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Braunschweig, Germany

Wang Y.Q.,Gansu College of Traditional Chinese Medicine | Schuchardt F.,Thunen Institute vTI
Landbauforschung Volkenrode | Year: 2010

We investigated the composting process of fresh, chopped vineyard pruning residues (DM 35 %) at various initial C:N ratios of 60:1 (original), 52:1,40:1, and 29:1 for 133 days in 250 litre rotting boxes with self-aeration. Urea (46 % N) was added as nitrogen supplement to attain a desirable C:N ratio. The composts were turned after 14, 23, 30, 38, 52, 65, 79, 93, 111, 122, and 133 days. The degradation of organic matter was between 19 % (at the initial C:N ratio of 60:1) and 39 % (at the initial C:N ration of 29:1) within 133 days, and the resulting C:N ratios were between 46:1 and 18:1. The compost maturity was evaluated by a self-heating test, C:N ratio, NH4 +/NO 3 + ratio, NH4 +-N content, E665, and germination index. A supplementation of about 1.5 litres water per kg fresh material was necessary to stabilize the biological activity of the composting process during the first 40 to 60 days. Nitrogen supplementation with urea, or another nitrogen source, can accelerate the rotting process, but the higher the urea supplementation, the higher the losses of nitrogen by ammonia evaporation. The optimum urea nitrogen supplementation was in the range of 2 g kg -1 dry matter. The parameters of C:N ratio, NH4 +/NO3 + ratio and E665 were no clear criteria for compost maturity, because they depend on the type of material. The simple germination test could be used to determine the compost maturity in the composting of vineyard pruning residues. Based on the results, a rotting period of at least 80 days was proposed for chopped vineyard pruning residues. Source

Bolte A.,Thunen Institute vTI | Degen B.,Thunen Institute vTI
Landbauforschung Volkenrode | Year: 2010

Forests are particularly affected by climate change since trees, as long-living and immovable organisms, have to adapt to environmental change over periods of 100 years and more. Reports on the projected increase of drought, heat and storm hazards make the development and application of adaptation strategies urgent: (1) Conservation of forest structures against increasing succession pressure increases the risk of catastrophic loss of forests (drought damage, wind throw) depending on the degree of local climate and site change. (2) Active adaptation, like the replacement of drought-sensitive tree species by less sensitive species or provenances, can lower the damage risk for forests. For this purpose, however, information on the regional und local adaptation and adaptability to future climate conditions is needed. (3) Passive adaptation with the deliberate use of spontaneous adaptation processes (natural succession and species migration) is the lowest-risk option, but eliminates the possibility of following specific forest management targets. The use of provenances of native and non-native tree species (e. g. Douglas fir) from regions with a climate corresponding to future climate in Germany is an important element of active adaptation. Provenance trials induced by forest genetic science that have been running for decades provide valuable basic information on adaptation of tree provenances. An integrative concept for adaptation is presented that interlinks focussed research and political processes from international to local scale. Source

High milk yield requires an appropriate level of feed intake in order to avoid excessive loss of weight and dangerous energy and nutrient deficiencies. Thus, estimators are used by dairy farmers and consultants to determine feed intake, aiming at the best possible feeding. The estimators of the NRC (2001) and Meinhold et al. (1976) are based solely on animal specific data. Although the estimators of Robinson (2006) and Gruber et al. (2004)) include additional statistics on feed and rations, the calculated feed intake is at a comparable level. Feed intake increases with the weight of the cow and thus also the maximally targetable milk yield. Feed intakes show significant animal-specific level differences that impact the maximal targetable performance just as strongly as weight differences. All estimators presume a strong cohesion between yield and feed intake. That is why the estimators of the NRC (2001) and Meinhold et al. (1976), even without a direct correlation to feed quality, show a similar level of feed intake as do the estimators of Robinson (2006) and Gruber et al. (2004), which take a positive correlation between feed quality and intake into account. Towards the end of lactation, assuming constantly highest quality feed, all estimators present feed intakes higher than needed. Dairy cows are generally provided a constantly adequate supply of (enriched) basic rations, as well as additional concentrates according to each cow's individual level of milk yield. The supply based on the average yield considers neither the animal-specific level of feed intake nor the amount of day to day shifts in milk yield. In the course of a necessary further development of the estimators of feed intake, variables like animal-specific differences, energy and nutrient balances, body condition, disease, climate and farm characteristics should be awarded a greater attention and meaning. Source

Offermann F.,Thunen Institute vTI | Gomann H.,Thunen Institute vTI | Kreins P.,Thunen Institute vTI | Von Ledebur O.,Johann Heinrich Von Thunen Institute | And 3 more authors.
Landbauforschung Volkenrode | Year: 2010

This article presents selected results of the vTI-Baseline as well as the underlying assumptions. The vTI-Baseline is established using and combining four models (GTAP, AGMEMOD, RAUMIS, FARMIS) of the vTI model network. It provides a reference scenario for the analysis of the impacts of alternative policies and developments. The projections are based on data and information available in summer 2009 and are thus characterised by the recession following the global financial crisis. The baseline assumes a continuation of the current policy framework and the implementation of the already agreed upon policy changes, respectively. According to the projections, the EU share in global agricultural trade rises from 16 % in 2004 to 19 % in 2019. Due to the reduced policy interventions in the milk market, the projected low world market prices for milk products affect the milk farm gate price in Germany, which in the baseline is 27 Euro/100 kg (3.7 % fat, excl. VAT) in 2019. Prices for other livestock products increase slightly. The prices for crop products benefit from a policy-induced demand for bioenergy, and while lower than the high prices observed in 2008, they will remain above the 2003 to 2005 period. In Germany, policy support for biomass production is the main driver for changes in agricultural land use. In the baseline, 1.2 million hectares are used for growing energy maize in 2019, at the expense of land subject to obligatory set-aside until 2007 as well as cereals and oilseeds. Milk production is slightly increasing because of milk quota abolishment. In comparison to the base period 2006 to 2008, farm net value added per work unit stagnates in real terms, and thus remains slightly above the average level observed during the last decade. Income in dairy farms (-6 %) and other grazing livestock farms (-6 %) decreases, while pig farms (+21 %) benefit from rising pork prices and lower feeding costs. Source

Planki R.,Thunen Institute vTI | Weingarten P.,Thunen Institute vTI | Nieberg H.,Thunen Institute vTI | Zimmer Y.,Thunen Institute vTI | And 2 more authors.
Landbauforschung Volkenrode | Year: 2010

The remuneration of public goods provided by agriculture plays a central role in the debate about the Common Agricultural Policy after 2013. Various opinions exist on what exactly these pubic goods constitute and how they can be quantified and assigned monetary values. The results of about 80 studies analysed show that there exists a willingness to pay for such public goods, the magnitude of which depends on socio-economic, socio-demographic and ecological determinants. Income is an important determinant. The evaluated case studies cannot be applied to the whole of Germany. The open space externality - if not provided free of cost as a by-product - involves costs which depend on whether the land is to be kept open with the least amount of effort or if, in addition, nature conservation goals are pursued simultaneously. The compliance with stricter environmental regulations is also often seen as a service which provides public goods. The results of the few existing studies on the costs of environmental regulations, and the exemplary comparison of two arable farms in Saxony Anhalt and the Ukraine indicate that these costs - in comparison to other cost components in Germany - tend to have less of an impact on the full costs of agricultural production. Source

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