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Nitrate‐N and Total N Concentration Relationships in Several Plant Species 1
Author(s) -
Terman G. L.,
Noggle J. C.,
Hunt C. M.
Publication year - 1976
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1976.00021962006800040006x
Subject(s) - spinach , festuca arundinacea , dry matter , brassica , agronomy , soil water , brassica oleracea , nutrient , chemistry , nitrogen , nitrate , horticulture , zoology , biology , poaceae , ecology , biochemistry , organic chemistry
Accumulation of NO 3 ‐N in plants is important in regard to plant N nutritional status, in the formation of NO 2 ‐N toxic to animals and people consuming the plants, and as a producer of lethal gas in silos. This paper describes relationships between NO 3 ‐N and total N concentrations in plants grown in several greenhouse pot experiments, as affected largely by response to applied N and by continuing growth. Corn ( Zea mays L.) was grown in soil with 200 to 800 mg of N/pot and in nutrient solutions with 2 to 16 ppm of N. Both crops were harvested at 4‐day intervals. Spinach ( Spinacea oleracea L.) and mustard ( Brassica pervirdis L.) were grown in soil with several rates of N, P, and K, and tall fescue ( Festuca arundinacea Shreb.) with 1.0 and 2.0 g of N/pot. These experiments conducted on N‐deficient soils resulted in marked yield response and higher concentrations of total N and NO 3 ‐N with increase in rates of applied N. Concentrations decreased with age, dry matter accumulation, and depletion of N. Total N was higher in leaves than in stems, but the reverse was true for NO 3 ‐N. Concentrations of NO 3 ‐N started to increase in various crops above minimum total N values of 1.5 to 4.5%, which were highest for leaves, intermediate for leaves + stems, and lowest for stems or petioles. Below these minimum total N values, NO 3 ‐N remained near zero (< 0.1%). Discontinuous regression models appear most satisfactory to fit the entire range of the relationships between total and NO 3 ‐N. It was concluded that NO 3 ‐N concentrations in plants are negligible if the total N was < 1.5% to 4.5%, depending largely on plant part composition, plant species, and N source.