Date: Tuesday, May 10th, 2022

1pm – 5pm
Location: Watsonville Public Library

275 Main St., Suite 100, Watsonville, CA  95076

We will hold a hands-on training on CropManage.  CropManage is a free online decision-support tool for water and nutrient management of vegetables, berry, agronomic, and tree crops. Based on in-depth research and field studies conducted by the University of California Cooperative Extension, CropManage provides real-time recommendations for efficient and timely irrigation and fertilization applications while maintaining or improving overall yield. 

At this free workshop, we will provide hands-on training so that you can learn to use the newest version of CropManage. Crops currently supported include many vegetables (carrots, cabbage, celery, broccoli, lettuce, tomato, spinach, etc.), berry crops (raspberry and strawberry), tree crops (almond, walnut, and pistachio), and agronomic crops (alfalfa and corn). CropManage is also available in Spanish.

 
Who should participate? Growers, farm managers, other farm staff, crop advisors, consultants, and technical service providers are welcome. The workshop is for both new and current CropManage users. Spanish translation will be available.

What to bring? This is a participatory workshop. Please bring a tablet or laptop computer so that you can follow along and participate in the exercises. Each participant will need a user account for CropManage. Please set up a free user account at https://cropmanage.ucanr.edu/ before the workshop. Please arrive early to set up your laptop or tablet computer on the wifi and get logged on to CropManage.

Registration is free: Please register at https://surveys.ucanr.edu/survey.cfm?surveynumber=37233 by May 9th, 2022. Seats are limited to the first 25 registrants.

 
Continuing Education Units (CEU) for Certified Crop Advisors (CCA) have been requested

Questions: Contact Michael Cahn at mdcahn@ucanr.edu / 831-214-3690 or Sacha Lozano at  slozano@rcdsantacruz.org / 831-224-0293                                                                                              

Agenda

1:00 – 1:20  Registration and computer set-up

1:20 – 1:40  Introduction

1:40 – 2:50  Getting started with CropManage

2:50 – 3:05  BREAK

3:05 – 3:50  Using CropManage for decision support and record-keeping

3:50 – 4:15  Group exercise

4:15- 4:40  Advanced features

4:40 – 5:00  Discussion / Q&A/ wrap up

NOTE: The following COVID-19 guidelines will be applied to this training workshop.

1. Wearing a face covering during the workshop is required.
2. Stay at home if you have COVID-19 symptoms, tested for positive, and/or close contacts with or exposure to others who have been tested for COVID-19.
3. Face masks and sanitation items will be provided at the workshop.

Coping with Rising Fertilizer Prices

Richard Smith and Michael Cahn, UCCE Farm Advisors, Monterey County

 Growers have been affected by a near doubling in fertilizer prices between the summer of 2020 and the end of 2021. The last time that fertilizer prices had a similar spike was in 2008 (Figure 1).  In a recent article in Agricultural and Resource Economics published by the Giannini Foundation of Agricultural Economics at UC, Davis, Aaron Smith discussed details in global dynamics in production and demand of fertilizers that are affecting this surge in prices (https://s.giannini.ucop.edu/uploads/pub/2022/02/24/v25n3.pdf ). The forces that he described not only affect nitrogen but phosphorus and potassium fertilizer prices as well.

 Figure 1. Trend of fertilizer prices over the past 30 years (DAP = diammonium phosphate)

The United States produces about 85% of the ammonia and 90% of the phosphate rock that it uses, both of which are mostly used to make fertilizers. However, we import 90% of the potash used. Domestic production of ammonia declined from 2000 to 2010 when natural gas prices were historically high. But after 2010, the use of hydraulic fracturing (fracking) increased the supply of natural gas and lowered the cost of production (but not necessarily the price of natural gas!). Aaron explained that supply side factors such as the price of natural gas, inclement weather events, COVID disruptions and shipping costs do not fully explain the sustained increase in fertilizer prices over the past 2 years. On the demand side corn, soybean and wheat prices increased 60% from the summer of 2020 through the end of 2021 which may have incentivized growers to apply more fertilizer which put pressure on fertilizer prices. These cost increases predate the Russian invasion of Ukraine, and at present, the war has not increased fertilizer prices further, but that situation could change.

 Central Coast growers are facing increased fertilizer prices and are looking for ways to reduce the use of fertilizers. In high value horticultural crops, fertilizer costs typically represent a smaller portion of production costs than they do for agronomic crops. For instance, in the 2019 romaine hearts cost study conducted by Tourte et al, fertilizer costs represented 8.5% of total crop production costs. However, in light of current price spikes, fertilizer prices have become more significant.

 Over the past 25 years we have been evaluating practices to improve the efficiency of applied nitrogen mostly with an eye to helping growers comply with water quality regulations. We have reported the results of our research at many meeting, articles and blog entries. However, we will revisit one study that we did in 2019 which illustrates the following concepts: 1) careful monitoring residual soil nitrates and accounting for them in making fertilizer application decisions, 2) careful irrigation water applications to reduce nitrate loss. These are the two key practices that can help growers efficiently manage nitrogen applications and minimize over application that is now so costly.

 In 2019 we conducted a trial with a cooperating grower to evaluate water and nitrogen management of romaine lettuce.   We split the field in half and on one side of the field irrigation and fertilizer decisions were guided using the CropManage decision support tool (cropmanage.ucanr.edu).  The other half of the field was managed according to grower's standard practices.

Irrigation details: Romaine lettuce was germinated using subsurface drip buried at a 3 to 4-inch depth in the center of 40-inch wide beds.  Flowmeters were installed to monitor irrigation on both the CropManage and grower standard treatments. Similar volumes of water were applied to in both treatments during germination/stand establishment: CropManage = 3.4 inches, grower standard = 3.7 (Fig. 2).  After thinning, until harvest different amounts of water were applied to the two treatments. The ideal amount of water recommended by CropManage was 3.8 inches of water. CropManage bases the recommendation on reference evapotranspiration data (ET) from the nearest CIMIS weather station, a crop coefficient model based on canopy development, and considerations of the application uniformity of the irrigation system.  In the grower standard practice 3.3 inches were applied and in the CropManage treatment 3.8 inches were applied.

Nitrogen fertilizer: Twenty gal/acre of 5-20-0 were applied to both management practices at planting as an anticrustant/starter fertilizer.  Soil nitrate was monitored in the upper foot in both management zones at regular intervals during the season (Fig. 3).   Soil nitrate levels were moderate at the thinning (< 15 ppm NO₃-N) and fertilizer was added to both management systems. The big difference between nitrogen management between the CropManage and grower standard treatments was the mid-October fertilizer applications. In the CropManage treatment we made a more moderate application in early October because soil nitrate levels were still moderately high (18 ppm NO₃-N). Later we applied a 4^th application of nitrogen fertilizer through the drip system (39 lbs N/acre) to supply sufficient N to match crop uptake demand until harvest.  In contrast, the grower standard practice applied 91 lbs N/acre through the drip system as a 3^rd and final application in mid-October. Total N applied to the CropManage treatment was 129 lbs N/acre and to the grower standard treatment was 191 lbs N/acre (Table 1).

Harvest:  Commercial yields evaluations were made in adjacent 12 bed-wide strips (by the length of the field).  Carton yield (lbs/acre) was about 5% higher in the CropManage area (Table 1) although cartons per acre were 3% higher in the grower management zone due to a higher final plant population (Table 2).  Disease pressure from INSV and Sclerotinia caused plant loss and affected the final plant populations in the management zones.  Net carton weight of the grower standard area averaged 2.4 lbs per box less than the CropManage area and plant tissue had a lower water content than the CropManage treatment (Table 1). The higher plant weight and water content measured in the CropManage area (Table 2) may be due to the extra water (0.5 inches) applied to this treatment during the final few weeks of the crop.  In contrast, the extra nitrogen (90 lbs/acre) applied to the grower management area did not increase plant weight and growth relative to the CropManage area. 

Take Home Message: Over the years we have conducted many side-by-side evaluations comparing grower standard practices with improved efficiency practices guided by the CropManage decision support program. In this example, both management treatments applied close to the recommend amount of water to avoid leaching of nitrate during the production season. The soil nitrate evaluations indicated that only moderate amounts of N were needed at each fertigation; in addition, adding one extra fertigation event in the CropManage treatments improved the ability to precisely manage what the crop needed. The high final fertilizer application on the grower treatment did not improve yields and resulted in more residual nitrogen in the soil at the end of the season. The bottom line is that careful irrigation scheduling and monitoring of soil nitrate helped reduce nitrogen fertilizer applications in this study and safeguarded yields.  If you need assistance in implementing better water and fertilizer nitrogen management practices on your farm, please give us a call. We are available to consult with you.

Table 1.  Applied water and nitrogen fertilizer, and commercial yield from strip plots on November 6, 2019.

 Table 2.  Nitrogen content, untrimmed plant weight, dry matter content, and plant population from strip plots on November 5, 2019.

Figure 2.  Applied water for CropManage and Grower Standard areas.

Figure 3.  Applied fertilizer nitrogen and soil nitrate concentration in the 0 to 1-foot depth.

The presentations from the 2022 UCCE Irrigation and Nutrient Management Meeting are now available on the UCCE Monterey Website.  You can download pdf versions of the presentations from the "Irrigation and Nutrient Management Presentations" link on the website.  You can also navigate to the presentations by clicking on this link.  Recordings of the presentations should be available soon too.  We will add the recorded presentation links to the blog and website when they become available.

2022 Irrigation and Nutrient Management Meeting

Wednesday, February 23, 2022

Register to join us for this webinar: https://surveys.ucanr.edu/survey.cfm?surveynumber=36536
Virtual Meeting registration cost: $10

Zoom Log-in info will be sent closer to the event date
For more info, contact: anrprogramsupport@ucanr.edu, 530-750-1361 (messages only)

Continuing Education Units

California DPR: 1 unit (applied for)
CCA: Nutrient Management (1), Soil & Water Management (2.5)

Schedule