Foliar and Soil Nutrients in Relation to Sugar Maple Decline1
- Donald L. Mader and
- Bruce W. Thompson2
The relationship of soil fertility to decline of the sugar maple (Acer saccharum Marsh.) was studied in forest and sugarbush stands by soil studies, foliar analyses and fertilization trials. Site studies of 21 stands indicated that foliar nitrogen was low among trees and stands exhibiting crown decline symptoms and reduced growth rates. Both low and high levels of total soil N were associated with low foliar N and poor growth. Foliar Ca and Mg were closely correlated with levels in the soil.
Fertilizers were applied to three stands and their influence evaluated after one growing season by visual leaf response and foliar nutrient changes. Fertilization at the rate of 224 kg of N/ha increased the low foliar N levels in the two stands where decline was present, resulting in improved foliage color and condition.
The studies demonstrated that foliar N deficiencies are a critical factor in sugar maple decline. Deficiencies were corrected by fertilization during a drought period. Drought is believed by many to be the cause of decline. Both N availability and uptake may be restricted during drought periods.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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