{"id":167,"date":"2017-01-11T08:00:20","date_gmt":"2017-01-11T16:00:20","guid":{"rendered":"http:\/\/blogs.cdfa.ca.gov\/FREP\/?p=167"},"modified":"2026-04-02T13:09:26","modified_gmt":"2026-04-02T20:09:26","slug":"research-update-n-fertilizer-requirements-of-crops-following-alfalfa","status":"publish","type":"post","link":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/research-update-n-fertilizer-requirements-of-crops-following-alfalfa\/","title":{"rendered":"Research Update: N Fertilizer Requirements of Crops Following Alfalfa"},"content":{"rendered":"

Research Project:<\/strong> Characterizing N Fertilizer Requirements of Crops Following Alfalfa – Putnam, D. et al.<\/i><\/p>\n

\"In<\/a>

In Davis, strips of alfalfa and wheat-sudangrass rotations were established to compare the effects on a wheat crop planted after both systems. Yields of wheat at different N rates were then compared.<\/em><\/p><\/div>\n

Issue:<\/strong> Alfalfa is a leguminous crop that converts atmospheric nitrogen (N) into organic compounds. While it is well-known that crops following alfalfa benefit from the residual N produced by alfalfa, the amount of residual N has rarely been measured. Previous estimates of N carryover from alfalfa range from 40 to 80 lb. of N per acre. This project is aimed at characterizing the residual N available for crops rotated after alfalfa.<\/p>\n

Methods\/Locations:<\/strong> Field-scale experiments were established at Davis, Tulelake, and Kearney, CA, and the effects of various rotations on N accumulation in wheat were examined.<\/p>\n

Main findings:<\/strong> The investigators found that wheat following alfalfa realized N credits of 70 to 130 lb. of N per acre, depending on location, soil type and other factors. This is a significantly larger credit than has been previously estimated.<\/p>\n

The researchers suggest that these amounts should be adjusted based upon other parameters that may influence N availability. These may include: whether the stand was adequate, whether foliage was vigorously growing when plowed down, plants per square foot, the degree of weed intrusion, soil-type, etc. Additionally, the time elapsing between plow-down and wheat planting must also be considered, since some of this N may be lost during crop rotation.<\/p>\n

Crop rotation with alfalfa caused improvements in wheat protein at virtually all N rates applied to the subsequent wheat. This is important since much of the N applied to wheat has the objective to improve wheat protein, which brings a premium to the grower.<\/p>\n

Potential Impact:<\/strong> Typically a minimum of 150,000 acres of alfalfa are rotated to other crops each year in California. If a conservative estimate of 80 lb. of N per acre credit is accounted for in the crops following alfalfa across the state, 2 million pounds of N fertilizer could be conserved each year. This would reduce production and labor costs incurred by growers and benefit the environment.<\/p>\n

Full Project Report:<\/strong> https:\/\/www.cdfa.ca.gov\/is\/docs\/12-0385-SAPutnam.pdf<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Research Project: Characterizing N Fertilizer Requirements of Crops Following Alfalfa – Putnam, D. et al. Issue: Alfalfa is a leguminous crop that converts atmospheric nitrogen (N) into organic compounds. While it is well-known that crops following alfalfa benefit from the residual N produced by alfalfa, the amount of residual N has rarely been measured. Previous estimates of N carryover from …<\/p>\n

Read More<\/a><\/div>\n","protected":false},"author":5516,"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":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[86],"tags":[23],"class_list":["post-167","post","type-post","status-publish","format-standard","hentry","category-all","tag-alfalfa"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p9r16A-2H","jetpack-related-posts":[{"id":235,"url":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/research-update-improving-n-use-efficiency-of-cool-season-vegetables-with-broccoli-rotations\/","url_meta":{"origin":167,"position":0},"title":"Research Update: Improving N Use Efficiency of Cool Season Vegetables with Broccoli Rotations","author":"Brooke Elliot","date":"July 1, 2017","format":false,"excerpt":"Research Project: Improving N Use Efficiency of Cool Season Vegetable Production Systems with Broccoli Rotations. Smith R. et al. Status: Completed Issue: The cool season vegetable production areas of the California\u2019s Central Coast frequently grow two or three crops during the growing season. The dominant crops\u2014like lettuce and spinach\u2014require high\u2026","rel":"","context":"In "All"","block_context":{"text":"All","link":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/category\/all\/"},"img":{"alt_text":"photograph of a field of vegetables","src":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2017\/05\/IMG_5337-300x199.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":189,"url":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/research-update-fertilizer-value-of-nitrogen-in-irrigation-water\/","url_meta":{"origin":167,"position":1},"title":"Research Update: Fertilizer Value of Nitrogen in Irrigation Water","author":"Brooke Elliot","date":"February 15, 2017","format":false,"excerpt":"Research Project: Determining the Fertilizer Value of Ambient Nitrogen in Irrigation Water - Cahn, M. et al. Status: Final year of study Issue: Irrigation water from many wells on the Central Coast contains a significant amount of nitrate-nitrogen (NO3-N). The N content in irrigation water has not been accounted for\u2026","rel":"","context":"In "All"","block_context":{"text":"All","link":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/category\/all\/"},"img":{"alt_text":"Manifold and injection system used for simulating irrigation water with different concentrations of nitrate-N.","src":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2016\/12\/Cahn-blog-300x200.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":139,"url":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/key-learnings-from-the-frepwpha-conference\/","url_meta":{"origin":167,"position":2},"title":"Key Learnings from the FREP\/WPHA Conference","author":"Brooke Elliot","date":"November 30, 2016","format":false,"excerpt":"The twenty fourth annual FREP\/WPHA Conference took place on October 26-27, where speakers from industry, academia, and agricultural consulting provided cutting edge information on nutrient management in California agriculture. The conference presentations covered a wide range of nutrient management topics including education and outreach, soil microbiology, government regulations and irrigation,\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":"Conf-Key-Learnings-Banner","src":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2016\/11\/Conf-Key-Learnings-Banner-1024x330.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2016\/11\/Conf-Key-Learnings-Banner-1024x330.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2016\/11\/Conf-Key-Learnings-Banner-1024x330.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":1252,"url":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/nitrate-quick-test\/","url_meta":{"origin":167,"position":3},"title":"Nitrate Quick Test","author":"Brooke Elliot","date":"June 25, 2019","format":false,"excerpt":"The nitrate quick test (NQT) is a cost-effective tool that can be used in nutrient management planning to determine the residual soil nitrate concentration. The results from the test can be used to improve fertilizer management and assist growers in accurately meeting crop needs. Here is an outline of the\u2026","rel":"","context":"In "Instructions"","block_context":{"text":"Instructions","link":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/category\/instructions\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2019\/06\/NQT-infographic.png?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2019\/06\/NQT-infographic.png?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2019\/06\/NQT-infographic.png?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2019\/06\/NQT-infographic.png?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2019\/06\/NQT-infographic.png?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2019\/06\/NQT-infographic.png?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":334,"url":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/grants-to-begin-funding-january-2018\/","url_meta":{"origin":167,"position":4},"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":79,"url":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/california-fertilization-guidelines-and-brochures\/","url_meta":{"origin":167,"position":5},"title":"California Fertilization Guidelines and Brochures","author":"Brooke Elliot","date":"January 21, 2016","format":false,"excerpt":"The California Fertilization Guidelines on the FREP website have been expanded to include recommendations for 18 crops, representing more than half of the irrigated agriculture in California. The recent additional recommendations are for plums, peaches and nectarines. Potato recommendations are coming soon. Additionally, FREP is pleased to announce that tomato,\u2026","rel":"","context":"In "Other"","block_context":{"text":"Other","link":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/category\/other\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2016\/01\/Brochures21.gif?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2016\/01\/Brochures21.gif?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2016\/01\/Brochures21.gif?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/blogs.cdfa.ca.gov\/FREP\/wp-content\/uploads\/2016\/01\/Brochures21.gif?resize=700%2C400&ssl=1 2x"},"classes":[]}],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/posts\/167","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\/5516"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/comments?post=167"}],"version-history":[{"count":10,"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/posts\/167\/revisions"}],"predecessor-version":[{"id":202,"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/posts\/167\/revisions\/202"}],"wp:attachment":[{"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/media?parent=167"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/categories?post=167"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.cdfa.ca.gov\/FREP\/index.php\/wp-json\/wp\/v2\/tags?post=167"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}