Jürgen Friedel | University of Natural Resources and Life Sciences, Vienna (BOKU) (original) (raw)

Papers by Jürgen Friedel

Rainfall is the single most important factor affecting yield and biomass accumulation by crops as... more Rainfall is the single most important factor affecting yield and biomass accumulation by crops as well as residue decomposition in the tropics. The ability to capture this resource in organic systems calls for appropriate techniques. Kenya experiences bimodal type of rainfall with two rainfall peaks; the long (730 mm) and the short (376 mm) rains. Rainfall fluctuations in both seasons are becoming more common in the recent years with a likelihood of crop failure in one out of five years. The question addressed was how to utilize the short rains for food and biomass production. Lablab (Dolichos lablab), a N-fixing legume was sown in the short rains and the seeds harvested. The effect of lablab biomass incorporation on organic maize and potatoes planted in the long rains was evaluated in comparison with farmyard manure application. The 3-year trial showed that dry matter biomass (1.95 t/ha) and grain yield (0.5 t/ha) of lablab was a factor of the amount of rainfall. The amount of labl...

Die Projektziele bestehen im Wesentlichen in der Optimierung und Bereitstellung der Daten- und Be... more Die Projektziele bestehen im Wesentlichen in der Optimierung und Bereitstellung der Daten- und Berechnungsgrundlagen im Bereich Pflanzenbau und Humusgehalte im Boden, um die Profile der treibhausgas-relevanten Emissionen und Senken in landwirtschaftlichen Betrieben Osterreichs darzustellen, sowie in der Modellierung treibhausgasrelevanter Emissionen und Senken der wichtigsten landwirtschaft-lichen Betriebstypen Osterreichs (Martkfrucht-, Futterbau-, Veredelungs-, Dauerkultur-, Kombinations-, und landwirtschaftliche Gemischtbetriebe) in den Hauptproduktionsgebieten.

The effect of different preceding crops and fertilisation systems on winter wheat yieldand qualit... more The effect of different preceding crops and fertilisation systems on winter wheat yieldand quality was assessed in a long-term field experiment in Eastern Austria. Winter wheat following a 2-years lucerne crop had lower yield but higher protein content than winter wheat following peas. Lucerne green manure use in a stockless system increased yield and protein content of a subsequent wheat crop compared to a livestock-keeping system with removal of the lucerne crop for fodder use. Wheat following peas that had received farmyard manure in the livestock-keeping system only, showed higher yield than in the stockless system but no differences in protein content. Likewise, an additional compost fertilisation in the stockless system increased yield of wheat following peas but had no effect on wheat protein content.

Fodder legumes, like lucerne, make a significant contribution to a positive humus balance and nit... more Fodder legumes, like lucerne, make a significant contribution to a positive humus balance and nitrogen supply on organic farms. To determine the required lucerne percentage to meet these targets, several shares of lucerne were modelled on the basis of empirical data of an eight-field crop rotation. The lower limit for ensuring optimum humus and nitrogen supply in this rotation was approximately 17 % lucerne. The calculation of the data was performed with the agricultural software REPRO.

In the pannonical region of Eastern Austria, forage legumes, mainly alfalfa, are commonly used as... more In the pannonical region of Eastern Austria, forage legumes, mainly alfalfa, are commonly used as green manure in organic farming. In a field experiment, alfalfa and alfalfa-grass mixtures were either cut and removed or used as green manure and mulched. Grass and rye were used as reference crops. The experiment was repeated in two consecutive years. Soil microbial biomass carbon and nitrogen was not affected by the annually grown forage legumes compared with grass or rye. One year of fodder legume crops is insufficient to increase microbial C and N at the study site where plant growth is limited by draught.

Problemstellung/Ziele:Die arbuskuläre Mykorrhiza ist eine Symbiose zwischen dem Grossteil der lan... more Problemstellung/Ziele:Die arbuskuläre Mykorrhiza ist eine Symbiose zwischen dem Grossteil der landwirtschaftlichen Kulturpflanzen und bodenbürtigen Pilzen. Der heterotrophe Pilz erhält Assimilate von der autotrophen Pflanze, als Gegenleistung fördert der Pilz die Nährstoffaufnahme in die Pflanze und erhöht die Resistenz gegenüber phytopathogenen Mikroorganismen, die in einer Wachstumssteigerung der Pflanze resultieren können. In zahlreichen Untersuchungen wurde festgestellt, dass mechanische Bodenbearbeitung das Besiedelungspotenzial von landwirtschaftlichen Kulturpflanzen durch arbuskuläre Mykorrhizapilze (AMP) vermindert (McGonigle et al. 1990a) und die Effizienz des Myzels der AMP bei der Aufnahme von Phosphor mit steigender Intensität der Bodenbearbeitung abnimmt (Douds et al. 1995). Ziel der Untersuchungen war, die Auswirkungen verschiedener Bodenbearbeitungsvarianten auf den Mykorrhizabesiedelungsgrad von Winterroggen unter den Bedingungen des Ökologischen Landbaues festzustellen.

Introduction and Project Aims In organic farming the replenishment of soil N mainly depends on bi... more Introduction and Project Aims In organic farming the replenishment of soil N mainly depends on biological nitrogen fixation (BNF) via forage legumes. Especially in the eastern regions of Austria where stockless organic farming is common, ensuring sufficient nitrogen supply to cereal crops such as winter wheat and winter rye is a very important topic. Due to the dry climate with high annual average temperatures (9,8°C) and low precipitation (550mm a-1) alfalfa is the

Data on the potential of catch crops to reduce soil nitrate contents, on their N accumulation and... more Data on the potential of catch crops to reduce soil nitrate contents, on their N accumulation and biological nitrogen fixation (BNF) are lacking for organic farming in the dry, pannonic region of Eastern Austria. The effect of legume, non-legume, and legume + non-legume crops used as catch crops on inorganic soil nitrogen, crop biomass and crop N, and BNF were tested in comparison to bare fallow. Non-legumes and legumes + non-legumes were more efficient than legumes in reducing inorganic soil N contents in autumn and nitrate contents in soil solution from the subsoil in winter. This reduction in inorganic soil N did not last until March of the following year due to N mineralisation from the mulch. The legume + non-legume mixture contained a larger amount of crop N than both legumes and non-legumes. This was due to the combined effect of soil-N uptake by the non-legumes and BNF by the legumes in the mixture. Einleitung: Neben zahlreichen anderen Funktionen sollen Zwischenfrüchte im ö...

Agronomy for Sustainable Development, 2008

Green manure catch crops promote the sustainability of agricultural systems by reducing soil erod... more Green manure catch crops promote the sustainability of agricultural systems by reducing soil erodibility and by nutrient uptake and transfer to the following main crops. This effect efficiently reduces the risk of nitrate leaching. Biological nitrogen fixation by legume catch crops is an additional benefit, mainly in organic farming. Such crops may, however, reduce nitrogen uptake from the soil and increase nitrate leaching. Additionally, under drought conditions, their extra water consumption may outweigh the beneficial effects. To determine the best catch crop management in stockless organic farming under dry, Pannonian site conditions in eastern Austria, four treatments were compared in 2002 and 2004: (1) legumes: field pea, common vetch and chickling vetch, (2) non-legumes: phacelia, oil radish and turnip, (3) a legume and non-legume mixture (all mentioned components), and (4) a bare fallow control. Our results show that catch crop biomass and N yield, biological N fixation, and crop N uptake from the soil were about 4 times higher under moderately dry conditions in 2002 than under drought conditions in summer and autumn 2004. In 2002, the legume/non-legume mixture had the highest biomass and N yield and the highest biological N fixation. Both the legume/non-legume mixture and the non-legumes were more efficient than legumes in N uptake from the soil (+32 kg N ha −1); and in reducing both soil inorganic N contents by-45 kg N ha −1 and nitrate concentrations in soil solution by-20 mg N L −1. These findings show that the legume/non-legume mixture combined the positive effects of non-legumes and legumes. In 2004, catch crop effects did not differ except for their above-mentioned effect on inorganic N contents. The only pre-crop effect was that of legumes compared with non-legumes on spring barley grain dry matter of +0.6 Mg DM ha −1 and grain N yield of +17 kg N ha −1 in 2005. The water consumption of catch crops never adversely affected the following crops. green manure / biological nitrogen fixation / nitrogen conservation / drought / legume catch crop

In organic farming, only limited use of selected fertilizers is allowed and plants have to meet t... more In organic farming, only limited use of selected fertilizers is allowed and plants have to meet their nutritional requirements through mobilization of nutrients provided by organic amendments, crop residue input within the rotation, and released from the soil reservoir. The crop varieties used in such systems shall be efficient in nutrient and water uptake. Root length, surface area and depth

Data on the potential of intercrops to reduce soil nitrate contents, on their N accumulation and ... more Data on the potential of intercrops to reduce soil nitrate contents, on their N accumulation and biological nitrogen fixation (BNF) are lacking for organic farming in the dry, pannonic region of Eastern Austria. The effect of legumes, non-legumes, and legumes + non -legumes used as intercrops on inorganic soil nitrogen, crop yield and biomass N, and BNF were tested in comparison to bare fallow. Non-legumes and legumes + non -legumes were more efficient than legumes in reducing inorganic soil N contents in autumn and nitrate contents in soil solution from the subsoil in winter. This reduction in inorganic soil N did not last until March of the following year due to an N mineralisation from the mulch. The legume + non -legume mixture contained a larger amount of crop N than both legumes and non-legumes. This was due to the combined effect of soil -N uptake by the non-legumes and BNF by the legumes in the mixture.

Journal of Plant Interactions, 2014

Bioresource Technology, 2007

Biogas production is of major importance for the sustainable use of agrarian biomass as renewable... more Biogas production is of major importance for the sustainable use of agrarian biomass as renewable energy source. Economic biogas production depends on high biogas yields. The project aimed at optimising anaerobic digestion of energy crops. The following aspects were investigated: suitability of different crop species and varieties, optimum time of harvesting, specific methane yield and methane yield per hectare. The experiments covered 7 maize, 2 winter wheat, 2 triticale varieties, 1 winter rye, and 2 sunflower varieties and 6 variants with permanent grassland. In the course of the vegetation period, biomass yield and biomass composition were measured. Anaerobic digestion was carried out in eudiometer batch digesters. The highest methane yields of 7500-10 200 m 3 N ha À1 were achieved from maize varieties with FAO numbers (value for the maturity of the maize) of 300 to 600 harvested at ''wax ripeness''. Methane yields of cereals ranged from 3200 to 4500 m 3 N ha À1. Cereals should be harvested at ''grain in the milk stage'' to ''grain in the dough stage''. With sunflowers, methane yields between 2600 and 4550 m 3 N ha À1 were achieved. There were distinct differences between the investigated sunflower varieties. Alpine grassland can yield 2700-3500 m 3 N CH 4 ha À1. The methane energy value model (MEVM) was developed for the different energy crops. It estimates the specific methane yield from the nutrient composition of the energy crops. Energy crops for biogas production need to be grown in sustainable crop rotations. The paper outlines possibilities for optimising methane yield from versatile crop rotations that integrate the production of food, feed, raw materials and energy. These integrated crop rotations are highly efficient and can provide up to 320 million t COE which is 96% of the total energy demand of the road traffic of the EU-25 (the 25 Member States of the European Union).

Archives of Agronomy and Soil Science, 2013

American Journal of Agricultural and Biological Sciences, 2009

Problem statement: It is generally considered that root turnover is a major contributor to organi... more Problem statement: It is generally considered that root turnover is a major contributor to organic matter and mineral nutrient cycles in organic managed agroecosystems. Approach: This study designed to investigate whether microbial activity could affect on root properties of Lucerne in an organically managed field under dry weather conditions. The trial was laid out as a factorial experiment in the fields of the University of Natural Resources and Applied Life Sciences, Vienna-Austria at Raasdorf in 2007. The experimental factors of Rhizobium (Sinorhizobium meliloti) and Arbuscular Mycorrhiza (AM) including Glomus etunicatum, G. intraradices and G. claroideum and irrigation levels were tested. Results: Results showed that increasing water deficit affected root dry weigh, specific root mass and root length significantly at 1% level and co-inoculation of rhizobium and mycorrhiza with irrigation increased all root parameters. Data's of variance analysis for mycorrhizal colonization showed that main effect of using mycorrhiza had significant effects on root parameters at 5 and 1% probability level at first and second harvest, respectively. Results of mean comparisons by Duncan's Multiple Range Test showed that mycorrhizal colonization was higher in the inoculated treatments by rhizobium, mycorrhiza and irrigated plots in both harvests. Double interaction of mycorrhiza and irrigation was higher in both harvests (37.05 and 65.73%, respectively). Conclusion: It can be suggested that the tripartite symbiosis of Rhizobium, AM and Lucerne can improve the performance of Lucerne in organic farming and under dry conditions. Such traits could be incorporated into breeding programs to improve drought tolerance especially in organic fields.

Agricultural Water Management, 2013

Lucerne (Medicago sativa L.) is a perennial legume with high importance as fodder crop under orga... more Lucerne (Medicago sativa L.) is a perennial legume with high importance as fodder crop under organic farming. Our study analyzes biomass growth and influence on soil water dynamics of three lucerne cultivars in a field experiment and using the simulation model CropSyst. The objective was to evaluate the model for a perennial legume crop, study the relation of cultivar traits with soil water relations and derive a lucerne ideotype for temperate, semi-arid conditions. Two cultivars of European origin (Sitel and Niva) were compared to an Iranian one (Mohajeran). Measurements were made under irrigated (non-water limited) and rain-fed (water limited) conditions. Sitel achieved a cumulative biomass (dry matter yield) of 36.8 t ha −1 (irrigated) and 25.3 t ha −1 (rain-fed) over six cuts during the two experimental years, being significantly higher compared to the other cultivars. It was depicted that for Sitel and Mohajeran biomass growth was determined by the ratio of rainfall-to-evapotranspiration. Niva on the contrary exhibited a distinct response of biomass growth to profile water content changes. Also the more even root distribution over the soil profile of Niva indicated an efficient water uptake for this cultivar. CropSyst simulated biomass growth (RMSE 0.58-3.52 t ha −1) and water content in the soil profile (RMSE 20.9-50.6 mm) satisfactorily. Indices of agreement revealed a better model performance for irrigated conditions compared to water-limited growth. Model deviations from measured biomass and profile water content were highest for Mohajeran and it can be attributed to an inadequate distribution of root water extraction over the soil profile in relation to rooting density. Scenario analysis revealed that for the temperate, semi-arid conditions at the site, a maximum root depth between 1.3 and 1.8 m is sufficient for optimum growth and water use. Optimization of growth is largely determined by leaf traits such as specific leaf area, but our analysis depicted that in a dry year the sustained water supply via the root system becomes decisive.

About one-third of the world’s land surface is used for farming, a fact that bears important impl... more About one-third of the world’s land surface is used for farming, a fact that bears important implications for biodiversity. In Europe, for instance, an estimated 50 percent of all wild species are reliant on agricultural habitats, while agricultural productivity often depends on the presence or absence of particular species. Despite this close coupling, surprisingly little is known about the status and evolution of farmland biodiversity. A team of European and African researchers, hoping to fill this gap in information, recently invented and piloted a new toolbox called the BioBio indicator set, which measures 23 different instances of biodiversity across a variety of farm types and scales in Europe. Applications were also tested in Tunisia, Ukraine, and Uganda, where they proved a feasible starting point for adaptation to the agricultural context of different countries.

Notulae Botanicae Horti Agrobotanici Cluj-Napoca

The effect of different fertilizing systems on the seed yield and phosphorus uptake in annual med... more The effect of different fertilizing systems on the seed yield and phosphorus uptake in annual medic (Medicago scutellata cv. Robinson) was examined at two locations under dry farming conditions in Kermanshah province, Iran, in 2009. Experiments were conducted based on a randomized complete block design with three replications; the treatments consisted of control (no fertilizer), chemical fertilizer, biological fertilizer and different combinations of chemical and biological fertilizing systems. The results showed that application of different fertilizing systems had a highly significant effect on the number of pods per plant. The highest values were obtained in the treatment using the urea chemical fertilizer + phosphorus-solubilizing bacteria + mycorrhiza. The highest soil seed bank was recorded in the nitrogen-fixing bacteria + phosphorus-solubilizing bacteria treatment; it increased the number of seeds by approximately 50 percent compared to the control (only 134 pod containing s...

Rainfall is the single most important factor affecting yield and biomass accumulation by crops as... more Rainfall is the single most important factor affecting yield and biomass accumulation by crops as well as residue decomposition in the tropics. The ability to capture this resource in organic systems calls for appropriate techniques. Kenya experiences bimodal type of rainfall with two rainfall peaks; the long (730 mm) and the short (376 mm) rains. Rainfall fluctuations in both seasons are becoming more common in the recent years with a likelihood of crop failure in one out of five years. The question addressed was how to utilize the short rains for food and biomass production. Lablab (Dolichos lablab), a N-fixing legume was sown in the short rains and the seeds harvested. The effect of lablab biomass incorporation on organic maize and potatoes planted in the long rains was evaluated in comparison with farmyard manure application. The 3-year trial showed that dry matter biomass (1.95 t/ha) and grain yield (0.5 t/ha) of lablab was a factor of the amount of rainfall. The amount of labl...

Die Projektziele bestehen im Wesentlichen in der Optimierung und Bereitstellung der Daten- und Be... more Die Projektziele bestehen im Wesentlichen in der Optimierung und Bereitstellung der Daten- und Berechnungsgrundlagen im Bereich Pflanzenbau und Humusgehalte im Boden, um die Profile der treibhausgas-relevanten Emissionen und Senken in landwirtschaftlichen Betrieben Osterreichs darzustellen, sowie in der Modellierung treibhausgasrelevanter Emissionen und Senken der wichtigsten landwirtschaft-lichen Betriebstypen Osterreichs (Martkfrucht-, Futterbau-, Veredelungs-, Dauerkultur-, Kombinations-, und landwirtschaftliche Gemischtbetriebe) in den Hauptproduktionsgebieten.

The effect of different preceding crops and fertilisation systems on winter wheat yieldand qualit... more The effect of different preceding crops and fertilisation systems on winter wheat yieldand quality was assessed in a long-term field experiment in Eastern Austria. Winter wheat following a 2-years lucerne crop had lower yield but higher protein content than winter wheat following peas. Lucerne green manure use in a stockless system increased yield and protein content of a subsequent wheat crop compared to a livestock-keeping system with removal of the lucerne crop for fodder use. Wheat following peas that had received farmyard manure in the livestock-keeping system only, showed higher yield than in the stockless system but no differences in protein content. Likewise, an additional compost fertilisation in the stockless system increased yield of wheat following peas but had no effect on wheat protein content.

Fodder legumes, like lucerne, make a significant contribution to a positive humus balance and nit... more Fodder legumes, like lucerne, make a significant contribution to a positive humus balance and nitrogen supply on organic farms. To determine the required lucerne percentage to meet these targets, several shares of lucerne were modelled on the basis of empirical data of an eight-field crop rotation. The lower limit for ensuring optimum humus and nitrogen supply in this rotation was approximately 17 % lucerne. The calculation of the data was performed with the agricultural software REPRO.

In the pannonical region of Eastern Austria, forage legumes, mainly alfalfa, are commonly used as... more In the pannonical region of Eastern Austria, forage legumes, mainly alfalfa, are commonly used as green manure in organic farming. In a field experiment, alfalfa and alfalfa-grass mixtures were either cut and removed or used as green manure and mulched. Grass and rye were used as reference crops. The experiment was repeated in two consecutive years. Soil microbial biomass carbon and nitrogen was not affected by the annually grown forage legumes compared with grass or rye. One year of fodder legume crops is insufficient to increase microbial C and N at the study site where plant growth is limited by draught.

Problemstellung/Ziele:Die arbuskuläre Mykorrhiza ist eine Symbiose zwischen dem Grossteil der lan... more Problemstellung/Ziele:Die arbuskuläre Mykorrhiza ist eine Symbiose zwischen dem Grossteil der landwirtschaftlichen Kulturpflanzen und bodenbürtigen Pilzen. Der heterotrophe Pilz erhält Assimilate von der autotrophen Pflanze, als Gegenleistung fördert der Pilz die Nährstoffaufnahme in die Pflanze und erhöht die Resistenz gegenüber phytopathogenen Mikroorganismen, die in einer Wachstumssteigerung der Pflanze resultieren können. In zahlreichen Untersuchungen wurde festgestellt, dass mechanische Bodenbearbeitung das Besiedelungspotenzial von landwirtschaftlichen Kulturpflanzen durch arbuskuläre Mykorrhizapilze (AMP) vermindert (McGonigle et al. 1990a) und die Effizienz des Myzels der AMP bei der Aufnahme von Phosphor mit steigender Intensität der Bodenbearbeitung abnimmt (Douds et al. 1995). Ziel der Untersuchungen war, die Auswirkungen verschiedener Bodenbearbeitungsvarianten auf den Mykorrhizabesiedelungsgrad von Winterroggen unter den Bedingungen des Ökologischen Landbaues festzustellen.

Introduction and Project Aims In organic farming the replenishment of soil N mainly depends on bi... more Introduction and Project Aims In organic farming the replenishment of soil N mainly depends on biological nitrogen fixation (BNF) via forage legumes. Especially in the eastern regions of Austria where stockless organic farming is common, ensuring sufficient nitrogen supply to cereal crops such as winter wheat and winter rye is a very important topic. Due to the dry climate with high annual average temperatures (9,8°C) and low precipitation (550mm a-1) alfalfa is the

Data on the potential of catch crops to reduce soil nitrate contents, on their N accumulation and... more Data on the potential of catch crops to reduce soil nitrate contents, on their N accumulation and biological nitrogen fixation (BNF) are lacking for organic farming in the dry, pannonic region of Eastern Austria. The effect of legume, non-legume, and legume + non-legume crops used as catch crops on inorganic soil nitrogen, crop biomass and crop N, and BNF were tested in comparison to bare fallow. Non-legumes and legumes + non-legumes were more efficient than legumes in reducing inorganic soil N contents in autumn and nitrate contents in soil solution from the subsoil in winter. This reduction in inorganic soil N did not last until March of the following year due to N mineralisation from the mulch. The legume + non-legume mixture contained a larger amount of crop N than both legumes and non-legumes. This was due to the combined effect of soil-N uptake by the non-legumes and BNF by the legumes in the mixture. Einleitung: Neben zahlreichen anderen Funktionen sollen Zwischenfrüchte im ö...

Agronomy for Sustainable Development, 2008

Green manure catch crops promote the sustainability of agricultural systems by reducing soil erod... more Green manure catch crops promote the sustainability of agricultural systems by reducing soil erodibility and by nutrient uptake and transfer to the following main crops. This effect efficiently reduces the risk of nitrate leaching. Biological nitrogen fixation by legume catch crops is an additional benefit, mainly in organic farming. Such crops may, however, reduce nitrogen uptake from the soil and increase nitrate leaching. Additionally, under drought conditions, their extra water consumption may outweigh the beneficial effects. To determine the best catch crop management in stockless organic farming under dry, Pannonian site conditions in eastern Austria, four treatments were compared in 2002 and 2004: (1) legumes: field pea, common vetch and chickling vetch, (2) non-legumes: phacelia, oil radish and turnip, (3) a legume and non-legume mixture (all mentioned components), and (4) a bare fallow control. Our results show that catch crop biomass and N yield, biological N fixation, and crop N uptake from the soil were about 4 times higher under moderately dry conditions in 2002 than under drought conditions in summer and autumn 2004. In 2002, the legume/non-legume mixture had the highest biomass and N yield and the highest biological N fixation. Both the legume/non-legume mixture and the non-legumes were more efficient than legumes in N uptake from the soil (+32 kg N ha −1); and in reducing both soil inorganic N contents by-45 kg N ha −1 and nitrate concentrations in soil solution by-20 mg N L −1. These findings show that the legume/non-legume mixture combined the positive effects of non-legumes and legumes. In 2004, catch crop effects did not differ except for their above-mentioned effect on inorganic N contents. The only pre-crop effect was that of legumes compared with non-legumes on spring barley grain dry matter of +0.6 Mg DM ha −1 and grain N yield of +17 kg N ha −1 in 2005. The water consumption of catch crops never adversely affected the following crops. green manure / biological nitrogen fixation / nitrogen conservation / drought / legume catch crop

In organic farming, only limited use of selected fertilizers is allowed and plants have to meet t... more In organic farming, only limited use of selected fertilizers is allowed and plants have to meet their nutritional requirements through mobilization of nutrients provided by organic amendments, crop residue input within the rotation, and released from the soil reservoir. The crop varieties used in such systems shall be efficient in nutrient and water uptake. Root length, surface area and depth

Data on the potential of intercrops to reduce soil nitrate contents, on their N accumulation and ... more Data on the potential of intercrops to reduce soil nitrate contents, on their N accumulation and biological nitrogen fixation (BNF) are lacking for organic farming in the dry, pannonic region of Eastern Austria. The effect of legumes, non-legumes, and legumes + non -legumes used as intercrops on inorganic soil nitrogen, crop yield and biomass N, and BNF were tested in comparison to bare fallow. Non-legumes and legumes + non -legumes were more efficient than legumes in reducing inorganic soil N contents in autumn and nitrate contents in soil solution from the subsoil in winter. This reduction in inorganic soil N did not last until March of the following year due to an N mineralisation from the mulch. The legume + non -legume mixture contained a larger amount of crop N than both legumes and non-legumes. This was due to the combined effect of soil -N uptake by the non-legumes and BNF by the legumes in the mixture.

Journal of Plant Interactions, 2014

Bioresource Technology, 2007

Biogas production is of major importance for the sustainable use of agrarian biomass as renewable... more Biogas production is of major importance for the sustainable use of agrarian biomass as renewable energy source. Economic biogas production depends on high biogas yields. The project aimed at optimising anaerobic digestion of energy crops. The following aspects were investigated: suitability of different crop species and varieties, optimum time of harvesting, specific methane yield and methane yield per hectare. The experiments covered 7 maize, 2 winter wheat, 2 triticale varieties, 1 winter rye, and 2 sunflower varieties and 6 variants with permanent grassland. In the course of the vegetation period, biomass yield and biomass composition were measured. Anaerobic digestion was carried out in eudiometer batch digesters. The highest methane yields of 7500-10 200 m 3 N ha À1 were achieved from maize varieties with FAO numbers (value for the maturity of the maize) of 300 to 600 harvested at ''wax ripeness''. Methane yields of cereals ranged from 3200 to 4500 m 3 N ha À1. Cereals should be harvested at ''grain in the milk stage'' to ''grain in the dough stage''. With sunflowers, methane yields between 2600 and 4550 m 3 N ha À1 were achieved. There were distinct differences between the investigated sunflower varieties. Alpine grassland can yield 2700-3500 m 3 N CH 4 ha À1. The methane energy value model (MEVM) was developed for the different energy crops. It estimates the specific methane yield from the nutrient composition of the energy crops. Energy crops for biogas production need to be grown in sustainable crop rotations. The paper outlines possibilities for optimising methane yield from versatile crop rotations that integrate the production of food, feed, raw materials and energy. These integrated crop rotations are highly efficient and can provide up to 320 million t COE which is 96% of the total energy demand of the road traffic of the EU-25 (the 25 Member States of the European Union).

Archives of Agronomy and Soil Science, 2013

American Journal of Agricultural and Biological Sciences, 2009

Problem statement: It is generally considered that root turnover is a major contributor to organi... more Problem statement: It is generally considered that root turnover is a major contributor to organic matter and mineral nutrient cycles in organic managed agroecosystems. Approach: This study designed to investigate whether microbial activity could affect on root properties of Lucerne in an organically managed field under dry weather conditions. The trial was laid out as a factorial experiment in the fields of the University of Natural Resources and Applied Life Sciences, Vienna-Austria at Raasdorf in 2007. The experimental factors of Rhizobium (Sinorhizobium meliloti) and Arbuscular Mycorrhiza (AM) including Glomus etunicatum, G. intraradices and G. claroideum and irrigation levels were tested. Results: Results showed that increasing water deficit affected root dry weigh, specific root mass and root length significantly at 1% level and co-inoculation of rhizobium and mycorrhiza with irrigation increased all root parameters. Data's of variance analysis for mycorrhizal colonization showed that main effect of using mycorrhiza had significant effects on root parameters at 5 and 1% probability level at first and second harvest, respectively. Results of mean comparisons by Duncan's Multiple Range Test showed that mycorrhizal colonization was higher in the inoculated treatments by rhizobium, mycorrhiza and irrigated plots in both harvests. Double interaction of mycorrhiza and irrigation was higher in both harvests (37.05 and 65.73%, respectively). Conclusion: It can be suggested that the tripartite symbiosis of Rhizobium, AM and Lucerne can improve the performance of Lucerne in organic farming and under dry conditions. Such traits could be incorporated into breeding programs to improve drought tolerance especially in organic fields.

Agricultural Water Management, 2013

Lucerne (Medicago sativa L.) is a perennial legume with high importance as fodder crop under orga... more Lucerne (Medicago sativa L.) is a perennial legume with high importance as fodder crop under organic farming. Our study analyzes biomass growth and influence on soil water dynamics of three lucerne cultivars in a field experiment and using the simulation model CropSyst. The objective was to evaluate the model for a perennial legume crop, study the relation of cultivar traits with soil water relations and derive a lucerne ideotype for temperate, semi-arid conditions. Two cultivars of European origin (Sitel and Niva) were compared to an Iranian one (Mohajeran). Measurements were made under irrigated (non-water limited) and rain-fed (water limited) conditions. Sitel achieved a cumulative biomass (dry matter yield) of 36.8 t ha −1 (irrigated) and 25.3 t ha −1 (rain-fed) over six cuts during the two experimental years, being significantly higher compared to the other cultivars. It was depicted that for Sitel and Mohajeran biomass growth was determined by the ratio of rainfall-to-evapotranspiration. Niva on the contrary exhibited a distinct response of biomass growth to profile water content changes. Also the more even root distribution over the soil profile of Niva indicated an efficient water uptake for this cultivar. CropSyst simulated biomass growth (RMSE 0.58-3.52 t ha −1) and water content in the soil profile (RMSE 20.9-50.6 mm) satisfactorily. Indices of agreement revealed a better model performance for irrigated conditions compared to water-limited growth. Model deviations from measured biomass and profile water content were highest for Mohajeran and it can be attributed to an inadequate distribution of root water extraction over the soil profile in relation to rooting density. Scenario analysis revealed that for the temperate, semi-arid conditions at the site, a maximum root depth between 1.3 and 1.8 m is sufficient for optimum growth and water use. Optimization of growth is largely determined by leaf traits such as specific leaf area, but our analysis depicted that in a dry year the sustained water supply via the root system becomes decisive.

About one-third of the world’s land surface is used for farming, a fact that bears important impl... more About one-third of the world’s land surface is used for farming, a fact that bears important implications for biodiversity. In Europe, for instance, an estimated 50 percent of all wild species are reliant on agricultural habitats, while agricultural productivity often depends on the presence or absence of particular species. Despite this close coupling, surprisingly little is known about the status and evolution of farmland biodiversity. A team of European and African researchers, hoping to fill this gap in information, recently invented and piloted a new toolbox called the BioBio indicator set, which measures 23 different instances of biodiversity across a variety of farm types and scales in Europe. Applications were also tested in Tunisia, Ukraine, and Uganda, where they proved a feasible starting point for adaptation to the agricultural context of different countries.

Notulae Botanicae Horti Agrobotanici Cluj-Napoca

The effect of different fertilizing systems on the seed yield and phosphorus uptake in annual med... more The effect of different fertilizing systems on the seed yield and phosphorus uptake in annual medic (Medicago scutellata cv. Robinson) was examined at two locations under dry farming conditions in Kermanshah province, Iran, in 2009. Experiments were conducted based on a randomized complete block design with three replications; the treatments consisted of control (no fertilizer), chemical fertilizer, biological fertilizer and different combinations of chemical and biological fertilizing systems. The results showed that application of different fertilizing systems had a highly significant effect on the number of pods per plant. The highest values were obtained in the treatment using the urea chemical fertilizer + phosphorus-solubilizing bacteria + mycorrhiza. The highest soil seed bank was recorded in the nitrogen-fixing bacteria + phosphorus-solubilizing bacteria treatment; it increased the number of seeds by approximately 50 percent compared to the control (only 134 pod containing s...