- Author: Michael D Cahn
Irrigations can be tracked for each planting by entering new watering events into the “Irrigation Summary” table (Fig. 1). In addition to keeping records on when and how much water was applied, CropManage will recommend an amount of water to apply and an optimum interval between irrigations using reference evapotranspiration data from CIMIS (California Irrigation Management Information System), crop development models, and information about the soil type of the field and irrigation system. CIMIS is operated by the California Department of Water Resources.
To add a new irrigation event, select the “new watering” button located below and to the left side of the irrigation summary table (Fig. 1) or select “New” and then “New Watering” from the “Quick View” screen (Fig 2).
Figure 1. Enter new irrigation events by selecting “New Irrigation” below the irrigation summary table.
Figure 2. New irrigation events can be entered from the quick view screen by selecting “New” and “New Watering.”
An entry form will display for adding a new irrigation event (Fig 3). Enter the intended date of the irrigation. The previous irrigation event will be displayed on the right side of the form. CropManage uses the days between the last irrigation or significant rainfall event and the next planned irrigation to estimate the water needs of the crop.
Next, select the method of irrigating. The choices are "Germination Sprinkler", "Sprinkler", "Drip", and "Rainfall." The irrigation method is used for estimating crop evapotranspiration and determining an appropriate amount of water to apply to compensate for non-uniformity of the irrigation system. Evaporative losses of moisture from the soil surface are normally greater under sprinklers than drip irrigation, and the application uniformity is usually higher under drip than sprinklers. The uniformity of the irrigation system must be entered when setting up the planting.
"Germination Sprinkler" is distinguished from "Sprinklers" because the method of irrigating with sprinklers during germination is sometimes different than when the crop is established. This distinction allow the user to set different levels of uniformity or application rate for sprinklers used in the germination and the establishment phase of the crop.
Significant rainfall events (more than 0.25 inches) recorded at the CIMIS station associated with the ranch, are automatically entered into the irrigation summary table if no other irrigation events were added for the same day. For cases where significant rainfall is recorded near the planting but not measured by the CIMIS station, one can manually enter the rainfall event by selecting “Rainfall."
Figure 3. Form for entering new irrigation events for a planting.
After saving the new watering, the form will update with a recommended amount and time to irrigate, and display a space to enter the amount of water that was applied (Fig. 4). One can save the form without entering the applied water amount, and after irrigating, enter the amount of water applied. Also, one can enter the amount of water intended to be applied and reenter the value after the irrigation is completed. The amount of applied water can be entered as depth of water applied over the area of the field in units of “inches”, or as time (hours) irrigated, which is converted to inches of water applied using the application rate of the irrigation system. If rainfall was selected, then enter the rainfall depth in units of “inches.”
Figure 4. Irrigation form updates with recommended water amount after entering the irrigation date and saving.
After selecting “Save Watering” the table will be updated with the new irrigation event (Fig. 5). The table displays the recommended irrigation interval, amount of water to apply, and hours to irrigate (Fig. 5). The next column to the right displays the amount of water that was applied. Note that no entry was made for the last watering on 9/18 since the irrigation had not occurred yet. The user can add this information later, or change or delete the irrigation event. The next columns display the estimated crop coefficient (Kc) used to convert reference ET to crop ET, and the estimated canopy cover of the crop, used for modeling the Kc values. The last 2 columns on the right display the average daily reference ET and total crop ET since the last irrigation event (Fig. 5).
Figure 5. The irrigation summary table displays recommended irrigation interval, water amount, and hours to irrigate as well as crop coefficient and reference ET values used for the recommendation.
Figure 6. Selecting “next columns” will also display precipitation and other data used for estimating the water needs of the crop.
Selecting the “Show Next Columns” button above the table to the right side, will display cumulative reference evapotranspiration (ETo), cumulative crop evapotranspiration, precipitation, and other data used for estimating the crop water needs. Selecting the “Show Next Columns” button again will display information of the estimated root depth of the crop, allowable soil moisture depletion, and flow meter data if one is used to measure applied water.
One can customize the column order of the table by clicking on a column heading with the mouse curser and dragging the heading to a new location on the table (Fig. 7). Clicking on previous order button will rearrange the columns to the original order. Additionally, one can temporarily hide specific columns from the table by clicking on the “Show/Hide columns” button.
Figure 7. The order of the columns can be changed by dragging the column heading to a new location./span>
- Author: Michael D Cahn
Cool season vegetable production requires significant inputs of water and nitrogen (N) fertilizer to maximize yield and quality. Proposed changes in water quality regulations on the Central Coast and higher fertilizer prices in recent years have prompted grower interest in increasing efficiency of nitrogen fertilizer use in lettuce. By improving water management and matching nitrogen applications to the uptake pattern of the crop, growers could potentially reduce fertilizer use and address water quality concerns.
Two tools available, the quick nitrate soil test and weather-based irrigation scheduling, have been shown to help lettuce producers better manage water and fertilizer nitrogen. Trials we conducted in commercial fields have demonstrated that soil nitrate concentrations greater than 20 ppm NO3-N, are sufficient to maximize crop production. In addition, we have shown that evapotranspiration data available from the California Irrigation Management and Information system (CIMIS), can be used to accurately estimate the appropriate volume of water to apply to meet crop needs and minimize potential leaching losses of nitrate-N.
Both the quick nitrate soil test and weather based irrigation scheduling require more management time for growers to implement in their farming operations. The quick nitrate soil test entails collecting a representative soil sample in the field, extracting the sample, and calculations to estimate the concentration of soil nitrate. Weather based irrigation scheduling requires calculating crop evapotranspiration (ET) from CIMIS reference ET data and a crop coefficient corresponding to the developmental stage of the lettuce crop. In addition, information on the soil type and irrigation system is needed to determine the optimal irrigation interval and run-time. With multiple fields and ranches to track throughout the season, customizing water and fertilizer for individual fields could become a significant cost for growers.
CropManage is an online database-driven tool that assists growers and farm managers in determining water and nitrogen fertilizer applications on a field-by-field basis. The software automates steps required to calculate crop water needs from CIMIS ET data, and estimates fertilizer N needs for lettuce using quick N test data and models of crop N uptake. The web application also helps growers track irrigation schedules and nitrogen fertilizer applications on multiple fields and allows users from the same farming operations to view and share data.
The software was developed by UC Cooperative Extension and is free to use, and can be accessed at: https://ucanr.edu/cropmanage The application can be accessed with a web browser using a smart phone, laptop, or tablet computer. The tool uses a secure login procedure so that only individuals with permission can view and/or edit water and nitrogen fertilizer records of a particular farming operation.
CropManage was designed to be as intuitive as possible for growers and farm managers to use. Once logged on, users can view a list of ranches/farms that they have permission to access. By following the hyperlink for an individual ranch, a user can view a list of all active plantings associated with the ranch. Each planting has a summary of the ranch name, lettuce type, planting configuration as well as soil type, field name and planting and harvest dates:
Tables summarizing soil nitrate tests, fertilizer applications, and irrigation schedule are shown for each planting:
Getting started with CropManage.
There are three steps to begin using CropManage:
- Obtain account username and password by following the “create new account link” at the bottom of the login page and completing the instructions. Read and accept UC privacy and data security policy to continue.
- Set up a new ranch in CropManage by selecting “new ranch” at the bottom of the ranch list page, or request to be assigned to an existing ranch/farm. All users are automatically assigned full access to a ranch named "UCCE Ranch" so that they can try out CropManage. To add a new ranch to CropManage, we recommend that you use the online form. One can also download the excel ranch template from the import/export options link. Fill in the required information and email the template to email@example.com so that it can be uploaded into CropManage. For more details on setting up a new ranch, click here.
- Set up new plantings in fields within a ranch. Select “new planting” at the bottom of the current planting list and fill in or select required information.
If you have interest to learn more about using CropManage, please contact Michael Cahn (831) 759-7377 or Barry Farrara (831) 759-7365.
Note: CropManage is still in the development stage, so new features will be added in the upcoming months. Recommendations are currently specific for romaine and iceberg lettuce production. We plan to expand this tool to a wider group of cool season vegetables in the upcoming months as funding permits.