Browsing by Subject "Samara"

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    Betriebswirtschaftliche Analyse des Einsatzes moderner Agrartechnik in der Körnerfrüchteproduktion in Russland.
    (2007) Vorontsova, Tatiana; Zeddies, Jürgen
    The dissertation in hand refers to the optimisation of conventional cultivation methods by the use of resource-saving technologies in cereal production at six agricultural survey enterprises in the Region of Samara/Russia. The aim of the optimisation is to estimate the economic efficiency of the changeover from conventional to resource-saving cultivation methods as well as to evaluate the use of agricultural machinery adapted to the specific technology, and, starting from this basis, to develop practice-oriented and efficiency-increasing solutions. Agriculture is still one of the most important branches of the economy in the Region of Samara on the middle Volga. The climatic conditions are not optimal for a successful grain production, while this branch plays an important role in the region. Despite of the positive development, in grain production in the Region of Samara the production potential has not yet been completely used. During the last years a considerable reduction in the agricultural machinery stock could be noticed, mainly because of obsolescence and wastage of the agricultural machinery as well as the small number of new purchases. The equipment at the disposal of the agricultural enterprises for plant cultivation, during the years 1990 to 2002 ? if compared to the requirements in agricultural technics ? amounted to approximately 46 percent of the tractors needed and approximately 56 percent of the combine harvesters needed. This entailed that the optimal time periods were not matched which, as a consequence, led to the reduction in the yields and an extension of the area not harvested. In order to create favorable conditions for an efficient grain production and for the development of the grain market in the Region of Samara, in 1998 the programme for the "Improvement of the grain production by the application of resource and accordingly watersaving cultivation methods 1998-2002" was starting to be implemented. The changeover from conventional cultivation methods to the use of resource-saving methods including modern and efficient agricultural technics represents a big challenge especially for medium-sized and small farms with a restricted financial potential. Through excluding ploughing from the soil cultivation work process as a most cost-intensive operation, as a result of the optimisation, machine costs can be reduced considerably under the system of preserving soil tillage. On average, these machine costs amount to 18.3 ?/ha with no-till cultivation, and are thus approximately 6 percent lower than with the conventional cultivation methods that were practised in the survey enterprises before. The average machine costs for direct drilling methods amount to approximately 15 ?/ha and can consequently be further reduced by about 18 percent if compared to no-till cultivation methods, and by approximately 22 percent if compared to conventional production methods. However, in the case of applying modern agricultural technics for resource-saving cultivation methods, the resulting fixed costs considerably surmount those of conventional cultivation methods. The modern agricultural machinery shows, however, a substantially higher performance potential. In the long-term, it can be assumed that the modern agricultural machines in this context are the more efficient solution. Moreover, the economic efficiency analysis of the cultivation methods? rearrangement rendered considerable advantages as to the development of labour demand and costs at the questioned agricultural enterprises. The application of resource-saving cultivation methods contributes to a noticeable decrease in labour demand. Under application of optimised cultivation methods, the labour cost is approximately 1.3 ?/ha or 60 percent lower than the total labour costs in the case of conventional cultivation methods. Although the implementation of resource-saving cultivation methods basically does not require an intensified application of fertilisers and pesticides, their aplication volume is being raised and adapted to the necessary level within the frame of the optimisation process. Under favourable weather conditions thus an increase of the yield per hectare as well as of the quality, and in the medium-term, a positive influence on the cereal production can be expected. As result of the conducted optimisation of cultivation methods and of the implementation of the recommended measures at the survey agricultural enterprises in the Region of Samara, a change in the obtained gross margin can be detained. The average gross margin decreases under no-till cultivation by approximately 24 percent and amounts to 58 ?/ha. The calculated gross margin for the direct drilling methods amounts to 61 ?/ha and is still below the amount effected under conventional cultivation methods. The calculated equilibrium points at the fact that the implementation of the optimised cultivation methods requires an increase of the hectare yield in the survey farms by 2.5 dt/ha on average. In order to reach a positive economic effect or at least the same economic efficiency as with use of conventional cultivation methods, the hectare yield should be increased to approximately 23 dt/ha or, by 12 percent. In spite of the findings resulting from the optimisation calculations that the gross margins are reduced with direct drilling as well as with no-till cultivation methods, the results in Samara Region, however, indicate a continuous increase of the economic efficiency under the condition of a long-term application of resource-saving cultivation methods in cereal production. The rearrangement of the conventional cultivation methods towards the optimised resource-saving technologies is under these conditions for the survey agricultural enterprises advantageous in a long-term view.
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    Improving measurements of the falling trajectory and terminal velocity of wind‐dispersed seeds
    (2022) Zhu, Jinlei; Buchmann, Carsten M.; Schurr, Frank M.
    Seed dispersal by wind is one of the most important dispersal mechanisms in plants. The key seed trait affecting seed dispersal by wind is the effective terminal velocity (hereafter “terminal velocity”, Vt), the maximum falling speed of a seed in still air. Accurate estimates of Vt are crucial for predicting intra‐ and interspecific variation in seed dispersal ability. However, existing methods produce biased estimates of Vt for slow‐ or fast‐falling seeds, fragile seeds, and seeds with complex falling trajectories. We present a new video‐based method that estimates the falling trajectory and Vt of wind‐dispersed seeds. The design involves a mirror that enables a camera to simultaneously record a falling seed from two perspectives. Automated image analysis then determines three‐dimensional seed trajectories at high temporal resolution. To these trajectories, we fit a physical model of free fall with air resistance to estimate Vt. We validated this method by comparing the estimated Vt of spheres of different diameters and materials to theoretical expectations and by comparing the estimated Vt of seeds to measurements in a vertical wind tunnel. Vt estimates closely match theoretical expectations for spheres and vertical wind tunnel measurements for seeds. However, our Vt estimates for fast‐falling seeds are markedly higher than those in an existing trait database. This discrepancy seems to arise because previous estimates inadequately accounted for seed acceleration. The presented method yields accurate, efficient, and affordable estimates of the three‐dimensional falling trajectory and terminal velocity for a wide range of seed types. The method should thus advance the understanding and prediction of wind‐driven seed dispersal.