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CDFA Inspection Services Division

Lettuce Nitrogen Uptake and Partitioning

Crops:

Almonds

Barley

Broccoli

Cauliflower

Citrus

Corn for Grain

Corn for Silage

Cotton

Grapevines

Lettuce

Pistachio

Rice

Strawberries

Tomatoes

Walnut

Wheat

Seasonal N Uptake



Nitrogen uptake was determined by harvesting the aboveground biomass at different times during lettuce development.
Early in the season, lettuce N uptake was low. Between heading and harvest, however, N demand of lettuce was high. During this period, which is generally the last month before harvest, 70-80% of total N was taken up (Bottoms et al., 2012).

Nitrogen Partitioning



Wrapper leaves and not marketable heads may contain 10-40% of the aboveground N (Thompson and Doerge, 1996; Hartz et al., 2000).

Nitrogen Removed at Harvest

Lettuce yield and N removed at harvest.



Links

Lettuce Fertilization Guidelines

References

Bottoms, T.G., Smith, R.F., Cahn, M.D., Hartz, T.K., 2012. Nitrogen requirements and N status determination of lettuce. HortScience 47, 1768-1774.

Hartz, T.K., Bendixen, W.E., Wierdsma, L., 2000. The value of presidedress soil nitrate testing as a nitrogen management tool in irrigated vegetable production. HortScience 35, 651–656.

Thompson, T.L., Doerge, T.A., 1996. Nitrogen and water interactions in subsurface trickle-irrigated leaf lettuce II. Agronomic, economic, and environmental outcomes. Soil Science Society of America Journal 60, 168-173.