Acidification of a Forest Tree Nursery Soil1
- R. E. Mullin2
Artificial acidification of nursery soils for coniferous seedling production is being studied on soils which have become alkaline through continuous use. Three methods of acidification are being examined, acidification of the irrigation water, incorporation of acid peat, and incorporation of powdered S. The experimental work is being done on red pine (Pinus resinosa, Ait.) seedbeds used for production of 3-0 shipping stock. The experiment is in three sections, starting in consecutive years, each running for three years in the nursery, and providing trees for observations in the laboratory and after outplanting. Acidification of the irrigation water, to pH 6.0 by automatic injection of H2SO4 has shown no measurable effect on soil pH or seedlings. Addition of acid peat, 60 cubic yards per acre, at about pH 5.0, showed some reduction in soil pH but not to the level desired, and no effect was determined on the seedlings. Addition of powdered S at 750, 1,500 and 2,250 pounds per acre has been most effective. The soil pH has been reduced proportionately, with that of the heaviest treatment to about pH 5.0, with some fluctuation, and the effect has not diminished after more than three years. The S treatment of 2,250 pounds caused mortality in the seedbeds, whereas the lesser treatments caused an increase in survival. Sulphur addition also resulted in taller, thicker, heavier seedlings with the first level causing a large increase, the second a minor (plateau effect), and the high level a large increase again. Information on the planting success of the seedlings is not yet available.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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