By Richard Scheetz
Do your lawn, corn, sugar beets or other crops need to be watered? How do you know? How much water have the plants used since the last rain, or irrigation? I can’t even begin to estimate that amount; fortunately there is help.
A very interesting Web site, operated by the United States Bureau of Reclamation (BOR), provides local plant water use information. An automatic weather collection site just south of Terry provides daily temperature, humidity and wind information. The site then utilizes that data, along with standard water use rates for different plants to determine how much water plants use every day. The site address is: http://www.usbr.gov/gp/agrimet/station_brtm_buffrapidsterry.cfm. On the Web site the first thing you will see is the daily weather information. This part is pretty cumbersome, but it does provide very good local weather data specific to Terry. As you scroll down you will find a section entitled “Crop Water Data”. It should list “BRTM=Buffalo Rapids Terry Montana” in the first drop down box. Don’t get overwhelmed by the crop codes, click on “Key to Crop Codes” for a complete list. Once you know what crop you’re looking for, click “SUBMIT” to get the water use chart, it will show a variety of crops.
A new window will open that shows the plant water use for the previous four days. Plants are listed down the left side of the screen with the projected crop growth start date. As I write this (May 18, 2010), lawns, for example, used 0.14” of water last Friday and Saturday, 0.19” on Sunday and 0.2” yesterday with 0.18” forecast for today. Total water use is also given for the last 7 and 14 days - 0.9” and 1.4” respectively.
How can all of this good information be used? It seems overwhelming, doesn’t it? By using the BOR site, we can schedule our watering based on what the plants are actually using. Farmers irrigating their crops know how much water they are applying each time they water and for those of us sprinkling our lawns a low can or rain gauge placed on the ground will measure the amount applied.
For example, if 0.5” is applied each time we water, using the above information we would want to water about every 4 days if the weather is cool like last Friday and Saturday, or every two days if it is hot like yesterday. Not only can we provide the plants the water they need to grow better, but we can also save water and money by not over irrigating and pumping unneeded water.
If you have questions concerning the use of this website, feel free to contact me at the USDA Office.
Published May 19, 2010