Apparatus for the improved dispensing of plant nutriments

Apparatus for transferring plant support reagents to a watered plant growing medium, such as soil, over a protracted period at an essentially constant rate which is a function essentially solely of the quantity of water added to such medium, comprising a container generally sealed throughout the protracted period and including a reservoir portion and an elongate probe portion adapted to be embedded in said growing medium, said probe portion being in communication with said reservoir portion, means in said probe portion for defining an aperture of a desired size larger than capillary size for communicating the interior of said probe to said growing medium, said probe and reservoir portions containing means for transferring plant support reagents to the watered plant growing medium and comprising an integral diffusion mass of stable, solid, water insoluble but permeable hydrophilic gel essentially saturated with a solution of water soluble plant support reagents wherein the concentration of plant support reagents within all areas of the gel system substantially equalizes between waterings, said aperture providing contact of said diffusion mass and the water of the plant growing medium, said container and said diffusion mass remaining integral during the protracted period whereby essentially constant quantities of plant support reagents are released at each watering.