Opportunities and Challenges of Sphagnum Farming & Harvesting Gilbert Ludwig Master’s thesis December 2019 Bioeconomy Master of Natural Resources, Bioeconomy Development Description Author(s) Type of publication Date Ludwig, Gilbert Master’s thesis December 2019 Language of publication: English Number of pages Permission for web 33 publication: x Title of publication Opportunities & Challenges of Sphagnum Farming & Harvesting Master of Natural Resources, Bioeconomy Development Supervisor(s) Kataja, Jyrki; Vertainen, Laura; Assigned by International Peatland Society Abstract Sphagnum sp. moss, of which there are globally about 380 species, are the principal peat forming organisms in temperate and boreal peatlands. Sphagnum farming & harvesting has been proposed as climate-smart and carbon neutral use and after-use of peatlands, and dried Sphagnum have been shown to be excellent raw material for most growing media applications. The state, prospects and challenges of Sphagnum farming & harvesting in different parts of the world are evaluated: Sphagnum farming as paludiculture and after-use of agricultural peatlands and cut-over bogs, Sphagnum farming on mineral soils and mechanical Sphagnum harvesting. Challenges of Sphagnum farming and harvesting as a mean to reduce peat dependency in growing media are still significant, with industrial upscaling, i.e. ensuring adequate quantities of raw material, and economic feasibility being the biggest barriers. Development of new, innovative business models and including Sphagnum in the group of agricultural products eligible for subsidies, could in the future open up new and sustainable livelihood opportunities for landowners and peat extraction professionals, and ultimately may be key in reducing the peat dependence of growing media. Keywords/tags (subjects) Peat, peat alternatives, paludiculture, growing media, sustainability, Sphagnum sp., Sphagnum farming, Sphagnum harvesting, climate change Miscellaneous (Confidential information) 1 Description Tekijä(t) Julkaisun laji Päivämäärä Ludwig, Gilbert Opinnäytetyö, YAMK Joulukuu 2019 Julkaisun kieli English Sivumäärä Verrkojulkaisu 33 myönnetty: x Työn nimi Rahkasammaleen viljelyn ja keruun mahdollisuudet ja haasteet Tutkinto-ohjelma Biotalouden edistäminen YAMK Ohjaaja(t) Kataja, Jyrki; Vertainen, Laura; Toimeksiantaja International Peatland Society/Kansainvälinen Suojärjestö ry Tiivistelmä Rahkasammalet ovat laaja sammalten suku, jotka muodostavat maatuessaan turvetta, ja sen viljelyä ja keruuta pidetään yhtenä lupaavana ja ilmastoystävällisenä soiden käyttömuotona. Kuivattuna raaka-aineena rahkasammal on ihanteellinen erilaisten kasvualustojen ainesosana. Tässä opinnäytetyössä selvitin rahkasammalviljelyn ja -keruun nykytilaa sekä tulevaisuuden näkymiä sekä haasteita eri puolilla maailmaa. Rahkasammal on nopeasti uusiutuva raaka-aine, jolla on vahva potentiaali kasvualustojen turveriippuvuuden vähentämisessä, mutta sen tuotannon nostaminen teolliselle tasolle, eli riittävien raaka-ainemäärien varmistaminen, sekä taloudellisuus ovat vielä suuri haaste. Uusien innovatiivisten liiketoimintamallien ja teknologian kehittäminen sekä muutokset maatalousstrategioissa voisivat tulevaisuudessa avata viljelijöille ja maanomistajille uusia ja kestäviä toimeentulomahdollisuuksia. Avainsanat Turve, turvevaihtoehdot, paludikulttuuri, kasvualustat, kestävyys, rahkasammal, sphagnum sp. Peat,Muut tpeatiedot alternatives, paludiculture, growing media, sustainability, Sphagnum sp., Sphagnum farming, Sphagnum harvesting, climate change 2 Contents 1 Background ................................................................................................... 4 2 Objectives...................................................................................................... 7 3 Methods ........................................................................................................ 7 4 Results........................................................................................................... 9 4.1 General ........................................................................................................ 9 4.2 Sphagnum farming as paludiculture and after-use of of agricultural peatland and cut-over bogs (Germany, Canada, Sweden) ...................................... 10 4.3 Sphagnum farming on mineral soils (China) ............................................. 14 4.4 Mechanical Sphagnum harvesting (Finland, Sweden) .............................. 18 5 Conclusions ................................................................................................. 20 5.1 Environmental Dimensions of Sphagnum Farming & Harvesting ............. 20 5.2 Economic Dimensions of Sphagnum Farming & Harvesting ..................... 23 5.3 Societal Dimensions of Sphagnum Farming & Harvesting ........................ 24 5.4 Technology Dimensions of Sphagnum Farming & Harvesting .................. 25 6 Discussion.................................................................................................... 26 References .......................................................................................................... 27 3 Figures Figure 1. Global peatland distribution derived from PEATMAP (Xu et al. 2018.) .......... 5 Figure 2. Experimental Sphagnum cultivation site, Hankahauser Moor, Rastede, Germany. Image by Gilbert Ludwig .............................................................................. 11 Figure 3. Sample of Sphagnum from first year harvest in Sweden. Image courtesy of Sabine Jordan ............................................................................................................... 14 Figure 4. Upper left: Dense Sphagnum growth, before harvest (Image courtesy of Zhu Longjin). Upper right: Annual growth (Image courtesy of Zhu Longjin). Bottom: Sphagnum cultivation site on former rice paddy, after harvest (Image courtesy of Gilbert Ludwig). All images Qiannan Prefecture, Guiding, Guizhou. ........................... 16 Figure 5. Mechanical harvesting in Finland. Image courtesy of Hannu Salo. .............. 19 Figure 6. Peatland uses in Finland as % of total surface. Adapted from Rantanen (2019a) ......................................................................................................................... 20 4 1 Background With the world population expected to reach 10 billion by 2050, the demand of vegetables, fruits and flowers is increasing rapidly. According to Hunter, Smith, Schipanski, Atwood & Mortensen (2017, 386), global food production will have to increase by up to 70% from current production levels by 2050, with vegetable production needs being likely even higher. At the same time, expansion of traditional agriculture is increasingly difficult and needs to be prevented (Ranganathan, Waite, Searchinger & Hanson 2018.). Intensive and large-scale production of vegetables and fruits in greenhouses using standardized high-quality growing media mixtures, or substrates, allow uniform high-quality plant seedlings to be grown economically with very high productivity (Altman 2008.). As an example, following its agricultural crisis in the end of the 20th century, China is increasingly shifting its production of vegetable, fruit and rice seedlings to controlled greenhouse plantations, resulting in a gradually increasing demand of growing media (Meng 2019.). According to Meng (2019), Chinas demand of growing media will increase from currently 2 mio m3 to 100 mio m3 within the next 10 to 20 years. Globally, growing media demand is expected to increase from 60 mio m3 in 2018 to 240 mio m3 by 2050 (Blok 2019.). Ensuring availability of raw materials in order to keep up supply of growing media is therefore a big challenge (Hofer 2019.), but also a necessity. The challenge is exacerbated by the fact that, for decades, Sphagnum peat (mostly white peat) has been, and still is, the single most important ingredient of most growing media mixtures, comprising commonly 60-90% of growing media mixtures. The unique physical and chemical properties, such as low pH, nutrient and nitrogen immobilization, its structural properties, slow decomposition, low bulk density, high porosity and unique water retention capacities, the fact that it is relatively free of weeds and pathogens, and, after all, its low price, make peat the most important constituent of professional high-quality growing media mixtures that allow easy adjustment to requirements of individual plants (Schmilewski & Köbbing 2016, Schmilewski 2008). The sustainability of peat based growing media, however, is an increasing concern of environmental lobbying. Covering over four million km2, or about 3% of the world’s 5 terrestrial & freshwater surface (Fig. 1), peatlands store and sequester more carbon than any other terrestrial ecosystem, about one quarter of the worlds soil carbon. Drained peatlands make up about 16% of the world’s peatlands, or 0.5% of the Earth’s land surface, yet their contribution to global greenhouse gas and cropland emissions are 5% and 32%, respectively (Joosten et al. 2016, Carlson et al. 2017). Peatlands and peatland use make therefore an important contribution to global climate change mitigation (Biancalani, Salvatore & Tubiello 2014.), the significance of rewetting and restoration of drained peatland is increasingly acknowledged (Leifeld & Menichetti 2018.). FAO (UN Food and Agriculture Organization) are actively promoting replacement of peat in growing media through sustainable peatland concepts. As a result, the use of peat as raw