Search

Reporting from the Open House Event 30. Sept. 2022 in Højbjerg visiting ComFerm who has produced the composting machine. Researchers from AU presented the first results on the effect of the compost on soil fertility and plant growth.

Compost application is one of the main tools to improve soil biodiversity, maintain soil fertility and sustainable food production. Despite the benefits of composting, existing farm-level traditional composting techniques cause substantial ammonia and GHG (N2O, CH4) emissions, which could potentially surpass the essential benefits of composting and compost application in the long term. To reduce the environmental impact and improve farm resource efficiency, a company developed a new automated composting drum which can turn organic wastes into compost and liquid nitrogen (N) fertilizer within 7-10 days without external chemical application. While the technology has several advantages, the compost quality and its potential to improve soil fertility need to be evaluated. Given the short retention time, we hypothesized that the compost may not be completely mature and could result in net immobilization of the native N in the soil solution. To test the hypothesis, we set up an incubation experiment with sandy soil mixed with the new compost (NewComp) and a standard windrow compost (WrComp) both made from organic vegetable wastes. Compost was applied at a rate of 20 t DM ha-1, and a commercial organic fertilizer (OF) at a rate of 6.5 t DM ha 1 which is equivalent with the total N applied with the NewComp compost. The moisture content was adjusted to 50% water-filled pore space. Three replicates were destructively removed after 0, 7, 21, 35, 49, 70, and 91 days of incubation in a chamber at 21 0C and analyzed for mineral N and the soil microbial enzyme, dehydrogenase, activities. A phytotoxicity assay was also conducted using Cress (Lepidium sativum) as a test plant in a separate experiment. The result showed that the NewComp compost has a high C:N (29.5:1) and NH4+:NO3- (34:1), indicating that the compost is still in the active decomposition stage. Furthermore, NewComp compost resulted in significantly higher net immobilization during the 90 days incubation experiment. On the other hand, the dehydrogenase activity was significantly higher (up to two-fold) in NewComp compost compared to the unamended control, WrComp and OF for 90 days showing that the compost has a substantial potential to improve the soil microbial activities. The phytotoxicity test showed that the NewComp compost could be mixed with soil up to 50% without significantly affecting germination. Further studies are needed to reduce the net N immobilization effect of the NewComp compost.

For environmental conservation, peat-based growing media are being phased-out in many countries. Peat-free alternatives need to be developed, preferably from local biomass ingredients. This paper describes the performance of peat-free substrates containing olive branch pruning materials in comparison with commercial growing media controls for olive saplings grown during April-October 2020 at the Olive Research Institute (ORI) in Turkey. The trial was conducted using a randomized plot design with 4 replications and 4 treatments: 1) (COMP) compost made of locally available plant materials with 70% olive prunings (100%, v v-1; 2) (FIBER) mixture of chipped and extruded olive prunings (50% chipped + 50% extruded, v v-1); 3) (SAND) a commercial mixture(sand 90% + vermiculite 10%, v v-1) (control); and 4) (PEAT+) a commercial mixture (peat 40% + coco coir 40% + perlite20%, v v-1) (control). The vegetative growth parameters and weed status (density and coverage) were recorded and root fungal diseases commonly found in Turkey were analyzed. After the first six months of growth, there were statistically significant differences between the treatments (p≤0.05); COMP and PEAT+ were comparable and produced the largest plants with 100% survival rate. 98% of plants survived in SAND, and 81% in FIBER.FIBER, which was the only treatment with no weed growth, had about 30% reduced growth as compared to SAND, which had 90 and 78% growth compared with PEAT+ and COMP. Still, it was remarkable that it was possible to grow olive saplings in treated olive prunings. It is very promising that a peat-free growing media like COMP performed as well as the commercial growing media with 40% peat. During the extrusion of olive material, the temperature rose to ca. 120°C and during composting the COMP reached 65-70°C; temperatures at which the materials are expected to be effectively sanatised from any fungal diseases.

In agriculture, with growing concerns about the excessive use of synthetic fertilizers and the decline in soil organic matter, the demand for organic forms of soil amendments, such as compost, is increasing. While traditionally it takes months to produce compost, a new composting technology (ComFerm Aps) can produce compost in few weeks. This thesis investigated the quality of this compost and its effects on the soil-plant system. A compost-soil incubation experiment was conducted with focus on N mineralization and soil microbial activity, as measured by dehydrogenase activity. A maturity assessment of compost stability (respirometry test Solvita®) and phytotoxicity (cress germination test) was conducted.

Achieving adequate phosphorus (P) levels without manure from conventional farms is challenging for organic vegetable farmers. The potential of plant-based fertilisers (PBFs) to replace animal-based fertilisers (ABFs) was examined based on a 5 year, multifactorial crop rotation experiment. Two crop rotations on a sandy loam soil were compared: a standard organic rotation (ST) with clover undersown in spring barley, cabbage, celeriac, corn, and onion. This rotation received inversion tillage, ABFs, and bare soil between cash crops. In contrast, a new organic management system aiming at sustainable intensification (SI) had pure clover without barley, and onion was intercropped in relay with lettuce. This rotation received reduced tillage, PBFs, and cover crops. Soil and crop P were analysed, yields were quantified, and a sequential soil P fractionation was conducted to analyse P dynamics.

Documentation of the effect of plant-based fertilizers and compost on plant growth and soil fertility in organic vegetable production (PP presentation at the Organic field day, Aarup June 2022)

Core Organic Cofund project funded in 2018 about new agronomic methods to improve biodiversity and soil fertility in the organic production of vegetables.

Date palm (Phoenix dactylifera L.) is an important crop in arid zones and plays significant ecological and socio-economic roles. During the last decades, date palm groves were subjected to degradation due to extensive soil exploitation and low soil fertility. The use of biological techniques is essential to improve date palm development. The present work aims at assessing the effect of two different doses of compost (5% and 20%) and inoculation with the arbuscular mycorrhizal fungus (AMF) Rhizoglomus irregulare on growth and development of date palm seedlings. The treatments comprised control and application of 5 and 20% of compost with R. irregulare individually or in combination. Growth, physiological, histological, and mycorrhization traits were assessed. Obtained results showed that compost applied at a low dose (5%) alone or in combination with the AMF stimulated root length, leaf area, root dry weight, nitrogen, phosphorus and potassium contents, stomatal conductance and chlorophyll fluorescence and increased the number of sclerenchyma fibers, the number of vascular bundles, root diameter, and lignification of the endodermis of date palm seedlings compared to control. Compost at low doses combined or not with AMF can successfully be applied as biofertilizers for improving the growth and development of date palm.

Seminar given to the vegetable consultants from the advisory company HortiAdvice

A field experiment was set up 2010 for the further development of reduced tillage in organic farming. The focus of the experiment is on the interaction between tillage and the type of fertilization as well as the fertilization level on loess soil. The mean yield over nine years was about 5 % reduced with RT compared to CT. We found no significant interaction between tillage and fertilization. Fertilization had a significant effect on yields in three years only. For SOC, the difference in the 0-10 cm layer became significant in 2019, while the difference in the 10-20 cm layer did not. Fertilization had a significant effect on SOC in the 0-10 cm layer but there was no significant interaction. Cmic increased in the 0-10 cm layer significantly and decreased in the 10-20 cm layer but not significantly in RT compared to CT. In conclusion, RT largely works in this location as the yield losses are low.

For studying the effect of soil fertility management practices on N mineralization, urease activity and maize yield, replicated field trials were established in 2015 at Misamfu and Msekera agricultural research stations (ARS) representing two geo-climatic regions of Zambia. The soil at Msekera ARS is a sandy clay loam (SCL) from a Paleustult, while that at Misamfu is a loamy sand (LS) from a Kandiustult. The field trials had three categories of treatments namely legumes, traditional and conventional. The legumes group consisted of researcher-recommended legume-cereal intercrop systems of maize with Cajanus cajan, Crotalaria juncea and Tephrosia vogelii in combination with compound D (10% N, 20% P2O5, 10% K2O) and urea (46% N) at the recommended rate (200 kg ha-1) and half of the recommended rate (100 kg ha-1). Composted cattle manure and Fundikila, a special plant biomass management technique, were the inputs under the traditional category. The conventional category consisted of a treatment to which only chemical fertilizer was applied. Urease activity was determined in surface soil samples (0-20 cm) collected from the field trials after 3 years. For N mineralization, a laboratory incubation study was conducted over 13 weeks. For the laboratory incubation, an additional treatment to which no input was applied was included as control. Application of organic inputs significantly increased the potentially mineralizable N (No) by 127% to 256% on the LS and by 51% to 131% on the SCL in comparison to the control. Similarly, the cumulative N mineralized (Ncum) was twice or thrice higher where organic inputs had been applied in comparison to the control. The No followed the order traditional > legumes > conventional > control, while the mineralization rate constant (k) followed the order legumes > conventional > traditional > control on both soils. The rate of N mineralization was significantly higher on the LS than the SCL. Higher rates of chemical fertilizer resulted in high Ncum and higher maize yield. Maize yield was significantly and positively correlated to Ncum, but inversely correlated to the amount of applied N that was mineralized (%Nmin). Urease activity was stimulated by application of organic inputs and suppressed by higher rates of chemical fertilizers. The type of organic inputs; the rate of chemical fertilizers; and soil texture are factors influencing N mineralization and maize yield. Urease activity was largely influenced by the rate of chemical fertilizer, but not the type of organic inputs or soil texture.

Results from the SureVeg field trial in Denmark on crop, root growth, N uptake, soil mineral N and fertility indicators showing effects of intercropping and fertiliser strategies

Agricultural management of soils has led to severe losses of soil organic matter (SOM), accompanied by an increased release of CO2 into the atmosphere and a reduction of soil fertility. Especially under the aspect of global warming and the increasing demand for food, there is a need for sustainable management options increasing soil organic carbon (SOC) storage in agricultural soils, but knowledge gaps exist regarding C persistence in, and its transfer between functional SOC pools, within different farming systems. Here we report on impacts of different farming systems on the temporal dynamics of SOM fractions within the DOK long-term trial (Switzerland), from 1982 to 2017. A purely minerally (CONMIN), a minerally and organically (CONFYM), and a purely organically fertilized farming system (BIODYN) were compared with an unfertilized control (NOFERT). We separated archived soils from the Haplic Luvisol (0–20 cm depth) into particulate (POM) and mineral-associated OM (MAOM) fractions, via physical fractionation, and analyzed the chemical composition of selected fractions via solid-state 13C CPMAS-NMR spectroscopy. We demonstrate that under none of the analyzed farming systems, additional SOC was sequestered in the clay-sized MAOM fraction (

Background and results from a pot trial testing different fertilizer and compost combinations on soil fertility and parsley growth

Wheat is a staple food crop and a major source of both the essential micronutrient zinc (Zn) and the toxic heavy metal cadmium (Cd) for humans. Since Zn and Cd are chemically similar, increasing Zn concentrations in wheat grains (biofortification), while preventing Cd accumulation, is an agronomic challenge. We used two Swiss agricultural long-term field trials, the “Dynamic-Organic-Conventional System Comparison Trial” (DOK) and the “Zurich Organic Fertilization Experiment” (ZOFE), to investigate the impact of long-term organic, mineral and combined fertilizer inputs on total and phytoavailable concentrations of soil Zn and Cd and their accumulation in winter wheat (Triticum aestivum L.). “Diffusive gradients in thin films” (DGT) and diethylene-triamine-pentaacetic acid (DTPA) extraction were used as proxies for plant available soil metals. Compared to unfertilized controls, long-term organic fertilization with composted manure or green waste compost led to higher soil organic carbon, cation exchange capacity and pH, while DGT-available Zn and Cd concentrations were reduced. The DGT method was a strong predictor of shoot and grain Cd, but not Zn concentrations. Shoot and grain Zn concentrations correlated with DTPA-extractable and total soil Zn concentrations in the ZOFE, but not the DOK trial. Long-term compost fertilization led to lower accumulation of Cd in wheat grains, but did not affect grain Zn. Therefore, Zn/Cd ratios in the grains increased. High Zn and Cd inputs with organic fertilizers and high Cd inputs with phosphate fertilizers led to positive Zn and Cd mass balances when taking into account atmospheric deposition and fertilizer inputs. On the other hand, mineral fertilization led to the depletion of soil Zn due to higher yields and thus higher Zn exports than under organic management. The study supports the use of organic fertilizers for reducing Cd concentrations of wheat grains in the long-term, given that the quality of the fertilizers is guaranteed., info:eu-repo/semantics/published

The DoubleCrop crop rotation field trial and studies focussed on soil fertility and root growth

Invited talk given at the Danish DAKOFA webinar on compost

Binding av karbon i jordbruksjord får økende anerkjennelse som en metode til å redusere mengden karbondioksid fra atmosfæren. På den annen side er jordkarbon (humus/mold/organisk materiale i jorda) viktig for jordfruktbarheten, avlingssikkerheten, vanninfiltrasjon og vannlagringsevne og evne til å motstå erosjon. Humusinnholdet i jordbruksjorda har etter andre verdenskrig blitt redusert i Norge og globalt gjennom moderne jordbruksmetoder (jordarbeiding, mineralsk gjødsel, plantevernmidler, ensidige vekstskifter og bar jord uten plantedekke). Den voksende regenerative jordbruksbevegelsen har som mål å snu denne trenden og regenerere jorda ved å binde inn mer karbon og samtidig øke jordas fruktbarhet. Dette prosjektet ville prøve ut i praksis under norske forhold et sett med metoder, med inspirasjon fra Mellom-Europa, for å øke jordfruktbarheten og karbonlagringa. Metodene var mineralsk utbalansering i henhold til en utvidet jordanalyse (Albrecht jordanalyse), permanent grønt plantedekke med et mangfold av plantearter, flatekompostering for mekanisk terminering av et grønt plantedekke, mikrobiell prosesstyring med ferment for å styre omdanningsprosessene mot det reduktive området og plantevitalisering/bladgjødsling for å fremme fotosyntesen i løpet av vekstsesongen. Fire referansegårder ble valgt ut, som ønsket å gjennomføre disse metodene i gårdsskala på sine gårder. Prosjektmålet var å tilpasse metodene til norsk klima og dyrkingsforhold, med fokus på korndyrking på Østlandet. De fire gårdene var Fossnes i Hvittingfoss, Nedre Skinnes ved Krøderen, Bygdø Kongsgård i Oslo og Sørli i Skjeberg. Tre driver økologisk planteproduksjon (korn) og Kongsgården driver økologisk melkeproduksjon. Gårdene fikk skreddersydd rådgiving til sin gård av kompetente rådgivere innen regenerativ dyrking og som kom på flere gårdsbesøk i løpet av sesongene. Det ble også et godt nettverk praktikerne imellom og med fagfolkene som var viktig for læringsprosessen. I løpet av prosjektperioden fikk vi prøvd ut og vist at alle metodene fungerer godt under norske forhold med lokale tilpasninger. I korndyrking fungerer en allsidig underkultur godt og bygger jordstruktur. Flatekompostering fungerer godt til å terminere et grønt plantedekke mekanisk når det agronomiske handverket beherskes. Imidlertid ser vi at dybdeløsning er viktig i tillegg for å mekanisk løsne jorda der den er pakket. Mineralsk utbalansering jamfør Albrechtanalysen er viktig, særlig der det er store ubalanser mellom kalsium, magnesium og kalium på kationbytteplassene i jorda. Dette ble særlig demonstrert på to skifter som hadde store ubalanser (overskudd og underskudd), og slet med ugras (høymole, kveke, burot). Urtefermentet (en antioksidant) bidro til mer innbindende og reduktive omdanningsprosesser ved flatekompostering og i husdyrgjødsel. Plantevitalisering viste seg å virke i noen tilfeller, men mer erfaring og kompetansebygging er nødvendig. Siden vi prøvde ut flere metoder samtidig kan vi ikke si sikkert hva som har ført til hva. Til det trengs forskningsprosjekt og mer dokumentasjon. Alt i alt kunne vi observere bedre jordstruktur, mer allsidig jordmikrobiologi, redusert ugrasmengde, bedre vanninfiltrasjon, mer lagelig jord og noen steder mørkfarging av jorda. Det var indikasjoner på økning av humusinnholdet på noen skifter, men det er vanskelig å si noe sikkert basert på de begrensede målingene fra prosjektet og den korte prosjektperioden.

Reduzierte Bodenbearbeitung und Mistkompost fördern Fruchtbarkeit und Humusaufbau. Das zeigen die bisherigen Ergebnisse des langjährigen Frick-Versuchs.

To get more detailed information on nutrient budgets in organic apple orchards, a case study was conducted in the Alte Land region (Lower Saxony, Germany). Semi-structured inter-views with organic apple growers and soil analyses of selected orchard sites were performed in order to verify how the fertilization practices affect the level of soil nutrients. The test of several alternative sources of organic fertilizers was carried out in field trials on organic apple located in Switzerland (FIBL), Italy (LAIM), Bulgaria (FGI), Poland (IN-HORT) and Germany (UHOH). As production intensities differed between the locations, different target N levels were applied by the project partners. In addition, since the sources of alternative fertilizers differ depending on the European region, the choice of the fertilizers was based on the product availability for local farmers. In Germany, for instance, access to com-mercially produced biogas digestates and composts is easy for organic growers, but this is not the case in Bulgaria. However, a common standard fertilizer, horn grit, was used on all sites in addition to an unfertilized control to allow for a multi-site comparison. At FGI, INHORT and UHOH field trials in intensive apple orchards were done for two (FGI) or three years (INHORT, UHOH), testing the fertilizers under conditions of local cultivation practices. Moreover, in order to better understand the N dynamics, incubation (LAIM) and pot trials (FIBL, LAIM) were carried out.

The work presented here focusses on the use of perennial or temporary herbaceous cover crops, settled along the tree-rows or on the interrows of orchards or vineyards, and used as components of a global production system, for the complementary services they can provide: substitution to the standard weed management practices, internal source of nitrogen supply, or additional income for the farmer by the use of secondary cash crops.

Det intensive DoubleCrop sædskifte med dyrkning af grønsager har bidraget med viden om anvendelse af efterafgrøder i det økologiske grønsagssædskifte. Der opnået en øget N-effektivitet i det intensive sædskifte, uden det har kostet udbytte.

In dem Artikel wird über den Einfluss der biodynamischen Präparate auf die Bodenqualität, Ertrag und Produktequalität im Fricker Langzeitversuch in den Jahren 2002-2019 berichtet.

Most nitrogen (N) in organic fertilizers must be mineralized to become available to plants, a process in which microorganisms play crucial roles. Droughts may impact microorganisms associated with the N cycle, negatively affecting N mineralization and plant N supply. The effects of drought on N-related processes may further be shaped by the farming system. We buried 15N-enriched plant material and reduced precipitation in conventionally and organically (biodynamically) managed wheat fields. On two sampling dates, we evaluated the soil water content, plant parameters and the plants’ 15N isotope signature. We intended to study the microbial communities associated with the N cycle to link potential treatment effects on plant N provisioning with characteristics of the underlying microbial community. However, floods impaired the experiment after the first sampling date, and the molecular work on the microbial communities was not performed. Focusing on the pre-flooding sampling date, our data suggested that processes associated with N transformation are sensitive to drought, but the role of the farming system needs further investigation. Since the underlying research question, the set-up and the lessons learned from this study may guide future experiments, we presented improvements to the set-up and provided ideas for additional analyses, hoping to promote research on this topic.

In dieser Untersuchung wurden Daten zur Nährstoff- und Humusversorgung sowie zur Fruchtfolgegestaltung von ökologisch wirtschaftenden Landwirtschaftsbetrieben im Freistaat Sachsen über einen Zeitraum von 6 Jahren gesammelt und ausgewertet. Insgesamt stand Datenmaterial von 810 ökologisch bewirtschaften Acker- und Grünlandschlägen und mehr als 4.800 Ernten zur Verfügung. Die Beurteilung des Nährstoff- und Humusmanagement erfolgte auf Schlag- und Betriebsebene für den pH-Wert und die Grundnährstoffe des Bodens. Ergänzend wurden Nährstoff- und Humusbilanzen sowie der Düngebedarf mit dem Programm BEFU, Teil Ökolandbau, berechnet. Für die Beurteilung des Fruchtfolgemanagements wurde ein geeignetes Bewertungsverfahren entwickelt und angewendet, mit dem der Erfüllungsgrad von Aufgaben und Regeln der Fruchtfolgegestaltung durch leicht erfass- und überprüfbare Kriterien abgeschätzt werden konnte.

In einem neuen Langzeit-Feldversuch "Bodenfruchtbarkeit im Biodynamischen Landbau" wird getestet, ob und ggf. wie vieharme Betriebe mit einem Viehbesatz

Dieses Mesokosmenexperiment befasst sich mit verschiedenen Maßnahmen zur Steigerung der Naturnahrung in Teichen unter Nutzung natürlicher Ressourcen. Das Ziel war, Naturertrag, Nachhaltigkeit und Produktqualität in der Karpfenteichwirtschaft zu verbessern. Durch organische Düngung mit Pferde- und Hühnermist (3t/ha) konnte in Teichen mit nährstoffärmeren Teichböden (P2O5-CAL 13,4 mg/100 g Boden) die Nährtierdichte erhöht und der Fischertrag durchschnittlich um etwa 200 kg/ha gesteigert werden. Zudem hatte die organische Düngung am Ende der Produktionsperiode keinen signifikanten Einfluss auf die Wasser- und Bodenqualitätsparameter.

Im europäischen Forschungsprojekt Greenresilient wollen Wissenschaftler Energieeffizienz und Bodenfruchtbarkeit im geschützten Anbau steigern.

Article from open-house in field trials in AU-Årslev 27. Aug. 2020 where scientists and advisors presented preliminary results and discussed the trials with the participant in the field-day.

Report from the open-house in field trials 2020 at AU-Aarslev from the ComCrop and ClimateVeg projects on organic vegetable production

Plan for the ComCrop field trial

Demands upon the sustainability of farming are increasing in step with climate change and diversity loss. Organic farming offers a viable approach. To further improve organic management, three strategies with potential to enhance soil quality are being tested in a long-term trial since 2002 on a clay loam in temperate Switzerland: reduced tillage vs. ploughing, solid vs. liquid manures and biodynamic preparations. A synthesis of 15 years reveals an increase in topsoil organic carbon (SOC, +25%), microbial biomass (+32%) and activity (+34%) and a shift in microbial communities with conversion from ploughing to reduced tillage. Soils under reduced tillage are more stratified in SOC and nutrients. Additional application of composted manure has increased SOC by 6% compared to pure slurry application, with little impact on soil microbes. Biodynamic preparations have had a minor impact on soil quality. Fertilisation and biodynamic preparations did not affect yields. Both higher and lower yields were harvested in the reduced tillage system in relation to ploughing. The main yield determinants were N supply and higher weed infestation under reduced tillage. Continuously reduced tillage in organic farming has been proven to enhance soil quality at this site, while also presenting more challenges in management.

It is the Mid-term report of the Project titled: "Dynamic Sod Mulching and Use of Recycled Amendments to Increase Biodiversity, Resilience And Sustainability of Intensive Organic Fruit Orchards and Vineyards" - DOMINO

A presentation given at the first Norwegian Organic Congress 2020 'Organic cropping systems for production of vegetables with focus on soil microbial activity, root growth, carbon and nitrogen'

En agriculture biologique, la gestion de la fertilisation repose essentiellement sur un raisonnement à long terme basé sur la fertilité du sol (rotation, légumineuses, apports de matières organiques). La spécialisation d’un nombre croissant de fermes bio en grandes cultures avec peu ou pas de bétail rend cette gestion de la fertilité du sol encore plus compliquée, en raison du manque d’engrais de ferme directement disponible sur l’exploitation et de l’absence de prairies dans la rotation. Dans le cas particulier des céréales, les besoins en azote aux stades tallage et début redressement sont importants, à une période où la minéralisation de l'azote du sol est encore faible (faible température du sol et faible activité des bactéries nitrifiantes). Ce manque d'azote minéralisé se marque dès le début du développement de la végétation et se poursuit pendant tout le cycle végétatif des céréales. Cela impacte les rendements et explique notamment les faibles teneurs en protéines des céréales cultivées en agriculture biologique en Wallonie ou en France. De surcroît, le retard de développement de la culture entraîne un manque de concurrence vis-à-vis des adventices. C’est pourquoi le recours aux engrais organiques du commerce (ou à certains engrais de ferme si disponibles) est fréquent afin de compenser le déficit en fourniture d’azote par le sol et répondre à des besoins en azote à des moments clés de la croissance.

The trials were carried out at a private farm in Plovdiv region with coordinates: 42°03’ N and 24°32’ E and 184 m on the sea level. The apple trees were planted in March 2016 at a spacing of 3,50 x 1,25 m with cvs “Golden B” and “Granny Smith”/M 26 in a North-South row orientation. Training system is spindle, irrigation system – drip and soil management natural sod mulch interrow. For the stydy were used 3 trees in 8 replicates. The trunk diameter was measured in the beginning and the end of vegetation season and the foliar analysis - in the begining of July and August. During the season 2019 were used organic fertilizers „Keratin“ and „Lumbreco“ according BBCH stages - first treatment before BBCH 60, second - after 69 and third - one after 73 stage. The dosage of „Keratin“ was 25 kg/ha and „Lumbreco“ - one liter concentrate plus 150 liters water and from this solution 10 liter per tree. According to Gorbanov S. (2018) the optimum value of N in apple leaves is 2.6%. Near the optimal content were data from July analysis at variant „Lumbreco“ following by „Keratin“. The optimum level of P (P2O5) is 0.4% and more of this level is for „Keratin“ only. For other macro nutrient K (K2O) the optimum content is 1.6% but the data from analysis and for variants are very variable. More than optimal level - 0.4% of Mg were in Keratin variant and for Ca optimum - 1.5% for Lumbreco. All these data demonstrated that Keratin and Lumbreco are suitble for organic fertilizers in apple orchards.

Baggrund: Hvis produktionen i økologisk landbrug skal opretholdes og potentielt forøges, samtidigt med at brugen af gødning og halm fra konventionelt landbrug udfases, er det nødvendigt at finde alternative gødningsprodukter fra det omgivende samfund (industrier og byer). Disse produkter indeholder nødvendige næringsstoffer og genanvendelsen vil bidrage til at opnå en bæredygtig cirkulær økonomi, men de kan også indeholde nogle potentielt problematiske stoffer som f.eks. mikroplastik og tungmetaller. Formål: Organic RDD-projektet RECONCILE kortlægger omfanget af skadelige effekter på jordens økosystem ved recirkulering af f.eks. spildevandsslam, komposteret husholdningsaffald og human urin gennem eksperimentelle undersøgelser og litteraturstudier. Jorden har et meget forskelligartet fødenet af mikroorganismer (bakterier, svampe, protozoer og nematoder) som er essentielle for fertiliteten, idet de udfører en række økosystemtjenester, såsom nedbrydning af organisk stof, mineralisering af næringsstoffer og opretholdelse af jordens struktur. Det er derfor vigtigt, at disse organismer - og de processer de udfører - ikke påvirkes negativt.

Aims Belowground legume nitrogen (N) composed of roots and rhizodeposition is an important N input to soils, but published data of belowground N vary broadly, probably due to extrapolation from short-term experiments and dissimilar growing conditions. We quantified belowground N inputs of red clover (Trifolium pratense L.) during two consecutive years in a clover-grass sward along a soil nutrient availability gradient. Methods We established a red clover-perennial ryegrass (Lolium perenne L.) model sward in microplots located in field plots of the DOK experiment, which has a 33-year history of organic and conventional cropping, resulting in a soil nutrient availability gradient. Four treatments were examined: the zero fertilisation control, bio-organic with half and full dose manure application, and the conventional system with mineral fertilisation at full dose. We studied the development of clover aboveground and belowground N using multiple pulse 15N urea leaf labelling. Results Belowground clover N increased over time and with rising nutrient availability and was proportional to aboveground clover N at all times. Belowground clover N amounted to 40% of aboveground clover N during two consecutive years, irrespective of the nutrient availability status. Belowground clover N development was initially dominated by fast root growth, followed by enhanced root turnover during the second year. Potassium availability limited clover growth and total N accumulation in treatments with low nutrient availability. Conclusions Belowground red clover N inputs could be estimated from aboveground N by a constant factor of 0.4, regardless of the nutrient availability and cultivation time. Root turnover led to a distinct absolute increase of N rhizodeposition over time. Hence, N rhizodeposition, with an 80% share of belowground N, was the predominant N pool at the end of the second year.

Speech given at meeting with the Sustainability board at Syddjurs Municipality

Presentation at the Organic Congress Nov. 2019 in Denmark about organic matter in soil

Presentation of preliminary results from the DoubleCrop project on sustainable intensification

Bør økologiske grøntsager gødes med konventionel husdyrgødning eller økologiske plantebaseret gødning.

Præsentation til åbent hus ifm DoubleCrops markforsøg den 27. juni 2019.

Strokenteelt biedt mogelijkheden om de opbrengst en de weerbaarheid van gewassen te verbeteren. In 2018 legde Inagro samen met ILVO een eerste proef aan met biologische teelt van knolselder en prei. Ook het effect van alternatieve bemesting op basis van groene reststromen werd getest. De eerste bevindingen zijn positief. Er waren geen verschillen in gewasstand of ziekte- en plaagdruk. De opbrengst lag wel hoger in de strokenteelt.

Die Langzeitversuche in Järna, Schweden, zeigen: Kompostierung und der Einsatz der biologisch-dynamischen Präparate steigern den Humusgehalt. Anhand verschiedener Düngungsvarianten konnte gezeigt werden, dass Mistkompost und Präparate den Humusgehalt im Boden innerhalb von 14 Jahren um 10% steigerte. Dies zeigt, wie wertvoll der hofeigene Dünger, in Form von Festmist, für den Hoforganismus ist.

Præsentation af avler-forsøg i DoubleCrop, erfaringer og resultater fra implementering i praksis

Die Klimawandel-bedingte Zunahme von Trockenperioden in Gegenden mit geringen Niederschlägen erfordert Anpassungsstrategien im ökologischen Ackerbau. Außer trockenheitstoleranten Sorten wurden in einem Langzeitversuch auf einem viehlosen Ackerbaubetrieb in der semi-humiden Region im Osten Österreichs vier hauptsächliche Strategien gemeinsam angewandt: eine Futterleguminosen-basierte Fruchtfolge mit Zwischenfruchtgemengen, organische Düngung mit Luzernemulch, Biokompost oder Stallmist, reduzierte, nicht-wendende Bodenbearbeitung und Gehölzstrukturen. Mit diesen kombinierten Strategien waren die Humusgehalte stabil bis ansteigend, die Wasserinfiltration und pilzliche Biomasse im Oberboden wurden gefördert, die Erträge der Marktfrüchte waren überdurchschnittlich hoch und die Erträge einiger Kulturen waren auf der Leeseite einer Hecke positiv beeinflusst. Durch die Kombination dieser Strategien konnte der Wasserknappheit offensichtlich erfolgreich begegnet werden.

Præsentation af DoubleCrop projektet og perspektiverne for plantebaseret gødning, og bæredygtig intensivering af dyrkningssystemer i øko-grønsager

Kastelers die willen omschakelen naar biologische teelt streven ernaar hun bodem in een zo kort mogelijke tijdspanne klaar te krijgen voor een robuuste teelt. Zeker voor telers die een verkorting van de omschakelingsperiode kregen en die intensief vruchtgroenten willen gaan telen, is dit een hele uitdaging. De bodem die lang onder plastiek heeft gelegen heeft vaak een laag organische stofgehalte, weinig voedingselementen en weinig bodemleven. Een koolstoftoediening van 16 ton C/ha over de 2 jaar verspreid kan zorgen voor een gemiddelde toename van het totaal organisch koolstofgehalte in de bodem van 0.42%.

Core organic cofund projekt bevilget i 2018, om udvikling af nye økologiske dyrkningssystemer til produktion af grøntsager. Målet er at forbedre systemernes bæredygtighed og resiliens, recirkulering af næringsstoffer og jordens lagring af kulstof.