wise use of mires and peatlands - Peatland Ecology Research Group

VALUES AND FUCTIONS OF MIRES AND PEATLANDS51countries like Ireland, some central Asianrepublics 34 , and China 35 . The latest availableinformation on industrial peat extractionvolumes is contained in the Tables in thesections dealing with peat in horticulture (ab)and for energy (ac).(aa) Peat as humus and organic fertiliserin agriculture 36Peat has been used as an organic raw materialin the production of organic fertilisers andcombined organic-mineral fertilisers and inthe improvement of degraded soils by addinghumus. Practice in this area differs greatlybetween different countries.The most important value of organic ororgano-mineral fertilisers produced with peatis in their organic matter containingbiologically active substances. Organicsubstances enrich the soil with trace elements,improve the physical properties of the soil,its pH level, and its productivity.Peat was used as an organic fertiliser in greatquantities in agriculture in the years 1950-1980 (Fig. 3/1). During this period differentmixtures, including composted mixtures, wereprepared, especially in the Soviet Union.Excavated peat, both raw and dried, was mixedwith sandy or loamy soils. This improvedthe physical properties of the soils but didnot change plant nutrition. In the SovietUnion, Ireland, France and Polandconsiderable research was carried out intothe liquid ammonia treatment of peat (15-35kg NH 4OH/Mg peat), used in agriculture in10-40 Mg/ha doses. These experiments didnot give positive results. Mixtures of peatand different mineral fertilisers had thenutrient value of the fertilisers only.Composts produced using peat with stablemanure, sewage sludge, faecal substances,liquid manure and different organic municipaland industrial wastes in 1:1-2:1 ratios wereexpensive to produce and were not effective.The results obtained from the use of peatpreparations have not shown any significantcorrelation between inputs and either thechemical properties of plants or their yield.Since the political changes in the formerSoviet Union, the volume of peat extractedfor agricultural purposes has substantiallydiminished (cf. Fig. 3/1 and Table 3/5).It is possible that in the future peat couldhave an economically effective role in theremediation of degraded soils and as topsoilreplacement in the regeneration of areas usedin open-cast mining.(ab) Peat as a substrate in horticulture 38After its use for energy generation (ac), themost common current use of peat is forhorticulture (cf. Tables 3/5 and 3/6). Theproduction of greenhouse and containercrops involves the integrated managementof water, fertilisers, pesticides and growingmedia. Of these probably the most importantis the type of growing media used. Due tothe limited volume of a pot, container or traymodule, growing media must provide theappropriate physical, chemical and biologicalconditions for plant growth. In countries witha modern horticultural industry peat hasemerged as the foremost constituent ofgrowing media. The production andprocessing of peat-based growing media hasbecome a precondition for horticulture. The‘John Innes Composts’, the ‘Einheitserde’and the ‘Torfkultursubstrat’ have beenmilestones in the development of peat-basedgrowing media.The use of standardised peat-based growingmedia in horticultural plant productiondeveloped for reasons of economics andbecause of technological advances.Industrially processed peat-based growingmedia have widely replaced growers’ selfmademixes. Continuous research andincreasing knowledge of the properties of theconstituents of growing media show thatgrowers run considerable risks if they apply