Growth and nutrient and nitrate accumulation of lettuce under different regimes of nitrogen fertilization

Abstract

For plant growth and composition, the effects of fertilizers including blood meal (BLO), cottonseed meal (CSM), dehydrated cow manure (COW), and urea (UREA) factored with lettuce (Lactuca sativa L.) of different morphological phenotypes including iceberg, romaine, loose head, and loose leaf were studied in a greenhouse. Lettuce growth increased with increasing nitrogen (N) applications from 0 to 800 mg N/pot (kg), but the top application of BLO, CSM, or UREA suppressed yields. Lettuce grown with BLO, CSM, or UREA had higher concentrations of N than with COW. Nitrate-N concentration in leaves of all varieties exceeded some standards at high application of organic fertilizer or urea except for COW. In general, increasing N application resulted in higher concentration of NH₄-N in lettuce with increases in applications of fertilizers. Organic fertilizers and urea were equally effective in supporting growth and affecting nutrient accumulation in lettuce if sufficient N was supplied.

Keywords:

• lettuce varieties
• Nutrient concentration
• Organic fertilizer
• Nitrate-N
• Biomass

Additional information

Funding

This material is based on work supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, the Center for Agriculture, Food and the Environment and the Stockbridge School of Agriculture at University of Massachusetts Amherst, under project number MAS 459. The contents are solely the responsibility of the authors and do not necessarily represent the official views of the USDA or NIFA.