Development of Waste Sawdust as a plant protection material for horticulture and agriculture
Lignin is one of the major wastes of modern society, in the form of wood waste such as sawdust. In nature, lignin is slowly digested to soil humus. This project is to ascertain whether sawdust could be digested into a plant protection material. The value of this would be that it would control some pests and diseases without being a pesticide nor fertilizer. There is considerable experience of such material anaerobically digested from the waste of a cellulose factory in Brazil. In this project sawdust from our own mill (Lothian Trees and Timber) was digested both anaerobically and aerobically over long periods, under different conditions. The product was either dried or diluted, and tested by spraying on a small representative samples of crop plants. While this preliminary work cannot yet give definitive results, it does appear that the most fully anaerobically digested sample improves leaf colour and perhaps delays end-of-season senescence. Enough materials are now in stock to continue testing next season and to prepare new samples, using the experience gained.