California Crop Fertilization Guidelines

UC Davis
A collaboration between CDFA, FREP and UC Davis

Tomato Nitrogen Uptake and Partitioning

The Fertilization guidelines can also be found on the UC Davis Nutrient Management website .

Seasonal N Uptake

Season N Uptake Curve Graph

Nitrogen uptake curve of processing tomatoes grown in research plots at UC Davis and in commercial fields. Uptake was determined by harvesting the aboveground biomass at different times during the season [3]. Early in the season, N uptake was low. The period of low uptake is shorter with transplants compared to seeds. The N uptake remained relatively high until harvest.

Nitrogen Partitioning

Nitrogen partitioning pie chart

Approximately 70% of the total aboveground N was in tomatoes, with the rest being in the vines [3].

Nitrogen Removed at Harvest

Nitrogen removed at harvest of processing tomatoes. The overall average is weighted for the number of observations in each trial. More information can be found here [2].

Location Years Removal (lbs N/ton fresh weight) Source
    Mean Range  
Central Valley, CA 2007-2008 3.00 2.6-3.3 [3]
Central Valley, CA 2015 3.12 2.8-3.6 [1]
Central Valley, CA 2013 2.52 1.9-3.1 [4]
Weighted Average   2.73 1.9-3.6  



  1. Aegerter, B., 2015. Potential for improved fertigation efficiency via field-based sensing devices. Report submitted to the California Tomato Research Institute. Complemented with unpublished data.
  2. Geisseler, D., 2016. Nitrogen concentrations in harvested plant parts -A literature overview. Report to the Kings River Watershed Coalition.
  3. Hartz, T.K., Bottoms, T.G., 2009. Nitrogen Requirements of Drip-irrigated Processing Tomatoes. HortScience 44, 1988-1993.
  4. Lazcano, C., Wade, J., Horwath, W.R., Burger, M., 2015. Soil sampling protocol reliably estimates preplant NO3- in SDI tomatoes. California Agriculture 69, 222-229.