SIDNEY, Mont. – A USDA-ARS sugarbeet tillage study under irrigation, that began last year and is set to run to 2023, utilizes soil moisture sensors system to help with managing irrigation.
The ARS team utilizes the IRROmesh Relay Node and Watermark sensors system that is connected with the Internet and can be read in real time on one’s Smartphone at remote locations.
The user can then make irrigation decisions based on the sensor readings.
Bart Stevens, an ARS research agronomist at the Northern Plains Agricultural Research Lab (NPARL) in Sidney, explained there would be three crops in the irrigated tillage study, including ND Genesis barley, GTS 437N sugarbeets and CDC Treasure yellow peas.
“Our primary focus is sugarbeets, and we want to evaluate side-by-side different tillage methods, conventional tillage, strip-till and no-till,” Stevens said. “We also want to look at this unit study in a system and how it could affect soil properties.”
Sugarbeets were being rotated with yellow peas and barley to mimic an actual irrigated producer’s system.
The team does have results from 2017, although they are starting the study officially in 2018, and using barley, instead of wheat. Barley is one of the main rotation crops with sugarbeets in the Yellowstone Valley.
Last year, they saw that peas responded well with irrigation, and it was a dry year in 2017.
“We’re interested in seeing how peas do this year under irrigation and seeing the yield results,” Stevens said.
With the wind, Stevens said they have started to see bacterial blight in mid-July, but no fungicides were applied. However, there was not much else for disease, and the peas looked good.
“One of things we’re looking at is row spacing in the barley, either 7 inch or 12 inch. The reason for that was to make the no-till beets perform a little better with emergence,” he said.
They will plant sugarbeets in between the 12-inch barley stubble rows in the no-till system next year, with the hope the stubble protects the beet seedlings well.
Early results showed the barley yielded well in 12-inch rows, yielding 142 bushels/acre, compared to 134 bushels/acre with the 7-inch row barley.
But studying tillage is not the only purpose for the study. Many scientists are involved, looking at the project in different ways.
Jay Jabro, a NPARL-ARS Research Soil Scientist, told producers he has many soil and water management research goals he is trying to achieve within the project.
Aziz Nilahyane, a post doctorate student at Montana State University’s Eastern Agricultural Research Center helped show the IRROmesh system to the producers at field days.
One of the goals is to utilize irrigation water efficiently and economically, as irrigation water management is a critical element in irrigation farming.
The IRROmesh system is a wireless, solar-powered data-logging system that simplifies irrigation management using transmitter nodes that talk to each other along a network that relays site-specific data.
They placed Watermark soil moisture sensors in several places in the field at different depths.
To install the WaterMark sensors, Nilahyane said they prepare a slurry, bore a hole, put in the PVC pipe, and put the slurry down in the hole.
“We make sure there is good contact between the soil and the sensor,” he said, adding it takes about “8-24 hours to get a reading after we put the slurry in.”
These sensors help farmers and researchers measure soil moisture to maximize irrigation efficiency, and minimize irrigation costs.
“This is a Watermark sensor and this one is an electrical resistance device in a porous ceramic wafer, coated by a granular matrix material, and encased in perforated stainless steel case to protect the sensor,” said Jabro, displaying the sensor to producers gathered for a MSU-EARC and Sidney ARS field day in June 19, 2018.
Each node is capable of reading three soil moisture sensors and a soil temperature sensor.
Inside the sensor are two electrodes that measure electrical resistance, which is converted to soil matric potential.
“Soil matric potential is a negative pressure or suction or tension, or how tight water is held by soil particles,” he said.
The team uses a chart or an equation to convert soil matric potential to volumetric soil moisture content.
The IRROmesh meter is a compact, solar-powered, wireless system, mounted on PVC pipe, and is used for routing in-field measurements of soil moisture, temperature, and other parameters.
Sensor data from each node is routed through the IRROmesh back to a central point (cellular provider, such as Verizon or AT&T) where it can be uploaded to the web and made accessible to anyone with an Internet-enabled computer or Smartphone or tablet.
Utilizing Watermark soil moisture sensors, IRROmesh allows farmers and researchers to collect real-time data from sensors placed all over the field and farm.
The data can be instantly viewed to make informed irrigation scheduling decisions.
“Logger radios talk to each other and to the cellular provider and we can upload DSL information (wireless technology information) back in our offices, and monitor soil moisture contents and decide when to irrigate,” Jabro said.
Another objective of the project is to evaluate the effect of tillage on soil physical properties.
They are using three tillage systems, including tilled, which has a lot of soil disturbance; no-till, which has minimal soil disturbance, and strip-till, which has some soil disturbance, for evaluation.
“Tillage has a profound effect on soil physical properties and entire soil ecosystems,” he said.
The team is also measuring soil bulk density, using a core method that quantify soil compaction.
Jabro showed a compaction meter to the producers, and explained how to use it.
“With this device, we quantify soil compaction. Soil compaction has been a problem here,” he said.
After turning it on, he pushes it in the ground at the right or steady speed and it gives results.
“The results can be downloaded to your computer or Smartphone,” Jabro said.
A producer asked how much difference there was in soil compaction with the three tillage systems.
“There is a lot,” Jabro said.
With the three tillage systems under irrigation, the team is also trying to find out how fast water enters the soil surface and how fast water moves through the soil profile, among other soil parameters.