{"id":1266,"date":"2019-07-02T13:47:33","date_gmt":"2019-07-02T20:47:33","guid":{"rendered":"https:\/\/blogs.cdfa.ca.gov\/FREP\/?p=1266"},"modified":"2019-07-02T13:47:44","modified_gmt":"2019-07-02T20:47:44","slug":"developing-nutrient-budget-in-citrus-groves","status":"publish","type":"post","link":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/developing-nutrient-budget-in-citrus-groves\/","title":{"rendered":"Developing Nutrient Budget in Citrus Groves"},"content":{"rendered":"\n

Research Update: <\/strong>Developing Nutrient Budget and Early\nSpring Nutrient Prediction Model for Nutrient Management in Citrus<\/p>\n\n\n\n

Project leaders: <\/strong>Patrick Brown and Douglas Amaral<\/p>\n\n\n\n

Project location: <\/strong>Fresno, Tulare and Ventura Counties<\/p>\n\n\n\n

Year of study: <\/strong>2 of 3<\/p>\n\n\n\n

Overview: <\/strong>Leaf analysis with critical value* interpretation is a common practice for determining nutrient applications in citrus. However, this practice can lead to over-application of nutrients and excess nitrogen (N) loss due to their insensitivity to over-fertilization. This ongoing project aims to develop nutrient demand curves, an early season leaf sampling protocol, and nutrient prediction model for mandarin and orange groves. Preliminary results indicate that small branches and leaves account for the majority biomass in trees and the shoots have the highest rate of nutrient accumulation before June. Accumulation of nutrients continues between June and October, but at a decreased rate.<\/p>\n\n\n\n

Issue: <\/strong>In the United States, most citrus is produced in Florida and California. However, there have been limited research studies conducted in California on total N demand of citrus species. Additionally, previous research can be insufficient due to variances such as climatic differences, reduced efficiency goals or simply being outdated. Given increasing regulatory pressures, growers need more precise data pertaining to season, species and yield-dependent information on N uptake in citrus.<\/p>\n\n\n\n

While critical\nvalue can provide information on nutrient adequacy or deficiency in the plant,\nit has minimal information on appropriate fertilizer rates or application\ntiming. This method is sensitive to deficiencies, but not to over-fertilization.\nThe critical value method may also not provide enough time to respond\nappropriately to in-season deficiencies. A more appropriate method to inform\nnutrient decisions may be through nutrient budgeting. This approach requires\nearly season estimation of expected yield, tree nutrient status, updated\nmid-season yield estimate, and in-season adaptation of N applications. <\/p>\n\n\n\n

Approach<\/strong>:<\/em> This project will create a phenology-based nutrient prediction model for mandarin and orange. With the data collected through this project, the principle investigators (PIs) are developing demand curves and early season leaf sampling protocol. This protocol will guide the quantity and time of fertilizer application for these crops. The PIs are achieving this through intensive monitoring of highly productive groves of mandarin and orange in Fresno and Tulare counties. <\/p>\n\n\n\n

\"Man
Figure 1: Sampling orange grove fruit at harvest.<\/figcaption><\/figure><\/div>\n\n\n\n

To develop nutrient demand curves, researchers are excavating whole trees of each species in spring, before flowering, and at the end of the first and second seasons. They are partitioning the trees to determine biomass accumulation and nutrient uptake and distribution. For each of the excavated trees, the researchers divide them into the following parts for analysis: roots, trunk, scaffold, canopy, branches and leaves. They are also monitoring trees of each species for changes in yield and nutrient concentrations in different organs throughout the season. <\/p>\n\n\n\n

Finally, the researchers are conducting\nextensive leaf sampling and analysis. Through this work, they are collecting\nand analyzing leaf samples from 25 orchards across Tulare, Fresno and Ventura\ncounties. They are collecting leaves in the spring and summer months and\nanalyzing them for macro and micro nutrients. <\/p>\n\n\n\n

Preliminary results:<\/strong><\/p>\n\n\n\n

Please note, the data shown in this report are preliminary data from year one and two, of a three-year project, and no conclusive data are shown. Preliminary results show that small branches and leaves accounted for most of the biomass in both orchards and included a large fraction of nutrients present in aboveground tissues (Figure 2). <\/p>\n\n\n\n

\"Macronutrient
Figure 2. Tree partitioning (% of total) of total tree biomass (TTB) and macronutrients (N,P, K, Ca and Mg) content. A and B are data from orange blocks and C is mandarin.<\/figcaption><\/figure>\n\n\n\n

In general, the shoots accumulated nutrients rapidly until the end of June, and continued afterward, but at a lower rate. Researchers did not observe net accumulation of nutrients in the shoots after late October\/early November. From December to February, the amount of nutrients present in the tree canopy remained stable or decreased (Figure 3), likely suggesting nutrient translocation to perennial organs. The seasonal demand of nutrients in orange was high early in the season from May through July suggesting that nutrients should be available in the soil for uptake by citrus trees from April to November. <\/p>\n\n\n\n

\"Amount
Figure 3. Seasonal trends of N accumulation in leaves during the season in orange and mandarin trees.<\/figcaption><\/figure>\n\n\n\n

For upcoming outreach events related to this project, and other FREP-funded research, please subscribe to the FREP Calendar<\/a> (https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/calendar-4\/<\/a>). <\/p>\n\n\n\n

*Critical Value is the nutrient concentration in a standard leaf sample at which yield is 90% of the maximum. <\/p>\n\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

Research Update: Developing Nutrient Budget and Early Spring Nutrient Prediction Model for Nutrient Management in Citrus Project leaders: Patrick Brown and Douglas Amaral Project location: Fresno, Tulare and Ventura Counties Year of study: 2 of 3 Overview: Leaf analysis with critical value* interpretation is a common practice for determining nutrient applications in citrus. However, this practice can lead to over-application …<\/p>\n

Read More<\/a><\/div>\n","protected":false},"author":9,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_EventAllDay":false,"_EventTimezone":"","_EventStartDate":"","_EventEndDate":"","_EventStartDateUTC":"","_EventEndDateUTC":"","_EventShowMap":false,"_EventShowMapLink":false,"_EventURL":"","_EventCost":"","_EventCostDescription":"","_EventCurrencySymbol":"","_EventCurrencyCode":"","_EventCurrencyPosition":"","_EventDateTimeSeparator":"","_EventTimeRangeSeparator":"","_EventOrganizerID":[],"_EventVenueID":[],"_OrganizerEmail":"","_OrganizerPhone":"","_OrganizerWebsite":"","_VenueAddress":"","_VenueCity":"","_VenueCountry":"","_VenueProvince":"","_VenueState":"","_VenueZip":"","_VenuePhone":"","_VenueURL":"","_VenueStateProvince":"","_VenueLat":"","_VenueLng":"","_VenueShowMap":false,"_VenueShowMapLink":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[86],"tags":[330,327,328,329],"class_list":["post-1266","post","type-post","status-publish","format-standard","hentry","category-all","tag-california-agriculture","tag-citrus-research","tag-frep-grant","tag-micronutrient-research"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p9r16A-kq","jetpack-related-posts":[{"id":72,"url":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/cdfa-accepting-concept-proposals-for-2016-fertilizer-research-and-education-grants\/","url_meta":{"origin":1266,"position":0},"title":"CDFA Accepting Concept Proposals for 2016 Fertilizer Research and Education Grants","author":"Brooke Elliot","date":"December 29, 2015","format":false,"excerpt":"The California Department of Food and Agriculture\u2019s Fertilizer Research and Education Program (FREP) is currently accepting concept proposals for the 2016 grant cycle. FREP\u2019s competitive grant program funds research that advances the agronomic and environmental performance of fertilizing materials. The 2016 Request for Proposals (RFP) includes several initiatives put forth\u2026","rel":"","context":"In "FREP Grant Program"","block_context":{"text":"FREP Grant Program","link":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/category\/frep-grant-program\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":195,"url":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/now-accepting-concept-proposals-for-2017-fertilizer-research-and-education-grants\/","url_meta":{"origin":1266,"position":1},"title":"Now Accepting Concept Proposals for 2017 Fertilizer Research and Education Grants","author":"Brooke Elliot","date":"December 16, 2016","format":false,"excerpt":"The California Department of Food and Agriculture\u2019s Fertilizer Research and Education Program (FREP) is currently accepting concept proposals for the 2017 grant cycle. FREP\u2019s competitive grant program funds research that advances the agronomic and environmental performance of fertilizing materials. The 2017 Request for Proposals (RFP) includes several initiatives put forth\u2026","rel":"","context":"In "FREP Grant Program"","block_context":{"text":"FREP Grant Program","link":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/category\/frep-grant-program\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":867,"url":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/4r-nutrient-stewardship-research-fund-request-for-pre-proposals\/","url_meta":{"origin":1266,"position":2},"title":"4R Nutrient Stewardship Research Fund Request for Pre-Proposals","author":"Brooke Elliot","date":"September 26, 2018","format":false,"excerpt":"Here is an announcement from the International Plant Health Institute (IPNI) that may be of interest to CDFA FREP stakeholders. The 4R Nutrient Stewardship Research Fund has released a request for pre-proposals to conduct field research and demonstration projects that evaluate and promote the economic, social, and environmental outcomes of\u2026","rel":"","context":"In "Other"","block_context":{"text":"Other","link":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/category\/other\/"},"img":{"alt_text":"4R Research Fund","src":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2018\/09\/4R-Research-Fund.png?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":334,"url":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/grants-to-begin-funding-january-2018\/","url_meta":{"origin":1266,"position":3},"title":"Grants to Begin Funding January 2018","author":"Brooke Elliot","date":"January 2, 2018","format":false,"excerpt":"The Fertilizer Research and Education Program (FREP) of the California Department of Food and Agriculture (CDFA) is pleased to announce the award of almost $800,000 in grant funds to agricultural organizations and universities this year. These grants will fund four projects that will improve the efficiency and reduce the environmental\u2026","rel":"","context":"In "FREP Grant Program"","block_context":{"text":"FREP Grant Program","link":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/category\/frep-grant-program\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":106,"url":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/save-the-date-for-the-frepwpha-conference\/","url_meta":{"origin":1266,"position":4},"title":"Save the Date for the FREP\/WPHA Conference","author":"Brooke Elliot","date":"March 8, 2016","format":false,"excerpt":"Every fall, the California Department of Food and Agriculture\u2019s Fertilizer Research and Education Program (FREP) and the Western Plant Health Association (WPHA) host a two-day nutrient management conference. The agenda focuses on the latest FREP-funded research results and practical applications of fertilizing materials for agricultural production in the state of\u2026","rel":"","context":"In "FREP Grant Program"","block_context":{"text":"FREP Grant Program","link":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/category\/frep-grant-program\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2016\/03\/2016-Conference-logo.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2016\/03\/2016-Conference-logo.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2016\/03\/2016-Conference-logo.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":269,"url":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/2017-frepwpha-conference-save-the-date-and-call-for-posters\/","url_meta":{"origin":1266,"position":5},"title":"2017 FREP\/WPHA Conference: Save the Date and Call for Posters","author":"Brooke Elliot","date":"August 4, 2017","format":false,"excerpt":"Every fall, the California Department of Food and Agriculture\u2019s Fertilizer Research and Education Program (FREP) and the Western Plant Health Association (WPHA) host a two-day nutrient management conference. The agenda focuses on the latest FREP-funded research results and practical applications of fertilizing materials for agricultural production in the state of\u2026","rel":"","context":"In "Nutrient Management Events"","block_context":{"text":"Nutrient Management Events","link":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/category\/nutrient-management-events\/"},"img":{"alt_text":"2017 FREP\/WPHA Conference November 1-2, 2017","src":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2017\/07\/2017-Conference-logo-25thannual.jpg?resize=350%2C200","width":350,"height":200},"classes":[]}],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/posts\/1266","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/comments?post=1266"}],"version-history":[{"count":4,"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/posts\/1266\/revisions"}],"predecessor-version":[{"id":1273,"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/posts\/1266\/revisions\/1273"}],"wp:attachment":[{"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/media?parent=1266"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/categories?post=1266"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/tags?post=1266"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}