- Author: Ben Faber
Practical Training in Nitrogen Planning & Management in Organic Production of Annual Crops
BUT All Growers Could Learn from these sessions
- Virtual Event – Habrá traducción al Español
3-part Workshop
Session 1: Monday, Nov. 27th, 2023, 1-3pm
Session 2: Monday, Dec. 4th, 2023, 1-3pm
Session 3: Monday, Dec. 11th, 2023, 1-3pm
Session 4*: Monday, Dec. 18th, 2023, 1-3pm
*attendance optional
Registration
tinyurl.com/NitrogenWorkshop
- Cost: $25*
*No one will be turned away due to lack of funds.
Please contact Rob Straser (rkstraser@ucanr.edu)
- Must enroll in Session 1-3 (Session 4 optional)
- Limited to 80 participants
- CEUs in progress
- CDFA-INMTP
- CCA
About this workshop
In this 3-part series, participants will learn how to estimate nitrogen release from diverse organic sources and translate that knowledge to nitrogen fertilization plans and regulatory reporting requirements. Over the 3 sessions, we will cover the most common sources of nitrogen and complete a nitrogen budget. In session 2 and 4, participants will be able to work on and receive feedback on their own nitrogen budgets.
Who should enroll?
Growers, CCAs, PCAs and other agricultural professionals who are interested in learning about nitrogen management in organic production are encouraged to enroll.
Program agenda
Session 1: Monday, Nov. 27, 2023, 1-3pm
Understanding nitrogen: the nutrient, the role of microbes and the
relevance of soil organic matter
Presenters: Daniel Geisseler, Radomir Schmidt and Margaret Lloyd
We will begin with an overview of the sources, transformations and fates of sources of organic nitrogen in soil. Foundational to this, we'll cover the role and dynamics of microbes in nitrogen management, and how that impacts management decisions. Lastly, we'll discuss using nitrogen budgets to understand the sources and proportions of available nitrogen to meet crop demand.
Session 2: Monday, Dec. 4, 2023, 1-3pm
Estimating nitrogen release from organic amendments and contributions
from cover crops
Presenters: Patricia Lazicki and Margaret Lloyd
This session will focus on estimating nitrogen release from compost, organic fertilizers and cover crops. In addition, participants will be invited to apply the training to their own operations and receive feedback on the budget calculations during this session.
2
Nitrogen Planning & Management Workshop UC Cooperative Extension
Session 3: Monday, Dec. 11, 2023, 1-3pm
Putting it all together: Completing a nitrogen budget, synchronizing
nitrogen release with nitrogen demand, soil tests, and frontiers in nitrogen
science
Presenters: Daniel Geisseler, Joji Muramoto, Michael Cahn and Margaret Lloyd
In this session, we will address specific aspects of organic soil fertility management in warm season vegetables. Discussions will include crop nitrogen demand and strategies to supply demand, as well as using and interpreting soil testing. Specific references will be made to strategies for complying with forthcoming regulations. We will conclude with a discussion on new frontiers in organic nitrogen management.
Session 4*: Monday, Dec. 18, 2023, 1-3pm
*attendance optional
Grower Panel and Open House
In this session we will have 1-2 growers share their experience managing nitrogen on their farms. Then, we will open it up to questions, share experiences and discuss the nitrogen budget file. Attendees are encouraged to bring their own data to receive feedback.
About the Presenters
Daniel Geisseler is a Cooperative Extension specialist in the Department of Land, Air and Water Resources at UC Davis.
Daniel's research and outreach focuses on nutrient turnover and plant nutrition in agricultural systems. He is interested in the
effects that different management practices have on nutrient use in California crops and how nutrient use efficiency can be
improved, particularly with nitrogen.
Patricia Lazicki is the Vegetable Crops Advisor for Yolo, Solano, and Sacramento Counties, working mainly in tomatoes.
Her research interests include soil health, and nutrient management and fertility in organic annual cropping systems.
Margaret Lloyd is the Organic Agriculture and Small Farms Advisor for Yolo, Solano and Sacramento Counties. She runs an
active research and outreach program focused on nutrient management and pest management for organic vegetable farms.
Joji Muramoto is an Assistant Cooperative Extension organic production specialist at UC Santa Cruz. His research and
extension focus on nitrogen and soilborne disease management in organic cropping systems across the state
.
Radomir Schmidt is a program manager at the Working Lands Innovation Center at the UC Davis Institute of the Environment.
As a soil microbiologist, Radomir conducts research on the effects of specific farming practices (organic amendment
application, enhanced rock weathering, cover cropping, no-till systems) on carbon sequestration and greenhouse gas fluxes in
soils, and on the roles of microbial communities in soil health improvement and maintenance
.
Michael Cahn is an irrigation and water resources Farm Advisor for UC Cooperative Extension in Monterey County. His
research and extension program focuses on irrigation efficiency, nutrient use of crops, and protecting water quality. He led
the development of CropManage, an online decision support tool for irrigation and nutrient management.
For more information, contact Rob Straser: (rkstraser@ucanr.edu) or Margaret Lloyd (530-564-8642, mglloyd@ucanr.edu).
The University of California prohibits discrimination or harassment of any person in any of its programs or activities. (Complete nondiscrimination policy statement
can be found at http://ucanr.org/sites/anrstaff/files/107734.doc). Inquiries regarding the University's equal employment opportunity policies may be directed to
Affirmative Action Contact and Title IX Officer, University of California, Agriculture and Natural Resources, 2801 2nd Street, Davis, CA 95618, (530) 750-1397
- Author: Konrad Mathesius
Overview
Three years of data indicate that liquid-injected biosolids-based fertilizers (LBF, using 'Lystegro' from Lystek) are a viable alternative to conventional forms of nitrogen (N) fertilizer on a total N basis in wheat rotations in the southern Sacramento Valley. Lab data comparing LBF, pelletized biosolids-based fertilizers (PBF), and urea provide additional insight into soil phosphorous (P), salinity (EC), soil pH, and N mineralization responses after additions of the treatments.
Above: Application of LysteGro (Liquid-Injected Biosolids-Based Fertilizer, LBF) in Solano County
Introduction
As more California municipalities begin to prioritize the diversion of waste products from landfills into agricultural systems, it is pressing for growers to understand how to utilize new inputs such as liquid-injected biosolids-based fertilizer (LBF) in their operations.
Biosolids-based fertilizers can generally provide subsidized and therefore cost-effective sources of N for small grains and other agronomic crops. However, while there have been long-term biosolids studies using materials derived from biosolids, near-term performance needs to be understood and documented to improve grower confidence and capacity in the utilization of these products.
Figure 1: Yield and protein data from field trials over three site years in the Southern Sacramento Valley. Conventional N fertilizer treatments are indicated in blue. Shades of green represent biosolids treatments, with higher rates represented by progressively darker shades of green. N equivalents are represented numerically in each of the labels (i.e. LBF_57 is 57 pounds of N per acre as Liquid-Injected Biosolids-Based Fertilizer). Letters above each column indicate whether there is a significant difference between treatments. Columns with the same letter are not significantly different from one another.
Figure 2: Yield and protein data from the trials across 3 years modeled at 60, 90, and 120 pounds of total N applied per acre. Differences in predictions are insignificant, indicating that both materials appear to perform similarly in terms of total N applied per acre.
Methods
The objective of this research was to evaluate the yield and protein performance of LBF as an N source in small grains relative to conventional forms of N fertilizer. Lab incubations were intended to provide information on the response of soil P, N, pH, and EC to different treatments over a period of 12 weeks.
Field trials took place over the course of three planting seasons (Table 1). Wheat was typically planted in late November to early December. LBF and nitrogen (as UAN 32 or anhydrous ammonia) were added to fields pre-plant. LBF and anhydrous ammonia treatments were injected six-inches deep. UAN 32 was added prior to incoming rain. No in-season additions of N were added in these trials because biosolids cannot be injected mid-season and the objective of the trial was to make an apples-to-apples comparison based on the type of material.
Table 1: Information on three growing sites/ years where trials took place.
Laboratory incubations were also carried out to examine the behavior of the LBF relative to a pelletized biosolids-based fertilizer (PBF), and conventional N fertilizers (as urea).
Results and Discussion
Results from the field trials indicate that LBF produces generally equivalent yield and protein results in small grains when compared to conventional forms of fertilizer as an N source (Figure 1) when used in pre-plant applications. Other findings indicate that there may be some ancillary benefits associated with the use of LBF as an N source by way of providing a source of P (Figure 3), carbon, micronutrients, and water.
Lab incubations reflected some of the patterns witnessed in the field: Increases in P, slower N mineralization rates, and otherwise similar soil chemistry outcomes relative to that of conventional fertilizer, particularly after 12 weeks (Figure 3).
Organic matter was not seen to increase significantly in-season, but the fact that the LBF material is 10% solids, and those solids are roughly 30% carbon from organic matter means that additions of carbon, micronutrients, and water could be advantageous to crop growth.
Incubations
Figure 3: N mineralization, available phosphorous, salinity (as electrical conductivity, EC ), and pH results from 12-week lab incubations at 70 degrees F, comparing LBF, PBF, and pelletized urea mixed into a Yolo loam at 90 lbs N / acre. Significant difference between treatments is indicated within a given week by different letters.
Conclusion
Small grain growers working in the southern Sacramento Valley or in similar climates should feel confident that LBFs will likely perform as well as conventional sources of N when applied at similar rates of total N. LBFs may also provide additional benefits to growers in the form of increased P, micronutrients, or additional soil moisture. Growers should also consider the combined use of biosolids and in-season conventional N additions when needed. As always, good N-management and monitoring can greatly improve grower capacity for success.
- Author: Konrad Mathesius
Join us next week for a workshop that will cover some basic wheat fertilization strategies and focus on how to use the Nitrogen Fertilizer Management for California Wheat Webtool.
Yolo County: Wednesday, October 11th 2023, 9 a.m. – 11:00 a.m.
70 Cottonwood Street, Woodland, CA
Register: click here
Given the high cost of Nitrogen (N) fertilizer and a tendency to apply the majority of N prior to planting, growers stand to potentially leave a lot of money on the table by failing to optimize their N-management in small grain systems. For example, early, heavy rains last year flushed a lot of nitrate out of the soil profile before wheat could take it up during the rapid growth phase. In-season applications provide an opportunity to take account of the water year, and the crop status before deciding on a season-long N fertilizer budget.
The Nitrogen Fertilizer Management Webtool for California Wheat offers in-season insight on whether and how much N to apply given the seasonal conditions. While the use of the webtool is pretty straightforward, we have found that it is helpful to offer workshops to help CCAs and growers become more familiar with its use. These two-hour trainings offer an introduction to principles of N-management in wheat and use/ interpretation of the webtool.
Agenda Below:
YOLO COUNTY
Small Grains Nitrogen Management Webtool Training
Wednesday, October 11th 2023, 9 a.m. – 11:00 a.m.
70 Cottonwood Street, Woodland, CA
Please RSVP using QR code or click here
Presented by:
Konrad Mathesius, UCCE Agronomy Advisor, Yolo, Sacramento, and Solano
Who should attend: CCAs and other crop consultants specializing in crop nutrient management.
Growers, Ag Industry, and the general public are also welcome
8:40 a.m. Registration, light refreshments
9:00 a.m. Welcome and Introduction
9:10 a.m. Principles of N fertilizer use in California small grains
9:40 a.m. Measuring field data pre-plant and in-season
N-rich reference zones
Soil sampling for nitrate
10:00 a.m. Soil nitrate quick test demonstration and data interpretation
10:15 a.m. Webtool example and case studies
10:25 a.m. Webtool walkthrough
10:45 a.m. Crop Consultant/ CCA forum, survey, feedback, troubleshooting, and discussion
11:00 a.m. Adjourn and Lunch, Please RSVP using the link or QR code above.
CE Credits
CCA: 2 (pending)
INMP/Cures: 2 (pending)
- Author: Michael Cahn
- Contributor: David Chambers
- Contributor: Tom Lockhart
- Contributor: Noe Cabrera
Minimizing suspended sediments in irrigation runoff is desirable for several reasons. For growers reusing tailwater for watering their crops, they must assure that the water has minimal food safety risks by testing it for generic E coli and/or treating it with chlorine. The concentration of free (or reactive) chlorine is reduced when tailwater contains a high concentration of suspended sediments. Treating a large volume of tailwater with chlorine can be a significant expense over a season so it is important to be able to remove as much of the suspended sediments as possible before treatment.
A second reason is that water quality regulations under Agriculture discharge Order 4.0 requires tailwater discharged into public water ways to not be toxic to aquatic organisms. Pesticides that strongly bind to soil, such as pyrethroids, are carried on the suspended sediments in runoff which can cause toxicity to aquatic organisms that live in creeks and rivers downstream from farms. Also, particulate forms of N and P which bind with the suspended sediments pose a water quality risk to receiving waterbodies such as the sloughs and wetlands along the coast. Both nutrients can spur algal blooms which reduces dissolved oxygen available to fish and other aquatic organisms.
In a previous article we discussed a new approach to using Polyacrylamide (PAM), an inexpensive polymer molecule for reducing soil erosion, to treat sprinkler water. This practice uses a specialized applicator (Fig. 1) to condition water flowing from a well with PAM. An advantage of this method is that the cartridges in the applicator release a small amount of PAM (1 to 2 ppm) into the irrigation water, which flocculates soil particles that could potentially become suspended and transported in runoff. Field tests using a prototype version of this applicator resulted in about 90% less suspended sediment in the tailwater when treated with PAM compared to untreated irrigation water.
Auger ditch applicator
A second approach we developed for reducing suspended sediment in runoff is to use a smart applicator that can automatically apply dry PAM to the runoff water flowing in farm ditches. This type of applicator is suspended on a platform above a ditch and uses a hopper filled with dry PAM and an auger system controlled by an electric motor and small computer to drop PAM down a tube into the flowing runoff (Fig. 2). A weir and float mechanism located upstream are used to monitor the flow rate of the runoff so that the computer can adjust the frequency that PAM is applied. A video at this link demonstrates how the auger applicator operates.
Field testing of the ditch applicator
A yearlong study at a commercial farm showed that the ditch applicator was effective in removing 98% of the suspended sediments transported in runoff (Table 1, Fig. 3). Based on the total runoff measured in a single drainage ditch during the 2022 season (21.5 acre-feet), an estimated 106 tons of sediment were removed (Fig. 4).
Turbidity in the runoff was reduced by more than 99%, and Total P and N were reduced on average by 89% and 60%, respectively, during the season (Table 1, Figs. 5 and 6). These reductions in nutrient load, suspended sediment, and turbidity could greatly improve water quality in water bodies downstream from farms that discharge irrigation runoff.
Table 1. Average concentration of N, P, and sediments carried in irrigation runoff before (upstream) and after (downstream) treatment with the PAM ditch applicator (April – October 2022). Average of 32 paired grab samples from 3 farm ditches. Downstream locations varied from 300 to 500 ft downstream from the PAM applicators.
Ditch applicator vs well applicator
Although more effective at reducing suspended sediment in runoff than the well applicator, the ditch applicator required more maintenance. PAM needed to be added to the hopper once or twice per week during the irrigation season, and sediment that settled in the ditches had to be cleaned out periodically using a backhoe. Also, removed sediment had to be spread back in the fields. The well applicator only required periodic refilling of the cartridges with PAM, and minimizes the amount of sediment that settles out in the drainage ditches.
PAM effects on chlorine requirement
To evaluate the effect of PAM on the quantity of chlorine needed to treat runoff, we performed a laboratory assay on samples of sprinkler runoff collected upstream and downstream of one of the ditch applicators. The turbidity of the upstream (untreated) and downstream samples (PAM treated) was 2276 and 9.5 NTU, respectively. The electrical conductivity of the runoff samples was 1.35 dS/m and the pH was 8.4 before adding chlorine. The main factors evaluated in the assay were sodium hypochlorite concentration and acidification with 10% sulfuric acid. Presumably, acidifying the runoff to a pH of 6.5 should increase the concentration of the more reactive form of chlorine, hypochlorous acid which is more effective as a microbial disinfectant. Residual free chlorine concentration of the treatments was evaluated 2 and 4 hours after adding 12.5% sodium hypochlorite at concentrations ranging 12.5 to 31.3 ul per liter of runoff (100 to 250 ul of 12.5% NaOCl per L of water).
The laboratory assay showed that reducing suspended sediment concentration using PAM increased the efficacy of chlorine treatment of runoff. The free chlorine concentration for PAM treated runoff was more than twice the concentration measured in the untreated runoff for all sodium hypochlorite concentrations evaluated after 2 hours and more than three times the concentration after 4 hours (Fig. 7). Free chlorine concentration in the PAM treated runoff was more than 2.5 ppm two hours after treatment at the lowest concentration of chlorine evaluated (12.5 ul/L) but was less than 0.5 ppm in the untreated runoff. To attain similar chlorine efficacy as PAM treated runoff, untreated runoff would require twice as much sodium hypochlorite (25 ul/L). These chlorine requirements would correspond to 26 and52 gallons of 12.5% sodium hypochlorite to treat and acre-foot of runoff with and without a PAM pretreatment, respectively.
Acidification of the runoff to a pH of 6.5 with sulfuric acid increased the free chlorine concentration in the PAM treated runoff at the highest concentration of sodium hypochlorite (31.3 ul/L) after 4 hours. Acidification did not have a significant effect on free chlorine concentration for the other treatments.
Summary
Both versions of the dry PAM applicators (well and ditch) show promise for greatly reducing soil erosion, as well as helping improve water quality and the efficacy of chlorine for treating tail water reused for irrigation. By considerably reducing the concentration of suspended sediment in irrigation runoff, chlorine can be more effective as a disinfection agent, and better control E. coli and other microbial pathogens that could potentially cause public health risks.
Acknowledgments: We greatly appreciate assistance in fabricating the prototype PAM applicators from RayFab. This project was funded by the California Leafy Green Research Board.
Further reading
- Author: Konrad Mathesius
If you haven't seen the announcements on the UC Small Grains blog, you should be subscribed to the UC Small Grains blog.
Additionally, a friendly reminder to stop by this Thursday for the UC Alfalfa/ Forages and Small Grains Field Day from 7:30 a.m. until 3:30 p.m.
Location: 2400 Hutchison Dr, Davis CA 38.5390, -121.7800
Alfalfa Talks: 8:00 – 10:00
Small Grains Agronomy Topics: 10:00 -12:00
LUNCH will be provided (please register below)
Small Grains Breeding Program Topics: 1:40 -3:00
Agenda: https://ucanr.edu/sites/small-grains/files/383475.pdf
Register: https://surveys.ucanr.edu/survey.cfm?surveynumber=40606
Continuing Education Units (CEUs): 3.5 CCA; 1.5 CDFA INMP (formerly CURES)
Looking forward to seeing you there.