Effect of Nitrogen, Potassium, and Plant Age on Certain Nitrogenous Constituents and Malate Content of Orchardgrass (Dactylis glomerata L.)¹

Abstract

Synopsis Malate, true protein nitrogen, free amino nitrogen, and nonprotein nitrogen other than free amino nitrogen were positively correlated with nitrogen supply with both 4‐ and 6‐week‐old orchardgrass leaves. The degree of association varied with plant age and potassium content. Nonprotein nitrogen compounds and malate were negatively correlated with potassium. True protein was positively correlated with the potassium content.

Influence of K on the Yield and Chemical Composition of Grasses Grown in Hydroponic Culture with 12, 50, and 75% of the N Supplied as NH4+1

“…The 250-ppm K concentration also caused reductions in percent Ca and Mg compared to the 50-ppm concentration. While it cannot be shown conclusively from the results of this experiment, the positive influence of K on protein synthesis 3 (1, 6) may be due in part to the influence of K on the Ca and Mg absorption and availability in the plant. Soluble N compounds were found to accumulate in each of the three grasses, with bromegrass and orchardgrass having somewhat higher percentages of nonprotein and reduced N than timothy.…”

“…JT HAS been shown by Tee! (11,12) and others (3,6,8,9) that grasses, when heavily fertilized with nitrogen, may accwnulate soluble nitrogen compounds or nonprotein nitrogen in sufficient concentration to cause stress in the metabolism of the plant as well as in the metabolism of the animal eating the plant. Source of nitrogen and the rate of nitrogen fertilization in relation to the potassium available to the plant are two factors which influence herbage composition 3 (9, 12).…”

“…In previous hydroponic experiments designed to compare nitrate and ammonium sources of N 3 ( 2) corn produced more dry matter with 75% of the nitrogen supplied as NH 4 + than with lesser amounts of NH 4 +. MacLeod and Carson (9) showed that with 250 ppm of nitrogen the 12% NH 4 + nitrogen source produced higher yields of orchardgrass than did the 7 5% NH 4 + source.…”

Effect of Fertilizer Nitrogen, Variety and Maturity on the Dry Matter Yield and Nitrogen Fractions of Corn Grown for Silage1

“…The acute and chronic toxic effects of high nitrate in plants and silage consumed by animals, and the lethal "silo gases" produced by ensiling plants high in nitrate have been treated in a recent review (18). In general, nutrient imbalance, drouth, and high available N levels tend to increase the nitrate content of corn tissue (6,7,8,10,11,12,18) although these effects vary among varieties (II,18).…”

Influence of nitrogen and potassium on growth, chemical composition and anatomical structure of Agrostis palustris Huds.

“…Sodium, a non-essential cation, increased as nitrogen levels increased. This response was due to the reduction in potassium content which occurred at high nitrogen levels allowing sodium, a cation which has been shown to be non competitive with ammonium, to passively enter the plant and accumulate(11). Copper content of the foliage varied direct ly with nitrogen supply possibly due to metabolic demand(56).The effect of increasing nitrogen supplies on the reduction of ash in the foliage reflects the relatively large decreases which occurred with the individual cations.…”