 up with irrigation over the past month. If a field's soil water balance is consistently below the trigger line, you might need to irrigate more frequently.
Soil water is near field capacity.
Field is drying, but irrigation might not be needed.
Check soil and crops to verify irrigation is needed.
This is the second monitoring option in the Crop Water Use application that can help a farmer make plans in their fields for the next week, assuming no rainfall occurs. It can help you plan ahead for labor needs and help anticipate future irrigation needs that might interfere with planned activities.
The Soil Dryness Index in Farm Summary is derived from the soil water balance and the irrigation trigger and can simplify irrigation management to save farmers time. For growers with 100 or more fields, keeping up with each field's irrigation trigger value can be difficult. For example, two fields of a crop planted on the same day can differ even when soil water balances are the same because the soils are not the same. A field with silt loam soil might last one or two days longer without water stress than a field with sandy loam soil, which might need to be irrigated sooner.
To make the process easier to interpret, a dryness index with four levels based on a critical soil water balance for each field is calculated from rooting depth, available water holding capacity and allowable depletion. Table 1 is an example from research fields irrigated at University of Missouri. Field 4 Pivot E and Lee Field 12-1a needed irrigation that day. The others could wait until later in the week. A warning is displayed on the Farm Summary screen based on the soil water balance trigger for each field. If a field shows an OK dryness index, that means the balance is greater than 70 percent of the critical level. One, two or three asterisks were shown when the balance exceeds 70, 80 or 90 percent of the critical level, respectively. The farm summary displays XXX when the balance exceeds the critical level and irrigation is needed.
The dryness indexes for each field assumed historical evapotranspiration, or ET, for the projected days and no rainfall will occur in the next week. Fields can be printed out to distribute to farm workers.
Example graph of soil water balance over a four-week period, with an irrigation trigger point of -0.90 inch.
Farmers using the Crop Water Use application might be eligible to receive federal funds from Environmental Quality Incentives Program (EQIP). To promote water conservation and reduce nutrient runoff in streams, the EQIP pays farmers in designated watersheds to use this application. Starting in 2015, the Crop Water Use application met the criteria for the Missouri 2015 General Conservation Stewardship Program, Enhancement Activity NRCS Code WQT07 (Regional weather networks for irrigation scheduling). The application has a reporting option that allows users to print season-long results for each field, which can be used as documentation to receive EQIP payments at the end of the year from the NRCS. This report could also be used to calculate the amount of water pumped per field or well for a field.
An example of a daily farm summary report from irrigated fields managed by the Fisher Delta Research Center Cropping Systems Project.
On the next screen, you have the option to either launch the application and bookmark the link or request the URL by email.
If you request an email link, you will receive an email containing a URL with a unique combination of 32 numbers and letters to link to your account. Only share your unique URL with people you trust. You can copy and paste the URL to your computer and mobile phone to save time not having to type in a password every day to check your fields.
The Crop Water Use application requires daily weather data from the Missouri weather station Mesonet to function. Currently, the program only works when you have internet access by Wi-Fi or a cellular data connection.
Screen for new users and login for existing accounts.
Using your unique URL, go to your Crop Water Use application account.