California Fertilization Guidelines

UC Davis
A collaboration between CDFA, FREP and UC Davis

Citrus Nitrogen Uptake and Partitioning

The fertilization guidelines on this site have been redesigned to be compliant with AB434. The guidelines in the traditional design with the latest updates can be found on the UC Davis Nutrient Management website .

Seasonal N Uptake

Season N Uptake Curve Graph

Seasonal pattern of the N content of 10-year old orange trees grown in Southern Italy. Oranges were harvested in February [9].

Nitrogen Partitioning

Nitrogen partitioning pie chart

Nitrogen distribution in mature Valencia orange trees in Tulare County. Whole trees were excavated and analyzed at fruit drop. Nitrogen in the fruits changed little until harvest [6].

Nitrogen Removed at Harvest

Nitrogen removed with harvested orange and lemon fruits. The overall average is weighted for the number of observations in each trial. More information can be found here [4].


Location Years Removal (lbs N/ton of fruits) Source
    Mean Range  
California 1950-74 2.97 2.44 - 3.46 [3]
California 1960-62 3.70 3.52 - 3.88 [7]
California 2004 3.26   [5]
Florida 1994-96 2.70 2.35 - 3 [1]
Italy 1990-92 2.71 2.36 - 3.19 [8]
Italy 2010 2.66   [9]
Brazil 1976 4.30 3.99 - 4.86 [2]
Various   3.31 3.3 - 3.33 [10]
Weighted Average 2.96 2.35 - 4.86  


Location Years Removal (lbs N/ton of fruits) Source
    Mean Range  
California 1950-74 2.51 2.3 - 2.8 [3]
Various   3.87   [10]
Weighted Average 2.58 2.3 - 3.87  

Average removal values for grapefruit range range between 1.6-3.25 lbs N/ton, and for tangerines between 2.02-3.06 lbs N/ton [4].



  1. Alva, A.K., Paramasivam, S., 1998. An evaluation of nutrient removal by citrus fruits. Proceedings of the Florida State Horticultural Society 111, 126-128.
  2. Bataglia, O.C., Rodriguez, O., Hiroce, R., Gallo, J.R., Furlani, P.R., Furlani, A.M.C., 1977. Composição mineral de frutos cítricos na colheita. Bragantia 36, 215-221.
  3. Embleton, T.W., Jones, W.W., 1974. Foliar-applied nitrogen for citrus fertilization. Journal of Environmental Quality 3, 388-391.
  4. Geisseler, D., 2016. Nitrogen concentrations in harvested plant parts -A literature overview. Report to the Kings River Watershed Coalition.
  5. Krueger, R.R., 2005. Seasonal variation in N uptake and nutrient concentration in mature field-grown citrus. Final Report submitted to the Citrus Research Board.
  6. Krueger, R.R., Arpaia, M.L., 2008. Seasonal uptake of nutrients by mature field-grown 'Valencia' (Citrus sinensis O.) trees in California. Proceedings of the International Society of Citriculture, 588-594. Complemented with unpublished data.
  7. Labanauskas, C.K., Handy, M.F., 1972. Nutrient removal by Valencia orange fruit from citrus orchards in California. California Agriculture 26 (12), 3-4.
  8. Rapisarda, P., Intrigliolo, F., Intelisano, S., 1995. Fruit mineral analysis of two 'Tarocco' clones of sweet orange to estimate fruit mineral removals. Acta Horticulturae 383, 125-133.
  9. Roccuzzo, G., Zanotelli, D., Allegra, M., Giuffrida, A., Torrisi, B.F., Leonardi, A., Quiñones, A., Intrigliolo, F., Tagliavini, M., 2012. Assessing nutrient uptake by field-grown orange trees. European Journal of Agronomy 41, 73-80.
  10. United States Department of Agriculture Natural Resources Conservation Service. Crop Nutrient Tool.