wise use of mires and peatlands - Peatland Ecology Research Group

VALUES AND FUCTIONS OF MIRES AND PEATLANDS53the wrong materials or the wrong quantitiesof materials. The major advantages ofSphagnum peat as a constituent of growingmedia include:● its cellular structure ensures good waterholding ability;● its low pH and nutrient status allow easyadjustment by the addition of crop-specificfertilisation and liming;● it is free from pathogens, pests and weeds;● it is easy to handle, process, grade andblend;● peat products are available on a world-widebasis;● ‘alternative’ growing media work best whenthey contain an element of peat.Peat substrates are used particularly inglasshouse horticulture for the cultivation ofyoung plants, pot plants and for the growingof crops such as bedding plants andvegetable plants in containers 40 . It is alsosold to amateur gardeners as a soilconditioner. In Europe, approximately 90%of all growing media for the professional andamateur markets are peat-based. In countriessuch as Finland, Germany, Ireland, Swedenand the U.K. domestic peat resources providehorticultural enterprises with peat-basedmedia for growing crops. Countries such asBelgium, France, Italy, the Netherlands andSpain depend on imports of peat and peatbasedgrowing media to support and sustaintheir horticultural business. The export ofpeat from the Baltic States to Western Europeis increasing. In North America the same istrue of exports from Canada to the U.S.A. 41Peat is used as a component of mushroomcasing for commercial production of ediblemushrooms (Agaricus bisporus) and oystermushrooms (Pleurotus ostreatus), and as acarrying medium for rhizobial inoculants forvegetable production (e.g. soybeans) 42 .Although peat has maintained its position asthe leading material for growing media, and isthe preferred product among amateurgardeners, ‘alternative’ materials haveemerged as substitutes for peat where feasibleand safe for use (Table 3/6). These materialsinclude coir 43 , wood fibre, composted barkand composted biogenic waste.Environmental awareness, increasingknowledge of the interactions of mediaproperties and product diversification havehelped introduce these alternative materials.The peat industry is now participating inresearch into ‘alternative’ materials and isintroducing products containing thesematerials. In spite of these developments,there is not at present any alternative materialavailable in large enough quantities andequally risk-free which could replace peat inhorticultural crop production.(ac) Peat for energy generation 45Within Europe, peat is an important local orregional energy source in Finland, Ireland andSweden. It also continues to be important inthe Baltic States 46 and in Belarus and Russia(Table 3/7). In Asia, peat is also used forenergy purposes in parts of China 47 andIndonesia, but reliable volume estimates arenot available. A small amount of sod peat isproduced for energy purposes in themountain regions of Burundi in Africa.The global use of peat for energy is estimatedto be 5 to 6 million tonnes of oil equivalent(Mtoe) (Table 3/8).In Finland, peat is used mainly in cogeneration(combined heat and power, CHP)and in heating facilities. It is an importantfuel for district heating in regions where othersources of energy are not readily available.The total installed capacity is over 750 MW eand 1500 MW th, and includes 60 districtheating plants, 34 CHP facilities, 30 industrialplants and one condensing power plant. InIreland peat is used for power generation incondensing power plants, and also as a fuelfor domestic heating. The older generationof pulverised fuel power plants is being