Annette Prochnow - Academia.edu (original) (raw)

Papers by Annette Prochnow

Research paper thumbnail of Nitrification inhibitors reduce N2O emissions induced by application of biogas digestate to oilseed rape

Nutrient Cycling in Agroecosystems

Winter oilseed rape (WOSR) is the major oil crop cultivated in Europe and the most important feed... more Winter oilseed rape (WOSR) is the major oil crop cultivated in Europe and the most important feedstock for biodiesel. Up to 90% of the greenhouse gas (GHG) emissions from biodiesel production can occur during oilseed rape cultivation. Therefore, mitigation strategies are required and need to focus on direct nitrous oxide (N2O) emission as one of the largest GHG contributors in biodiesel production. Earlier studies show that nitrification inhibitors (NIs) can reduce N2O emissions derived from N-fertilization. Since information on the effect of biogas digestates with or without NIs on N2O emissions from WOSR fields is scarce, the aim of this study was to evaluate their effects on N2O emissions, mineral N dynamics, and oil yield in WOSR production fertilized with digestate. The study was conducted at five sites across Germany over three years resulting in 15 full site-years data sets. Across all sites and years, N2O emission from WOSR fertilized with biogas digestate (180 kg NH4+-N ha−...

Research paper thumbnail of Multi-variable experimental data set of agronomic data and gaseous soil emissions from maize, oilseed rape and other energy crops at eight sites in Germany

Open Data Journal for Agricultural Research

Greenhouse gas emissions (GHG), as well as other gaseous emissions and agronomic variables were c... more Greenhouse gas emissions (GHG), as well as other gaseous emissions and agronomic variables were continuously measured for three years (2011/2012 – 2014/2015) at eight experimental field sites in Germany. All management activities were consistently documented. The GHG-DB-Thuenen stores these multi-variable data sets of gas fluxes (CO2, N2O, CH4 and NH3), crop parameters (ontogenesis, aboveground biomass, grain and straw yield, N and C content, etc.), soil characteristics (nitrogen content, NH4-N, NO3-N, bulk density etc.), continuously recorded meteorological variables (air and soil temperatures, radiation, precipitation, etc.), management activities (sowing, harvest, soil tillage, fertilization, etc.), and its metadata (methods, further information about variables, etc.). In addition, NOx data were measured and analyzed. Also available are site-specific calculated C and N balances for the respective crops and crop rotations.

Research paper thumbnail of Two-Stage Leach-Bed Reactor System is Advantageous Over Single-Stage Continuously Stirred Tank Reactor in Mesophilic Anaerobic Digestion of Fibrous Sorghum

Research paper thumbnail of Effects of irrigation and nitrogen fertilization on the greenhouse gas emissions of a cropping system on a sandy soil in northeast Germany

European Journal of Agronomy

Research paper thumbnail of The Future Agricultural Biogas Plant in Germany: A Vision

Energies

After nearly two decades of subsidized and energy crop-oriented development, agricultural biogas ... more After nearly two decades of subsidized and energy crop-oriented development, agricultural biogas production in Germany is standing at a crossroads. Fundamental challenges need to be met. In this article we sketch a vision of a future agricultural biogas plant that is an integral part of the circular bioeconomy and works mainly on the base of residues. It is flexible with regard to feedstocks, digester operation, microbial communities and biogas output. It is modular in design and its operation is knowledge-based, information-driven and largely automated. It will be competitive with fossil energies and other renewable energies, profitable for farmers and plant operators and favorable for the national economy. In this paper we discuss the required contribution of research to achieve these aims.

Research paper thumbnail of Rainfall interception by winter rapeseed in Brandenburg (Germany) under various nitrogen fertilization treatments

Agricultural and Forest Meteorology

Research paper thumbnail of Process Disturbances in Agricultural Biogas Production—Causes, Mechanisms and Effects on the Biogas Microbiome: A Review

Energies

Disturbances of the anaerobic digestion process reduce the economic and environmental performance... more Disturbances of the anaerobic digestion process reduce the economic and environmental performance of biogas systems. A better understanding of the highly complex process is of crucial importance in order to avoid disturbances. This review defines process disturbances as significant changes in the functionality within the microbial community leading to unacceptable and severe decreases in biogas production and requiring an active counteraction to be overcome. The main types of process disturbances in agricultural biogas production are classified as unfavorable process temperatures, fluctuations in the availability of macro- and micronutrients (feedstock variability), overload of the microbial degradation potential, process-related accumulation of inhibiting metabolites such as hydrogen (H2), ammonium/ammonia (NH4+/NH3) or hydrogen sulphide (H2S) and inhibition by other organic and inorganic toxicants. Causes, mechanisms and effects on the biogas microbiome are discussed. The need for...

Research paper thumbnail of Accounting for inter-annual variability of farm activity data for calculation of greenhouse gas emissions in dairy farming

The International Journal of Life Cycle Assessment

Research paper thumbnail of Particle Size Reduction during Harvesting of Crop Feedstock for Biogas Production I: Effects on Ensiling Process and Methane Yields

BioEnergy Research

... Growth of clostridia led to low lactic acid concentration within these silages, a rise in pH,... more ... Growth of clostridia led to low lactic acid concentration within these silages, a rise in pH, and high fermentation losses even at short chopping lengths (Table 4). Steinhöfel and Thaysen [23] stated that at ripening, whole crop cereals often show low nitrate contents. ...

Research paper thumbnail of Appropriateness of on-combine moisture measurement for the management of harvesting and postharvest operations and capacity planning in grain harvest

Biosystems Engineering, 2017

Research paper thumbnail of Quantity- and Quality-Based Farm Water Productivity in Wine Production: Case Studies in Germany

The German wine sector has encountered new challenges in water management recently. To manage wat... more The German wine sector has encountered new challenges in water management recently. To manage water resources responsibly, it is necessary to understand the relationship between the input of water and the output of wine, in terms of quantity and quality. The objectives of this study are to examine water use at the farm scale at three German wineries, and to develop and apply, for the first time, a quality-based indicator. Water use is analyzed in terms of wine production and wine-making over three years. After the spatial and temporal boundaries of the wineries and the water flows are defined, the farm water productivity indicator is calculated to assess water use at the winery scale. Farm water productivity is calculated using the AgroHyd Farmmodel modeling software. Average productivity on a quantity basis is 3.91 L wine per m3 of water. Productivity on a quality basis is 329.24 °Oechsle per m3 of water. Water input from transpiration for wine production accounts for 99.4&ndas...

Research paper thumbnail of CUDe—Carbon Utilization Degree as an Indicator for Sustainable Biomass Use

Sustainability, 2016

Carbon (C) is a central element in organic compounds and is an indispensable resource for life. I... more Carbon (C) is a central element in organic compounds and is an indispensable resource for life. It is also an essential production factor in bio-based economies, where biomass serves many purposes, including energy generation and material production. Biomass conversion is a common case of transformation between different carbon-containing compounds. At each transformation step, C might be lost. To optimize the C use, the C flows from raw materials to end products must be understood. The estimation of how much of the initial C in the feedstock remains in consumable products and delivers services provides an indication of the C use efficiency. We define this concept as Carbon Utilization Degree (CUDe) and apply it to two biomass uses: biogas production and hemp insulation. CUDe increases when conversion processes are optimized, i.e., residues are harnessed and/or losses are minimized. We propose CUDe as a complementary approach for policy design to assess C as an asset for bio-based production. This may lead to a paradigm shift to see C as a resource that requires sustainable exploitation. It could complement the existing methods that focus solely on the climate impact of carbon.

Research paper thumbnail of Drinking and Cleaning Water Use in a Dairy Cow Barn

Water, 2016

Water is used in dairy farming for producing feed, watering the animals, and cleaning and disinfe... more Water is used in dairy farming for producing feed, watering the animals, and cleaning and disinfecting barns and equipment. The objective of this study was to investigate the drinking and cleaning water use in a dairy cow barn. The water use was measured on a well-managed commercial dairy farm in NorthEast Germany. Thirty-eight water meters were installed in a barn with 176 cows and two milking systems (an automatic milking system and a herringbone parlour). Their counts were logged hourly over 806 days. On average, the cows in the automatic milking system used 91.1 (SD 14.3) L drinking water per cow per day, while those in the herringbone parlour used 54.4 (SD 5.3) L per cow per day. The cows drink most of the water during the hours of (natural and artificial) light in the barn. Previously published regression functions of drinking water intake of the cows were reviewed and a new regression function based on the ambient temperature and the milk yield was developed (drinking water intake (L per cow per day) =´27.937 + 0.49ˆmean temperature + 3.15ˆmilk yield (R 2 = 0.67)). The cleaning water demand had a mean of 28.6 (SD 14.8) L per cow per day in the automatic milking system, and a mean of 33.8 (SD 14.1) L per cow per day in the herringbone parlour. These findings show that the total technical water use in the barn makes only a minor contribution to water use in dairy farming compared with the water use for feed production.

Research paper thumbnail of Comparative Advantage of Maize- and Grass-Silage Based Feedstock for Biogas Production with Respect to Greenhouse Gas Mitigation

Sustainability, 2016

This paper analyses the comparative advantage of using silage maize or grass as feedstock for ana... more This paper analyses the comparative advantage of using silage maize or grass as feedstock for anaerobic digestion to biogas from a greenhouse gas (GHG) mitigation point of view, taking into account site-specific yield potentials, management options, and land-use change effects. GHG emissions due to the production of biogas were calculated using a life-cycle assessment approach for three different site conditions with specific yield potentials and adjusted management options. While for the use of silage maize, GHG emissions per energy unit were the same for different yield potentials, and the emissions varied substantially for different grassland systems. Without land-use change effects, silage maize-based biogas had lower GHG emissions per energy unit compared to grass-based biogas. Taking land-use change into account, results in a comparative advantage of biogas production from grass-based feedstock produced on arable land compared to silage maize-based feedstock. However, under current frame conditions, it is quite unrealistic that grass production systems would be established on arable land at larger scale.

Research paper thumbnail of Irrigation water demand of selected agricultural crops in Germany between 1902 and 2010

Science of The Total Environment, 2016

Irrigation water demand (IWD) is increasing worldwide, including in regions such as Germany that ... more Irrigation water demand (IWD) is increasing worldwide, including in regions such as Germany that are characterized with low precipitation levels, yet grow water-demanding crops such as sugar beets, potatoes, and vegetables. This study aimed to calculate and analyze the spatial and temporal changes in the IWD of four crops-spring barley, oat, winter wheat, and potato-between 1902 and 2010 in Germany by using the modeling software AgroHyd Farmmodel. Climatic conditions in Germany continued to change over the investigation period, with an increase in temperature of 0.01K/yr and an increase in precipitation of 1mm/yr. Nevertheless, no significant increasing or decreasing trend in IWD was noted in the analysis. The IWD for the investigated crops in the area of the current "Federal Republic of Germany" over the 109years was 112mm/yr, varying between 100 and 127mm/yr. Changes in cropping pattern and cultivated area over the last century caused large differences in the IWD calculated for each administrative district. The mean annual IWD of over the study period (which was divided into 4 parts) varied between 13,455Mm(3)/yr in the earliest period (1902-1919) and 4717Mm(3)/yr in the latest period (1990-2010). Policy and management measures to adapt to climate change are currently being debated in Germany. The presented results suggest that the effects of the choice of crops (in this case, changes in cropping pattern in the German nation states) had a stronger influence on regional water resources than those of climate variability. Thus, the influence of climate change on water resources is relativized which brings an important input into the debate.

Research paper thumbnail of Energy balance, greenhouse gas emissions, and profitability of thermobarical pretreatment of cattle waste in anaerobic digestion

Research paper thumbnail of Water use indicators at farm scale: methodology and case study

Food and Energy Security, 2012

Indicators for water use at farm scale can assist farmers in understanding the water flows on the... more Indicators for water use at farm scale can assist farmers in understanding the water flows on their farms and in optimizing water use by adapting agronomic measures and farm management. The objective of this work is to develop a methodology to estimate water flows at the farm scale, to derive indicators for farm water use, and to apply them in a first case study. After the spatial and temporal boundaries of the farm system and the water flows are defined, three indicators to assess water use at the farm scale are developed: farm water productivity, degree of water utilization, and specific inflow of technical water. Farm water productivity describes the ratio of farm output to water input, where the water input is the total of those water inflows into the farm system that can be assigned to the generation of farm output. Farm output is expressed on a mass basis, food energy basis, and monetary basis. The degree of water utilization characterizes the relationship between productive water to the total water inflow into the farm system, where productive water comprises those water flows that directly contribute to biomass generation via plant and animal metabolism. The specific technical water inflow quantifies the water inflow into the system by technical means relative to the farm area. The application of the methodology in a first case study for a mixed crop-livestock farm with 2869 ha in Germany results in a farm water productivity of 2.30 kg fresh mass per m À3 Winput , 1.03 kg dry mass per m À3 Winput , 5.96 GJ m À3 Winput , and 0.25 € m À3 Winput. The degree of water utilization is 0.56. The specific technical water inflow is 36.5 m 3 ha À1 year À1. Factors that mainly effect these indicators and general approaches to optimize water use in farms are discussed as well as the further research required for practical implementation. Water inflows and outflows Once the system is defined, water flows into and out of the system can be determined (Fig. 1). The term water 30

Research paper thumbnail of Nitrous oxide emissions from potato cropping under drip-fertigation in eastern Germany

Archives of Agronomy and Soil Science, 2014

ABSTRACT In this article, a drip-fertigation system was compared to a control without irrigation ... more ABSTRACT In this article, a drip-fertigation system was compared to a control without irrigation concerning the amount of nitrous oxide (N2O) emissions under the climatic conditions of north-east Germany. The investigation was carried out at a field research station in the federal state of Brandenburg. The mean N2O emissions under drip-fertigation were significantly higher than under non-irrigation. The higher N2O emissions under drip-fertigation can be explained by a constantly higher water-filled pore space (WFPS). These higher values in WFPS were caused by the necessary nutrient supply in combination with additional water application in periods with frequent rainfall.

Research paper thumbnail of The influence of dairy management strategies on water productivity of milk production

Agricultural Water Management, 2015

ABSTRACT Livestock production is the main user of water resources in agricultural production. The... more ABSTRACT Livestock production is the main user of water resources in agricultural production. The objective of this study is to quantify the effects of dairy management strategies such as feeding strategies, milk yield and replacement rate on the water productivity of milk. The study is based on site conditions of North-East Germany. The water input is considered as the sum of crop transpiration from precipitation, the total irrigation water and the drinking water of the animals. Four feeding strategies, based on the maximization of grass silage, maize silage, pasture and concentrate, were analyzed. The milk yield varied between 4000 and 12,000 kg fat corrected milk (FCM) cow−1 year−1 in steps of 2000 kg. Feed water productivity on a dry mass (DM) base varied widely between 1.5 kg(DM) m−3 of water input for grass silage and 2.6 kg(DM) m−3 for maize silage, 0.8–1.8 kg(DM) m−3 for grain and 0.4 kg(DM) m−3 for soybeans from Brazil. The water productivity of milk increased with an increasing milk yield. The lowest water productivity was calculated at 4000 kg(FCM) with 1.1 kg(FCM) m−3 water input. At a milk yield of 8000 kg(FCM) the water productivity was 1.5 kg(FCM) m−3 and at 10,000 and 12,000 kg(FCM) it was 1.6 kg(FCM) m−3. The most beneficial conditions related to water productivity in dairy farming exemplarily for site conditions of North-East Germany are found to be with a milk yield about 10,000 kg(FCM) and a grass silage and maize silage based feeding.

Research paper thumbnail of Influence of silage additives on methane yield and economic performance of selected feedstock

Ensiling is an appropriate way of preserving feedstock for anaerobic digestion. Biological and ch... more Ensiling is an appropriate way of preserving feedstock for anaerobic digestion. Biological and chemical silage additives were used to improve silage quality and to prevent silage losses due to aerobic instability. Lab-scale experiments were conducted using alfalfa, grass and maize. Silages without additives and with chemical and biological additives were compared to the fresh material as well. The effect of silage additives was investigated using batch anaerobic digestion tests and comparing the results on an organic dry matter basis as well as on a hectare basis. In an economic assessment the costs of silage additives were compared to the additional proceeds which can be achieved from improving digestability and preventing silage losses. In many cases the costs of additive application exceeds the additional income from surplus methane formation. Nevertheless, in case of aerobic instability of opened silos the additional income can over-compensate the costs of the application of che...

Research paper thumbnail of Nitrification inhibitors reduce N2O emissions induced by application of biogas digestate to oilseed rape

Nutrient Cycling in Agroecosystems

Winter oilseed rape (WOSR) is the major oil crop cultivated in Europe and the most important feed... more Winter oilseed rape (WOSR) is the major oil crop cultivated in Europe and the most important feedstock for biodiesel. Up to 90% of the greenhouse gas (GHG) emissions from biodiesel production can occur during oilseed rape cultivation. Therefore, mitigation strategies are required and need to focus on direct nitrous oxide (N2O) emission as one of the largest GHG contributors in biodiesel production. Earlier studies show that nitrification inhibitors (NIs) can reduce N2O emissions derived from N-fertilization. Since information on the effect of biogas digestates with or without NIs on N2O emissions from WOSR fields is scarce, the aim of this study was to evaluate their effects on N2O emissions, mineral N dynamics, and oil yield in WOSR production fertilized with digestate. The study was conducted at five sites across Germany over three years resulting in 15 full site-years data sets. Across all sites and years, N2O emission from WOSR fertilized with biogas digestate (180 kg NH4+-N ha−...

Research paper thumbnail of Multi-variable experimental data set of agronomic data and gaseous soil emissions from maize, oilseed rape and other energy crops at eight sites in Germany

Open Data Journal for Agricultural Research

Greenhouse gas emissions (GHG), as well as other gaseous emissions and agronomic variables were c... more Greenhouse gas emissions (GHG), as well as other gaseous emissions and agronomic variables were continuously measured for three years (2011/2012 – 2014/2015) at eight experimental field sites in Germany. All management activities were consistently documented. The GHG-DB-Thuenen stores these multi-variable data sets of gas fluxes (CO2, N2O, CH4 and NH3), crop parameters (ontogenesis, aboveground biomass, grain and straw yield, N and C content, etc.), soil characteristics (nitrogen content, NH4-N, NO3-N, bulk density etc.), continuously recorded meteorological variables (air and soil temperatures, radiation, precipitation, etc.), management activities (sowing, harvest, soil tillage, fertilization, etc.), and its metadata (methods, further information about variables, etc.). In addition, NOx data were measured and analyzed. Also available are site-specific calculated C and N balances for the respective crops and crop rotations.

Research paper thumbnail of Two-Stage Leach-Bed Reactor System is Advantageous Over Single-Stage Continuously Stirred Tank Reactor in Mesophilic Anaerobic Digestion of Fibrous Sorghum

Research paper thumbnail of Effects of irrigation and nitrogen fertilization on the greenhouse gas emissions of a cropping system on a sandy soil in northeast Germany

European Journal of Agronomy

Research paper thumbnail of The Future Agricultural Biogas Plant in Germany: A Vision

Energies

After nearly two decades of subsidized and energy crop-oriented development, agricultural biogas ... more After nearly two decades of subsidized and energy crop-oriented development, agricultural biogas production in Germany is standing at a crossroads. Fundamental challenges need to be met. In this article we sketch a vision of a future agricultural biogas plant that is an integral part of the circular bioeconomy and works mainly on the base of residues. It is flexible with regard to feedstocks, digester operation, microbial communities and biogas output. It is modular in design and its operation is knowledge-based, information-driven and largely automated. It will be competitive with fossil energies and other renewable energies, profitable for farmers and plant operators and favorable for the national economy. In this paper we discuss the required contribution of research to achieve these aims.

Research paper thumbnail of Rainfall interception by winter rapeseed in Brandenburg (Germany) under various nitrogen fertilization treatments

Agricultural and Forest Meteorology

Research paper thumbnail of Process Disturbances in Agricultural Biogas Production—Causes, Mechanisms and Effects on the Biogas Microbiome: A Review

Energies

Disturbances of the anaerobic digestion process reduce the economic and environmental performance... more Disturbances of the anaerobic digestion process reduce the economic and environmental performance of biogas systems. A better understanding of the highly complex process is of crucial importance in order to avoid disturbances. This review defines process disturbances as significant changes in the functionality within the microbial community leading to unacceptable and severe decreases in biogas production and requiring an active counteraction to be overcome. The main types of process disturbances in agricultural biogas production are classified as unfavorable process temperatures, fluctuations in the availability of macro- and micronutrients (feedstock variability), overload of the microbial degradation potential, process-related accumulation of inhibiting metabolites such as hydrogen (H2), ammonium/ammonia (NH4+/NH3) or hydrogen sulphide (H2S) and inhibition by other organic and inorganic toxicants. Causes, mechanisms and effects on the biogas microbiome are discussed. The need for...

Research paper thumbnail of Accounting for inter-annual variability of farm activity data for calculation of greenhouse gas emissions in dairy farming

The International Journal of Life Cycle Assessment

Research paper thumbnail of Particle Size Reduction during Harvesting of Crop Feedstock for Biogas Production I: Effects on Ensiling Process and Methane Yields

BioEnergy Research

... Growth of clostridia led to low lactic acid concentration within these silages, a rise in pH,... more ... Growth of clostridia led to low lactic acid concentration within these silages, a rise in pH, and high fermentation losses even at short chopping lengths (Table 4). Steinhöfel and Thaysen [23] stated that at ripening, whole crop cereals often show low nitrate contents. ...

Research paper thumbnail of Appropriateness of on-combine moisture measurement for the management of harvesting and postharvest operations and capacity planning in grain harvest

Biosystems Engineering, 2017

Research paper thumbnail of Quantity- and Quality-Based Farm Water Productivity in Wine Production: Case Studies in Germany

The German wine sector has encountered new challenges in water management recently. To manage wat... more The German wine sector has encountered new challenges in water management recently. To manage water resources responsibly, it is necessary to understand the relationship between the input of water and the output of wine, in terms of quantity and quality. The objectives of this study are to examine water use at the farm scale at three German wineries, and to develop and apply, for the first time, a quality-based indicator. Water use is analyzed in terms of wine production and wine-making over three years. After the spatial and temporal boundaries of the wineries and the water flows are defined, the farm water productivity indicator is calculated to assess water use at the winery scale. Farm water productivity is calculated using the AgroHyd Farmmodel modeling software. Average productivity on a quantity basis is 3.91 L wine per m3 of water. Productivity on a quality basis is 329.24 °Oechsle per m3 of water. Water input from transpiration for wine production accounts for 99.4&ndas...

Research paper thumbnail of CUDe—Carbon Utilization Degree as an Indicator for Sustainable Biomass Use

Sustainability, 2016

Carbon (C) is a central element in organic compounds and is an indispensable resource for life. I... more Carbon (C) is a central element in organic compounds and is an indispensable resource for life. It is also an essential production factor in bio-based economies, where biomass serves many purposes, including energy generation and material production. Biomass conversion is a common case of transformation between different carbon-containing compounds. At each transformation step, C might be lost. To optimize the C use, the C flows from raw materials to end products must be understood. The estimation of how much of the initial C in the feedstock remains in consumable products and delivers services provides an indication of the C use efficiency. We define this concept as Carbon Utilization Degree (CUDe) and apply it to two biomass uses: biogas production and hemp insulation. CUDe increases when conversion processes are optimized, i.e., residues are harnessed and/or losses are minimized. We propose CUDe as a complementary approach for policy design to assess C as an asset for bio-based production. This may lead to a paradigm shift to see C as a resource that requires sustainable exploitation. It could complement the existing methods that focus solely on the climate impact of carbon.

Research paper thumbnail of Drinking and Cleaning Water Use in a Dairy Cow Barn

Water, 2016

Water is used in dairy farming for producing feed, watering the animals, and cleaning and disinfe... more Water is used in dairy farming for producing feed, watering the animals, and cleaning and disinfecting barns and equipment. The objective of this study was to investigate the drinking and cleaning water use in a dairy cow barn. The water use was measured on a well-managed commercial dairy farm in NorthEast Germany. Thirty-eight water meters were installed in a barn with 176 cows and two milking systems (an automatic milking system and a herringbone parlour). Their counts were logged hourly over 806 days. On average, the cows in the automatic milking system used 91.1 (SD 14.3) L drinking water per cow per day, while those in the herringbone parlour used 54.4 (SD 5.3) L per cow per day. The cows drink most of the water during the hours of (natural and artificial) light in the barn. Previously published regression functions of drinking water intake of the cows were reviewed and a new regression function based on the ambient temperature and the milk yield was developed (drinking water intake (L per cow per day) =´27.937 + 0.49ˆmean temperature + 3.15ˆmilk yield (R 2 = 0.67)). The cleaning water demand had a mean of 28.6 (SD 14.8) L per cow per day in the automatic milking system, and a mean of 33.8 (SD 14.1) L per cow per day in the herringbone parlour. These findings show that the total technical water use in the barn makes only a minor contribution to water use in dairy farming compared with the water use for feed production.

Research paper thumbnail of Comparative Advantage of Maize- and Grass-Silage Based Feedstock for Biogas Production with Respect to Greenhouse Gas Mitigation

Sustainability, 2016

This paper analyses the comparative advantage of using silage maize or grass as feedstock for ana... more This paper analyses the comparative advantage of using silage maize or grass as feedstock for anaerobic digestion to biogas from a greenhouse gas (GHG) mitigation point of view, taking into account site-specific yield potentials, management options, and land-use change effects. GHG emissions due to the production of biogas were calculated using a life-cycle assessment approach for three different site conditions with specific yield potentials and adjusted management options. While for the use of silage maize, GHG emissions per energy unit were the same for different yield potentials, and the emissions varied substantially for different grassland systems. Without land-use change effects, silage maize-based biogas had lower GHG emissions per energy unit compared to grass-based biogas. Taking land-use change into account, results in a comparative advantage of biogas production from grass-based feedstock produced on arable land compared to silage maize-based feedstock. However, under current frame conditions, it is quite unrealistic that grass production systems would be established on arable land at larger scale.

Research paper thumbnail of Irrigation water demand of selected agricultural crops in Germany between 1902 and 2010

Science of The Total Environment, 2016

Irrigation water demand (IWD) is increasing worldwide, including in regions such as Germany that ... more Irrigation water demand (IWD) is increasing worldwide, including in regions such as Germany that are characterized with low precipitation levels, yet grow water-demanding crops such as sugar beets, potatoes, and vegetables. This study aimed to calculate and analyze the spatial and temporal changes in the IWD of four crops-spring barley, oat, winter wheat, and potato-between 1902 and 2010 in Germany by using the modeling software AgroHyd Farmmodel. Climatic conditions in Germany continued to change over the investigation period, with an increase in temperature of 0.01K/yr and an increase in precipitation of 1mm/yr. Nevertheless, no significant increasing or decreasing trend in IWD was noted in the analysis. The IWD for the investigated crops in the area of the current "Federal Republic of Germany" over the 109years was 112mm/yr, varying between 100 and 127mm/yr. Changes in cropping pattern and cultivated area over the last century caused large differences in the IWD calculated for each administrative district. The mean annual IWD of over the study period (which was divided into 4 parts) varied between 13,455Mm(3)/yr in the earliest period (1902-1919) and 4717Mm(3)/yr in the latest period (1990-2010). Policy and management measures to adapt to climate change are currently being debated in Germany. The presented results suggest that the effects of the choice of crops (in this case, changes in cropping pattern in the German nation states) had a stronger influence on regional water resources than those of climate variability. Thus, the influence of climate change on water resources is relativized which brings an important input into the debate.

Research paper thumbnail of Energy balance, greenhouse gas emissions, and profitability of thermobarical pretreatment of cattle waste in anaerobic digestion

Research paper thumbnail of Water use indicators at farm scale: methodology and case study

Food and Energy Security, 2012

Indicators for water use at farm scale can assist farmers in understanding the water flows on the... more Indicators for water use at farm scale can assist farmers in understanding the water flows on their farms and in optimizing water use by adapting agronomic measures and farm management. The objective of this work is to develop a methodology to estimate water flows at the farm scale, to derive indicators for farm water use, and to apply them in a first case study. After the spatial and temporal boundaries of the farm system and the water flows are defined, three indicators to assess water use at the farm scale are developed: farm water productivity, degree of water utilization, and specific inflow of technical water. Farm water productivity describes the ratio of farm output to water input, where the water input is the total of those water inflows into the farm system that can be assigned to the generation of farm output. Farm output is expressed on a mass basis, food energy basis, and monetary basis. The degree of water utilization characterizes the relationship between productive water to the total water inflow into the farm system, where productive water comprises those water flows that directly contribute to biomass generation via plant and animal metabolism. The specific technical water inflow quantifies the water inflow into the system by technical means relative to the farm area. The application of the methodology in a first case study for a mixed crop-livestock farm with 2869 ha in Germany results in a farm water productivity of 2.30 kg fresh mass per m À3 Winput , 1.03 kg dry mass per m À3 Winput , 5.96 GJ m À3 Winput , and 0.25 € m À3 Winput. The degree of water utilization is 0.56. The specific technical water inflow is 36.5 m 3 ha À1 year À1. Factors that mainly effect these indicators and general approaches to optimize water use in farms are discussed as well as the further research required for practical implementation. Water inflows and outflows Once the system is defined, water flows into and out of the system can be determined (Fig. 1). The term water 30

Research paper thumbnail of Nitrous oxide emissions from potato cropping under drip-fertigation in eastern Germany

Archives of Agronomy and Soil Science, 2014

ABSTRACT In this article, a drip-fertigation system was compared to a control without irrigation ... more ABSTRACT In this article, a drip-fertigation system was compared to a control without irrigation concerning the amount of nitrous oxide (N2O) emissions under the climatic conditions of north-east Germany. The investigation was carried out at a field research station in the federal state of Brandenburg. The mean N2O emissions under drip-fertigation were significantly higher than under non-irrigation. The higher N2O emissions under drip-fertigation can be explained by a constantly higher water-filled pore space (WFPS). These higher values in WFPS were caused by the necessary nutrient supply in combination with additional water application in periods with frequent rainfall.

Research paper thumbnail of The influence of dairy management strategies on water productivity of milk production

Agricultural Water Management, 2015

ABSTRACT Livestock production is the main user of water resources in agricultural production. The... more ABSTRACT Livestock production is the main user of water resources in agricultural production. The objective of this study is to quantify the effects of dairy management strategies such as feeding strategies, milk yield and replacement rate on the water productivity of milk. The study is based on site conditions of North-East Germany. The water input is considered as the sum of crop transpiration from precipitation, the total irrigation water and the drinking water of the animals. Four feeding strategies, based on the maximization of grass silage, maize silage, pasture and concentrate, were analyzed. The milk yield varied between 4000 and 12,000 kg fat corrected milk (FCM) cow−1 year−1 in steps of 2000 kg. Feed water productivity on a dry mass (DM) base varied widely between 1.5 kg(DM) m−3 of water input for grass silage and 2.6 kg(DM) m−3 for maize silage, 0.8–1.8 kg(DM) m−3 for grain and 0.4 kg(DM) m−3 for soybeans from Brazil. The water productivity of milk increased with an increasing milk yield. The lowest water productivity was calculated at 4000 kg(FCM) with 1.1 kg(FCM) m−3 water input. At a milk yield of 8000 kg(FCM) the water productivity was 1.5 kg(FCM) m−3 and at 10,000 and 12,000 kg(FCM) it was 1.6 kg(FCM) m−3. The most beneficial conditions related to water productivity in dairy farming exemplarily for site conditions of North-East Germany are found to be with a milk yield about 10,000 kg(FCM) and a grass silage and maize silage based feeding.

Research paper thumbnail of Influence of silage additives on methane yield and economic performance of selected feedstock

Ensiling is an appropriate way of preserving feedstock for anaerobic digestion. Biological and ch... more Ensiling is an appropriate way of preserving feedstock for anaerobic digestion. Biological and chemical silage additives were used to improve silage quality and to prevent silage losses due to aerobic instability. Lab-scale experiments were conducted using alfalfa, grass and maize. Silages without additives and with chemical and biological additives were compared to the fresh material as well. The effect of silage additives was investigated using batch anaerobic digestion tests and comparing the results on an organic dry matter basis as well as on a hectare basis. In an economic assessment the costs of silage additives were compared to the additional proceeds which can be achieved from improving digestability and preventing silage losses. In many cases the costs of additive application exceeds the additional income from surplus methane formation. Nevertheless, in case of aerobic instability of opened silos the additional income can over-compensate the costs of the application of che...