SWOT ANALYSIS OF THE USE OF COMPOSTS AS GROWING MEDIA COMPONENTS

SWOT analysis is a method used to evaluate the Strengths, Weaknesses, Opportunities and Threats involved in a project or a process. In the context of growing media (GM) this paper will analyse the strengths, weaknesses, opportunities and threats involved with the use of various composts in GM. Each SWOT analysis must start with defining a desired end-result. Peat moss serves as the main organic component of GM due to its superior physical properties. Recently a rising demand for peat substitutes is driven by the need to recycle organic wastes in an environ-mentally-sensitive manner, by the high cost of peat and due to the understanding of the role of peat bogs in the global carbon cycle. Also, frequently peat is conducive to soil-borne diseases. The desired end-result is therefore the maximization of compost use as peat substitutes in GM, based on the understanding of the role composts can play. In addition to the above-mentioned weaknesses of peat, the strengths of composts are its low cost, its potential nutritional contribution and its suppressive effect against several root pathogens. Weaknesses of composts are a result of lack of uniformity, salinity high pH and inferior physical properties, as compared to peat. The oppor¬tunities that are linked to the use of composts are related to the need of the society to recycle wastes in a sound environmental manner. The threats stem mainly from potential human, zoonotic and plant pathogens, as well as the high heavy metal content of some composts. A well-controlled composting process is, in most cases, essential in order to obtain a good peat substitute, characterized by acceptable stability and minimal shrinkage. The composting process should be aerobic to prevent formation of acidogenic, phytotoxic compounds. The compost should be exposed to thermophilic conditions in order to eradicate human and plant pathogens and weed seeds. Other important objectives of the process are the lowering of C/N ratio in order to prevent N immobilization and minimization of oxygen demand by microorganisms. The results of the SWOT analysis suggests a bright future for the use of composts in GM. Required future research includes the study of the linkage between feedstocks and composting techniques on the one hand, and compost characteristics and expected performance on the other hand. The effect of compost storage on the shelf life of its desirable properties should also be studied.