Reducing CO
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emissions is one of the highest priorities in animal production. Regarding methane reduction, feed additives are of growing importance. As shown in a meta-analysis, the use of the ...essential oil (EO) blend Agolin Ruminant affects methane production per day (− 8.8%), milk yield (+ 4.1%), and feed efficiency (+ 4.4%). Building on these results, the present study investigated the effect of varying individual parameters on the carbon footprint of milk. The environmental and operational management system REPRO was applied to calculate the CO
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emissions. Calculation of CO
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emissions include enteric and storage-related CH
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, storage-, and pasture-related N
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O as well as direct and indirect energy expenditures. Three feed rations were created, differing in their basic feed components such as grass silage, corn silage, and pasture. Each feed ration was differentiated into three variants: variant 1 CON (no additive), variant 2 EO, and variant 3 (15% reduction of enteric methane compared to CON). Due to the reducing effect of EO on enteric methane production, a reduction potential of up to 6% could be calculated for all rations. Considering other variable parameters, such as the positive effects on ECM yield and feed efficiency, a GHG reduction potential of up to 10% can be achieved for the silage rations and almost 9% for the pasture ration. Modeling showed that indirect methane reduction strategies are important contributors to environmental impacts. Reduction of enteric methane emissions is fundamental, as they account for the largest share of GHG emissions from dairy production.
•Sustainable straw potentials can be determined with the help of humus balance tools.•A sustainable straw potential of 8–13Tg is estimated to be available in Germany.•Energetic use of this straw ...could lead to GHG emission reduction of 73.3–92.3% compared to fossil references.•Lowest GHG emissions occur for straw-based heat production.•Highest reduction potential can be achieved with combined heat and power production.
The energetic use of residues from agriculture can foster the transition towards a more renewable energy supply. However, sustainability issues have to be considered along the entire provision chain as they affect the resource and energy potential as well as the achievable contribution to climate mitigation. Straw is one of the most important agricultural residues in Germany. It is not yet used for energy purposes extensively and compared to other agricultural feedstock it shows low competition with food, feed or fiber.
This paper analyses on the one hand the sustainable potential of cereal straw for energy application in Germany considering the actual agricultural conditions, and on the other hand the global warming potential from different energy provision chains based on straw. Different humus-balance tools that are able to assess the organic matter (OM) demand to presume soil fertility. The analysis of straw potentials was applied at NUTS 3 level for Germany, based on statistical data. The results of this analysis were used as input data for the modeling of concepts for straw provision and use. Greenhouse gas (GHG) emissions were calculated for each concept in order to compare the global warming potential of various energy applications, to investigate the relative contribution of different production steps and to compare them with fossil energy applications.
In total, 29.8Tg of straw (fresh matter) are produced annually in Germany (1999–2007). Approximately 4.8Tg of the total straw occurrence are annually required by animal husbandry. Between 7.97 and 13.25Tg straw can be classified as sustainable straw. Highest straw potential (3.99Mgha−1) can be found in parts of Schleswig-Holstein, Mecklenburg–West Pomerania, North Rhine-Westphalia and Lower Saxony. But there are also regions that show a net deficit.
The cumulated GHG emissions for the resulting concepts are between 8 and 35gCO2-eq.MJ−1. In comparison to fossil energy applications, the highest reduction potential occurs for concepts for combined heat and power (CHP) provision, i.e. 223gCO2-eq.MJel-1. This study highlights the possible contribution of straw as renewable energy carrier, but also demonstrates that there are regional restrictions for straw use.
•Soil compaction impairs all essential soil functions, including plant growth.•One method of preventing soil compaction could be based on mathematical modelling.•A model is presented which calculates ...and assesses the risk of soil compaction.•The model uses information on soil, weather and specific husbandry.•The model was successfully validated in numerous trials and applied in arable farms.
Soil compaction impairs all essential soil functions, which are crucial for the lives of humans, animals, plants and soil organisms. In order to secure the various soil functions, soil compaction must be avoided. One successful method of preventing soil compaction could be based on the precautionary principle, and mathematical modelling might be used to support farmers or consultants when making decisions about husbandry operations. This paper presents a model which calculates an indicator and assesses the risk of soil compaction on arable land based on site-specific data including information on soil, weather and specific husbandry. The first step is to estimate the soil strength in response to soil stress for a topsoil (20cm) and a subsoil (35cm) layer. The estimations of these parameters take into account changes in soil moisture throughout the year. Soil strength compared with soil stress is used to calculate the indicator Soil Compaction Index (SCI) for each time the machinery passes over the soil. The results from the separate passes are then integrated for a comprehensive assessment of the risk of soil compaction at farm level. The model was validated in numerous trials. It was found that the calculated SCI was a good reflection of the actual change in soil structure. The model is already being applied on arable farms in Germany. As an example presented in this paper, the calculations for the subsoil at these farms result in low to medium compaction risks.
Untersuchungen mit Bodenfallen zum Einfluss der Kulturarten auf die Dynamik von Arthropodengesellschaften werden vorgestellt. Sie betreffen vier perennierende Kulturen (extensives Grünland, ...Chinaschilf und die Baumarten Pappel und Weide) sowie die Wintergerste als annuelle Frucht. Die Kulturarten prägten die Diversität (Shannon-Weaver-Index) der Arthropodengesellschaften, wobei die Diversität der Baumkulturen statistisch meist von der Diversität in den Ackerbaukulturen unterschieden war. Dieser Befund war auf zeitliche Änderungen im Artenbestand (Artenidentität) sowie der Artendominanz (Dominanzidentität) zurück zu führen und belegt eine hohe Dynamik des Arthropodenauftretens innerhalb und zwischen den Kulturen. Über die Kulturarten werden zeitlich und örtlich getrennte Teilpopulationen ausgebildet. Mögliche Triebkräfte für die Anpassung der Arthropodengesellschaften an die Fruchtarten wurden über die Erfassung des Energiestatus der Anbausysteme analysiert. Grundlage waren Bewirtschaftungsdaten, die Pflanzenerträge sowie begleitende Informationen zum Anfall von Biomasse. Die Kennzahl „landwirtschaftlicher Energiegewinn“ fasst diese Einflüsse auf energetischer Ebene zusammen. Der Rückfluss von Biomasse in das Anbausystem wurde als „ökosystemarer Energiegewinn“ beschrieben. Beide Parameter beschreiben das Auftreten der Arthropoden in den Kulturen. Ansteigender landwirtschaftlicher Energiegewinn wirkte sich negativ aus, ökosystemarer Energiegewinn bewirkte das Gegenteil. Weiterhin konnte eine Zuordnung der Arthropoden in funktionale Gruppen die Arten- und Dominanzunterschiede der Arthropodengemeinschaften in den Kulturen erklären. Sie beruhen auf der Notwendigkeit der Energiedissipation und berühren den Energiefluss über die Trophiestufen. Die Stellung der Arthropodenarten im Nahrungsnetz wird modifiziert. Aus den Befunden ist ersichtlich, dass Energie basierte Daten Hinweise auf den Biodiversitätsstatus der Anbausysteme geben. Sie können Grundlage für die Ableitung indirekter Status- und Wirkungsindikatoren sein. Daneben fördern die Befunde das Verständnis über Ökosystemprozesse und zu den Inhalten des Begriffes „Intensität“ im Kontext der Bewertung ökologischer Nachhaltigkeit.
The aim of this study was to evaluate the interaction between yield levels of nonleguminous crops and soil organic matter (SOM) under the specific conditions of organic and conventional farming, ...respectively, and to identify implications for SOM management in arable farming considering the farming system (organic vs. conventional). For that purpose, correlations between yield levels of nonlegume crops and actual SOM level (Corg, Nt, Chwe, Nhwe) as well as SOM‐level development were examined including primary data from selected treatments of seven long‐term field experiments in Germany and Switzerland. Yield levels of nonlegume crops were positively correlated with SOM levels, but the correlation was significant only under conditions of organic farming, and not with conventional farming treatments.
While absolute SOM levels had a positive impact on yield levels of nonlegumes, the yield levels of nonlegumes and SOM‐level development over time correlated negatively. Due to an increased demand of N from SOM mineralization, higher yield levels of nonlegumes obviously indicate an increased demand for OM supply to maintain SOM levels. Since this observation is highly significant for farming without mineral‐N fertilization but not for farming with such fertilization, we conclude that the demand of SOM‐level maintenance or enhancement and thus adequate SOM management is highly relevant for crop production in organic farming both from an agronomical and ecological point of view. Under conventional management, the agronomic relevance of SOM with regard to nutrient supply is much lower than under organic management. However, it has to be considered that we excluded other possible benefits of SOM in our survey that may be highly relevant for conventional farming as well.
The question of whether organic farming leads to higher soil organic matter (SOM) levels in arable soils compared with conventional farming is an ongoing debate. Building on several studies reported ...in the literature, we hypothesize that the impact on SOM levels is not an intrinsic characteristic of any farming system but is the result of the actual structure of the farming system, in particular, the composition and management of crop rotations, and the availability and utilization of organic manure. The SOM balances for organic versus conventional farming in Germany are compared by considering data on the structure of organic and conventional farming systems from agricultural census reports and then applying the SOM balance model HU-MOD. Preliminary testing confirmed the applicability of the model using a survey on soil organic carbon (SOC) change and SOM balances in four long-term field experiments in Germany and Switzerland and found that more positive SOM balances coincided with higher SOC levels. We therefore conclude that, where the SOM supply level of organic farming systems is higher than in conventional management, a shift from conventional to organic agriculture would increase SOM levels. Upscaling using agricultural census data in Germany, we found that SOM balances of organic farming were more positive than for conventional farming in the scenarios without consideration of animal manure application, but SOM balances for the two systems were not different where animal manure application rates were assumed to be at the current average rate for all cropped land. However, in fact, animal manure availability and application shows strong regional variations, and it is likely that this would affect the mean cropland SOM balance if it were possible to calculate it based on such spatially disaggregated data. We confirm the applicability of simple SOM balance models to compare the impact of farming systems and cropland structures on SOC levels. More work is needed to develop data inputs at a sufficient spatial and structural resolution to support more detailed evaluation.
Seit 1990 wird in Sachsen auf landwirtschaftlichen Dauertestflächen der Nitratgehalt im Frühjahr und im Herbst gemessen. Aus den gleichzeitig erhobenen Bewirtschaftungsdaten kann mit dem Modell REPRO ...der potenzielle Nitrataustrag unterhalb der durchwurzelbaren Bodenzone abgeschätzt werden.
Im Ergebnis zeigt sich, dass weiterhin, vor allem in Trockengebieten in Nordsachsen, mit teilweise hohen Nitratkonzentrationen gerechnet werden muss. Die Düngungsauflagen in Wasserschutzgebieten bewirken sowohl geringere Stickstoffsalden als auch abnehmende Nitratgehalte im Boden. Auf ökologisch bewirtschafteten Flächen war die auswaschungsgefährdete Nitratmenge sehr gering.
Seit 1990 wird in Sachsen auf landwirtschaftlichen Dauertestflächen der Nitratgehalt im Frühjahr und im Herbst gemessen. Aus den gleichzeitig erhobenen Bewirtschaftungsdaten kann mit dem Modell REPRO ...der potenzielle Nitrataustrag unterhalb der durchwurzelbaren Bodenzone abgeschätzt werden.
Im Ergebnis zeigt sich, dass weiterhin, vor allem in Trockengebieten in Nordsachsen, mit teilweise hohen Nitratkonzentrationen gerechnet werden muss. Die Düngungsauflagen in Wasserschutzgebieten bewirken sowohl geringere Stickstoffsalden als auch abnehmende Nitratgehalte im Boden. Auf ökologisch bewirtschafteten Flächen war die auswaschungsgefährdete Nitratmenge sehr gering.
