Critical nitrate levels for leaf lettuce, radish, and spinach plants
Title:
Critical nitrate levels for leaf lettuce, radish, and spinach plants
Author:
Maynard, Donald N. Barker, Allen V.
Appeared in:
Communications in soil science and plant analysis
Paging:
Volume 2 (1971) nr. 6 pages 461-470
Year:
1971
Contents:
Leaf lettuce (Lactuca sativa var. crispa L.), radish (Raphanus sativus L.), and spinach (Spinacea oleracea L.) plants were grown in sand culture under variable N concentrations from 0.187 to 48.0 meq/l. The plants were harvested when those grown at 12 meq N/l had attained approximate market maturity. Growth was restricted, and symptoms of N deficiency were evident at the low levels of N. Growth was also restricted at the highest N level. Approximate critical levels for leaf lettuce, radish roots, and spinach are 2000 ppm, 5000 ppm, and 4000 ppm, nitrate-N respectively, on a dry weight basis.