Long-term fertiliser rods

摘要

A long-term fertiliser rod for plants esp. trees, consists of a biodegradable nutrient shell, made of several sleeve-shaped segments of polymer material which biodegrade at a different rate. The most easily biodegradable polymer is starch acetate, (R)-polyhydroxybutyric acid or polyalkylene carbonate and the most difficultly biodegradable polymer is polyglycols of propylene oxide or ethylene oxide. The nutrient shells are filled with nutrients specific to the crop and location.