1967•Canadian Journal of Plant ScienceRequires access
EFFECT OF AMMONIUM NITROGEN AND NITRATE NITROGEN, SEPARATELY AND IN COMBINATION, ON THE GROWTH OF THE HIGHBUSH BLUEBERRY
L. R. Townsend
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Abstract
A greenhouse sand-culture study with two sands revealed that growth was significantly better with ammonium nitrogen, or ammonium nitrogen plus nitrate nitrogen, than with nitrate nitrogen. Roots of plants receiving NO3-N were dark brown or black, whereas roots of those receiving NH4-N or NH4-N + NO3-N were light brown. Nutrient levels in leaves and roots were significantly affected by the form of applied N. Plants receiving NH4-N had significantly higher leaf levels of N, P and Fe and significantly lower levels of K, Ca, Mg, Mn and Al than did plants receiving NO3-N. Levels in plants receiving NH4-N + NO3-N were generally intermediate. Effluent pH from NH4-N or NH4-N + NO3-N plants decreased during growth, but pH of effluents from NO3-N plants increased.