September 25, 2009

UNL Extension Tools You Can Use

From its start in 2005 with 15-18 cooperators, the Nebraska Agricultural Water Management Demonstration Network (NAWMDN) has grown to more than 220 producers, crop consultants, and NRCS and Extension personnel in 36 counties across Nebraska.

These cooperators are using ETgages and soil moisture equipment to monitor crop water use and soil water status. They post weekly changes to the online ETgage tool 

ETgages

Atmometers (ETgages) are economical tools that mimic evapotranspiration (ET) rates and are used to monitor or estimate crop water use. Knowing the crop's ET rate and growth stage can help you better manage your irrigation and water use. 

ETgages are simple to use and interpret and are relatively inexpensive, costing about $200. NAWMDN uses ETgages to estimate crop water use and Watermark sensors to measure soil moisture to determine irrigation timing and amount.

The advantage of using an ETgage is that it is located near your field and you can be actively involved in reading the gages on a weekly basis. ETgages are usually placed at the edge of an irrigated field or service road for easy access. For more information about using Atmometers, check out the UNL Extension NebGuide, Modified Atmometers (ETgages) for Irrigation Management (G1579).

We are actively seeking more reporting sites around the state. Producers or consultants who have ETgages and would like to post their readings to the site should register at: http://water.unl.edu/cropswater/nawmdn.

Watermark Granular Matrix Sensors

Another tool used by NAWMDN cooperators are Watermark Granular Matrix sensors. These sensors are economical, durable, simple, and accurate tools to monitor soil water status. One of the goals of the network is to utilize as much off season precipitation and dry down the soil profile as we near the end of the growing season! By knowing your crop's soil water status and stage of development and by monitoring precipitation and irrigation applications, you can accurately predict when to make that last irrigation.  For more information on this method, see the archived story in CropWatch, Measuring Soil Water Status Using Watermark Sensors.

Also see these sites for more information on crop water use and irrigation management .

Gary Zoubek
Extension Educator, York County