- Author: Michael D Cahn
Fertilizer applications can be tracked for an individual planting by entering each fertilizer application into the “Fertilizer Summary Table.” Additionally, a recommended nitrogen fertilizer rate can be determined using recently measured soil nitrate test values. Ideally, the soil should be sampled within a few days of the planned fertilizer application. Since soil nitrate can readily leach with percolating water, any irrigation events between soil sampling and fertilizing could affect the nitrate level of the soil.
To add a new fertilizer application, select the “new fertilization” button below and to the left side of the fertilizer summary table (Fig. 1) or select “New” and then “New Fertilization” from the “Quick View” screen (Fig 2).
Figure 1. Enter new fertilizer events by selecting “New Fertilization” below the fertilizer summary table.
Figure 2. New fertilizer events can be entered from the quick view screen by selecting “New” and “New Fertilization.”
A fertilizer entry form will display for adding a new fertilizer event (Fig 3). Enter the intended date for the fertilizer application and the estimated number of days until the next fertilizer application. A default value for the fertilizer interval is displayed in the form, but it is important to change the value if it is not equal to the expected interval between fertilization events. CropManage uses the days between fertilizer applications to estimate the nitrogen demand of the crop.
Figure 3. Form for entering new fertilization events for a planting.
After entering the interval, choose the most recent soil nitrate sample to use for the nitrogen fertilizer recommendation (Fig. 4). If no soil sample was collected or no recommendation is needed, then choose “no soil sample.” One can update the N recommendation later if a new soil nitrate test is conducted.
Figure 4. Select the most recent soil nitrate sample to use for the N fertilizer recommendation.
Finally, choose the fertilizer that will be used from the drop down list (Fig. 5). If the fertilizer is not on the list, you may need to ask the "virtual" ranch owner to add the fertilizer to the list.
Figure 5. Choose the fertilizer that will be used for the application from the fertilizer list.
Figure 6. Save after entries on the Fertilizer Application form.
After saving the entries to the fertilizer application form (Fig. 6), CropManage should take a few seconds to estimate the N requirement of the crop in units of lbs of N per acre and the fertilizer requirement in units of gallons per acre for liquid products or lbs per acre for dry products (Fig. 7). If no soil sample was selected then CropManage will not recommend a nitrogen fertilizer rate.
Figure 7. The N recommendation for the crop is calculated after saving.
Figure 8. The amount of fertilizer applied can be entered or left blank so that it can be entered at a later time.
Enter the amount of fertilizer or nitrogen that will be applied into the form or leave this entry blank until a decision is made (Fig. 8). Saving the form will add the new fertilizer application to the “Fertilizer Summary Table” (Fig. 9.) The fertilizer entries can be edited at any time so that one can update the table when new information becomes available.
Figure 9. The fertilizer summary table displays the new fertilizer entry which includes the total N recommended and applied, the type of fertilizer applied and rate.
- Author: Michael D Cahn
CropManage can recommend a nitrogen fertilizer rate for a crop based on the current nitrate status of the soil. Ideally, the soil should be sampled within a few days of the planned fertilizer application. Since soil nitrate can readily leach with percolating water, any irrigation events between soil sampling and fertilizing could affect the nitrate level of the soil.
After analyzing for the nitrate in the soil, one can enter the nitrate value for the planting into CropManage. All soil test values are summarized in a soil summary table (Fig. 1) for each planting. Although a range of soil test nutrients can be entered into the table, the default view displays soil nitrate values. Soil nitrate values from either laboratory analyses or determined using the soil nitrate quick test can be entered for a planting by selecting the “new soil sample” button below the soil summary table (Fig. 1) or by selecting “New” and then “New Soil Sample” from the “Quick View” screen (Fig 2).
Figure 1. Enter new sample values by selecting “New Soil Sample” below the soil summary table.
Figure 2. New soil sample values can be entered from the quick view screen by selecting “New” and “New Soil Sample.”
After selecting “new soil sample,” a blank form will display for entering soil test values (Fig 3). Enter the date that the soil sample was collected and select whether the soil sample was analyzed by a laboratory test or using the quick nitrate test strip. For analyses by the quick nitrate test strip, enter the strip reading in units of ppm of nitrate. For laboratory analyses of nitrate, enter the nitrate value in units of ppm of N. The conversion between nitrate and nitrogen equivalents is: Nitrate (ppm) = Nitrate-N (ppm) ×4.43
Figure 3. Form for entering new soil test values for a planting.
Select if the soil was collected moist or dry when using the soil nitrate quick test. The soil moisture information is not needed for laboratory analyses, since these samples are air-dried, and therefore the initial moisture content of the sample will not affect the calculations for estimating soil nitrate concentration. Next enter the depth that the soil sample was collected. If the sample was collected from both the 1 and 2 foot depths on the same day, then enter one sample for the 1st foot and then enter another sample for the 2nd foot depth. After selecting the crop stage when the field was sampled, click on “save sample” before leaving the screen (Fig. 4).
Figure 4. Soil test entry form is filled out for new soil test value before saving.
After selecting save sample, CropManage will add the sample to the soil summary table (Fig. 5). CropManage automatically convert values from the soil nitrate quick test to ppm of soil nitrate-N. The software will also express the soil nitrate value in pounds (lbs) of N/acre per foot of soil depth for the laboratory and soil nitrate quick tests. After entering the soil nitrate test values the data is available for making nitrogen fertilizer recommendations in the fertilizer summary table.
Figure 5. Soil Summary table is updated after entering a new soil sample value.
- Author: Michael D Cahn
Dear CropManage Users,
We would like to bring to your attention 2 important educational meetings on irrigation and nutrient management. The first meeting is the California Plant and Soil Conference that will be held in Fresno CA on Feb 4th and 5th. This conference has several sessions covering state-wide issues on irrigation and nutrient management, including the management of salinity and preparing for drought conditions. Please refer to the announcement below for further details.
In addition to the Plant and Soil Conference, the 2014 Irrigation and Nutrient Management Meeting will be held on February 12th at the UC Cooperative Extension Office in Salinas CA (see announcement below). This meeting will focus on coastal vegetables, presenting current research results on water and nutrient management. Results of replicated trials evaluating using ET data for scheduling irrigations in lettuce and broccoli will be presented as well as results from N management trials. Also, an overview of salt management in vegetable systems will be covered. There is no registration fee for this meeting.
We will provide a pizza lunch after the morning session, and then hold a brief field meeting on cover crop management in organic vegetables and strawberries at the USDA-ARS Spence research farm in the afternoon.
With growers facing drought conditions during the upcoming season and ever stricter water quality regulations, both meetings should be very worthwhile.
Best Regards,
Michael Cahn and Richard Smith
UC Cooperative Extension, Monterey County
University of California Cooperative Extension, Monterey County
2014 Irrigation and Nutrient Management Meeting
Agricultural Center 1432 Abbott Street, Salinas, CA
Wednesday, February 12
7:45 a.m. to 1:45 p.m.
7:45 Registration and Refreshments
8:00 Fertilizer value of nitrate in irrigation water Mike Cahn, Irrigation and Water Resources Farm Advisor, Monterey County
8:30 Strategies to reduce nitrate losses from leaching and runoff on organic farms Eric Brennan, Research Horticulturalist, USDA ARS, Salinas
9:00 Update on nitrogen uptake by cole crops Richard Smith, Vegetable Crop Farm Advisor, Monterey County
9:30 ET-based irrigation scheduling of lettuce, broccoli, and other cool-season vegetables Lee Johnson, Senior Research Scientist, CSUMB/NASA
10:00 Break
10:30 Nutrient budgets for vegetables Tim Hartz, Vegetable Crops Specialist, UC Davis
11:00 Managing salts in vegetable production Steve Grattan, Extension Specialist
11:30 Controlled release N sources for desert vegetables and evaluation of AVP-OX vegetables
for improved P use efficiency Charles Sanchez, Soil Science Professor, University of Arizona, Yuma Agricultural Center
12:00 Conclusion and Pizza Lunch
Afternoon Session:
12:45 Low residue mustard cover crops for organic vegetable and strawberry production, USDA ARS Spence Farm, 1572 Old Stage Road, Salinas
Eric Brennan, Roy Fuentes, Richard Smith and Mike Cahn
1:45 Conclusion
* Sponsors: University of California Cooperative Extension; Resource Conservation District (RCD);
* Certified Crop Advisor Credits have been requested
* For more information call Richard Smith 759-7357 or Michael Cahn 759-7377
Plant and Soil Conference Announcement
The 43th annual California ASA Plant and Soil Conference will be held on Tuesday and Wednesday, Feb. 4 & 5, 2014 at the Radisson Hotel and Convention Center in Fresno, CA. Sponsored by the California Chapter of the American Society of Agronomy and the California Certified Crop Advisors, the conference will focus on current agronomic topics that are of importance to growers, consultants, suppliers, educators and governmental organizations.
The theme of this year’s general session is “Building Resiliency in California Agriculture” with speakers from the agriculture industry and research institutions.
The conference includes technical sessions on a wide range of topics including:
- Nutrient management in annual and perennial crops
- Salinity management in crop production
- Water and drought management
- Pest management
- Waste water and manure management issues
- Soil quality and the effect of agricultural practices
A poster session including submissions from students and professionals will be featured at a complimentary reception with wine and hors d’oeuvres at the end of the first day of the conference. Continuing education credit will be available for Pest Control Advisors and Certified Crop Advisors.
A detailed program for the 2014 conference, along with the registration and continuing education credit information, is available at the California ASA website http://calasa.ucdavis.edu . For more Information, contact Steve Grattan srgrattan@ucdavis.edu or Dave Goorahoo, ASA California Chapter President at dgooraho@csufresno.edu or (559) 278-8448
Hotel reservation information:
Radisson Hotel and Conference Center Fresno
2233 Ventura Street
Fresno, CA 93721
Phone: 559-268-1000
Toll free: 800-333-3333
Tell them you are with the California Chapter of the American Society of Agronomy meeting
Online: www.radisson.com/agronomy
Room rate $99.00
End date for the conference room rate is January 21, 2014
- Author: Michael D Cahn
Users often need to export data entered into CropManage. Perhaps the irrigation or soil data for a planting is needed for another software application or to email to someone. One can export data for a ranch by selecting the export option below the list of plantings (button next to the arrow in Fig. 1). If this button does not appear below the list of plantings, then the “ranch owner,” the person in charge of the ranch, has not set the permissions for the user to export data.
Figure 1. Select “Export Data” to view data export options.
Figure 2. Choose the data option for exporting all ranch data to an excel workbook.
Assuming that one has permission to export data, select the “Export Data” button and the options to export “ranch and planting data” or “ranch, planting, and raw data” will be displayed (Fig. 2). Selecting either option will download the ranch data and all the data in the planting tables (soil, fertilizer, water) into excel worksheet files (Fig. 3).
Figure 3. Data from a ranch are exported to a zip file with separate excel spreadsheet files for each planting.
Selecting the option with “raw data” will also download the daily data used in the decision support calculations for each planting. Usually one would not select this second option unless interested to view the calculations behind CropManage recommendations. Note that each planting has a separate excel file entitled “Events for name of planting”. Each planting file has tables summarizing soil, fertilizer, and irrigation information displayed in CropManage (Fig. 4). The ranch data (list of fields, soil type, well data, etc) is downloaded to a separate file entitled “ranch .”
Figure 4. Excel spreadsheet displaying soil, fertilizer, and water data for a planting.
- Author: Michael D Cahn
Now that you have a ranch established in CropManage, you are ready to add plantings to the ranch. Each “planting” in CropManage consists of a set of tables for keeping records of soil tests, irrigations, and fertilizer applications associated with a specific crop planted on a ranch.
Each planting is unique, and should correspond to an actual crop planted on your farm or ranch, with a specific establishment and harvest date, field location, and acres. The planting also requires information about the irrigation system, crop type, and previous crop residues. This initial information is used later by CropManage to provide decision support on irrigation and fertilizer applications. Once a planting is established in CropManage, there is no need to reenter the initial information unless updating is needed.
After selecting a ranch, a list of current plantings will be displayed in “Ranch Home“ (Fig. 1). Selecting new planting below the planting list table will navigate to the “new planting form”(Fig. 2).
Figure 1. A table in ranch home displays a list of current plantings. Select “new planting” below the summary table to start a begin editing a new planting.
Give the planting a name and select a crop Fill in the name of the planting, start (first irrigation) and end dates (last harvest) of the crop, year, and select the field or lot from the pull down menu. The soil type of the lot is used for irrigation, soil test, and fertilizer calculations. If the lot is not listed, then the virtual ranch owner needs to enter the lot information in the “edit ranch” form. Also select the crop type and planting configuration from the pull down menu.
Select save after all information is entered and a new window will display for entering additional information (Fig. 3). In many cases, default values are provided in the forms that are typical for coastal vegetable crops. When in doubt, use the default values.
Previous crop CropManage estimates N contribution from incorporated residue of the crop when calculating the nitrogen fertilizer needs of the current crop. Select the type of previous crop that preceded the current planting (Fig. 3). If the previous crop is not displayed in the pull down menu, then select a crop that approximates the amount and type of residue observed. If no crop preceded the planting or if the interval was more than 2 months, then select “no crop residue within 2 months.” Change the interval between residue incorporation and planting from the default value (30 days) to the actual value.
Figure 2. To begin a new planting, enter the name of the planting, crop type, first irrigation and end dates (harvest date) of the crop into the new planting form.
Figure 3. Enter previous crop information so that CropManage can estimate N contribution from incorporated plant residues.
Figure 4. Irrigation system information is entered into the new planting form for calculating the volume of water (inches) and time to irrigate.
Irrigation information CropManage uses information about the irrigation system for calculating the amount of water and time to irrigate (Fig. 4). If drip and sprinklers will be used for irrigating the crop, enter values for both types of irrigation methods. Currently, CropManage does not support furrow irrigation.
The application rate of the irrigation system in units of inches per hour must be entered to convert the volume of water applied to application time. Default values are provided in the form, but these values may vary greatly from the actual rate if the irrigation system is atypical. A calculator for estimating the application rate appears when the cursor is placed in the application rate form for drip or sprinkler (Fig. 5). Application rate can be estimated for sprinklers by entering sprinkler head type, lateral pipe spacing, sprinkler head spacing, nozzle pressure, and nozzle orifice diameter (Fig. 5). Application rate can be estimated for drip by entering the flow rate of the tape, bed width, and number of tapes per bed (Fig. 5).
Leaching fraction for salt management A leaching fraction value greater than default value of 0% should be entered if the irrigation water has a salinity concentration that would reduce yield (Fig. 4). Bulk salinity is measured with an electrical conductivity (EC) meter in units of deciSiemens per meter. EC increases with salinity content of water or soil. The salinity threshold of irrigation water at which yield is reduced for lettuce is approximately 1 to 1.5 dS/m depending on the specific types of salts in the water. A leaching fraction that adds an additional 15% to 30% more water to the irrigation recommendation would be typical if the irrigation water has salinity levels in the range of 1 to 2 dS/m.
Figure 5. Calculators for drip and sprinklers can be used to estimate the application rate of the irrigation systems.
Irrigation distribution uniformity The irrigation recommendations for the planting are adjusted for non-uniformity of the irrigation system using values entered for distribution uniformity (DU) of the drip and sprinkler systems. Distribution uniformity is the ratio between the average application volume for the driest part of the field (typically the driest quarter) and the average application volume of the entire field:
The DU of an irrigation system that provides perfect uniformity would be equal to 100%. Typical default values are provided for sprinklers and drip but they should be adjusted to reflect actual conditions of the crop. Drip tape that has been retrieved and reused for more than 8 crops may have a DU substantially less than 90%. Likewise, sprinklers that are operated under high wind conditions may have a DU lower than 75%.
Two different DU values can be entered for the sprinkler system if different equipment configurations are used for the germination and post establishment phases, or to reflect different tolerances for dry zones in the field during germination and post-establishment. During crop establishment (germination or transplant establishment), one may want to assure that dry areas in the field are minimized by lowering the DU value. A DU corresponding to the driest tenth of the field typically will be 10% to 15% less than a DU for the driest quarter of the field.
Total amount of nitrogen taken up by the crop The N fertilizer recommendation is based on an N uptake curve for each crop type and planting configuration. This curve can be adjusted by increasing or decreasing the total N uptake value or increasing the interval between the first irrigation and the harvest (end of crop). For each crop type and planting configuration supported, CropManage provides a default value for the total amount of nitrogen that the crop will take up in units of pounds of nitrogen per acre (Fig. 6). The default values are averages of measurements from commercial fields. The value may need to be increased or decreased to reflect factors such as a lower or higher plant population, smaller or larger than normal sized plants, or varietal differences.
Figure 6. Planting form entries for N fertilization recommendations: crop total N uptake, maximum fertilizer N recommendation, and days between consecutive fertilizer events.
Two other entries needed for making the fertilizer N recommendation are the maximum N recommendation and a default value for the days to next fertilization. To prevent fertilizer N recommendations that are excessive due to incorrectly entering information, CropManage includes a maximum N recommendation value that limits the amount of N fertilizer recommended. This value may need to be increased for plantings where only 1 or 2 nitrogen fertilizer applications are made. An estimate of the days until then next fertilizer application is needed to predict future N uptake of a crop. A default value can be set in the planting form, but adjusted later when fertilizer events are entered.
Flow meter data retrieval Water applications can be monitored using a flow meter capable of producing an electronic output signal that can be recorded with a datalogger. Currently, automated retrieval of flowmeter data to CropManage is limited to using Campbell Scientific™ dataloggers equipped with cell phone modem or radio communications. CropManage can be configured to automatically retrieve flowmeter data for a planting at hourly intervals by entering the datalogger file name and the areas monitored under drip and/or sprinkler irrigation (Fig. 7). Leave these entries blank if no flow meter will be used with the planting. Contact Michael Cahn (mdcahn@ucdavis.edu) or Barry Farrara (bffarrara@ucdavis.edu) for further details on how to use flow meters for monitoring water applications using CropManage. 
Figure 7. Form entries for flowmeter information and lot latitude and longitude coordinates.
Lot coordinates The lot is the actual planted area within a field. Because some fields are split into several plantings, lots can be small than the field area. Latitude and longitude coordinates of the planting (lot) can be entered in the planting form (Fig. 7). A mapping tool will appear to assist in locating the field when the curser is placed in the Lot Coordinates box (Fig. 8).
Figure 8. Mapping tool for finding the latitude and longitude coordinates of a lot
Don’t forget to save! When satisfied with all planting entries select save at the bottom of the planting form. Edit entries at anytime to update planting information.
