Effects of mycorrhiza and plant growth promoting rhizobacteria inoculants on rice crops in Northern India

Mutualistic root microorganisms such as arbuscular mycorrhizal fungi (AMF) and plant growth promoting rhizobacteria (PGPR) can ameliorate plant nutrition through an extended extra-radical hyphal network and by nutrient mobilisation. Running under the Indo-Swiss Collaboration in Biotechnology (ISCB), our project focuses on the integration of AMF and PGPR as biofertilisers in wheat-rice and wheat-black gram systems

Förderung von arbuskulären Mykorrhizapilzen in einer Chenopodiaceae - Mais Fruchtfolge durch Untersaaten

Crops of the families Brassicaceae or Chenopodiaceae are non-host plants for symbiotic arbuscular mycorrhiza fungi (AMF), and thus the AMF infection potential of the soils decreases after cultivation of these crops similar to a fallow. This study aims to sustain the survival of AMF in a fodder beet (non-host) - maize cropping sequence through undersowing of different host and non-host green manure plant species (GMS). Maize served as indicator plant for potential after-effects of the GMS. As expected the AMF green manure hosts were well colonized by AMF (19 to 36%), while AMF structures in roots of the non-host GMS and beet roots were negligible. The fodder beet yield was not affected by the GMS compared to a GMS free control. Forty days after sowing of AMF compatible maize, there was no significant effect of the different GMS from the previous year on maize biomass, plant height and SPAD values (an indirect measure of chlorophyll). At flowering, maize fresh matter was 10% higher in plots previously undersown by AMF compatible GMS, compared to non-host GMS, although AMF root colonisation of maize was similar in all treatments

Selektion der Soja und deren Symbiosepartner auf Kühletoleranz und Effizienz der biologischen Stickstoff-Fixierung

In Central Europe low temperature is limiting soybean growth and biological nitrogen fixation (BNF). The BNF efficiency was shown to increase with bradyrhizobia strains selected for their cold tolerance. Significant bradyrhizobia x soybean variety interactions were reported. Co-inoculation with arbuscular mycorrhiza fungi (AMF) may promote bradyrhizobia and improve plant phosphorus uptake. The aim of this study is to identify (i) bradyrhizobia showing improved nodulation under cool conditions, (ii) bradyrhizobia x soybean variety and (iii) bradyrhizobia x AMF interactions. In 2011 twelve bradyrhizobia inoculants were tested with three soybean (Glycine max [L.]) varieties under three temperature regimes (14/10°C, 16/12°C, 22/20 °C) in a pot trial. In 2012 the five most promising bradyrhizobia were inoculated on twenty soybean varieties and an additional trial testing co-inoculated bradyrhizobia and AMF strains was conducted. A significant bradyrhizobia x temperature interaction was found for the number of nodules per plant and the SPAD values (indirect chlorophyll measurement; p ≤ 0,001). Significant bradyrhizobia x variety interactions were observed (p ≤ 0,01). The present results show that the selection of cold tolerant inoculants is as important as adapted soybean varieties. The efficiency of single bradyrhizobia x soybean variety combinations depends on the temperature regime

The plant availability of phosphorus from thermo-chemically treated sewage sludge ashes as studied by 33P labeling techniques

Aims: Phosphorus resources have to be managed sustainably and therefore the recycling of P from waste streams is essential. A thermo-chemical recycling process has been developed to produce a P fertilizer from sewage sludge ash (SSA) but its plant availability is unknown. Methods: Two SSA products prepared with either CaCl2 (SSACa) or MgCl2 (SSAMg) as chemical reactant during the thermal treatment were mixed with three soils previously labeled with 33P. Reference treatments with water-soluble P added at equal amounts of total P were included. The transfer of P from SSACa and SSAMg to Lolium multiflorum or P pools of sequentially extracted soil-fertilizer incubations were quantified. Results: The shoot P uptake from SSAMg was higher than from SSACa. For SSAMg the relative effectiveness compared to a water-soluble P fertilizer was 88% on an acidic and 71% on a neutral soil but only 4% on an alkaline soil. The proportion of P derived from the fertilizer in the plant and in the first two extraction pools of soil-fertilizer incubations were strongly correlated, suggesting that it is sufficient to conduct an incubation study to obtain robust information on plant P availability. Conclusions: We conclude that under acidic to neutral conditions SSAMg presents an appropriate alternative to conventional P fertilizers and the dissolution of P from SSAMg seems to be governed by protons and cations in the soil solution

Breeding for improved soybean-Bradyrhizobia symbiosis for cool growing conditions in Central Europe

Background In recent years soybean (Glycine max L.) has gained significant attention in Europe due to its ability to produce high quality protein for human and animal consumption. Under the climatic conditions prevalent in Central Europe, low temperature is the major factor limiting soybean growth and symbiotic nitrogen fixation

Ausweitung des Sojaanbaus in Deutschland durch züchterische Anpassung sowie pflanzenbauliche und verarbeitungstechnische Optimierung

Die Arbeiten im Sojaforschungsprojekt waren erfolgreich und konnten wichtige Impulse für die Ausweitung des Sojaanbaus in Deutschland geben. So sind die entwickelten Stämme und Kreuzungsnachkommen eine Basis für den Aufbau einer eigenständigen deutschen Sojazüchtung. Die Sorten Korus und Protibus erwiesen sich als besonders geeignet für die Tofuherstellung. Die im Projekt entwickelte Labortofurei ist ein Züchtungsinstrument zur Identifikation vielversprechender Genotypen, mit dem auch die weitere Entwicklung frühreifer Tofusojasorten unterstützt werden kann. In Gefäßversuchen konnte gezeigt werden, dass die Reaktion auf Kühlestress während der Hülsenansatzphase zwischen den Sorten variiert und es tolerante, kompensierende und sensitive Sorten gibt. Die praktische Selektion auf Kältetoleranz war erfolgreich und für die Selektion auf Unkrauttoleranz konnte ein System etabliert werden. Bis auf das Präparat Radicin können die vorhandenen kommerziellen Bradyrhizobienpräparate für den Praxiseinsatz empfohlen werden. Die Hypothese, dass die Selektion des Symbiosepartners auf Kühletoleranz lohnenswert ist, wurde bestätigt. Bei der Sortenprüfung in ganz Deutschland zeigte sich, dass die Anbauwürdigkeit von Soja gut und nur an wenigen der geprüften Standorte nicht gegeben war. Die 00-Sorte ES-Mentor lieferte insgesamt die höchsten Relativerträge sowie den höchsten Rohproteinertrag, bei den 000-Sorten schnitt Sultana besonders gut ab. Eine Variation der Saatzeit sowie verschiedene Verfrühungstechniken erweisen sich nicht als ertragsrelevant. Beim Erfolg der Unkrautregulierung mit Torsionshacke, Fingerhacke und Flachhäufler gab es keine Unterschiede. Im Dammanbau lassen sich Sojabohnen mit gutem Unkrautregulierungserfolg kultivieren. Bei der Sojaaufbereitung sollte eine unnötig hohe Erhitzung der Bohnen bei der Aufbereitung vermieden werden, da durch die Erhitzung neben der Trypsininhibitoraktivität auch Eiweißverdaulichkeit reduziert werden. Mit ausschließlich indirekter, länger einwirkender, trockener Wärme (z. B. Biogasabwärme), ist es schwierig, gute Aufbereitungsqualitäten zu erzielen. Der Wissenstransfer mit Feldtagen und Website www.sojainfo.de war wichtig und erfolgreich zur Steigerung des Interesses am heimischen Sojaanbau

The plant availability of phosphorus from thermo-chemically treated sewage sludge ashes as studied by 33P labeling techniques

Aims Phosphorus resources have to be managed sustainably and therefore the recycling of P from waste streams is essential. A thermo-chemical recycling process has been developed to produce a P fertilizer from sewage sludge ash (SSA) but its plant availability is unknown. Methods Two SSA products prepared with either CaCl2 (SSACa) or MgCl2 (SSAMg) as chemical reactant during the thermal treatment were mixed with three soils previously labeled with 33P. Reference treatments with water-soluble P added at equal amounts of total P were included. The transfer of P from SSACa and SSAMg to Lolium multiflorum or P pools of sequentially extracted soil-fertilizer incubations were quantified. Results The shoot P uptake from SSAMg was higher than from SSACa. For SSAMg the relative effectiveness compared to a water-soluble P fertilizer was 88 % on an acidic and 71 % on a neutral soil but only 4 % on an alkaline soil. The proportion of P derived from the fertilizer in the plant and in the first two extraction pools of soil-fertilizer incubations were strongly correlated, suggesting that it is sufficient to conduct an incubation study to obtain robust information on plant P availability. Conclusions We conclude that under acidic to neutral conditions SSAMg presents an appropriate alternative to conventional P fertilizers and the dissolution of P from SSAMg seems to be governed by protons and cations in the soil solution.ISSN:0032-079XISSN:1573-503

Effect of mycorrhiza and plant growth-promoting rhizobacteria on rice in Northern India: results from 2005-2008

Beneficial migroorganisms such as arbuscular mycorrhizal fungi (AMF) and plant growth promoting rhizobacteria (PGPR) can ameliorate plant nutrition through an extended extra-radical hyphal network and by nutrient mobilisation. In the past, host specificity may not have been adequately considered when microbial inoculants were developed for different crops. In the Bio-fertilizer Network oft he Indo-Swiss Collaboration in Biotechnology (ISCB), AMF and PGPR are integrated as bio-inoculants in wheat-rice and wheat-black gram systems

Selektion von kühletoleranten Bradyrhizobien Stämmen und Interaktion mit frühreifen Sojasorten

- Arbeitshypothese - Inokulationsversuche bei unterschiedlichem Temperaturregime - Feldversuche mit verschiedenen kommerziellen Produkten - Erste Schlussfolgerunge