Back to the roots the art of composting and the humus challenge

Transcription

1 3 rd INTERNATIONAL CONFERENCE on Sustainable Solid Waste Management Tinos, 2-4 June 2015 Back to the roots the art of composting and the humus challenge Florian Amlinger in cooperation with Urs Hildebrandt 1

2 Changing the dynamics of the global carbon cycle C-Kreislauf_Neu_3 a 760 CO 2 c Every ton of carbon lost from soil adds 3.67 tons of carbon dioxide (CO 2 ) gas to the atmosphere. Conversely, every 1 t/ha increase in soil organic b 560 MRT: 25 yrs carbon represents 3.67 tons of CO 2 sequestered from the atmosphere and Fossil C SOC=1.550 MRT: 25 yrs removed from the greenhouse gas equation. a) Reduction of emissions from burning of fossile fuels b) Utilisation of plant biomass C as renewable energy source c) Increasing the C sink in soils and plant biomass Sheet 2

3 Soil Carbon Dynamics and Soil Management Organic vs conventional farming (Germany, Hülsbergen) + 0.2% Corg + 9 t C/ hectare 300 to 500 kg C build-up / year Sheet 3

4 Key agricultural practices supporting C-sequestration in in soils Lal, 2008

5 Soil C Stocks & Dynamics < 1 % C org 1-2 % C org 14 % 34 % Total 48 % Mediterr. 75 % Loss of Soil Organic Matter and its Restoration; By William A. Albrecht; Soils and Men, Yearbook of Agriculture 1938, pp Sheet 5

6 Erosion and soil loss a result of man made desertification Foto: Hartl, W. Foto: Hartl, W. NATURE (Vol. 437), 8 September 2005 CARBON CONTENT OF SOIL in England and Wales fell steadily in the period , with some 13 million tonnes of carbon released from British soil each year. On average, British soils have lost 15% of their carbon. Sheet 6

7 Plants provide up to 25% of the photosynthesis process for their symbionts guess the evolution did not make a mistake with this interaction?! The root sphere contains 50-times the microbial colonisation than the environment soil! Sheet 7

8 Soil Living Organ of the Biosphere... For plants there is no sharp boundary between life within and the environment of the plant in which it grows Mediator between dead mineral /rock (= lithosphere) and plant life Picture: M.H. Gerzabek Fertilisation must constitute a vitalisation of the soil, in order to prevent that the plant may grow in a dead environment. This is essential because otherwise it would be not easy for the pant to form biomass and fruits out of its own vitality. Compost... Here we have a vitalisation agent for the soil... R. Steiner, Agricultural Course, 1924 Sheet 8

9 What clay-humus complex provides Provides a conducive environment for beneficial microbes Enhances N, P, K, and other nutrient uptake Aids in the decomposition of soil minerals by forming metal-clay-organic processes Improves the soil s water holding capacity Loosens the soil structure Aids in the degradation or inactivation of toxic substances Buffers soil ph Liberates CO2 needed for photosynthesis Stabilizes soil temperatures Reduces water evaporation Reduces leaching of trace elements Increases seed germination and seedling development Accelerates root growth Increases the uptake of the high-energy adenosine tri-phosphate (ATP) within the plant cell Increases yield & quality directly and indirectly Increases the permeability of nutrients back and forth through the cell wall Speeds up the plant s metabolism Enhances the chlorophyll content of leaves Sheet 9

10 sand loam < [m²/g] clay soil humified org. matter µm Sheet 10 Foto: Blum, W.W. Prof. W.W. Blum

11 Organic Matter increase in compost amended soils field trials Foto: Hartl et al. (2014); Vienna compost trial from 1992 Sheet 13

12 Organic Matter increase in compost amended soils C5 C10 C14 N1 N2 N3 Control Compost Mineral fertiliser Combined compost + mineral fertiliser Hartl et al. (2014) Mean compost application per year = 5 14 t f.m. /ha*a Sheet 14

13 Carbon balance & sequestration C5 C10 C14 N1 N2 N3 NET CO 2 -Emission NET CO 2 -Sequestration C5 C10 C14 N1 N2 N3 Hartl et al. (2014) Sheet 15

14 Organic Matter increase in compost amended soils Mean compost application per year = 6 7 t/ha d.m. OM-Input = 2,5 3,0 t/ha d.m. Increase SOM in soil (%) to 1000 kg C per ha *yr Kluge et al. (2008) Supply of organic matter to soil (t dry matter/ha ) Sheet 16

15 Carbon sequestration in compost fertilisation systems Rodale Institute 10-years composted manure Carbon sequestration of up 2,000 kg/hectare 7,000 kg CO2 per Hectare Standard tillage + chemical fertilizers lost almost 300 kg/hectare] Sheet 17

16 Carbon distribution in humic fractions 21 years DOCtrial FiBl CH C distribution in humic fractions Humines, the most stable humic fraction, are significantly increased in bio-dyn manure compost plots N control M mineral fertilisation D2 Bio-Dynamic composted manure O2 organic fresh manure K2 mineral fert. + pesticides + herbicides Sheet 18 Fließbach et al. (2000)

17 Hypothesis The idea that fertilisation means supplying plant nutrients is one of the biggest misconceptions of the 20th century and we have still not overcome Org. Matter = extremely limited resource Entire potential of ca Mt biowaste. Needs 4-5 % of EU agric. Soils! Organic matter should be transformed in a way that it best contributes to create the self sustaining biological soil system (phyto-microbial symbiosis) Fertilisation = making soil fertile and not feeding the plants directly with nutrients. This is the basic concept of eco farming World market / external economic drivers lead to concentration and industrialisation of farming systems (slurry lagoons) The new paradigm in fertilisation must prioritise: humus efficiency instead of nutrient efficiency By this the plant root / soil microbial biocenosis will be - in combination with ecoorientated crop varieties also effective in nutrient uptake from soil mineral and organic compartments Sheet 19

18 What compost do we need? Compost from an industrial waste treatment facility Compost from an open windrow composting plant

19 Windrow Composting Natural Aeration Sufficient material structure & pore volume + FREQUENT turning Air supply Oxigen supply by diffusion & convection

20 Inhomogene conditions induce inefficient composting process!

21 The main task: create and maintain the the optimum environment for the transformation & humus build-up process Temperature max. 65 C Sufficient OXIGEN min. 5 % Sufficient CO 2 min % Humidity % C : N ratio : 1 Addition of clay SOIL % Addition of COMPOST % Fresh residues min. 15 % Bulking agents % + WATER WATER WATER

22

23 o C & CO 2 in a controlled process o C The controlled process: C & CO 2 CO 2

24 Every plant manager MUST have experience in composting by his own hands

25 Austria

26 Oman Ka

27 Mexico

28 Australia Ka

29 Ethiopia

30 Sekem - Egypt

31 Kenya

32 China

33 Usbekistan

34 Ευχαριστω πολυ 36