthesis or respiration. This method is accurate, but complex, and to get good results, we pay detailed attention to specifics.
The EC tower uses the following sensors to telemeter several parameters needed to accurately calculate ET:
You can measure the water passing through the soil with lysimeters, located near the EC tower. Sites need careful preparation and require a significant amount of excavation to create two underground bunkers where the measurement equipment is housed.
You can use a containment vessel, or barrel, to isolate a cylindrical core of the crop along with the soil it grows in. You then reposition this, with the lysimeter opening at ground surface level, so it looks like and shares the same environment as the rest of the crop, in this case pasture. You can measure the amount of water leaching through the contained soil by piping it out the bottom of the barrel to a rain-gauge located below it in the underground bunker. You can then compare the amount of water that flows through the lysimeter (water out) with the rainfall or irrigation (water in) that we measure in another rain-gauge at the same location. You can also use more than one lysimeter at each site to measure soil moisture sensors at different depths within the barrel, to give a continuous representative vertical soil-moisture profile
|Options for Application Specific Instruments / Inputs||Unidata Part Number||Description|
|EnviroPro Soil Moisture and Temperature Probes||6513GL-XX||Soil Moisture and temperature probes with number of sensors from 4 to 12|
|Vaisala Weather Transmitter WXT536 measures barometric pressure, humidity, precipitation, temperature and wind speed and direction||6501V-H||Vaisala WXT536 Weather Transmitter RS232/422/485 SDI-12 With Bird Spikes|
|Rain Gauge||6506C||Rain Gauge / Tipping Bucket|
|Options for Neon Telemetry - NRT / RTU / Field Units||Unidata Part Number||Description|
|Cellular RTU 3G||2013F-AB03||Neon Metering Module 3G with Antenna and Li Battery|
|Cellular RTU 4G||2013F-AB04||Neon Metering Module 4G with Antenna and Li Battery|
|Cellular RTU 3G - Industrial||2016F-AB03||Neon Remote Terminal 3G with Antenna and Li Battery|
|Cellular RTU 4G - Industrial||2016F-AB04||Neon Remote Terminal 4G with Antenna and Li Battery|
|Low Earth Orbit Satellite Globalstar||2015E-AB0||Neon Remote Terminal - Satellite Globalstar Modem with Antenna and three Li Batteries|
|Ethernet||2017E-0B0-1 or 3||NRT Ethernet with single or triple Ethernet Ports|
with three Li Batteries
|Equatorial Orbit Satellite - Inmarsat||2018E-AB0-1 or 3||NRT Ethernet with single or triple Ethernet Ports|
with three Li Batteries
|LCD Display||2500E||NRT LCD Display|
|NRT Field Termination Strip||2103F||2015E,2016F,2017E, and 2018E NRT FTS|
|NRT Firmware Option||2303A-8M||8M Extended Memory Option|
|NRT Firmware Option||2303A-8M-CAM||8M Extended Memory & Serial Camera Option|
|NRT Firmware Option||2303A-CAM||Serial Camera Option|
|Options for Neon Application Software - Customer Server||Unidata Part Number||Description|
|Neon Application Software||2302A||Neon Server Software Licence Incl 5 NAL |
|Neon Application Software||2302A-10||Additional 10 NRT Access Licences|
|Neon Application Software||2302A-20||Additional 20 NRT Access Licences|
|Neon Application Software||2302A-50||Additional 50 NRT Access Licences|
|Options for Neon Application Software - Unidata Server||Unidata Part Number||Description|
|Neon Application Software||2301A||Neon Data Initial Subscription Setup Fee|
|Neon Hosting Service||2301A-01||Neon Data Service Fee for 1-50 NRTs|
|Neon Hosting Service||2301A-02||Neon Data Service Fee for 51-100 NRTs|
|Neon Hosting Service||2301A-10||Neon Data Service Fee Metering|
|Options for Conventional Dataloggers / Field Units||Unidata Part Number||Description|
|Standards Starlogger||6004D-11||Red Logger 512K with Alkaline Battery|
|Display Starlogger||6004D-21||Blue Logger 512K with LCD and Alkaline Battery|
|Prologger||7001D-11||Green Logger 1M with LCD and Alkaline Battery|
|Starlogger Field Termination Strip||6103E||6004D FTS|
|Prologger Field Termination Strip||7100E||7001D FTS|
|Starlog V4 Management Software||6308A-AUE||Starlog V4 Full Licence Key|