ISSN:
1573-5036
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary The effects were studied of varying amounts and forms of N fertilizers on the chemical composition of soil solution and on the uptake of N, K, Na, Ca and Mg by barley. In isolated soil solution the concentrations as well as the ratios of individual cations depended on form and amount of added nitrogen. The concentration of Σcations increased proportionally with applications of nitrate+sulphate. Cation-activity ratios in isolated soil solution were governed by the ratios of corresponding exchangeable cations. During the entire growth period the absorption by the plants of individual as well as of Σcations was independent of their concentrations in soil solution. So long as NH4 ions were present in the soil solution, plants with NH4 addition contained less Σcations than those with NO3 addition. Thereafter the amounts of Σcations in the plant were closely correlated with N absorption, but not affected by form of applied N. The ratios K/(Ca+Mg) and Ca/Mg in the plant were closely correlated with corresponding activity ratios but independent of concentration ratios of these ions in isolated soil solution. It is postulated that uptake of Σcations is governed by N-metabolic processes in the plant, whereas ratios of absorbed cations are influenced by cation-activity ratios in the soil solution.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01348517
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