The availability of mineral plant food

Abstract

The assumption that plants feed in the soil just as they feed in water culture solution is unjustified and contrary to the facts. In modification of the usual hypothesis two possibilities are discussed. 1. The absorption of colloids by the plant. 2. The union of the root hair with soil and other mineral particles (so that the plant and the soil form one system) and the dissolution of the particle by the organic matter of the root hair so attached.