Biochar application as a soil additive is gaining global acceptance. In this era of climate change, biochar use for improved soil productivity is not just a sustainable eco-friendly substitute to synthetic fertilizer, but a noble contributor to the fight against climate change. Although biochar has been accredited with some environmental and agricultural benefits, most studies concentrated on agricultural and biowaste products as feedstocks. This research was designed to explore P-enriched modified-Douglas fir biochar potential as a soil additive. Using corn as a test crop, greenhouse studies were performed on acidic sandy soil, comparing phosphorus enriched modified-Douglas fir biochar efficacy to a commercial synthetic triple superphosphate fertilizer and a control treatment. Incubation studies were also performed to evaluate the liming and heavy metal immobilization efficacies. Firstly, P-enriched modified-Douglas fir biochar’s ability to release plant soluble P was investigated. At various P enrichment concentration, soil plant availability P from P enriched modified-Douglas fir biochar treatments differed insignificantly from superphosphate fertilizer treatment. The direct correlations between both K and Mg recoveries with available soil P, suggested P enriched modified-Douglas fir biochar potential to supply multiple plant nutrients. Secondly, the influence of P uptake on plant growth and P use efficiency was examined. The greater agronomic P use efficiency obtained in P enriched modified-Douglas fir biochar (~32 kg kg-1) than the triple supper phosphate fertilizer (~17 kg kg-1) treatment confirmed P enriched modified-Douglas fir biochar potential as a multiple nutrient released soil additive. Thirdly, biochar-supported phosphate (BP) effectively reduced Pb2+ mobility in simulated contaminated soil. Pb2+reacted with phosphate from Ca10(PO4)6(OH)2 embedded in the biochar supported phosphate at pHPb10(PO4)6(OH)2. Finally, the amendment of acidic soils with modified P-enriched modified-biochar improved soil buffering capacity because of its enhanced ash contents, alkalinity, and surface functional groups. Spectroscopic methods were used to analyze biochar, soil, and plant materials extracts. Several other analytical methods including BET and thermogravimetric analyses were used to characterized biochar. These findings suggest that the use of phosphorus enriched modified-Douglas fir biochar in agricultural soil is a feasible relatively low-cost, effective, and environmentally sustainable soil management and P recycling strategy

A long-held practice is to mix agricultural soil with a soil amendment to improve growing conditions in crops. A common soil amendment is biosolids produced from both municipal and dairy wastewater due to the macro- and micronutrients within it. Both the agricultural and wastewater industries are participating in the Circular Economy concept (CEC). Two experiments explored using expended bioelectrochemical systems (BES) that treated either synthetic dairy wastewater (DWW) or synthetic municipal wastewater (SWW) as soil amendments to improve corn plant growth when treated with three different nutrient treatments: 100%- 50%- and 0% Hoagland Nutrient Solutions. Biochar and used terracotta clay were used as soil amendments too. Additionally, the DWW and SWW soil amendments are being invested to see if soil moisture can be retained during simulated drought conditions. The experiments took place in the late fall and winter of 2021 and summer of 2022 in Starkville, Mississippi.

In  Kenya, lack of clean cooking services affect around 80 % of the population. A range of improved cookstoves (ICS) have been produced to address this. This study aims to investigate the long-term usage of an improved stove, the biochar producing gasifier. The stove was distributed to 150 rural households divided between three regions in Kenya, in a research project in 2016. This follow-up study looked at areas of stove satisfaction and dissatisfaction among participants, as well as identifying key factors which separate users from non-users. All 150 were asked a few questions over the phone and 30 were visited for in-depth, survey-based interviews. Most households used the traditional three stone open fire stove for everyday purposes, sometimes complemented by the gasifier or other ICSs[CS1] [CS2] . 60 % of households used the gasifier at least monthly. Users and non-users rated the gasifier stove similarly. They varied in terms of stove ownership with users owning on average half a stove more than non-users. User households were generally larger. The gasifier was a fuel efficient stove and created little smoke, but was considered too small and required tiresome fuel preparation. The reported problems cannot be fixed unless thoroughly changing the stove design and possibly the gasification process itself, and without addressing them the gasifier is unlikely to replace the three stone stove. The study recognizes the potential of the gasifier as an improved stove, but calls for creative redesign in order to achieve mass adoption. / I Kenya påverkar bristen på matlagningsutrustning som är säker ur hälso- och miljösynpunkt runt 80 % av befolkningen. Traditionellt lagas mat över öppen  eld. En mängd spisar har producerats i syfte att förändra detta. I denna studie undersöktes långtidsanvändningen av en spis, en biokolsproducerande förgasningsspis. Spisen delades ut till 150 hushåll på landsbygden, jämnt fördelade på tre regioner i landet i ett forskningsprojekt år 2016-7. Denna uppföljningsstudie tittar på vilka aspekter hos spisen som forskningsdeltagarna tyckt om respektive funnit utmanande, samt vad som skiljde användare från de som slutat använda spisen. En kort telefonintervju gjordes med alla, och med 30 gjordes djupgående, enkätbaserade intervjuer. Resultaten visade att de flesta hushåll lagade mat över öppen eld till vardags, ibland kompletterat med förgasningsspisen eller andra spisar. 60 % av hushållen använde förgasningsspisen  minst en gång i månaden. Användare och icke-användare hade liknande åsikter om förgasningsspisen. Användare ägde i genomsnitt en halv spis mer än icke-användare. Hushåll som använde förgasningsspisen var generellt sett större. Förgasningsspisen ansågs vara en bränslesnål spis och bara skapa en liten mängd rök, men ansågs vara för liten. Den krävde också mer ansträngande bränsleförberedning. De rapporterade problemen går inte att åtgärda utan att ändra förgasningsspisens design i grunden och eventuellt själva förgasningprocessen, och utan att åtgärda dem kommer förgasningsspisen sannolikt inte att ersätta matlagning över öppen eld. Studien understryker förgasningsspisen potential, men kräver kreativ omdesign för att uppnå massanvändning.

This study develops a novel pyrolysis process combined with in-line catalytic reforming toproduce high purity hydrogen and carbon products from waste plastics. The input resource is waste plastic material in the form of discarded Covid masks. Results show that for the optimized pyrolysis followed by in-line biochar-based catalytic reforming process, the hydrogen yield is 98.2 mg/g-mask (up to 87% purity), and the carbonyield is 642.4 mg/g-mask, with over 70% of the waste plastic being completely cracked to elemental carbon and hydrogen. The overall process has virtually no CO2 emissions. The use of biomass char catalysts has been studied to contribute to increased hydrogen yield. This is because the unique porous structure of the biochar catalyst increases the residence time of the pyrolysis vapor in the catalytic layer, allowing sufficient cracking of the macromolecular vapor, therefore, increasing the hydrogen yield. The process is also facilitated by the cracking temperature, which increases the cracking of the pyrolysis vapor, resulting in an increase in char yield. However, high temperatures may breakdown the structure of the biomass char catalyst, causing more of the pyrolysis vapor to be converted to CH4, reducing the hydrogen yield. The optimum hydrogen yield was obtained at process parameters of a Biochar catalyst-to-Maskratio (C/M ratio) of 2 and a cracking temperature of 900 oC. / Detta examensarbete utvecklar en ny pyrolysprocess kombinerad med en katalytisk reformeringsprocess i följd för att producera högrenade väte- och kolprodukter från plastavfall. Resursen till processen består av avfallsprodukter i form av kasserade munskydd. Resultaten visar att för den optimerade pyrolys- och biokol-katalytiska reformeringsprocessen är vätgasavkastningen 98,2 mg/g plastavfall (upp till 87 % renhet) och kolavkastningen 642,4 mg/g plastavfall, med över 70 % av plastavfallet fullständigt knäckt till enkla kol- och vätemolekyler. Den genomgripande processen har praktiskt taget inga koldioxidutsläpp. Användningen av biokol-katalysatorer av biomassa har studerats för att bidra till ett ökat vätgasutbyte. Detta beror på att biokolkatalysatorns unika porösa struktur ökar uppehållstiden för pyrolysångorna i det katalytiska skiktet, vilket möjliggör tillräcklig krackning av de makromolekylära ångorna och därmed ökar vätgasutbytet. Processen underlättas också av krackningstemperaturen, som ökar krackningen av pyrolysångorna, vilket leder till ökad kolavkastning. Höga temperaturer kan dock bryta ned strukturen hos katalysatorn för biomassakol, vilket gör att en större del av pyrolysångorna omvandlas till CH4, vilket minskar vätgasutbytet. Det optimala vätgasutbytet uppnåddes vid C/M-parameter (katalysator-till-munskydd förhållande) = 2och en krackningstemperatur på 900 0C.

Sewage sludge is a byproduct of wastewater treatment plants. It is a kind of waste. however, it contains several valuable nutrients like phosphorous and nitrogen that are used to rich the soil as a fertilizer compound. On the other hand, it contains some harmful and toxic compounds such as pathogens, pharmaceuticals, Polychlorinated biphenyl (PCBs), Polycyclic aromatic hydrocarbons (PAHs), endocrine-disruption, hormones, and heavy metals which are contaminants and pollutants in the environment. Pyrolysis is a way to treat these contaminants and reduces the quantity of heavy metals and removes pathogens. This project derives to pyrolysis the sewage sludge at three different temperatures 500°C,700°C, and 900°C, and evaluates the result according to the remained quantities of heavy metals and phosphorous. Each experiment was repeated three times. Then, the samples weighted and analyzed by bomb calorimeter, microwave digestion, and MP-AES. Bomb calorimetry was used for measuring the heating value to compare the remaining heating value in the samples to the raw sewage sludge. The microwave digestion system was used for chemical processing of the samples in order to break down the samples to liquid form and then the concentration of elements such as Cd, Co, Cr, Cu, Ni, Mn, Zn, Pb, and P were measured by MP-AES. The results were gathered and compared with the Regulation by European, Union, (DirectiveE86/278/EEC), and Regulation by Swedish law, (Regulation1998:994). The raw sewage sludge was delivered from Borås wastewater treatment unit after digestion in an anaerobic fermentation process. It contained about 74% water which was dried in an oven at 105°C. The results show that Cd and Co were removed from the sewage sludge and the most amount of phosphorus remained in the resulting char. The results show that the quantity of phosphorus was almost the same between 500°C-700°C. The data shows that the amount of Pb was reduced by increasing the temperature of the pyrolysis reaction. The heating value in the char was extremely close to each other in the different range of reaction temperatures between 500°C to 900°C.

On the fourth of November 2016, The Paris Agreement entered into force, stating that nations worldwide should pursue efforts to limit the global temperature increase to 1,5 °C. Since then, the Intergovernmental Panel on Climate Change has specified that carbon dioxide removal, such as biochar sequestration, is necessary to achieve this goal. Biochar is a solid and porous material, rich in carbon, produced when biomass undergoes a process called pyrolysis and can, if buried in soil, sequester carbon for hundreds or even thousands of years while at the same time acting as a soil amendment. When biomass is pyrolyzed to produce biochar, a pyrolysis gas is also produced, which can be used to generate both heat and electricity. This thesis investigates if constructing and operating a plant, called a combined pyrolysis and CHP plant, which combines biochar production with heat and electricity generation, could be economically feasible and thus be an effective method for carbon dioxide removal. The findings show that constructing and operating a combined pyrolysis and CHP plant can be economically feasible. However, the economic feasibility is greatly affected by the price of biochar as a soil amendment product. The biochar market is also an undeveloped market, making price estimates of biochar far from accurate. Another factor that could significantly affect the economic feasibility of the plant is the fraction of carbon in biochar, which can be accounted for as sequestered. A higher fraction means that significantly more governmental support can be given to provide financing of the plant as well as potential revenue from carbon credits could increase. The capital cost of constructing the plant is also a factor with high uncertainty, which has a substantial effect on the economic feasibility. From this thesis, it is concluded that more research regarding the biochar market, as well as the capital costs of constructing the plant, is needed. More research could further ascertain whether or not the plant could be economically feasible and thus, an effective method for carbon dioxide removal. / Den fjärde november 2016 trädde Parisavtalet i kraft vilket uppgav att länder över hela världen ska sträva efter att begränsa den globala temperaturökningen till 1,5 grader Celsius. I enlighet med detta mål har FN:s mellanstatliga klimatpanel, IPCC, specificerat att koldioxidavlägsnande åtgärder, såsom kolinlagring genom produktion av biokol, är nödvändigt. Biokol är ett fast och poröst material, rikt på kol, som produceras när biomassa genomgår en process som kallas pyrolys. Om biokol blandas ner i jord kan det binda kol i hundratals eller tusentals år samtidigt som det fungerar som jordförbättrare. När biomassa pyrolyseras produceras också en pyrolysgas som kan användas för att generera värme och elektricitet. Det här examensarbetet undersöker om det kan vara ekonomiskt genomförbart att bygga och driva en anläggning, benämnd en kombinerad pyrolys- och kraftvärmeanläggning, som kombinerar biokolsproduktion med värme- och elproduktion för att avlägsna koldioxid från atmosfären. Resultaten från arbetet visar att det kan vara ekonomiskt genomförbart att bygga och driva en kombinerad pyrolys- och kraftvärmeanläggning. Den ekonomiska genomförbarheten påverkas dock i hög grad av priset på biokol som jordförbättringsprodukt. Marknaden för biokol är dessutom outvecklad vilket gör att priset för biokol osäkert. En annan faktor som i hög grad skulle kunna påverka den ekonomiska genomförbarheten för anläggningen är andelen kol i biokol som kan anses vara lagrad. En högre andel innebär att betydligt mer statligt stöd kan ges för att finansiera anläggningen samt att potentiella intäkter från kolkrediter kan öka. Kapitalkostnaderna för att bygga anläggningen är också en faktor med hög osäkerhet som har stor effekt på den ekonomiska genomförbarheten. Från detta examensarbete dras slutsatsen att mer forskning kring biokolsmarknaden samt kring kapitalkostnaderna för att bygga anläggningen behövs. Detta behövs för att ytterligare fastställa den ekonomiska genomförbarheten hos en sådan anläggning för att avlägsna koldioxid från atmosfären.

Ett stort antal förorenade områden finns idag i Sverige och tillämpning av riskreducerande åtgärder som till exempel schakt och deponi är vanligt förekommande. De möjliga hanteringsvägarna för uppschaktade massor är många, men en stor andel av massorna hamnar på deponier runt om i landet. Tidigare studier har visat att en ökad återanvändning av massor kan innebära både klimat- och resursbesparingar. Syftet med denna studie var att undersöka detta vidare och att studera både riskbedömningens och åtgärdsvalets effekt på klimatpåverkan och kostnaden för åtgärderna. En hypotetisk platsspecifik riskbedömning genomfördes för PAH, bly, koppar och zink och dess effekter på massklassning och möjlig återanvändning, och i sin tur effekt på klimatpåverkan studerades. Utöver det studerades även ökad återanvändning av schaktmassor i form av återanvändning inom projektområdet efter behandling med biokol. Två olika beräkningsverktyg användes vid klimatberäkningarna, Trafikverkets Klimatkalkyl och SGF:s verktyg Carbon footprint från efterbehandling och andra markarbeten. Beräkningarna i verktygen kompletterades med egen datainventering och beräkningar i de fall verktygen inte omfattade nödvändiga moment. Resultatet i studien visade att om platsspecifik biotillgänglighet beaktades i riskbedömningen, kunde riktvärdena höjas och en ökad återanvändning möjliggöras. Klimatpåverkan vid en högre grad av återanvändning, antingen utan vidare behandling eller efter behandling med biokol, var lägre än då masshantering baserades på Naturvårdsverkets generella riktvärden. Lägst klimatpåverkan kunde tillhandahållas då massor återanvändes efter behandling med biokol, där åtgärden i ett scenario resulterade i negativa växthusgasutsläpp. Samtliga scenarier som innebar ökad återanvändning av massor, resulterade även i en lägre kostnad. / A large number of contaminated areas exist in Sweden and risk-reducing measures such as dig and dump are often applied. Excavated masses can be managed in many different ways and there are several routes for which the masses can follow, but a large share of the masses often ends up on landfills all around Sweden. Previous studies have shown that an increase in reuse of masses could lead to both climate and resource savings. The aim of this study was to investigate this matter further and to study the effect on the climate impact of both risk assessment approaches and the choice of remediation method. A hypothetical risk assessment was performed for PAH, lead, copper and zinc and its effects on the mass classification and the possible reuse, and in turn its effect on the climate impact was studied. Furthermore, the increase in reuse of excavated masses within the project was studied, when using biochar as a treatment method. Two different calculation tools were used to calculate the climate impact, i.e. Trafikverkets “Klimatkalkyl” and SGF:s tool “Carbon footprint från efterbehandling och andra markarbeten”. The calculations in the tools were supplemented with data inventory and calculations, in cases where the tools did not cover the needed processes. The results showed that site specific risk assessment, where site specific bioavailability was included, could lead to higher risk limits. Higher risk limits enable increased reuse. The climate impact was lower as a result of a higher degree of reuse of masses. This applied for both scenarios when the masses were reused without any further treatment and when the masses were treated with biochar and then reused on site. The lowest climate impact was found when masses were treated with biochar, where this measure in one scenario implied negative greenhouse gas emissions. In all scenarios, an increase in reuse of masses also resulted in a lower cost.

Utilizing biomass such as lignin, bamboo, soybean, corn stalk, rice husk, etc., as a carbon source to produce graphene-based nanomaterials has been reported recently. However, the potential of using such nanomaterials for engineering and environmental applications has not been realized. This dissertation investigates the use of graphene-based nanomaterials synthesized from using biomass as a carbon source for water remediation and cement-based composites’ (CBCs) property enhancement. The first chapter introduces graphene and graphene-based nanomaterials, as well as the synthesis and application of graphene-based nanomaterials for removing heavy metals in an aqueous solution and for property enhancement in CBCs. The experimental investigation on the pyrolytic synthesis of graphene-encapsulated iron nanoparticles from biochar (BC) as the carbon source (BC-G@Fe0) was covered in the second chapter. Two synthetic routes for producing BC-G@Fe0, i.e., impregnation-carbonization (route-I) and pyrolysis-impregnation-carbonization (route-II) processes, were investigated experimentally using different characterization techniques and heavy metal removal methods. The third chapter reports the experimental performances of the heavy metal removal of Pb2+, Cu2+, and Ag+ from an aqueous solution using BC-G@Fe0. The effectivenesses of various adsorption benchmarks, such as pH, kinetics, and isotherms were assessed. Additionally, the removal efficiency of BC-G@Fe0 was evaluated. BC-G@Fe0 sample made from route II, in particular, FeCl2-impregnated-BC with 15% wt% iron loading carbonized at 1000 ℃ for 1h showed promising Pb2+, Cu2+, and Ag+ removal capacities of 0.30, 1.58, and 1.91 mmol/g, respectively. The fourth chapter experimentally investigated the reinforcement effect of commercially sourced, industrial graphene nanoplates (IG) on the mechanical properties of CBCs. This investigation was based on a hypothesis that the uniform dispersion of IG would significantly enhance the compressive strength of CBC. The main outcome of this research was that, while the wet dispersion mixing process of IG into CBC did not consistently yield significant increases in the composite compressive strength, but the newly proposed dry dispersion process demonstrated significant increases (22%) in the composite compressive strength. Chapter Five investigated the synthesis of lignin-based graphene nanoplatelets (LG) and their application in CBC reinforcement. The main findings were that LG did not show impressive increases compared to IG, even when dry dispersion was introduced. This was attributed to LG's lack of effective surface area compared to IG. Finally, a general conclusion and outlook for the future of research into biomass-based graphene nanomaterials were discussed in chapter six.

Diese Arbeit zeigt, dass Agroforstsysteme einen Beitrag zur Lösung der 3 größten aktuellen Probleme der brandenburgischen Landwirtschaft leisten können: der Biodiversitätskrise, Klimakrise und der wirtschaftlichen Krise vieler landwirtschaftlicher Unternehmen. Hierfür wurden insgesamt 642 verschiedene 20 ha große Modellschläge mit den 5 verschiedenen Brandenburger Landbaugebieten und verschieden strukturierten Agroforstsystemen über einen Zeitraum von 24 Jahren betrachtet. Die Kalkulationen der Agroforstsysteme ermöglichten einen ökonomischen Vergleich unter Einbeziehung der durch diese zusätzlich erbrachten Ökosystemdienstleistungen. Die kalkulierten Agroforstsysteme in dieser Arbeit bestehen aus ackerbaulich genutzten Flächen und Gehölzstreifen, welche aus Pappeln (Populus spp.) im Kurzumtrieb in Kombination mit Kiefern (Pinus sylvestris) im Mittelumtrieb bestehen. Ohne Abzinsung können diese Agroforstsysteme dieselben Erlöse wie eine rein ackerbaulich genutzte Fläche erreichen. Bei einer Berücksichtigung eines Zinssatzes von 3,5% erreichen die Agroforstsysteme maximal 97.60% der Annuität einer rein ackerbaulich genutzten Fläche. Die höchsten Annuitäten erreichen Agroforstsysteme mit der Produktion von Pflanzenkohle oder einem maximal großen Anteil an Ackerbaufläche. Die Produktion von Pflanzenkohle und deren Einarbeitung in den Ackerboden ist besonders vorteilhaft, wenn dadurch eine Steigerung der Ackererträge bewirkt wird. Wird das im Agroforstsystem dauerhaft gespeicherte CO2 mit einem CO2-Preis von 55€/t bepreist, können Agroforstsysteme auch bei einem Zinssatz von 3,5% genauso wirtschaftlich wie reine Ackerbauflächen sein. In diesem Fall haben Agroforstsysteme mit Pflanzenkohleproduktion oder integrierten Kiefern die höchsten Annuitäten. Für die ökologische Aufwertung der Gehölzstreifen sind die Integration von ökologisch wertvollen Gehölzen und die zeitversetzte Teilernte der Gehölzstreifen mit durchschnittlichen Annuitätskosten von 4,01 €/ha wesentlich günstiger als 4m breite Brachstreifen neben den Gehölzstreifen mit durchschnittlichen Annuitätskosten von 20,45 €/ha. Die ökonomisch optimale Gestaltung eines Agroforstsystems hängt neben dem jeweiligen Landbaugebiet von vielen weiteren Faktoren ab. Für die großflächige erfolgreiche Etablierung von Agroforstsystemen in Brandenburg sind daher 4 Maßnahmen nötig: sicherer Rechtsrahmen für die Bewirtschaftung und Förderung, Bezahlung der zusätzlich bereitgestellten Ökosystemdienstleistungen durch die Gesellschaft, Beratung der landwirtschaftlichen Betriebe vor der Etablierung eines Agroforstsystems, deutliche Verringerung der verpachteten landwirtschaftlichen Flächen.:Abstract 1 Introduction: actual problems in agricultural………………………..………………….11 1.1 Climate change and erosion……………………………………….………….……...11 1.2 Biodiversity…………………………………………………………...…………………13 1.3 Economy………………………………………………………………….……….……13 1.4 Potential of agroforestry systems………………………………………….…………13 2 Characteristics and basics of agroforestry systems................................................14 2.1 Definition…………………………………………………………………....……..……14 2.2 Policy……………………………………………………………………….……...……15 2.2.1 Legal framework…………………………………………………………............….15 2.2.2 Grants……………………………………………………………………............…..15 2.2.2.1 Current situation……………………………………………….....................…...15 2.2.2.2 Outlook into the future……………………………….....................…………….16 2.3 Different systems (outline)………………………………………………….…………18 2.4 Tree-environment interactions……………………………..…………………………22 2.5 Characteristics of short rotation alley cropping systems (SRACS)……….………23 2.5.1 Influence of woody stripes in SRACS on the arable crop yields in modelling..25 2.5.2 Wind speed reduction……………………………………………………….35 2.5.3 Carbon sequestration………………………………………………………..35 2.5.4 biochar production through pyrolysis………………………………………37 2.5.5 Influence of outer rows on the wood yields (WS)…………………..……...41 2.6 Limitations of the assumptions of this thesis…...…………………………………41 3 Research question……………………………………………………………….….…42 3.1 Research field……………………………………………………………….……..…42 3.2 Research gaps……………………………………………………………….……..…46 3.2.1 Modelling long standing valuable wood production…………………………46 3.2.2 Short rotation alley cropping systems (SRACS)……………………….….…48 3.2.2.1 Medium to long standing trees for log production (timber)……….….48 3.3 Elected Questions……………………………………………………………….……49 4 Methods…………………………………………………………………………….…….50 4.1 Characteristics of the examined agroforestry systems (AS)…………..……….…50 4.2 Economic calculations…………………………………………………………………54 4.3 Carbon storage…………………………………………………………………………60 4.4 Reference arable area……………………………………………………..…………62 4.5 Discounting.……………………………………………………………………………66 4.6 Calculated model plots (MP)………………………………………………..………67 Results………………………………………………………………………………….……69 5.1 Analysis of the individual parameters………………………………………….…...73 5.1.1 Alley width (AW)…………………………………………………………….….73 5.1.2 Integrated timber production with pines……………………..…………….……74 5.1.3 Fallow strips, staggered partial harvest of the SRC and integration of ecological valuable coppices in the SRC…………………………………………………….……75 5.1.4 Biochar…………………………………………………………………….…….76 5.2 Compilation of the most economically advantageous agroforestry systems…….79 5.2.1 Analysis of the MP #47-48/6/0-LBGI-biochar……………………………….….80 5.2.2 Effects of establishing agroforestry systems all over Brandenburg…….…….81 6 Discussion……………………………………………………………………………..82 6.1 Limitations……………………………………………………………………..…..82 6.2 Answers to research questions………………………………………………….….87 7 Conclusions…………………………………………………………………..………..89 8 Outlook…………………………………………………………………………..…….90 9 Bibliography………………………………………………………………………………92 / This thesis shows that agroforestry systems can make a contribution to solving the 3 biggest current problems of Brandenburg agriculture: the biodiversity crisis, climate crisis and the economic crisis of many agricultural companies. For this purpose, a total of 642 different 20-hectare model plots with the 5 different Brandenburg agricultural areas and differently structured agroforestry systems were considered over a period of 24 years. The calculations of the agroforestry systems enabled an economic comparison, taking into account the additional ecosystem services provided by them. The calculated agroforestry systems in this thesis consist of arable land and strips of wood, which consist of poplars (Populus spp.) in short rotation in combination with pines (Pinus sylvestris) in middle rotation. Without discounting, these agroforestry systems can achieve the same revenues as a purely arable land. If an interest rate of 3.5% is taken into account, the agroforestry systems achieve a maximum of 97.60% of the annuity of a purely arable land. Agroforestry systems achieve the highest annuities with the production of biochar or a maximum proportion of arable land. The production of biochar and its incorporation into the arable soil is advantageous if it results in an increase in arable yields. If the CO2 permanently stored in the agroforestry system is priced at a CO2 price of 55 €/t, agroforestry systems can be just as economical as pure arable land, even at an interest rate of 3.5%. In this case, agroforestry systems with biochar production or integrated pines have the highest annuities. For the ecological upgrading of the wood strips, the integration of ecologically valuable coppices and the timeshifted partial harvest of the wood strips with average annuity costs of 4.01 € / ha are much cheaper than 4m wide fallow strips next to the wood strips with average annuity costs of 20.45 €/ha. The economically optimal design of an agroforestry system depends on the respective agricultural area and many other factors. For the large-scale successful establishment of agroforestry systems in Brandenburg, 4 measures are therefore identified: Secure legal framework for the management and granting, payment of the additionally provided ecosystem services by society, advice to farms before the establishment of an agroforestry system, significant reduction of the leased agricultural land.:Abstract 1 Introduction: actual problems in agricultural………………………..………………….11 1.1 Climate change and erosion……………………………………….………….……...11 1.2 Biodiversity…………………………………………………………...…………………13 1.3 Economy………………………………………………………………….……….……13 1.4 Potential of agroforestry systems………………………………………….…………13 2 Characteristics and basics of agroforestry systems................................................14 2.1 Definition…………………………………………………………………....……..……14 2.2 Policy……………………………………………………………………….……...……15 2.2.1 Legal framework…………………………………………………………............….15 2.2.2 Grants……………………………………………………………………............…..15 2.2.2.1 Current situation……………………………………………….....................…...15 2.2.2.2 Outlook into the future……………………………….....................…………….16 2.3 Different systems (outline)………………………………………………….…………18 2.4 Tree-environment interactions……………………………..…………………………22 2.5 Characteristics of short rotation alley cropping systems (SRACS)……….………23 2.5.1 Influence of woody stripes in SRACS on the arable crop yields in modelling..25 2.5.2 Wind speed reduction……………………………………………………….35 2.5.3 Carbon sequestration………………………………………………………..35 2.5.4 biochar production through pyrolysis………………………………………37 2.5.5 Influence of outer rows on the wood yields (WS)…………………..……...41 2.6 Limitations of the assumptions of this thesis…...…………………………………41 3 Research question……………………………………………………………….….…42 3.1 Research field……………………………………………………………….……..…42 3.2 Research gaps……………………………………………………………….……..…46 3.2.1 Modelling long standing valuable wood production…………………………46 3.2.2 Short rotation alley cropping systems (SRACS)……………………….….…48 3.2.2.1 Medium to long standing trees for log production (timber)……….….48 3.3 Elected Questions……………………………………………………………….……49 4 Methods…………………………………………………………………………….…….50 4.1 Characteristics of the examined agroforestry systems (AS)…………..……….…50 4.2 Economic calculations…………………………………………………………………54 4.3 Carbon storage…………………………………………………………………………60 4.4 Reference arable area……………………………………………………..…………62 4.5 Discounting.……………………………………………………………………………66 4.6 Calculated model plots (MP)………………………………………………..………67 Results………………………………………………………………………………….……69 5.1 Analysis of the individual parameters………………………………………….…...73 5.1.1 Alley width (AW)…………………………………………………………….….73 5.1.2 Integrated timber production with pines……………………..…………….……74 5.1.3 Fallow strips, staggered partial harvest of the SRC and integration of ecological valuable coppices in the SRC…………………………………………………….……75 5.1.4 Biochar…………………………………………………………………….…….76 5.2 Compilation of the most economically advantageous agroforestry systems…….79 5.2.1 Analysis of the MP #47-48/6/0-LBGI-biochar……………………………….….80 5.2.2 Effects of establishing agroforestry systems all over Brandenburg…….…….81 6 Discussion……………………………………………………………………………..82 6.1 Limitations……………………………………………………………………..…..82 6.2 Answers to research questions………………………………………………….….87 7 Conclusions…………………………………………………………………..………..89 8 Outlook…………………………………………………………………………..…….90 9 Bibliography………………………………………………………………………………92

Le phytomanagement de matrices contaminées en métaux couple leur réhabilitation écologique avec la production de biomasses végétales pour la bioéconomie. Un front de science est d’identifier des assemblages végétaux et d’optimiser leur production, aidée ou non par l’ajout d’amendements. Le phytomanagement de deux sols, l’un contaminé en Cu, l’autre en Cd, Pb et Zn, a été testé en conditions contrôlées. L’emploi conjoint de biochar et de grenaille d’acier diminue la phytotoxicité des 2 sols. En pots, sur 2 ans, cette combinaison d’amendements séquestre du carbone, diminue la phytotoxicité du sol contaminé en Cu et produit une biomasse d’Arundo donax L. et de Populus nigra L. non contaminée, utilisable par le secteur de l’énergie. Ces modalités de culture et d’amendement ont été installées pour un suivi à long terme sur le site contaminé en Cu. Parallèlement, en microcosmes, parmi 4 macrophytes utilisées en zone humide construite (CW) pour décontaminer des matrices aqueuses (i.e. Arundo donax L., Cyperus eragrostis Lam., Iris pseudacorus L. et Phalaris arundinacea L.), A. donax est la mieux adaptée pour fournir des racines à forte concentration en Cu utilisables pour produire un écocatalyseur riche en Cu. Le phytomanagement d’un effluent de bouillie bordelaise (EB, 69 μM Cu) par A. donax a été testé en CW pilote. Il est décontaminé en 48h, sa concentration en Cu respectant la réglementation du rejet d’effluent en réseau d'assainissement. Cependant, après un cycle de circulation, la concentration en Cu des racines d’A. donax (623 ± 140 mg Cu kg-1) est inférieure aux besoins de l’éco-catalyse, et le cycle serait à répéter pour atteindre les 1000 mg Cu kg-1 requis. / The phytomanagement of metal-contaminated matrices (soils and water) combines their ecological remediation and the production of non-food crops for the bioeconomy. One science frontier is to identify plant assemblage and to optimize their biomass production, aided or not by amendment addition and cultural practices. A Cu-contaminated soil and a Cd/Pb/Zn-contaminated one were phytomanaged in controlled conditions. The combination of biochar and iron grit reduced the phytotoxicity in both soils. In a 2-year pot experiment, this amendment combination decreased the phytotoxicity of the Cu-contaminated soil, enhanced soil C sequestration and produced an uncontaminated biomass of Arundo donax L. and Populus nigra L. adapted for bioenergy production. These combinations of culture and amendment are tested in field trial at the Cu-contaminated site. In parallel, in microcosm experiment, out of 4 macrophytes commonly used in constructed wetlands (CW) to clean up aqueous matrices (i.e. Arundo donax L., Cyperus eragrostis Lam., Iris pseudacorus L. and Phalaris arundinacea L.), A. donax was the best adapted to produce a high Cu-rich root mat potentially usable as Cu-ecocatalyst. Clean up of a Bordeaux mixture effluent (BME, 69 μM Cu) by A. donax was tested in a pilot-scale CW. The BME was decontaminated in 48 hours, its Cu concentration being in compliance for indirect discharge of chemical industry effluents. However, after one BME circulation cycle, root Cu concentration of A. donax roots (623 ± 140 mg kg-1) was lower than threshold value for Cu-ecocatalysts (1000 mg kg-1) and successive treatments must be repeated to achieve required Cu concentration.