Browsing by Subject "Minimalbearbeitung"

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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.
Land Preparation Methods and Soil Quality of a Vertisol Area in the Central Highlands of Ethiopia
(2005) Jijo, Teklu Erkossa; Stahr, Karl
The industrialization of agriculture led to societal concerns for environmental protection and food quality in developed countries. On the other hand, the need for increased agricultural productivity to address the persistent poverty and food insecurity in developing countries is intensified. Thus, improved management systems to meet the double objectives of increased productivity and sustained environmental quality are increasingly required. The assessment of soil quality and productivity are among the means of monitoring the various management systems to achieve the goals. Among the interrelated definitions formulated for soil quality, a committee established by Soil Science Society of America for the same purpose defined it as the capacity of soil to function within natural and managed ecosystem boundaries to sustain plant and animal productivity, maintain or enhance soil, water and air quality and support human health and habitation. The central idea in most of the definitions is the capacity of the soil to function. The capacity of a soil to function depends on its inherent properties derived from its genesis and the dynamic properties resulting from the prevailing management systems. Most of the hitherto soil quality assessments considered agricultural production as the major management goal. As this study was conducted in the highlands of Ethiopia where food security remains a basic challenge, the primary management goal could not be different. Shortage and fragmentation of land driven by population pressure have become issues of concern in the area. With a continually dwindling national land-holding average of only one ha per household, farmers struggle to produce enough to feed their families. Since the possibility of expanding agricultural land is limited, increased production is realistic only from higher productivity per unit land per unit time. Covering about 8 million ha, Vertisols are among the high potential soils, where significant increase in productivity is likely. However, their productivity is constrained by their physical and hydrological properties, manifested by their hardness when dry and their stickiness when wet, impeding land preparation. The traditional management systems led neither to increased productivity nor to enhanced soil quality. Thus, the need for alternative technologies is paramount. Despite a concerted effort during the last two decades to develop improved technologies for the soils, land preparation for agricultural productivity and sustaiability remains a major challenge. In addition to technical difficulties associated with their nature and deep-rooted poverty and illiteracy, lack of farmers? participation is believed to have hampered the development and adoption of robust technologies. The challenge facing the soil management research in Ethiopia is thus double fold: development of technologies that swiftly increase agricultural production and ensure judicious use of the land resources. Farmers are the ultimate decision makers on their plots, at least in Ethiopia, often irrespective of the consequences of their decisions. Simple technologies are required to manipulate their decisions in favour of the desired goals. This requires development of technologies that fit into their aspiration, tradition and socio-cultural values with their participation in the generation and evaluation of the technologies. This study was to identify alternative land preparation methods for increased productivity and economic profitability, while maintaining or enhancing the soil quality of the Vertisols. The hypothesis tested was that the alternative land preparation methods improve soil productivity and maintain or enhance soil quality. Three alternatives, Broad Bed and Furrow (BBF), Green Manure (GM) and Reduced Tillage (RT) with the traditional method, Ridge and Furrow (RF) were compared for 6 years, setting crop yield, economic profitability, and soil erosion and soil quality as performance indicators. This on station experiment was complemented by a participatory assessment at a small watershed scale. The objectives of the latter were identification of local soil functions, definition of soil quality concepts, and identification of soil quality indicators and evaluation of the soils for the major functions. Land preparation methods influence soil functions through their effects on soils qualities. Among the soil physical quality indicators considered, GM increased aggregate stability and reduced surface crust strength due to its increased OM content and microbial activities. While RT led to least penetration resistance, infiltration, water-holding capacity, and moisture content were less sensitive to the treatments. The chemical characteristics and plant nutrients response was not consistent indicating the need of longer time for the effects to show a clear trend. Organic carbon and MBC content of the soil increased due to RT and GM, but the increment was not proportional leading to lower microbial quotient. This indicates SOM build up with a long-term soil quality improvement. The effect on runoff was inconsistent during the first three years (1998-2000), but BBF and RT slightly increased. In 2001 and 2002, BBF drained 67% and 54 %, respectively, of the seasonal rainfall as runoff while RT routed 61% and 53%. There is a non significant tendency of increased soil and nutrient losses from BBF and RT due to the increased runoff. BBF significantly increased the grain yield of lentils by 59% (1.03 t ha-1 to 1.63 t ha-1) compared to the control. Similarly, RT resulted in the highest grain yield of wheat (1.86 t ha-1) and tef (1.34 t ha-1). Economically, BBF is the most profitable option for lentils with 65% increase in total gross margin while RT resulted in 11% and 8% increase in gross margin of wheat and tef, respectively, as compared to the control. The soil quality index was not significantly affected by the land preparation methods. Nevertheless, GM has shown a slight enhancement with the highest SQI, followed by BBF and RT. Thus, the land preparation methods are favoured in order of GM> BBF> RT> RF, for soil quality. The relative enhancement of soil quality by GM was linked mainly to its increased Corg content. The performance indicators (productivity, economic profitability, soil conservation and soil quality) are also affected differently. A matrix ranking of the effects on the indicators showed that none of treatments is superior for all the indicators. The average of the ranks (no weight attached) showed that BBF was the most favourable followed by RT. Therefore, the methods are preferred in the order of BBF> RT>GM=RF considering the overall indicators. The superiority of BBF and RT corresponds to their productivity and economic benefits. For soil quality and erosion control, GM is a favourable option. However, as its economic benefit was low, further improvement is required. In addition, lack of fast growing legumes tolerant to both shortage and excess water, failure of the short rain for planting, cost of chopping and incorporating the cover crops and the possible need of special equipment for incorporating may hinder its wider application and hence need further investigation. The success of the alternatives depends on the farmers? capacity and willingness to invest. As the issues of soil quality and land degradation are more of societal concerns than of the individual farmers, external technical and financial incentives are desirable to enhance their capacity and to initiate their interest. Institutional and policy issues influencing agriculture and natural resource management and uncertainties like variation in weather deserve judicious consideration.
Re-plant problems in long-term no-tillage cropping systems : causal analysis and mitigation strategies
(2016) Afzal; Neumann, Günter
No-tillage is considered as a promising alternative for tillage-based conventional farming, by saving energy-input and time, reducing groundwater pollution and counteracting soil erosion and losses of the soil-organic matter. However, in the recent past, no-tillage farmers in Southwest Germany repeatedly reported problems particularly in winter wheat production, characterized by stunted plant growth in early spring, chlorosis, impaired fine root development and increased disease susceptibility. These symptoms were particularly apparent on field sites with long-term (≥ 10 years) no-tillage history (LT) but not on adjacent short-term (≤ 2 years) no-tillage plots (ST). The effects could be reproduced in pot experiments under controlled conditions, with soils collected from the respective field sites in five different locations, providing a basis for causal analysis. The expression of damage symptoms in pot experiments with sieved soils, excluded differences in soil compaction, induced by long-term no-tillage farming as a potential cause. Soil analysis revealed higher levels of soil organic matter in the topsoil, as expected for LT field sites and no apparent mineral nutrient deficiencies, both, on LT and ST soils. However, phosphate (P) deficiency was characteristic for plants grown on LT soils. Obviously, this was caused by the limited acquisition of sparingly soluble soil P, due to impaired root development but not by low P availability on LT soils. In four out of five cases, gamma-ray soil sterilization did not affect the expression of plant damage symptoms on LT soils, excluding pathogen effects as a major cause. Soil application of biochar, at a rate of 5% (v/v), rapidly restored plant growth on LT soils, detectable already during the first week after sowing. This finding points to the presence of a phytotoxic compound since binding of soil xenobiotics by biochar is well documented. Accumulation of allelopathic compounds, originating from crop residues and root exudates remaining in the topsoil, is a problem related to no-tillage farming, particularly in cases of limited crop rotations or in monocultures, which also applied to the investigated field sites. However, a specific wheat auto-allelopathic effect is unlikely, since similar crop damage was also observed in soybean, sunflower, oilseed rape and various cover crops. Typical for allelopathic effects, in the pot experiments, plant damage symptoms in winter wheat appeared rapidly during emergence and early seedling development. However, under field conditions, germination and early growth were usually not affected, and symptoms were first detectable during re-growth in early spring. Moreover, damage symptoms disappeared when soil sampling was performed in summer instead of early spring, suggesting degradation of the toxic compound, which is also not compatible with the hypothesis of long-term accumulation of allelopathic compounds. The observed temporal pattern of plant damage rather resembled residual effects, occasionally observed after application of certain herbicides with soil activity (e.g., sulfonylureas, propyzamide). Therefore, a systematic survey of herbicide residues was conducted for topsoils on six pairs of LT and ST-field sites. Characteristic for no-tillage farming, glyphosate was the only herbicide, commonly and regularly used on all investigated field sites. The soil analysis revealed higher levels of glyphosate residues on all investigated LT, soils as compared with directly neighboured ST plots. Particularly on LT plots with strong expression of plant damage symptoms, high concentrations of glyphosate (2-4 mg kg-1 soil), and of its metabolite AMPA were detected in the 10 cm topsoil layer. This concentration range is characteristic for residual levels, usually observed several days after glyphosate applications but was still detectable in early spring, six months after the last glyphosate treatment, while only trace concentrations below the detection limit (0.05 mg kg-1 soil) were found in ST soils. Coinciding with the declining plant damage potential, residual glyphosate and AMPA concentrations on LT plots declined during the vegetation period until early summer. No comparable pattern was detectable for residues of other herbicides, such as pendimethalin and propyzamide. Degradation of glyphosate residues in soils correlates with microbial activity. Accordingly, reduced soil respiration as an indicator for microbial activity was detected in four out of five cases in soil samples collected from LT field sites, suggesting delayed glyphosate degradation as compared with ST plots. Due to rapid adsorption, glyphosate usually exhibits extremely limited soil activity. However, at least trace concentrations of glyphosate and AMPA (1.5-3.5 µg L-1) were detectable also in the potentially plant-available, water-soluble phase in spring samples, collected from LT field plots with high potential for plant damage. Nutrient solution experiments, with 3-6 weeks exposure of winter wheat to the residual herbicide concentrations detected in the LT soil solution, revealed the development of chlorosis and similar to soil experiments, a 30%-50% reduction in fine root production, which surprisingly was mainly induced by AMPA and to a lesser extent by glyphosate itself. Accordingly, both, in hydroponics and LT soil experiments, the plant damage symptoms were not associated with shikimate accumulation in the root tissue as a physiological indicator for glyphosate but not for AMPA toxicity. The dominant role of AMPA toxicity also became apparent by the fact that, both, glyphosate resistant (GR) and non-resistant (NR) soybean plants were affected on LT no-tillage soils since transgenic GR plants are not resistant to AMPA. A preliminary RNAseq gene expression analysis of the root tissue just prior to the appearance of visible plant damage symptoms, revealed down-regulation of genes involved in general stress responses, down-regulation of aquaporin genes (PIPs and TIPs) with functions in water uptake and root elongation, down-regulation of ethylene-related genes but up-regulation of cytokinin-related gene expression indicating interferences with hormonal balances. These changes in gene expression patterns relative to the untreated control were detected in plants treated with AMPA and glyphosate+AMPA but not with glyphosate alone. The findings suggest that long-term exposure to subtoxic levels of AMPA, as major glyphosate metabolite temporally accumulated in LT no-tillage soils, can finally interfere with metabolic processes essential for normal root development. A series of pot and field experiments were initiated to test the potential of selected commercial formulations of plant growth-promoting microorganisms, based on strains of Pseudomonas sp., Bacillus amyloliquefaciens, and Trichoderma harzianum, for mitigation of plant stress symptoms, expressed on LT no-tillage field sites in spring. For members of the selected microbial genera, root growth-promoting effects, pathogen suppression, and glyphosate degradation potential have been reported. Unfortunately, plant growth promotion was detectable only on ST soils but was not successful on LT plots, both, in pot and field experiments, probably related to limited root development for microbial colonization and early summer drought under field conditions. As an alternative approach, incorporation of pyrolysis biochar from woody substrates at a rate of 5 % (v/v) to the top 10 cm soil layer of LT soils, equivalent to approx. 35 t ha-1, were able to restore plant growth completely in pot experiments and protected wheat plants from glyphosate overdose applications (up to 8 L Roundup Ultramax® ha-1), even on artificial substrates with low potential for glyphosate adsorption. As a short-term mitigation strategy, field-testing with different biochar concentrations is recommended. During the last two years, farmers also modified their no-tillage management strategies on the investigated field sites by introducing more variable crop rotations including, winter wheat, winter rape, maize and soybean and using mustard, pea, and Crotalaria as cover crops. Despite further annual applications of glyphosate (3 L ha-1 of a 360 g ai L-1 formulation), plant performance on the respective field sites was significantly improved. These observations suggest that limited crop rotation favored the development of a soil microflora with low degradation potential for glyphosate, leading to a decline in degradation rates of glyphosate soil residues and underline the importance of crop diversity management.
Soil erosion in Andean Cropping Systems: The impact of Rainfall Erosivity
(2002) Sonder, Kai; Leihner, Dietrich
Rationale and methods The Andean region of Colombia, 30% of the country, has about 15% of the tot. population and 50% of the rural population. A great part of the countries food-crops are grown on the hillsides of the region, which are severely degraded or threatened by degradation. The objectives of the present study were: a) to determine the applicability of the USLE rainfall erosivity factor to the Andean Region, particularly the energy-intensity term b) to calculate long-term erosivity data c) to establish the long-term erosivity of two soil types in the research area d) to evaluate the yield and soil conservation performance of several cassava-based cropping systems. Research was carried out at two sites in the Cauca department in the southwest of Colombia. Santander de Quilichao is located at 3o 6' N, 76 o 31' W, at an altitude of 990 m a.m.s.l., with an annual precipitation of 1,789 mm and an average temperature of 23.7 o C. Mondomo, which lies 2o 53' N, 76 o 35' W at an altitude of 1,450 m a.m.s.l., has an annual precipitation of 2,133 mm and an average temperature of 18.2 o C. The soils at both sites belong to the inceptisols, which form about 77% of the soils of the Cauca departments. In 1987 erosion plots were established at both sites on slopes of between 7% and 20% consisting of 8 treatments and 3 repetitions at Quilichao with 2 at Mondomo. During the research in this study, the 8 treatments comprised: 1) Continuous bare fallow, 2) Traditional cassava-based rotation, 3) Continuous sole cassava, 4) Cassava-based rotation with minimum tillage and mulch, 5) Cassava-based rotation with two previous years of bush fallow, 6) Cassava-based rotation with vetiver grass barriers, 7) Cassava-based rotation with legume strips, and 8) Cassava-based rotation with improved fallow element. Rainfall erosivity Drop size distribution measurements with a Joss-Waldvogel Distrometer showed that the USLE R factor is applicable for the research region as no significant differences were found between the measured kinetic energy of rainfall events and calculated values according to the USLE. The average annual r-factor values during the 12 year research period for Quilichao and Mondomo were 10,037 and 9,016 MJ ha-1 mm h-1 a-1 respectively. A highly significant relationship was found between a modified Fournier index based upon average monthly rainfall amounts and the equivalent monthly r-factor values. Soil losses K-factor values measured of 0.017 t h MJ-1 mm-1 at Quilichao and 0.011 t h MJ﷓1 mm-1 at Mondomo may be regarded as being between medium and low, although soil losses on the bare fallow plots were very high due to the extreme erosivity of the climate. Total soil losses in Quilichao on the bare fallow from 1986 to 1998 were 1,840 t ha-1. In Mondomo it was 2,380 t ha-1. From June 1994 to July 1997, the 7 cropped treatments in Quilichao showed susceptibility to erosion in the following order (from high to low): Sole continuous cassava, bush fallow >> farmer rotation, legume strips > improved fallow > minimum tillage, grass barriers. In Mondomo the susceptibility to erosion for the same period was: Sole continuous cassava >> legume strips >> bush fallow > improved fallow, farmer rotation > grass barriers, minimum tillage. When calculating soil loss for a representative plot only the minimum tillage and grass barrier treatments reached levels below the tolerable average annual soil losses under both the Quilichao and Mondomo conditions.The erosivity and erodibility values for the whole 12-year duration of this project showed that there is a highly significant relationship between annual soil loss amounts and the R-factor of the USLE. The continuous bare fallow plots showed strong declines of organic matter at both sites. Yield performance The two conservation treatments, minimum tillage and grass barriers, showed no significant differences regarding yield compared to the widely used continuous cassava system. The farmer rotation treatment showed the highest yield levels, but there were no significant differences between this treatment and the minimum tillage treatment at Mondomo and Quilichao. Conclusions The results confirm the high erosivity of the climate and support the necessity of maintaining permanent soil cover. The proven applicability of the R-Factor of the USLE for the region and the long-term soil erodibility values determined should enable the potential erosion risk to be estimated and appropriate soil conservation measures offered. Of the cropping systems evaluated, both the minimum tillage and the vetiver grass barrier treatments proved to be interesting alternatives to the local cropping systems as they reduced soil erosion to a sustainable level and at the same time reached or even surpassed the yields of the traditional cassava monocropping. All the other systems would lead to degradation if long-term permanent cropping was practised.