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The nutrient response of seedlings of ponderosa pine, dee-brush, chamise, and western mountain mahogany was studied in pot tests with three types of upland soils taken from the Sierra Nevada and the Coast ranges. The soils were deficient in nitrogen and phosphorus as determined by the growth response of standard agricultural test plants, lettuce and barley. The pine and brush seedlings responded to the addition of nitrogen, except for a few ceanothus plants which were found to have nodules on the root systems. On two of the soils studied the pine and brush seedlings gave little or no response to phosphorus. Seedlings grown in the third soil gave a substantial response to phosphorus, and it was established by chemical , tests that this soil was of the phosphate-fixing type. There was no significant response to potassium on any of the soils.

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