HUMUS FROM SAWDUST

Te Ao Hou, March 1961, Page 54

HUMUS FROM SAWDUST At this time of the year most gardeners are considering the means for building up a supplementary supply of humus for their gardens to be used for the next spring and summer planting, therefore it is often difficult for those living in confined areas to obtain animal manure or rotted hay from stack bottoms etc. and therefore it is suggested that in the hunt for humus-forming organic matter with which to enrich the soil, gardeners seldom think of sawdust, yet it is wholly a plant product, which will decompose to humus and plant foods. During the period of decomposition it is unobjectionable and inexpensive. The disadvantages are that it is coarse and tough and ineligible for immediate use when fresh, and if incorporated in the soil of the garden will undoubtedly create an acid condition, unless scientifically handled. Sawdust can contribute usefully to the restoration and maintenance of soil fertility. Briefly the main disadvantages are that it takes some time to decompose and the key to success as a humus-forming agent is to weather it before incorporating with the soil. For instance, it should be exposed to sun, wind and rain and turned frequently. Another useful way of weathering it is to use it as a summer mulch, an inch or two deep around perennial plants, around fruit trees or shrubs. As previously stated, if the material is to be used in the compost heap, small quantities should be incorporated regularly and the entire volume of compost thoroughly forked or turned over at approximately eight-weekly intervals.