- Author: Michael D Cahn, Ph.D.
Monterey County Agricultural Center
1432 Abbott Street, Salinas, CA
Thursday, February 23
7:45 a.m. to 12:30 p.m
3.5 CCA Continuing Education Units
8:00 Approaches for complying with water quality regulations, Tim Hartz, Vegetable Specialist, UCD
8:30 CropManage update, Michael Cahn, Irrigation and Water Resources Advisor, Monterey County
9:00 ET scheduling of romaine lettuce, Lee Johnson, Senior Research Scientist, CSUMB/NASA
9:30 Organic fertilizer evaluations, Richard Smith, Vegetable Crops Farm Advisor, Monterey County
10:30 Distribution uniformity evaluations of irrigation systems, Gerry Spinelli, Agricultural Technical Specialist, RCD Santa Cruz Co.
11:00 Evaluating crop nitrogen status – tissue and soil testing, Tim Hartz, Vegetable Specialist, UCD
11:30 Hydrology of the Salinas Valley, Howard Franklin, Senior Hydrologist, Monterey County Water Resources Agency
12:00 Conclusion and Pizza Lunch
- Author: Michael D Cahn, Ph.D.
Tomorrow we will host the 2016 UC Irrigation and Nutrient Meeting at the Agricultural Center in Salinas CA. We also have a field meeting following a pizza lunch to discuss the use of cover crops in strawberries. 4.5 hours of Certified Crop Adviser educational credits will also be available. This year we will include a panel discussion about how growers are implementing practices to better manage water and nitrogen fertilizer as well as a presentation on the sustainable groundwater management act. Please see the agenda below:
2016 Irrigation and Nutrient Management Meeting
Agricultural Center 1432 Abbott Street, Salinas, CA
Wednesday, February 17
7:45 a.m. to 1:45 p.m.
4.5 CCA Credits applied for
8:00 Summary of N use of crops in Region 3 and current water quality regulations
Chris Rose, Central Coast Regional Water Quality Control Board
8:30 Fertilizer value of N in irrigation water
Michael Cahn, Irrigation and Water Resources Farm Advisor, Monterey County
9:00 Field studies on N and water management (broccoli and spinach)
Richard Smith, Vegetable Crops Farm Advisor, Monterey County
9:30 Denitrification beds for removing nitrate from tile water
Tim Hartz, Vegetable Specialist, UCD
10:30 Potential for increasing groundwater recharge on agricultural land
Toby O'Geen, Soil Specialist, Dept of Land, Air and Water Resources, UCD
11:00 Groundwater Sustainability Act – Where are we headed in Monterey County
Stephanie Hastings: Brownstein, Hyatt, Farber and Schreck Law Firm
11:30 Panel discussion on Grower implementation of BMP's
Salvador Montes, Christensen and Giannini; Manual Mercado, River Valley Farms;
Eric Morgan, Morgan Consulting
12:00 Conclusion and Pizza Lunch
12:45 Field trip to see conservation practices
- Author: Michael D Cahn
CropManage Workshop: Hands-on training
Monterey County Agricultural Center Conference Room
1432 Abbott St, Salinas CA 93901
Thursday, April 2nd 2015
(8:30 am – 12 pm)
We will offer a hands-on training to learn in depth about the features of CropManage, a free online decision support tool for water and nutrient management of coastal crops. In addition to head and romaine lettuce, CropManage now supports broccoli, cauliflower, cabbage, and strawberries.
Considering that the drought is continuing into a 4th year, and nutrient management continues to be linked to water quality regulations, efficiently using water and nitrogen fertilizer is a high priority for Central Coast growers. CropManage can play an important role in providing quick decision support on water and nutrient management on a field-by-field basis.
This training will provide an opportunity to learn how to use CropManage for improving the efficiency of your farming operations or for adding value to your consulting services. We will provide in depth hands-on training so that you can learn step-by-step how to navigate and use CropManage for assisting with fertilizer and water management decisions and record keeping. Wi-Fi internet access is available at our conference room so please bring a laptop or tablet computer so that you can follow along as we tour through the features of the software. There should be sufficient time to answer questions as we cover the following topics:
8:30 – 9:00 Registration and Refreshments
9:00 – 9:30 Introduction and update on CropManage
9:30-10:15 Getting started with CropManage
10:30 – 11:15 Strategies for using CropManage for decision support and record keeping
11:15- 11:45 Advanced features and interfacing sensors with CropManage
11:45-12:00 Discussion of new features or changes needed.
To keep the group size manageable so that we can provide individual help, we would like to limit the workshop to 30 participants. If you have attended previous workshops and or feel proficient in using the on-line tool, then you are welcome to just attend the second half of the workshop (10:30-12 pm). Whether or not you plan to attend the entire or part of the workshop, please RSVP in advance by sending an email to firstname.lastname@example.org or email@example.com with the subject heading “CropManage workshop” and let us know the number of participants in your group. We will email you a confirmation. Thank you, and I hope to see you soon.
Michael Cahn, Irrigation and Water Resources Advisor
Certified Crop Adviser CEU hours requested (1.5 hrs irrigation management, 1.5 hrs nutrient management)
- Author: Michael D Cahn
If you missed the 2015 Irrigation and Nutrient Meeting or you would like to review the presentations, you can download pdf versions of the powerpoint files from the UCCE Monterey County Website (http://cemonterey.ucanr.edu). The direct link to the presentations is:
We want to thank all of you who attended for your participation and for the many constructive comments that we received verbally and through the evaluation surveys. Let us know of any topics that you would like us to address in the next irrigation and nutrient management meeting or ways to improve the meeting.
If you are interested to learn more about CropManage for improving irrigation and nutrient management, I plan to host a hands-on training on using this on-line decision support tool on April 2nd. I will send out a formal announcement in the upcoming weeks.
Establishing strawberry transplants using drip has several potential advantages compared to overhead sprinklers. Irrigation run-off can be greatly reduced, which protects surface water quality. Some growers have found that they can save water using drip for transplant establishment, and save costs associated with using overhead sprinklers. Often nitrogen fertilizer can be spoon fed to the crop through the drip system earlier in the season than in fields established with sprinklers, thereby reducing the reliance on pre-plant fertilizers that may result in nitrate leaching losses.
Nevertheless, growers are concerned that irrigating transplants using mainly drip may result in less vigorous growth and more dead plants during the establishment period, and yields during the production season will be lower than crops established with sprinklers. One of the specific concerns is that the drip lines adjacent to plant rows may not be as effective in leaching salts from the root zone of young plants as overhead sprinklers. Another worry is that if the transplants are not properly planted and gaps exist between the root crown and the soil, moisture will not move toward and imbibe young roots, and the plant may be set back or die.
Last year was challenging for establishing strawberries is many fields on the Central Coast due to the lack of rain, which normally helps to leach salts that may accumulate around young strawberry transplants. However, these challenging conditions were perfect for comparing vigor and yield of strawberries established using drip and overhead sprinklers.
Field trial description
We conducted a demonstration trial at a ranch in North Salinas beginning November 13, 2013. Soil was a loam texture. The field was planted with UC Albion variety in 2 rows on 52-inch wide beds. Two plots, each of approximately 1-acre in size, were located adjacent to each other in one of the irrigation blocks. Transplants were established using drip in one of the plots and with overhead sprinklers in the other plot. The irrigation foreman made all decisions on how long and often to irrigate both plots. Overhead sprinklers were used for the first 2 irrigations in the drip plot to assure that the transplants were in good contact with the soil. All subsequent irrigations were made using 2 lines of drip tape per bed. In the plot established with overhead sprinklers, transplants were also irrigated twice using the drip system. The last sprinkler irrigation was on January 25th, after which both plots were irrigated with only drip.
Applied water was monitored using flow meters installed on the drip submain and on the sprinkler main line until the end of February. Soil moisture was evaluated in the upper 6 inches of soil next to the transplants using a volumetric moisture sensor at weekly intervals during establishment. Soil salinity was also periodically monitored to a 4 inch depth next to the transplants using a soil salinity sensor (Fig 1.), or by sampling soil and analyzing saturated paste extracts for salts. Plants were rated for vigor and evaluated for canopy cover until mid February (Fig 2.). Marketable fruit yield was evaluated between late April and mid July.
Figure 1. A 5TE decagon probe was used to measure bulk salinity near strawberry plants.
Figure 2. Transplants were periodically evaluated for canopy size by measuring plant width or using a multi-spectral NDVI camera.
Applied water during transplant establishment was about 25% less for the drip treatment compared to the standard sprinkler treatment. As shown in Fig. 3, irrigation water applied to the drip treatment equaled 6.8 inches between Nov. 13 and Feb. 20th. During the same period, water applied in the sprinkler treatment equaled 9.1 inches. An additional 1.5 inches of rainfall were also measured during this period. Estimated evapotranspiration (ET) losses during establishment were 3.2 and 1.1 inches for the sprinkler and drip treatments, respectively. The lower estimated ET amount for drip was due to less wetting of the furrows than in the sprinkler treatment.
Figure 3. Irrigation water and rainfall for the drip and sprinkler treatments between Nov. 13 and Feb. 20th.
Soil moisture measured near the transplants was similar among the drip and sprinkler establishment treatments except for 4 dates between mid December and mid January when the sprinkler plot had higher soil moisture levels than the drip plot (Fig 4).
Figure 4. Volumetric soil moisture measured next to transplants for the drip and sprinkler treatments.
Bulk electrical conductivity (EC), an indirect measure of soil salinity, was slightly higher next to the drip established transplants than the sprinkler established transplants for 4 of 5 dates measured between December and early February (Fig. 4). Bulk EC values were generally low for both treatments, which was confirmed from the saturated paste extracts of soil sampled on January 24 2014 (3rd evaluation date). The EC of the saturated paste extract was 0.80 and 1.83 dS/m, respectively, for the sprinkler and drip established plots. Saturated pasted extract values below 2 dS/m would not be expected to harm strawberry plant growth. Plant vigor (Fig. 5) and canopy cover (Fig. 6) were not different between the sprinkler and drip establishment treatments. Likewise cumulative fruit yields (Fig. 7) were the same for the two methods of irrigation establishment.
Figure 5. Bulk electrical conductivity of the soil adjacent to strawberry transplants, measured using the Decagon 5TE probe.
Figure 6. Plant vigor of drip and sprinkler established transplants, where 0 equates to dead or dying plants, and 5 signifies all plants are very healthy.
Figure 8. Cumulative marketable fruit yield for sprinkler and drip established plants.
Discussion and Conclusions
The results of this field trial demonstrated that drip can be successfully used to establish strawberry transplants during the winter on the Central Coast, even during drought conditions when rainfall is minimal. Marketable fruit yields were the same between the drip and sprinkler established plots. Additionally, 25% less water was used under drip than in the sprinkler plots during the initial establishment phase. Salinity was maintained at a sufficiently low level in the soil as to not impair transplant vigor and initial growth under drip.
Low water demand of plants during the late fall and early winter is an import factor that helped us successfully establish plants using drip. New transplants have few leaves and reference evapotranspiration, on average, is less than 0.07 inches per day. Since water demand is low, the main purpose of irrigation during establishment is to keep crown roots hydrated and to leach salts from the root zone. Using good planting techniques is critical to successfully using drip for establishment. Transplant roots need to be in contact with the soil and should not be “J” rooted. Also, soil salinity should be low as possible before planting. Preplant fertilizer bands should be located a sufficient distance from the transplant roots so that emerging new roots are not burned by fertilizer salts.
For this trial, we irrigated the drip treatment twice with overhead sprinklers to assure that the roots were in good contact with the soil. Under normal weather conditions on the Central Coast, rain often occurs between late November and February, which can also assist with the establishment of transplants by maintaining high soil moisture and leaching salts from the root zone of young plants.
We thank Dole and their employees for their help and partnership with this trial, and we thank Walmart for funding this project.