- Author: Richard Smith
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 4th 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 3rd 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.
- Author: Michael D Cahn
- Author: Richard Smith
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.
- Author: Richard Smith
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
7:55 |
Introduction |
8:00 |
Nitrogen Mineralization From Organic Fertilizers and Composts—Joji Muramoto, Organic Production CE Specialist, UC Santa Cruz |
8:30 |
Using Weather-Based Irrigation Scheduling for Optimizing Artichoke and Cabbage Production—Michael Cahn, UCCE Irrigation Advisor, Monterey County |
9:00 |
Navigating the State Water Efficiency (SWEEP) and Healthy Soils (HSP) Grant Programs—Aparna Gazula, UCCE Small Farm Advisor, Santa Clara County |
9:30 |
Update on AgOrder 4.0—Monica Barricarte, Environmental Scientist, Central Coast Regional Water Quality Control Board |
10:00 |
Break |
10:15 |
Progress in Implementing the Sustainable Ground Water Management Act (SGMA) in the Salinas Valley—Emily Gardner, Deputy General Manager, Salinas Valley Basin Groundwater Sustainability Agency |
10:35 |
Third Party Program for Ag Order 4.0—Sarah Lopez, Executive Director, Central Coast Water Quality Preservation Inc. |
10:55 |
Factors Affecting the R Side of the A-R Metric Equation in Ag Order 4.0—Richard Smith, UCCE Weed and Vegetable Advisor, Monterey County |
11:30 |
Update on Using Polyacrylamide (PAM) for Controlling Sediment and Pesticides in Irrigation Runoff—Michael Cahn, UCCE Irrigation Advisor, Monterey County |
12:00 |
Adjourn |
- Author: Richard Smith
Junta sobre Manejo de Riego y Nutrientes 2022
Miércoles, 23 de Febrero
Registrar Reunión Virtual: https://surveys.ucanr.edu/survey.cfm?surveynumber=36536
Reunión Virtual Costo: $10.00
La información de inicio de sesión de Zoom se enviará más cerca de la fecha del evento
Para más información, contactar a:anrprogramsupport@ucanr.edu, 530-750-1361 (solo mensajes)
Habrá traducción al Español Enlace para
Crédito de Educación Continuada
CCA 3.5 créditos aprobados
CDPR 1.0 crédito de educación continuada pendiente
Para más información, contactar a Richard Smith, rifsmith@ucdavis.edu, 831-759-7353
Calendario
7:55 |
Introducción |
8:00 |
Mineralización de nitrógeno en compost y fertilizantes orgánicos —Joji Muramoto, Especialista en Producción Orgánica, UC Santa Cruz |
8:30 |
Uso de programación de riego basada en el clima para optimizar la producción de alcachofa y repollo —Michael Cahn, Consejero de Riego UCCE, Monterey County |
9:00 |
Como participar en los programas estatales de incentivos para eficiencia de agua (SWEEP) y suelos saludables (HSP)—Aparna Gazula, Consejera de Ranchos Pequeños UCCE, Santa Clara County |
9:30 |
Informe actualizado sobre la Orden Agrícola (Ag Order 4.0)—Monica Barricarte, Científica Ambiental, Junta Regional para el Control de Calidad de Agua de la Costa Central |
10:00 |
Descanso |
10:15 |
Avances en la implementación del Plan de Manejo Sustentable de Agua Subterránea (SGMA) —Emily Gardner, Sub-Gerente General, Agencia para la Sustentabilidad del Agua Subterránea, Cuenca del Valley de Salinas |
10:35 |
Programa de verificación independiente para la Orden Agrícola (Ag Order 4.0)—Sarah Lopez, Directora Ejecutiva, Central Coast Water Quality Preservation Inc. |
10:55 |
Factores que afectan la variable R en la ecuación A-R del Ag Order 4.0 —Richard Smith, Consejero de Vegetales y Malezas UCCE, Monterey County |
11:30 |
Reporte sobre el uso de Poliacrilamida (PAM) para controlar sedimentos y pesticidas en la escorrentía de riego.—Michael Cahn, Consejero de Riego UCCE, Monterey County |
12:00 |
Cierre |
- Author: Richard Smith
The Michelmore lab at the University of California, Davis routinely monitors isolates of Bremia lactucae, the pathogen that causes lettuce downy mildew for their ability to overcome disease resistance genes and for insensitivity to fungicides. Isolates are currently being monitored for insensitivity to Revus, Forum, and Orondis. During 2021, 70 isolates were tested for growth on seedlings pretreated with 2 ppm Revus, 5 ppm Forum, or 0.5 ppm Orondis. Nearly all isolates were sensitive and showed no growth at these concentrations. However, two isolates were insensitive to Forum and when retested, grew on 4 ppm treated seedlings. Another isolate was insensitive to Revus and could grow on seedlings pretreated with 3 ppm Revus when retested. All three isolates were collected in Oceano. No isolates have been detected that are insensitive to Orondis. We are interested in receiving additional isolates from Oceano and other areas, particularly when there has been an apparent failure of control.
Please see the attached for instructions as to how to send samples.
Thank you for your help.
Richard Michelmore.
Distinguished Professor and Director
The Genome Center
Genome and Biomedical Sciences Facility
451 Health Sciences Drive
University of California
Davis, CA 95616
rwmichelmore@ucdavis.edu
http://genomecenter.ucdavis.edu
http://michelmorelab.ucdavis.edu
Please fill in as completely as possible. This will help entry into the database but do not worry if some/most of this information is not available.
Please include this datasheet when sending isolates.
Date Collected: ____/____/_____ Collector ID: _________________
Collector: _______________________________ (UC Lab ID: _________________)
Location: _____________________________________________________________________________________________
GPS coordinates if known: ____________________________
Disease Intensity / Level of infection (circle one):
Low (Few infected plants),
Intermediate (Infected plants scattered throughout field).
Severe (Many infected plants)
Please comment whether collected from a single plant or from several plants and whether from multiple locations in the field.
Comments: __________________________________________________________________________________________________________________________________________________________________________________________________________________
Fungicide treatment: Yes No Not known
If yes: Alliete Ridomil Revus Orondis Forum Other:__________________
Type: Crisphead Romaine Looseleaf Butterhead Babyleaf Other:______________
Cultivar/Variety: ____________________________________________________________________________
Approximate planting/water date ________________________________________________________
Other Comments: _________________________________________________________________________________________________________
_________________________________________________________________________________________________________Thank you for your help. Please address questions to Juliana Gill (giljuliana@gmail.com), and/or Richard Michelmore, rwmichelmore@ucdavis.edu.
Results will be available from http://bremia.ucdavis.edu/bremia_database.php.
Collection and Shipping Instructions:
Please send leaves with fresh sporulating lesions. These should be green or only slightly chlorotic:
Please not send leaves with dark necrotic lesions; it is difficult to rescue isolates from such samples because of bacterial contamination:
Please send overnight by Fed Ex (Account # 2630-4693-5) in a box rather than an envelope (to prevent samples being crushed) along with the datasheet and the words “Refrigerate upon arrival” on the outermost packaging to:
Attn: Juliana Gil
The Genome Center
Genome and Biomedical Sciences Facility
451 East Health Sciences Drive
University of California
Davis, CA 95616
Tel. 530-752-8889
Please notify Juliana Gil (giljuliana@gmail.com) with the tracking number when sent.
Please time the sending so that the isolate is not in the Fed Ex system over a weekend (i.e. do not send on a Friday). Isolates can be kept in a fridge at 5oC for a few days before sending if necessary, although sending samples immediately after collection is best.